Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”l...Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”liquid natural rubber oligomers obtained by controlled chemical degradation of NR.The chain ends of such oligomers can then be functionalized(with acrylate functions in the present case)and reacted with multifunctional crosslinkers in order to form networks.What’s more,the initial solubility of such thermosetting system in an ionic liquid(IL)can be used for the formulation of ionogels.Such solid networks typically containing 80%of IL were produced,resulting in high ionic conductivity performances.The oligomer chain length was shown to affect IL fragility due to confinement and specific interactions of ions with the host polymer network.展开更多
Polymer ionogel(PIG)is a new type of flexible,stretchable,and ion-conductive material,which generally consists of two components(polymer matrix materials and ionic liquids/deep eutectic solvents).More and more attenti...Polymer ionogel(PIG)is a new type of flexible,stretchable,and ion-conductive material,which generally consists of two components(polymer matrix materials and ionic liquids/deep eutectic solvents).More and more attention has been received owing to its excellent properties,such as nonvolatility,good ionic conductivity,excellent thermal stability,high electrochemical stability,and transparency.In this review,the latest research and developments of PIGs are comprehensively reviewed according to different polymer matrices.Particularly,the development of novel structural designs,preparation methods,basic properties,and their advantages are respectively summarized.Furthermore,the typical applications of PIGs in flexible ionic skin,flexible electrochromic devices,flexible actuators,and flexible power supplies are reviewed.The novel working mechanism,device structure design strategies,and the unique functions of the PIG-based flexible ionic devices are briefly introduced.Finally,the perspectives on the current challenges and future directions of PIGs and their application are discussed.展开更多
Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate sma...Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate smart sensors with high robustness,reliability,and visible readout.Herein,high-performance electrochromic(EC),electro-fluorochromic(EFC),and double-network ionogels with excellent transmissivity,high mechanical robustness,and ultrastable reversibility are prepared by combination of thienoviologen-containing ionic liquids with poly(ethyl acrylate)elastomer.The ionogels exhibit good mechanical properties(1000%stretchability and 3.2 kJ m^(−2) fracture energy).The ionogel-based EC devices have a significantly simplified device fabrication process as well as superior cycling stability in which 88%of the contract ratio is maintained at 88%at 500 cycles,even after being stored for 2 years under ambient atmosphere(relative humidity:30%∼40%,25°C).The conductivity of ionogels showed a fast and reproducible response to strain,and the conductivity decreased with increased strain.By virtue of the EC and EFC properties of the thienoviologen component,the EC and EFC efficiency decreased with the increased strain loaded on the ionogels,and almost no EC or EFC phenomena were observed when the strain was above 300%.This feasible strategy provides an opportunity for the development of visible strain sensors to monitor the body’s movements through color and fluorescence emission.展开更多
Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels re...Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels remains a significant challenge.Here, a nanocomposite ionogel with skin-like stretchability, high i-TE performance, thermostability and durability is prepared by hybridizing ionic liquid(IL) and Laponite nanosheets into waterborne polyurethane(WPU). With multiple H-bond, WPU can accommodate a higher content of IL, thereby improving its ionic conductivity. After cation exchange between IL and Laponite,the negatively charged Laponite sheets and released Na+can enhance the ionic Seebeck coefficient by enlarging thermophoretic mobility difference between the cations and anions in ionogel. Besides, incorporation of Laponite causes the decrease of thermal conductivity. Thus, the WPU-IL-Laponite ionogel exhibits a high ionic thermopower of 44.1 m V K-1, high ionic conductivity of 14.1 m S cm-1and low thermal conductivity of 0.43 W m-1K-1at a relative humidity of 90%. The corresponding ionic figure of merit of the ionogel is 1.90±0.27. Moreover, the ionogel demonstrates excellent durability during repeated stretching process.The stretchable ionogel can be fabricated into ionic thermoelectric capacitor to convert thermal energy from solar radiation into electricity.展开更多
Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),whi...Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),which show significant influence on the physicochemical properties of the ionogels,has been rarely studied.Herein,we elucidate a lower critical solution temperature(LCST)-type phase behavior of ionogels composed of polyacrylates and hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ILs.We systematically study the structural effects of ILs and monomers on the LCST of ionogels.Our work illustrates that the LCST of ionogels is primarily determined by the polarity of polymer side chains and the alkyl chain on cations of ILs.The oriented solvation between polymers and ILs caused by hydrogen-bonding effects and van der Waals interactions may serve as the driving force for the LCST phase behavior in our system.Furthermore,by varying the mixing ratio of two structurally similar ILs in their blends,the LCST of ionogels can be tuned to exhibit a linear variation within a wide temperature range(from subzero to over 200℃).Finally,thermoresponsive ionogels with desired patterns are prepared using photomasks.These nonvolatile ionogels with tunable LCST enriched the functionality of state-of-the-art ionogels,which provides insight into the design and fabrication of smart and flexible electronic/optical devices.展开更多
Perovskite solar cells have emerged as a promising technology for renewable energy generation.However,the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and l...Perovskite solar cells have emerged as a promising technology for renewable energy generation.However,the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and long-term stable photorechargeable systems remains a persistent challenge.Issues such as electrical mismatch and restricted integration levels contribute to elevated internal resistance,leading to suboptimal overall efficiency(η_(overall))within photorechargeable systems.Additionally,the compatibility of perovskite solar cells with electrolytes from energy storage devices poses another significant concern regarding their stability.To address these limitations,we demonstrate a highly integrated photorechargeable system that combines perovskite solar cells with a solid-state zinc-ion hybrid capacitor using a streamlined process.Our study employs a novel ultraviolet-cured ionogel electrolyte to prevent moisture-induced degradation of the perovskite layer in integrated photorechargeable system,enabling perovskite solar cells to achieve maximum power conversion efficiencies and facilitating the monolithic design of the system with minimal energy loss.By precisely matching voltages between the two modules and leveraging the superior energy storage efficiency,our integrated photorechargeable system achieves a remarkableηoverall of 10.01%while maintaining excellent cycling stability.This innovative design and the comprehensive investigations of the dynamic photocharging process in monolithic systems,not only offer a reliable and enduring power source but also provide guidelines for future development of self-power off-grid electronics.展开更多
Thermally chargeable supercapacitors can collect low-grade heat generated by the human body and convert it into electricity as a power supply unit for wearable electronics.However,the low Seebeck coefficient and heat-...Thermally chargeable supercapacitors can collect low-grade heat generated by the human body and convert it into electricity as a power supply unit for wearable electronics.However,the low Seebeck coefficient and heat-to-electricity conversion efficiency hinder further application.In this paper,we designed a high-performance thermally chargeable supercapacitor device composed of ZnMn_(2)O_(4)@Ti_(3)C_(2)T_(x)MXene composites(ZMO@Ti_(3)C_(2)T_(x) MXene)electrode and UIO-66 metal–organic framework doped multichannel polyvinylidene fluoridehexafluoro-propylene ionogel electrolyte,which realized the thermoelectric conversion and electrical energy storage at the same time.This thermally chargeable supercapacitor device exhibited a high Seebeck coefficient of 55.4 mV K^(−1),thermal voltage of 243 mV,and outstanding heat-to-electricity conversion efficiency of up to 6.48%at the temperature difference of 4.4 K.In addition,this device showed excellent charge–discharge cycling stability at high-temperature differences(3 K)and low-temperature differences(1 K),respectively.Connecting two thermally chargeable supercapacitor units in series,the generated output voltage of 500 mV further confirmed the stability of devices.When a single device was worn on the arm,a thermal voltage of 208.3 mV was obtained indicating the possibility of application in wearable electronics.展开更多
