Owing to the abundant reserves and low cost, potassium ion batteries(PIBs), as potential alternatives to lithium ion batteries(LIBs) in the field of grid-level electrical energy storage systems, have triggered extensi...Owing to the abundant reserves and low cost, potassium ion batteries(PIBs), as potential alternatives to lithium ion batteries(LIBs) in the field of grid-level electrical energy storage systems, have triggered extensive research interest recently. Taking into consideration of the cost, environmental benignity and sustainability, carbon-based materials are supposed to be a promising choice for PIB anodes. In this perspective, we summarize the carbon-based materials with various microstructures toward PIBs and try to offer comprehensive understanding the underlying mechanism of potassium(K) ion storage. In addition, several strategies including heteroatom doping, morphology engineering, defect engineering, interlayer engineering, and composition engineering are proposed to rationally design the nanostructures of the advanced carbon-based PIB anodes. Finally, we conclude the current challenges and provide our perspectives on the development of high-performance carbon materials for PIB anodes.展开更多
While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,...While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion storage.According to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition reactions.The optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental results.When assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical performance.The rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art results.When assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for applications.Moreover,the stepwise K+storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy techniques.Hence,this work not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials.展开更多
Considering their superior theoretical capacity and low voltage plateau,bismuth(Bi)-based materials are being widely explored for application in potassium-ion batteries(PIBs).Unfortunately,pure Bi and Bibased compound...Considering their superior theoretical capacity and low voltage plateau,bismuth(Bi)-based materials are being widely explored for application in potassium-ion batteries(PIBs).Unfortunately,pure Bi and Bibased compounds suffer from severe electrochemical polarization,agglomeration,and dramatic volume fluctuations.To develop an advanced bismuth-based anode material with high reactivity and durability,in this work,the pyrolysis of Bi-based metal-organic frameworks and in-situ selenization techniques have been successfully used to produce a Bi-based composite with high capacity and unique structure,in which Bi/Bi_(3)Se_(4)nanoparticles are encapsulated in carbon nanorods(Bi/Bi_(3)Se_(4)@CNR).Applied as the anode material of PIBs,the Bi/Bi_(3)Se_(4)@CNR displays fast potassium storage capability with 307.5 m A h g^(-1)at 20 A g^(-1)and durable cycle performance of 2000 cycles at 5 A g^(-1).Notably,the Bi/Bi_(3)Se_(4)@CNR also showed long cycle stability over 1600 cycles when working in a full cell system with potassium vanadate as the cathode material,which further demonstrates its promising potential in the field of PIBs.Additionally,the dual potassium storage mechanism of the Bi/Bi_(3)Se_(4)@CNR based on conversion and alloying reaction has also been revealed by in-situ X-ray diffraction.展开更多
Benefiting from the environmental friendliness of organic electrodes and the high security of aqueous electrolyte,an all-organic aqueous potassium dual-ion full battery(APDIB) was assembled with 21 M potassium bis(flu...Benefiting from the environmental friendliness of organic electrodes and the high security of aqueous electrolyte,an all-organic aqueous potassium dual-ion full battery(APDIB) was assembled with 21 M potassium bis(fluoroslufonyl)imide(KFSI) water-in-salt as the electrolyte.The APDIB could deliver a reversible capacity of around 50 mAh g^(-1) at 200 mA g^(-1)(based on the weight of total active materials),a long cycle stability over 900 cycles at 500 mA g^(-1) and a high coulombic efficiency of 98.5%.The reaction mechanism of APDIB during the charge/discharge processes is verified:the FSI-could associate/disassociate with the nitrogen atom in the polytriphenylamine(PTPAn) cathode,while the K^(+) could react with C=O bonds in the 3,4,9,10-perylenetetracarboxylic diimide(PTCDI) anode reversibly.Our work contributes toward the understanding the nature of water-into-salt electrolyte and successfully constructed all-organic APDIB.展开更多
Carbonaceous materials are considered as ideal anode for potassium ion batteries(PIBs)due to their abundant resources and stable physical and chemical properties.However,improvements of reversible capacity and cycle p...Carbonaceous materials are considered as ideal anode for potassium ion batteries(PIBs)due to their abundant resources and stable physical and chemical properties.However,improvements of reversible capacity and cycle performance are still needed,aiming to the practical application.Herein,S/N/O tridoped carbon(SNOC)nanospheres are prepared by in-situ vulcanized polybenzoxazine.The S/N/O tridoped carbon matrix provides abundant active sites for potassium ion adsorption and effectively improves potassium storage capacity.Moreover,the SNOC nanospheres possess large carbon interlayer spacing and high specific surface area,which broaden the diffusion pathway of potassium ions and accelerate the electron transfer speed,resulting in excellent rate performance.As an anode for PIBs,SNOC shows attractive rate performance(438.5 mA h g^(-1) at 50 mA g^(-1) and 174.5 mA h g^(-1) at2000 mA g^(-1)),ultra-high reversible capacity(397.4 mA h g^(-1) at 100 mA g^(-1) after 700 cycles)and ultra-long cycling life(218.9 mA h g^(-1) at 2000 mA g^(-1) after 7300 cycles,123.1 mA h g^(-1) at3000 mA g^(-1) after 16500 cycles and full cell runs for 4000 cycles).Density functional theory calculation confirms that S/N/O tri-doping enhances the adsorption and diffusion of potassium ions,and in-situ Fourier-transform infrared explores explored the potassium storage mechanism of SNOC.展开更多
Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphoru...Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphorus-based anodes,in reality,are far from the theoretical capacity corresponding to the formation of K3P alloy.And,their underlying potassium storage mechanisms remain poorly understood.To address this issue,for the first time,we perform high-resolution solid-state31P NMR combined with XRD measurements,and density functional theory calculations to yield a systemic quantitative understanding of(de)potassiation reaction mechanism of phosphorus anode.We explicitly reveal a previously unknown asymmetrical nanocrystalline-to-amorphous transition process via rP←→(K_(3)P_(11),K_(3)P_(7),beta-K_(4)P_(6))←→(alpha-K4P6)←→(K_(1-x)P,KP,K_(4-x)P3,K_(1+x)P)←→(amorphous K4P3,amorphous K3P)that are proceed along with the electrochemical potassiation/depotassiation processes.Additionally,the corresponding KP alloys intermediates,such as the amorphous phases of K_(4)P_(3),K_(3)P,and the nonstoichiometric phases of“K_(1-x)P”,“K_(1+x)P”,“K_(4-x)P_(3)”are experimentally detected,which indicating various complicated K-P alloy species are coexisted and evolved with the sluggish electrochemical reaction kinetics,resulting in lower capacity of phosphorus-based anodes.Our findings offer some insights into the specific multi-phase evolution mechanism of alloying anodes that may be generally involved in conversion-type electrode materials for PIBs.展开更多
Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scal...Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scale application.Here,a facile template method is utilized to synthesize boron doping carbon nanobubbles(BCNBs).The incorporation of boron into the carbon structure introduces abundant defective sites and improves conductivity,facilitating both the intercalation-controlled and capacitivecontrolled capacities.Moreover,theoretical calculation proves that boron doping can effectively improve the conductivity and facilitate electrochemical reversibility in PIBs.Correspondingly,the designed BCNBs anode delivers a high specific capacity(464 mAh g^(-1)at 0.05 A g^(-1))with an extraordinary rate performance(85.7 mAh g^(-1)at 50 A g^(-1)),and retains a considerable capacity retention(95.2%relative to the 100th charge after 2000 cycles).Besides,the strategy of pre-forming stable artificial inorganic solid electrolyte interface effectively realizes high initial coulombic efficiency of 79.0%for BCNBs.Impressively,a dual-carbon potassium-ion capacitor coupling BCNBs anode displays a high energy density(177.8 Wh kg^(-1)).This work not only shows great potential for utilizing heteroatom-doping strategy to boost the potassium ion storage but also paves the way for designing high-energy/power storage devices.展开更多
Large-scale and low-cost preparation of carbon-based potassium anode with long life and high capacity is one of the footstones for the development of potassium ion batteries(PIBs).Herein,a low-cost carbon-based materi...Large-scale and low-cost preparation of carbon-based potassium anode with long life and high capacity is one of the footstones for the development of potassium ion batteries(PIBs).Herein,a low-cost carbon-based material,cross-linked hollow graphitic carbon(HGC),is large scale synthesized to apply for PIBs anode.Its hollow structure can afford sufficient space to overcome the damage caused by the volume expansion of graphitic carbon(GC).While the cross-linked structure forms a compact interconnection network that allows electrons to rapid transfer between different GC frameworks.Electrochemical measurements demonstrated that the HGC anode exhibited low charge/discharge plateau(about 0.25 V and 0.1 V)and excellent specific capacity as high as 298 m A h g^(-1)at the current density of 50 m A g^(-1).And more important,after 200 cycles the capacity of HGC anode still shows 269 m A h g^(-1)(the decay rate of per cycle is only 0.048%).Meanwhile,the use of commercial traditional electrolyte(KPF_(6))and cheap raw materials that provide new hope for trying and realizing the large-scale production of PIBs based on carbon anode materials.展开更多
We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,...We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.展开更多
InSb alloy is a promising candidate for sodium/potassium ion batteries(SIBs/PIBs)but challenged with achieving high performance by dramatic volumetric changes.Herein,nanoporous(np)-InSb with dualscale phases(cubic/hex...InSb alloy is a promising candidate for sodium/potassium ion batteries(SIBs/PIBs)but challenged with achieving high performance by dramatic volumetric changes.Herein,nanoporous(np)-InSb with dualscale phases(cubic/hexagonal(C/H)-InSb)was fabricated by chemical dealloying of ternary Mg-In-Sb precursor.Operando X-ray diffraction(XRD)and ex-situ characterizations well rationalize the dealloying/alloying mechanisms and the formation of dual-scale microstructures/phases.As an anode for SIB/PIBs,the np-InSb electrode exhibits superior reversible capacities and lifespan compared with the monometallic porous(p)-In electrode,stemming from the dealloying-induced dual-scale nanoporous architecture and alloying strategy with proper composition.The operando XRD results demonstrate that the(de)sodiated mechanism of the np-InSb electrode involves a two-step(de)alloying process,while the(de)potassiated mechanism is associated with a full electrochemically-driven amorphization upon cycling.Additionally,the gas evolution during the(dis)charge process was monitored by on-line mass spectrometry.展开更多
Hard carbon material is one of the most promising anode materials for potassium ion batteries(PIBs)due to its distinct disordered and non-expandable framework.However,the intrinsically disordered microarchitecture of ...Hard carbon material is one of the most promising anode materials for potassium ion batteries(PIBs)due to its distinct disordered and non-expandable framework.However,the intrinsically disordered microarchitecture of hard carbon results in low electric conductivity and poor rate capability.Herein,nitrogendoped and partially graphitized hard carbons(NGHCs)derived from commercial coordination compound precursor-ethylenediaminetetraacetic acid(EDTA)disodium cobalt salt hydrate are designed and prepared as high-performance PIBs anode materials.By means of a facile annealing method,nitrogen elements and graphitic domains can be controllably introduced to NGHCs.The resulting NGHCs show structural merits of mesoporous construction,nitrogen doping and homogeneous graphitic domains,which ensures fast kinetics and electron transportation.Applying in anode for PIBs,NGHCs exhibit robust rate capability with high reversible capacity of 298.8 m Ah g^-1 at 50 m A g^-1,and stable cycle stability of 137.6 mAh g^-1 at 500 m A g^-1 after 1000 cycles.Moreover,the ex situ Raman spectra reveal a mixture"adsorption-intercalation mechanism"for potassium storage of NGHCs.More importantly,full PIBs by pairing with perylenetetracarboxylic dianhydride(PTCDA)cathode demonstrate the promising potential of practical application.In terms of commercial precursor,facile synthesis and long cycle lifespan,NGHCs represent a brilliant prospect for practical large-scale applications.展开更多
Potassium ion batteries(PIBs)with the prominent advantages of sufficient reserves and economical cost are attractive candidates of new rechargeable batteries for large-grid electrochemical energy storage systems(EESs)...Potassium ion batteries(PIBs)with the prominent advantages of sufficient reserves and economical cost are attractive candidates of new rechargeable batteries for large-grid electrochemical energy storage systems(EESs).However,there are still some obstacles like large size of K+to commercial PIBs applications.Therefore,rational structural design based on appropriate materials is essential to obtain practical PIBs anode with K+accommodated and fast diffused.Nanostructural design has been considered as one of the effective strategies to solve these issues owing to unique physicochemical properties.Accordingly,quite a few recent anode materials with different dimensions in PIBs have been reported,mainly involving in carbon materials,metal-based chalcogenides(MCs),metal-based oxides(MOs),and alloying materials.Among these anodes,nanostructural carbon materials with shorter ionic transfer path are beneficial for decreasing the resistances of transportation.Besides,MCs,MOs,and alloying materials with nanostructures can effectively alleviate their stress changes.Herein,these materials are classified into 0D,1D,2D,and 3D.Particularly,the relationship between different dimensional structures and the corresponding electrochemical performances has been outlined.Meanwhile,some strategies are proposed to deal with the current disadvantages.Hope that the readers are enlightened from this review to carry out further experiments better.展开更多
Potassium-based dual ion batteries(KDIBs)have attracted significant attention owing to high working voltage,high safety,low processing cost,and environmental friendliness.Nevertheless,one great challenge for practical...Potassium-based dual ion batteries(KDIBs)have attracted significant attention owing to high working voltage,high safety,low processing cost,and environmental friendliness.Nevertheless,one great challenge for practical KDIBs is to develop suitable anode materials with high specific capacity.Herein,we report an architecture of hierarchically porous antimony nanoparticles/carbon nanofibers(HPSb CNFs)as flexible,free-standing anode for high-performance KDIBs.The HPSb CNFs with hierarchically porous structure,and high-content nitrogen doping,not only offer sufficient free space to tolerate the repetitive volume expansion of Sb nanoparticles during long-term cycling,but also greatly facilitate the transport of electrons and ions within electrode,ensuring high material utilization ratio.Thus,the KDIBs,constituted by HPSb CNFs-700(calcined at 700°C)anode and graphite cathode,exhibited a high reversible capacity of 440 m Ah g^(-1)with high discharge medium voltage of 4.5 V at a specific current of 200 m A g^(-1)(the highest capacity for all KDIBs normalized by the mass of the anode),and excellent cyclic life.Outstanding electrochemical reversibility of the KDIBs was further demonstrated by ex situ XRD,ex situ Raman spectrum,and HRTEM.These results suggest the as-designed HPSb CNFs-700 with highcapacity and long-term cycling stability is a promising anode material for high-performance KDIBs.展开更多
Demand for efficient and continuous application for high-grid energy storage systems involves the study towards novel battery technologies. Hence, considering the vast naturally available resources of potassium all ov...Demand for efficient and continuous application for high-grid energy storage systems involves the study towards novel battery technologies. Hence, considering the vast naturally available resources of potassium all over the world and its encouraging intercalation chemistries, it has recently enticed attention in electrochemical energy storage industry in the form of potassium ion batteries (PIBs). The major factor in this K+ based battery, is to develop efficient approaches to manufacture electrode substance to intercalate its big size potassium ions with considerable voltage, kinetics, charge/discharge capacity, capacity retention, cost, etc. This study contributes in the recent developments of anode and cathode materials for PIBs, including several electrode materials in regards to synthesis, structure, electrochemical performance, and K-storage mechanisms. Finally, the review contributes to provide helpful sources for the increasing number of scientists working in this industry regarding its critical issues and challenges and also to indicate the future direction of electrode materials in PIBs.展开更多
Potassium-ion batteries(PIBs)represent one of the most promising alternatives to lithium-ion batteries(LIBs),owing to their exceptional attributes such as high voltages,potent power capabilities,and cost-effectiveness...Potassium-ion batteries(PIBs)represent one of the most promising alternatives to lithium-ion batteries(LIBs),owing to their exceptional attributes such as high voltages,potent power capabilities,and cost-effectiveness.Nonetheless,challenges arise from the sluggish kinetics and significant volume expansion observed during the insertion/extraction of large-radii potassium ions,leading to subpar rate performance and considerable capacity degradation in potassium-ion batteries.Consequently,it becomes imperative to explore advanced anode materials exhibiting high electrochemical activity and robust structural stability.In this regard,the present review focuses on recent progress in metal-organic compounds(MOCs)as anode materials for potassium-ion batteries,systematically discussing their outstanding merits from the perspective of metal speciation.Additionally,the principal mechanism of K ion storage within relevant MOCs is presented.Furthermore,a comprehensive summary of existing drawbacks that hinder the broader application of MOCs-based materials is provided,along with proposed guidelines and strategies for addressing the inferior performance characteristics.This review serves to illuminate the development of MOCs-based anode materials for potassium-ion batteries and offers a valuable reference for future research endeavors.展开更多
Oxygen-containing functional groups were found to e ectively boost the K^(+)storage performance of carbonaceous materials,however,the mechanism behind the performance enhancement remains unclear.Herein,we report highe...Oxygen-containing functional groups were found to e ectively boost the K^(+)storage performance of carbonaceous materials,however,the mechanism behind the performance enhancement remains unclear.Herein,we report higher rate capability and better long-term cycle performance employing oxygen-doped graphite oxide(GO)as the anode material for potassium ion batteries(PIBs),compared to the raw graphite.The in situ Raman spectroscopy elucidates the adsorption-intercalation hybrid K^(+)storage mechanism,assigning the capacity enhancement to be mainly correlated with reversible K^(+)adsorption/desorption at the newly introduced oxygen sites.It is unraveled that the C=O and COOH rather than C-O-C and OH groups contribute to the capacity enhancement.Based on in situ Fourier transform infrared(FT-IR)spectra and in situ electrochemical impedance spectroscopy(EIS),it is found that the oxygen-containing functional groups regulate the components of solid electrolyte interphase(SEI),leading to the formation of highly conductive,intact and robust SEI.Through the systematic investigations,we hereby uncover the K^(+)storage mechanism of GO-based PIB,and establish a clear relationship between the types/contents of oxygen functional groups and the regulated composition of SEI.展开更多