With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we re...With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we report a facile strategy of using the green choline chloride-acrylamide deep eutectic solvent(CC-AM DES)to guide the in-situ ring-opening polymerization ofα-lipoic acid(LA),leading to the successful development of a stretchable ionogel material.The as-prepared ionogel from CC-AM DES system exhibits multifunctional merits including the super stretchability(>9000%),100%UV-blocking ability,tunable adhesiveness(29-414 kPa),high ionic conductivity(4.45×10^(-4) S/cm),and ideal anti-freezing(-27℃).In addition,this outstanding ionogel can be readily coated on various material substrates with designable shapes and patterns.Owning to these promising properties and performances,a scalable flexible strain sensor is assembled from the ionogel and exhibits stable resistance variations(R/R_(0))towards multiple external mechanical stimulus.This study provides a green,cost effective,and scalable strategy to fabricate ionogel materials and multifunctional flexible strain sensors,showing a great potential in the fast-emerging highly stretchable wearable/flexible electronics.展开更多
Neurological injuries and disorders have a significant impact on individuals’quality of life,often resulting in motor and sensory loss.To assess motor performance and monitor neurological disorders,non-invasive techn...Neurological injuries and disorders have a significant impact on individuals’quality of life,often resulting in motor and sensory loss.To assess motor performance and monitor neurological disorders,non-invasive techniques such as electroencephalography(EEG)and electromyography(EMG)are commonly used.Traditionally employed wet electrodes with conductive gels are limited by lengthy skin preparation time and allergic reactions.Although dry electrodes and hydrogel-based electrodes can mitigate these issues,their applicability for long-term monitoring is limited.Dry electrodes are susceptible to motion artifacts,whereas hydrogel-based electrodes face challenges related to water-induced instability.Recently,ionogels and eutectogels derived from ionic liquids and deep eutectic solvents have gained immense popularity due to their non-volatility,ionic conductivity,thermal stability,and tunability.Eutectogels,in particular,exhibit superior biocompatibility.These characteristics make them suitable alternatives for the development of safer,robust,and reliable EEG and EMG electrodes.However,research specifically focused on their application for EEG and EMG signal acquisition remains limited.This article explores the electrode requirements and material advancements in EEG and EMG sensing,with a focus on highlighting the benefits that ionogels and eutectogels offer over conventional materials.It sheds light on the current limitations of these materials and proposes areas for further improvement in this field.The potential of these gel-based materials to achieve a seamless interface for high-quality and long-term electrophysiological signal acquisition is emphasized.Leveraging the unique properties of ionogels and eutectogels holds promise for future advancements in EEG and EMG electrode materials,leading to improved monitoring systems and enhanced patient outcomes.展开更多
New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh o...New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.展开更多
Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment o...Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment on the electrodes.Although the urgent demand of energy conversion-storage(ECS)has emerged in the field of wearable electronic,achieving the integrated bi-functional device remains challenge due to the different mechanisms of electrical transportation and storage.Here,we report an ionic thermoelectric supercapacitor that relies on the synergistic functions of thermoelectricity and supercapacitor in the thermoelectric ionogel electrolyte and high-performance hydrogel electrodes to enhance the ECS performance under a thermal gradient.The thermoelectric electrolyte is composed of polyacrylamide hydrogel and sodium carboxymethyl cellulose(PMSC),possessing cross-linked network with excellent cation selectivity,while the ionic thermoelectric properties are further improved in the presence of NaCl.The corresponding Seebeck coefficient and ionic conductivity of the NaCl–PMSC electrolyte reach 17.1 mV K^(-1)and 26.8 mS cm^(-1),respectively.Owing to good stretchability of both gel-based electrolyte and electrode,the fullstretchable integrated ECS device,termed ionic thermoelectric supercapacitor,presents promising thermal-charge storage capability(~1.3 mC,ΔT≈10 K),thus holds promise for wearable energy harvesting.展开更多
Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electric...Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.展开更多
Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound heali...Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound healing at the wound site by constructing robust and ecofriendly composite patch under opto-electric stimulation.The wearable patch is composed of ionic gel doped with Ti3C2Tx(MXene),which possesses good photothermal response to kill the bacteria via effective inhibition of the expression of inflammatory factors,preventing wound infection.Importantly,the composite ionogel patch is capable of providing green and on-demand electrical stimulation for wound site,guiding cell migration and proliferation by improved bioenergy and expression up-regulation of growth factor.In mice wound models,the treatment group healed~31%more rapidly.Mechanistically,the wearable devices could enable visual and real-time supervising treatment effect due to their good transmittance.The proposed strategy would be promising for future clinical treatment of wound healing.展开更多
The rapid development of wearable electronic products brings challenges to corresponding power supplies.In this work,a thermally stable and stretchable ionogel-based triboelectric nanogenerator(SI-TENG)for biomechanic...The rapid development of wearable electronic products brings challenges to corresponding power supplies.In this work,a thermally stable and stretchable ionogel-based triboelectric nanogenerator(SI-TENG)for biomechanical energy collection is proposed.The ionic conductivity of the ionogel increased to 0.53 S·m^(−1) through optimal regulation of the amount of aminoterminated hyperbranched polyamide(NH2-HBP),which also has high strain of 812%,excellent stretch recovery,and wide operating temperature range of−80 to 250°C.The SI-TENG with this ionogel as electrode and silicone rubber both as the triboelectric layer and encapsulation layer exhibits high temperature stability,stretchability,and washability.By adding appropriate amount of nano SiO2 to triboelectric layer,the output performance is further improved by 93%.Operating in singleelectrode mode at 1.5 Hz,the outputs of a SI-TENG with an area of 3 cm×3 cm are 247 V,11.7μA,78 nC,and 3.2 W·m^(−2),respectively.It was used as a self-charging power supply to charge a 22μF capacitor to 1.6 V in 167 s with the palm patting and then to power the electronic calculator.Furthermore,the SI-TENG can also be used as a self-powered motion sensor to detect the amplitude and frequency of finger bending,human swallowing,nodding,and shaking of the head motion changes through the analysis of the output voltage.展开更多
Human skin can function steadily regardless of surrounding circumstarices(dry or wet),while it is still a challenge for artificial ionic skins,which tend to release solvents in dry air and leach electrolytes in wetted...Human skin can function steadily regardless of surrounding circumstarices(dry or wet),while it is still a challenge for artificial ionic skins,which tend to release solvents in dry air and leach electrolytes in wetted state.Herein,a series of hierarchically crosslinked ionogels containing hydrophobic ionic liquids(ILs)is fabricated by combining a crystalline fluorinated copolymer with hydrophobic ILs.With a reasonable combination of nonvolatility,transparency,stretchablility,and sensitivity,such ionogels can work as reliable sensors for real-time monitoring huma n motions and operate steadily in complex environments as human skin does,which can contribute to the developme nt of durable sen sing devices with a simple design.展开更多
Highly durable and stretchable ionic conductors are indispensable components of flexible electronics.However,fabricating such ionic conductors that are also non-toxic and biodegradable remains a challenge.In this stud...Highly durable and stretchable ionic conductors are indispensable components of flexible electronics.However,fabricating such ionic conductors that are also non-toxic and biodegradable remains a challenge.In this study,highly stretchable,elastic,healable,and ultra-durable ionic conductors capable of non-hazardous disposal are conveniently fabricated by complexation of vanillin-grafted polyvinyl alcohol(VPVA)and ionic liquids(ILs)(denoted as VPVA-IL).展开更多