In recent years,the anode materials of bismuth(Bi)-based potassium ion batteries with high theoretical capacity and suitable potassium ion insertion potential have attracted extensive attention.However,due to the volu...In recent years,the anode materials of bismuth(Bi)-based potassium ion batteries with high theoretical capacity and suitable potassium ion insertion potential have attracted extensive attention.However,due to the volume expansion of Bi,the performance of Bi-based anode materials is not ideal during potassium ion(de)intercalation.In order to solve these problems,we report a three-dimensional(3D)ternary bismuth nanoparticles/conductive polymers/carbon nanotubes(Bi/PPy/CNT)hybrid anode material for K-ion batteries.At a current density of 100 mA·g^(-1),its reversible capacity reaches 302 mAh·g^(-1) after 200 cycles,while it reaches 195.7 mAh·g^(-1) after 600 cycles at 1 A·g^(-1).Its excellent performance is attributed to the hydrogel network which provides a range of electron transport networks and high porosity.Carbon nanotubes are used as electron enhancers to reduce the volume expansion of Bi particles during the reaction.This study provides a prerequisite for expanding the application of 3D ternary materials.展开更多
An effective method is designed to construct three-dimensional(3D)Nb_(2)C/reduced graphene oxide(rGO)hybrid aerogels through a low-temperature graphene oxide(GO)-assisted hydrothermal self-assembly followed by freeze-...An effective method is designed to construct three-dimensional(3D)Nb_(2)C/reduced graphene oxide(rGO)hybrid aerogels through a low-temperature graphene oxide(GO)-assisted hydrothermal self-assembly followed by freeze-drying and annealing.The intimately coupled Nb_(2)C/rGO hybrid aerogel combines the advantages of large specific surface area and rich 3D interconnected porous structure of aerogel as well as high conductivity and low potassium diffusion energy barrier of Nb_(2)C,which not only effectively prevents the self-restacking of Nb2C nanosheets to allow more active sites exposed and accommodate the volume change during the charge/discharge process,but also increases the accessibility of electrolyte and promotes the rapid transfer of ions/electrons.As a result,Nb_(2)C/rGO-2 as the anode of potassium ion batteries(KIBs)delivers a large reversible specific capacity(301.7 mAh·g^(−1)after 500 cycles at 2.0 A·g^(−1)),an ultrahigh rate capability(155.5 mAh·g^(−1)at 20 A·g^(−1)),and an excellent long-term large-current cycle stability(198.8 mAh·g^(−1)after 1,000 cycles at 10 A·g^(−1),with a retention of 83.3%).Such a high-level electrochemical performance,especially the ultrahigh rate capability,is the best among transition metal carbides and nitride(MXene)-based materials reported so far for KIBs.The diffusion kinetics of K+is investigated thoroughly,and the synergetic charge–discharge mechanism and the structure–performance relationship of Nb_(2)C/rGO are revealed explicitly.The present work provides a good strategy to solve the self-restacking problem of two-dimensional materials and also enlarges the potential applications of MXenes.展开更多
Due to the high theoretical capacity and electrode potential,Prussian blue is regarded as promising cathode material for potassium ion batteries.However,inferior structural stability,poor electronic conductivity,ambig...Due to the high theoretical capacity and electrode potential,Prussian blue is regarded as promising cathode material for potassium ion batteries.However,inferior structural stability,poor electronic conductivity,ambiguous energy storage mechanism have limited the application of Prussian blue materials.Herein,a highly stable Prussian blue-polypyrrole(PB-PPY)composite has been prepared by a facile one-step method.PB-PPY displays higher discharging capacity,better rate capacity,and longer cycling lifespan than that of pure Prussian blue in potassium ion batteries.The superior electrochemical performance can be attributed to the unique synthesis strategy to reduce the content of vacancies and crystal water in Prussian blue and enhance the conductivity.Furthermore,partial K ions have been evidenced that could remain in the Prussian blue framework,which contributes the long-term cycling stability.The K ions in the framework play the role of“pillars”to support the framework of Prussian blue and relieve the structural stress during the intercalation and de-intercalation of K ions.This work will reveal a new energy storage mechanism of Prussian blue and promote the design of high stability Prussian blue in the future.展开更多
Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent str...Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent structural stability. However, the excessive stacking of interlayer electron clouds makes it difficult to expose internal active sites. Strategies to design functional COFs with controllable morphology and copious active sites are promising but still challenging. Herein, by utilizing the condensation between1,3,5-triformylbenzene(TFB) and p-phenylenediamine(PPD) and using amino-modified SiO_(2) nanospheres as templates, we synthesize core-shell NH_(2)-SiO_(2)@TP-COF. Through NaOH etching of NH_(2)-SiO_(2)@TP-COF, we obtain imine-based TP-COF hollow nanospheres, which shows excellent potassium storage performance when applied to the anode for PIBs. Ex-situ analysis and density functional theory calculations reveal that C=N groups and benzenes are active sites for K^(+) storage.展开更多
基金Supported by the Beijing Natural Science Foundation(JQ18005)National Key R&D Program of China(2016YFB0100201)+2 种基金National Natural Science Foundation of China(51671003)Young Thousand Talented Program,Initiative Postdocs Supporting Program(BX20180001)China Postdoctoral Science Foundation(2018M640024)
文摘Owing to the abundant reserves and low cost, potassium ion batteries(PIBs), as potential alternatives to lithium ion batteries(LIBs) in the field of grid-level electrical energy storage systems, have triggered extensive research interest recently. Taking into consideration of the cost, environmental benignity and sustainability, carbon-based materials are supposed to be a promising choice for PIB anodes. In this perspective, we summarize the carbon-based materials with various microstructures toward PIBs and try to offer comprehensive understanding the underlying mechanism of potassium(K) ion storage. In addition, several strategies including heteroatom doping, morphology engineering, defect engineering, interlayer engineering, and composition engineering are proposed to rationally design the nanostructures of the advanced carbon-based PIB anodes. Finally, we conclude the current challenges and provide our perspectives on the development of high-performance carbon materials for PIB anodes.
基金financially supported by the Natural Science Foundation of Jiangsu Province of China(BK20211172)the Jiangsu Provincial Department of Science and Technology Innovation Support Program(BK20222004,BZ2022036)+1 种基金the National Natural Science Foundation of China(52002366,22075263)the Fundamental Research Funds for the Central Universities(WK2060000039)。
文摘While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion storage.According to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition reactions.The optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental results.When assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical performance.The rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art results.When assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for applications.Moreover,the stepwise K+storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy techniques.Hence,this work not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials.
基金financially supported by the National Natural Science Foundation of China (22209057)the Guangdong Basic and Applied Basic Research Foundation (2021A1515010362)+1 种基金the Guangzhou Basic and Applied Basic Research Foundation (202102020995)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications (2020B121201005)。
文摘Considering their superior theoretical capacity and low voltage plateau,bismuth(Bi)-based materials are being widely explored for application in potassium-ion batteries(PIBs).Unfortunately,pure Bi and Bibased compounds suffer from severe electrochemical polarization,agglomeration,and dramatic volume fluctuations.To develop an advanced bismuth-based anode material with high reactivity and durability,in this work,the pyrolysis of Bi-based metal-organic frameworks and in-situ selenization techniques have been successfully used to produce a Bi-based composite with high capacity and unique structure,in which Bi/Bi_(3)Se_(4)nanoparticles are encapsulated in carbon nanorods(Bi/Bi_(3)Se_(4)@CNR).Applied as the anode material of PIBs,the Bi/Bi_(3)Se_(4)@CNR displays fast potassium storage capability with 307.5 m A h g^(-1)at 20 A g^(-1)and durable cycle performance of 2000 cycles at 5 A g^(-1).Notably,the Bi/Bi_(3)Se_(4)@CNR also showed long cycle stability over 1600 cycles when working in a full cell system with potassium vanadate as the cathode material,which further demonstrates its promising potential in the field of PIBs.Additionally,the dual potassium storage mechanism of the Bi/Bi_(3)Se_(4)@CNR based on conversion and alloying reaction has also been revealed by in-situ X-ray diffraction.
基金financially supported by the National Natural Science Foundation of China (Nos.51922038 and 51672078)the Hunan Outstanding Youth Talents(No.2019JJ20005)+1 种基金Hunan Provincial Natural Science Foundation of China(2019JJ40031)the Fundamental Research Funds for the Central Universities(531119200156)。
文摘Benefiting from the environmental friendliness of organic electrodes and the high security of aqueous electrolyte,an all-organic aqueous potassium dual-ion full battery(APDIB) was assembled with 21 M potassium bis(fluoroslufonyl)imide(KFSI) water-in-salt as the electrolyte.The APDIB could deliver a reversible capacity of around 50 mAh g^(-1) at 200 mA g^(-1)(based on the weight of total active materials),a long cycle stability over 900 cycles at 500 mA g^(-1) and a high coulombic efficiency of 98.5%.The reaction mechanism of APDIB during the charge/discharge processes is verified:the FSI-could associate/disassociate with the nitrogen atom in the polytriphenylamine(PTPAn) cathode,while the K^(+) could react with C=O bonds in the 3,4,9,10-perylenetetracarboxylic diimide(PTCDI) anode reversibly.Our work contributes toward the understanding the nature of water-into-salt electrolyte and successfully constructed all-organic APDIB.
基金financially supported by the National Natural Science Foundation of China(21975069 and 21872045)the Key Project of Research and Development Plan of Hunan Province(2019SK2071)+1 种基金the Natural Science Foundation of Hunan Province,China(2020JJ4169)the State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Development and Reform Commission of Hunan Province。
文摘Carbonaceous materials are considered as ideal anode for potassium ion batteries(PIBs)due to their abundant resources and stable physical and chemical properties.However,improvements of reversible capacity and cycle performance are still needed,aiming to the practical application.Herein,S/N/O tridoped carbon(SNOC)nanospheres are prepared by in-situ vulcanized polybenzoxazine.The S/N/O tridoped carbon matrix provides abundant active sites for potassium ion adsorption and effectively improves potassium storage capacity.Moreover,the SNOC nanospheres possess large carbon interlayer spacing and high specific surface area,which broaden the diffusion pathway of potassium ions and accelerate the electron transfer speed,resulting in excellent rate performance.As an anode for PIBs,SNOC shows attractive rate performance(438.5 mA h g^(-1) at 50 mA g^(-1) and 174.5 mA h g^(-1) at2000 mA g^(-1)),ultra-high reversible capacity(397.4 mA h g^(-1) at 100 mA g^(-1) after 700 cycles)and ultra-long cycling life(218.9 mA h g^(-1) at 2000 mA g^(-1) after 7300 cycles,123.1 mA h g^(-1) at3000 mA g^(-1) after 16500 cycles and full cell runs for 4000 cycles).Density functional theory calculation confirms that S/N/O tri-doping enhances the adsorption and diffusion of potassium ions,and in-situ Fourier-transform infrared explores explored the potassium storage mechanism of SNOC.
基金financially supported by National Nature Science Foundation of China(Grant No.22272175,21805278,52072323,52122211)the Fujian Science and Technology Planning Projects of China(2020T3022,2022T3067)+3 种基金the National Key R&D Program of China(No.2021YFB3500400)the Future-prospective and Stride-across Programs of Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2022-GH02)the Youth Innovation Foundation of Xiamen City(Grant No.3502Z20206083)the Opening Project of PCOSS,Xiamen University(Grant No.202014)。
文摘Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphorus-based anodes,in reality,are far from the theoretical capacity corresponding to the formation of K3P alloy.And,their underlying potassium storage mechanisms remain poorly understood.To address this issue,for the first time,we perform high-resolution solid-state31P NMR combined with XRD measurements,and density functional theory calculations to yield a systemic quantitative understanding of(de)potassiation reaction mechanism of phosphorus anode.We explicitly reveal a previously unknown asymmetrical nanocrystalline-to-amorphous transition process via rP←→(K_(3)P_(11),K_(3)P_(7),beta-K_(4)P_(6))←→(alpha-K4P6)←→(K_(1-x)P,KP,K_(4-x)P3,K_(1+x)P)←→(amorphous K4P3,amorphous K3P)that are proceed along with the electrochemical potassiation/depotassiation processes.Additionally,the corresponding KP alloys intermediates,such as the amorphous phases of K_(4)P_(3),K_(3)P,and the nonstoichiometric phases of“K_(1-x)P”,“K_(1+x)P”,“K_(4-x)P_(3)”are experimentally detected,which indicating various complicated K-P alloy species are coexisted and evolved with the sluggish electrochemical reaction kinetics,resulting in lower capacity of phosphorus-based anodes.Our findings offer some insights into the specific multi-phase evolution mechanism of alloying anodes that may be generally involved in conversion-type electrode materials for PIBs.
基金supported by the National Natural Science Foundation of China(No.22179123 and 21471139)the Shandong Provincial Natural Science Foundation,China(ZR2020ME038)the Fundamental Research Funds for the Central Universities(No.202262010 and 201941010)
文摘Carbonaceous material with favorable K^(+)intercalation feature is considered as a compelling anode for potassium-ion batteries(PIBs).However,the inferior rate performance and cycling stability impede their large-scale application.Here,a facile template method is utilized to synthesize boron doping carbon nanobubbles(BCNBs).The incorporation of boron into the carbon structure introduces abundant defective sites and improves conductivity,facilitating both the intercalation-controlled and capacitivecontrolled capacities.Moreover,theoretical calculation proves that boron doping can effectively improve the conductivity and facilitate electrochemical reversibility in PIBs.Correspondingly,the designed BCNBs anode delivers a high specific capacity(464 mAh g^(-1)at 0.05 A g^(-1))with an extraordinary rate performance(85.7 mAh g^(-1)at 50 A g^(-1)),and retains a considerable capacity retention(95.2%relative to the 100th charge after 2000 cycles).Besides,the strategy of pre-forming stable artificial inorganic solid electrolyte interface effectively realizes high initial coulombic efficiency of 79.0%for BCNBs.Impressively,a dual-carbon potassium-ion capacitor coupling BCNBs anode displays a high energy density(177.8 Wh kg^(-1)).This work not only shows great potential for utilizing heteroatom-doping strategy to boost the potassium ion storage but also paves the way for designing high-energy/power storage devices.
基金financially supported by National Natural Science Foundation of China(Nos.51922038 and 51672078)Hunan Outstanding Youth Talents(No.2019JJ20005)
文摘Large-scale and low-cost preparation of carbon-based potassium anode with long life and high capacity is one of the footstones for the development of potassium ion batteries(PIBs).Herein,a low-cost carbon-based material,cross-linked hollow graphitic carbon(HGC),is large scale synthesized to apply for PIBs anode.Its hollow structure can afford sufficient space to overcome the damage caused by the volume expansion of graphitic carbon(GC).While the cross-linked structure forms a compact interconnection network that allows electrons to rapid transfer between different GC frameworks.Electrochemical measurements demonstrated that the HGC anode exhibited low charge/discharge plateau(about 0.25 V and 0.1 V)and excellent specific capacity as high as 298 m A h g^(-1)at the current density of 50 m A g^(-1).And more important,after 200 cycles the capacity of HGC anode still shows 269 m A h g^(-1)(the decay rate of per cycle is only 0.048%).Meanwhile,the use of commercial traditional electrolyte(KPF_(6))and cheap raw materials that provide new hope for trying and realizing the large-scale production of PIBs based on carbon anode materials.
基金Funding information National Natural Science Foundation of China,Grant/Award Numbers:22179123,21471139Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2020ME038+1 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:201941010National Science Foundation,Division of Materials Research,Grant/Award Number:1938833。
文摘We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.
基金financial support by the National Natural Science Foundation of China(51871133)the Taishan Scholar Foundation of Shandong Province,the Key Research and Development Program of Shandong Province(2021ZLGX01)the program of Jinan Science and Technology Bureau(2019GXRC001)。
文摘InSb alloy is a promising candidate for sodium/potassium ion batteries(SIBs/PIBs)but challenged with achieving high performance by dramatic volumetric changes.Herein,nanoporous(np)-InSb with dualscale phases(cubic/hexagonal(C/H)-InSb)was fabricated by chemical dealloying of ternary Mg-In-Sb precursor.Operando X-ray diffraction(XRD)and ex-situ characterizations well rationalize the dealloying/alloying mechanisms and the formation of dual-scale microstructures/phases.As an anode for SIB/PIBs,the np-InSb electrode exhibits superior reversible capacities and lifespan compared with the monometallic porous(p)-In electrode,stemming from the dealloying-induced dual-scale nanoporous architecture and alloying strategy with proper composition.The operando XRD results demonstrate that the(de)sodiated mechanism of the np-InSb electrode involves a two-step(de)alloying process,while the(de)potassiated mechanism is associated with a full electrochemically-driven amorphization upon cycling.Additionally,the gas evolution during the(dis)charge process was monitored by on-line mass spectrometry.
基金support of the Innovation Program of Central South University(No.2018zzts139)。
文摘Hard carbon material is one of the most promising anode materials for potassium ion batteries(PIBs)due to its distinct disordered and non-expandable framework.However,the intrinsically disordered microarchitecture of hard carbon results in low electric conductivity and poor rate capability.Herein,nitrogendoped and partially graphitized hard carbons(NGHCs)derived from commercial coordination compound precursor-ethylenediaminetetraacetic acid(EDTA)disodium cobalt salt hydrate are designed and prepared as high-performance PIBs anode materials.By means of a facile annealing method,nitrogen elements and graphitic domains can be controllably introduced to NGHCs.The resulting NGHCs show structural merits of mesoporous construction,nitrogen doping and homogeneous graphitic domains,which ensures fast kinetics and electron transportation.Applying in anode for PIBs,NGHCs exhibit robust rate capability with high reversible capacity of 298.8 m Ah g^-1 at 50 m A g^-1,and stable cycle stability of 137.6 mAh g^-1 at 500 m A g^-1 after 1000 cycles.Moreover,the ex situ Raman spectra reveal a mixture"adsorption-intercalation mechanism"for potassium storage of NGHCs.More importantly,full PIBs by pairing with perylenetetracarboxylic dianhydride(PTCDA)cathode demonstrate the promising potential of practical application.In terms of commercial precursor,facile synthesis and long cycle lifespan,NGHCs represent a brilliant prospect for practical large-scale applications.
基金the Start-up Funding of Jinan University(Grant No.88016105 and Grant No.55800001)the discipline construction outstanding young backbone project(Grant No.12819023)the Fundamental Research Funds for the Central Universities(Grant No.11620317).
文摘Potassium ion batteries(PIBs)with the prominent advantages of sufficient reserves and economical cost are attractive candidates of new rechargeable batteries for large-grid electrochemical energy storage systems(EESs).However,there are still some obstacles like large size of K+to commercial PIBs applications.Therefore,rational structural design based on appropriate materials is essential to obtain practical PIBs anode with K+accommodated and fast diffused.Nanostructural design has been considered as one of the effective strategies to solve these issues owing to unique physicochemical properties.Accordingly,quite a few recent anode materials with different dimensions in PIBs have been reported,mainly involving in carbon materials,metal-based chalcogenides(MCs),metal-based oxides(MOs),and alloying materials.Among these anodes,nanostructural carbon materials with shorter ionic transfer path are beneficial for decreasing the resistances of transportation.Besides,MCs,MOs,and alloying materials with nanostructures can effectively alleviate their stress changes.Herein,these materials are classified into 0D,1D,2D,and 3D.Particularly,the relationship between different dimensional structures and the corresponding electrochemical performances has been outlined.Meanwhile,some strategies are proposed to deal with the current disadvantages.Hope that the readers are enlightened from this review to carry out further experiments better.
基金financially supported by the National Natural Science Foundation of China(Grant No.21673070)the Fundamental Research Funds of the Central Universities(No.531107051048)Hunan Key Laboratory of Two-Dimensional Materials(No.801200005)
文摘Potassium-based dual ion batteries(KDIBs)have attracted significant attention owing to high working voltage,high safety,low processing cost,and environmental friendliness.Nevertheless,one great challenge for practical KDIBs is to develop suitable anode materials with high specific capacity.Herein,we report an architecture of hierarchically porous antimony nanoparticles/carbon nanofibers(HPSb CNFs)as flexible,free-standing anode for high-performance KDIBs.The HPSb CNFs with hierarchically porous structure,and high-content nitrogen doping,not only offer sufficient free space to tolerate the repetitive volume expansion of Sb nanoparticles during long-term cycling,but also greatly facilitate the transport of electrons and ions within electrode,ensuring high material utilization ratio.Thus,the KDIBs,constituted by HPSb CNFs-700(calcined at 700°C)anode and graphite cathode,exhibited a high reversible capacity of 440 m Ah g^(-1)with high discharge medium voltage of 4.5 V at a specific current of 200 m A g^(-1)(the highest capacity for all KDIBs normalized by the mass of the anode),and excellent cyclic life.Outstanding electrochemical reversibility of the KDIBs was further demonstrated by ex situ XRD,ex situ Raman spectrum,and HRTEM.These results suggest the as-designed HPSb CNFs-700 with highcapacity and long-term cycling stability is a promising anode material for high-performance KDIBs.
基金The authors express their thanks to the research starting foundation from Shaanxi University of Science and Technology(Grant No.2018GBJ-04).
文摘Demand for efficient and continuous application for high-grid energy storage systems involves the study towards novel battery technologies. Hence, considering the vast naturally available resources of potassium all over the world and its encouraging intercalation chemistries, it has recently enticed attention in electrochemical energy storage industry in the form of potassium ion batteries (PIBs). The major factor in this K+ based battery, is to develop efficient approaches to manufacture electrode substance to intercalate its big size potassium ions with considerable voltage, kinetics, charge/discharge capacity, capacity retention, cost, etc. This study contributes in the recent developments of anode and cathode materials for PIBs, including several electrode materials in regards to synthesis, structure, electrochemical performance, and K-storage mechanisms. Finally, the review contributes to provide helpful sources for the increasing number of scientists working in this industry regarding its critical issues and challenges and also to indicate the future direction of electrode materials in PIBs.
基金the auspices of the National Natural Science Foundation of China(52277219,61974072).
文摘Potassium-ion batteries(PIBs)represent one of the most promising alternatives to lithium-ion batteries(LIBs),owing to their exceptional attributes such as high voltages,potent power capabilities,and cost-effectiveness.Nonetheless,challenges arise from the sluggish kinetics and significant volume expansion observed during the insertion/extraction of large-radii potassium ions,leading to subpar rate performance and considerable capacity degradation in potassium-ion batteries.Consequently,it becomes imperative to explore advanced anode materials exhibiting high electrochemical activity and robust structural stability.In this regard,the present review focuses on recent progress in metal-organic compounds(MOCs)as anode materials for potassium-ion batteries,systematically discussing their outstanding merits from the perspective of metal speciation.Additionally,the principal mechanism of K ion storage within relevant MOCs is presented.Furthermore,a comprehensive summary of existing drawbacks that hinder the broader application of MOCs-based materials is provided,along with proposed guidelines and strategies for addressing the inferior performance characteristics.This review serves to illuminate the development of MOCs-based anode materials for potassium-ion batteries and offers a valuable reference for future research endeavors.
基金financially supported by the National Natural Science Foundation of China(51802091,51902102,22075074)Outstanding Young Scientists Research Funds from Hunan Province(2020JJ2004)+2 种基金Major Science and Technology Program of Hunan Province(2020WK2013)Creative Research Funds from Hunan Province(2018RS3046)Natural Science Foundation of Hunan Province(2020JJ5035)。
文摘Oxygen-containing functional groups were found to e ectively boost the K^(+)storage performance of carbonaceous materials,however,the mechanism behind the performance enhancement remains unclear.Herein,we report higher rate capability and better long-term cycle performance employing oxygen-doped graphite oxide(GO)as the anode material for potassium ion batteries(PIBs),compared to the raw graphite.The in situ Raman spectroscopy elucidates the adsorption-intercalation hybrid K^(+)storage mechanism,assigning the capacity enhancement to be mainly correlated with reversible K^(+)adsorption/desorption at the newly introduced oxygen sites.It is unraveled that the C=O and COOH rather than C-O-C and OH groups contribute to the capacity enhancement.Based on in situ Fourier transform infrared(FT-IR)spectra and in situ electrochemical impedance spectroscopy(EIS),it is found that the oxygen-containing functional groups regulate the components of solid electrolyte interphase(SEI),leading to the formation of highly conductive,intact and robust SEI.Through the systematic investigations,we hereby uncover the K^(+)storage mechanism of GO-based PIB,and establish a clear relationship between the types/contents of oxygen functional groups and the regulated composition of SEI.
基金We gratefully acknowledge the financial support from the following sources:the National Natural Science Foundation of China(NSFC)(Grants 51772073,51762013)the Key Project of Hebei Natural Science Foundation(E2020201030)+4 种基金the Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project(21344301D)the Second Batch of Young Talent of Hebei Province(Nos.70280016160250,70280011808)the Key Fund in Hebei Province Department of Education China(ZD2021014)the Central Government Guide Local Funding Projects for Scientific and Technological Development(216Z4404G)the Graduate Innovation Fund Project of Hebei University(HBU2021ss071).
文摘In recent years,the anode materials of bismuth(Bi)-based potassium ion batteries with high theoretical capacity and suitable potassium ion insertion potential have attracted extensive attention.However,due to the volume expansion of Bi,the performance of Bi-based anode materials is not ideal during potassium ion(de)intercalation.In order to solve these problems,we report a three-dimensional(3D)ternary bismuth nanoparticles/conductive polymers/carbon nanotubes(Bi/PPy/CNT)hybrid anode material for K-ion batteries.At a current density of 100 mA·g^(-1),its reversible capacity reaches 302 mAh·g^(-1) after 200 cycles,while it reaches 195.7 mAh·g^(-1) after 600 cycles at 1 A·g^(-1).Its excellent performance is attributed to the hydrogel network which provides a range of electron transport networks and high porosity.Carbon nanotubes are used as electron enhancers to reduce the volume expansion of Bi particles during the reaction.This study provides a prerequisite for expanding the application of 3D ternary materials.
基金the National Natural Science Foundation of China(No.21773116)and Modern Analysis Center of Nanjing University.
文摘An effective method is designed to construct three-dimensional(3D)Nb_(2)C/reduced graphene oxide(rGO)hybrid aerogels through a low-temperature graphene oxide(GO)-assisted hydrothermal self-assembly followed by freeze-drying and annealing.The intimately coupled Nb_(2)C/rGO hybrid aerogel combines the advantages of large specific surface area and rich 3D interconnected porous structure of aerogel as well as high conductivity and low potassium diffusion energy barrier of Nb_(2)C,which not only effectively prevents the self-restacking of Nb2C nanosheets to allow more active sites exposed and accommodate the volume change during the charge/discharge process,but also increases the accessibility of electrolyte and promotes the rapid transfer of ions/electrons.As a result,Nb_(2)C/rGO-2 as the anode of potassium ion batteries(KIBs)delivers a large reversible specific capacity(301.7 mAh·g^(−1)after 500 cycles at 2.0 A·g^(−1)),an ultrahigh rate capability(155.5 mAh·g^(−1)at 20 A·g^(−1)),and an excellent long-term large-current cycle stability(198.8 mAh·g^(−1)after 1,000 cycles at 10 A·g^(−1),with a retention of 83.3%).Such a high-level electrochemical performance,especially the ultrahigh rate capability,is the best among transition metal carbides and nitride(MXene)-based materials reported so far for KIBs.The diffusion kinetics of K+is investigated thoroughly,and the synergetic charge–discharge mechanism and the structure–performance relationship of Nb_(2)C/rGO are revealed explicitly.The present work provides a good strategy to solve the self-restacking problem of two-dimensional materials and also enlarges the potential applications of MXenes.
基金the National Natural Science Foundation of China(Nos.22109060,52071171,and 52202248)the 2021 Annual Scientific Research Funding Project of the Educational Department of Liaoning Province(No.LJKZ0101)+7 种基金Liaoning BaiQianWan Talents Program(No.LNBQW2018B0048)Shenyang Science and Technology Project(No.21-108-9-04)Young Scientific and Technological Talents Project of the Department of Education of Liaoning Province(No.LQN202008)Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization,Anhui University of Technology(No.CHV22-05)Australian Research Council(ARC)through Future Fellowship(Nos.FT210100298 and FT210100806)Discovery Project(No.DP220100603)Linkage Project(No.LP210100467,LP210200504,and LP210200345)Industrial Transformation Training Centre(No.IC180100005)schemes,CSIRO Energy Centre and Kick-Start Project.
文摘Due to the high theoretical capacity and electrode potential,Prussian blue is regarded as promising cathode material for potassium ion batteries.However,inferior structural stability,poor electronic conductivity,ambiguous energy storage mechanism have limited the application of Prussian blue materials.Herein,a highly stable Prussian blue-polypyrrole(PB-PPY)composite has been prepared by a facile one-step method.PB-PPY displays higher discharging capacity,better rate capacity,and longer cycling lifespan than that of pure Prussian blue in potassium ion batteries.The superior electrochemical performance can be attributed to the unique synthesis strategy to reduce the content of vacancies and crystal water in Prussian blue and enhance the conductivity.Furthermore,partial K ions have been evidenced that could remain in the Prussian blue framework,which contributes the long-term cycling stability.The K ions in the framework play the role of“pillars”to support the framework of Prussian blue and relieve the structural stress during the intercalation and de-intercalation of K ions.This work will reveal a new energy storage mechanism of Prussian blue and promote the design of high stability Prussian blue in the future.
基金supported by the National Natural Science Foundation of China (No. 22179063)。
文摘Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent structural stability. However, the excessive stacking of interlayer electron clouds makes it difficult to expose internal active sites. Strategies to design functional COFs with controllable morphology and copious active sites are promising but still challenging. Herein, by utilizing the condensation between1,3,5-triformylbenzene(TFB) and p-phenylenediamine(PPD) and using amino-modified SiO_(2) nanospheres as templates, we synthesize core-shell NH_(2)-SiO_(2)@TP-COF. Through NaOH etching of NH_(2)-SiO_(2)@TP-COF, we obtain imine-based TP-COF hollow nanospheres, which shows excellent potassium storage performance when applied to the anode for PIBs. Ex-situ analysis and density functional theory calculations reveal that C=N groups and benzenes are active sites for K^(+) storage.