Ionogels with high transparency,stretchability and self-healing capability show great potential for wearable electronics.Here,a kind of highly transparent,stretchable and self-healable ionogels are designed using doub...Ionogels with high transparency,stretchability and self-healing capability show great potential for wearable electronics.Here,a kind of highly transparent,stretchable and self-healable ionogels are designed using double physical cross-linking including hydrogen bonding and dipole–dipole interaction.Owing to the dynamic and reversible nature of the ion–dipole interaction and hydrogen bonds of polymeric chains,the ionogel possesses good self-healing capability.The multifunctional sensors for strain and temperature are fabricated based on ionogel.The ionogel can serve as strain sensor that exhibited high sensitivity[gauge factor(GF)=3.06]and durability(1000 cycles)to a wide range of strains(0–300%).Meanwhile,the ionogel shows rapid response to temperature,due to the temperature dependence of its ionic conductivity.Furthermore,the ionogel fbers with excellent antifreezing(−20°C)capability are fabricated,and the fbers show the good sensing performance to human motions and temperature.Importantly,the antifreezing ionogel-based triboelectric nanogenerator(ITENG)is assembled for efcient energy harvesting.The ITENG shows a short circuit current(ISC)of 6.1μA,open circuit voltage(VOC)of 115 V,and instantaneous peak power density of 334 mW m−2.This work provides a new strategy to design ionogels for the advancement of wearable electronics.展开更多
A flexible and stable power supply is essential to the rapid development of wearable electronic devices.In this work,a transparent,flexible,temperature-stable and ionogel electrode-based self-healing triboelectric nan...A flexible and stable power supply is essential to the rapid development of wearable electronic devices.In this work,a transparent,flexible,temperature-stable and ionogel electrode-based self-healing triboelectric nanogenerator(IS-TENG)was developed.The ionogel with excellent stretchability(1,012%),high ionic conductivity(0.3 S·m^(−1))and high-temperature stability(temperature range of−77 to 250℃)was used as the electrode of the IS-TENG.The IS-TENG exhibited excellent transparency(92.1%)and stability.The output performance did not decrease when placed in a 60℃oven for 48 h.In addition,the IS-TENG behaved like a stable output in the range of−20 to 60℃.More importantly,the IS-TENG could also achieve self-healing of electrical performance at temperatures between−20 and 60℃and its output can be restored to its original state after healing.When the single-electrode IS-TENG with an area of 3 cm×3 cm was conducted under the working frequency of 1.5 Hz,the output values for open-circuit voltage,short-circuit current,short-circuit transferred charge,and maximum peak power density were 189 V,6.2μA,57 nC,and 2.17 W·m^(−2),respectively.The IS-TENG enables to harvest biomechanical energy,and drive electronic devices.Furthermore,the application of IS-TENGs as self-driven sensors for detecting human behavior was also demonstrated,showing good application prospects in the field of wearable power technology and self-driven sensing.展开更多
Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature ph...Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb205 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5 nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g^-1. Additionally, non-aqueous asymmetric supercapacitors （ASCs） were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg^-1 at 715.2 W·kg^-1. The working potential could be further enhanced to 4 V when a polymer ionogel separator （PVDF-HFP/LiTFSI/EMIMBF4） and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60℃ and delivered a maximum energy density of 70 Wh·kg^-1 at 1 kW·kg^-1.展开更多
In order to avoid leakage problem caused by liquid electrolyte, a new ionogel electrolyte was developed by in situ immobilizing organosilicon-functionalized ionic liquid within a nanoporous silica matrix. The ionic li...In order to avoid leakage problem caused by liquid electrolyte, a new ionogel electrolyte was developed by in situ immobilizing organosilicon-functionalized ionic liquid within a nanoporous silica matrix. The ionic liquid evenly coats on the surface of porous silica and fills in the silica framework pores with no strong chemical interaction. The ionogel electrolyte has the dual advantages of a silica solid support and a wide electrochemical stability window of ionic liquid （4.87 V vs. Li^＋/Li）. The half-cells assembled with this electrolyte and LiFePO4 electrode have excellent performance at room temperature and 60 ℃. The Li/SiO2-IGE/LiFePO4 cell displays a discharge capacity of 129.1 mAh·g^-1 after 200 charge/discharge cycles at room temperature.展开更多
文摘Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”liquid natural rubber oligomers obtained by controlled chemical degradation of NR.The chain ends of such oligomers can then be functionalized(with acrylate functions in the present case)and reacted with multifunctional crosslinkers in order to form networks.What’s more,the initial solubility of such thermosetting system in an ionic liquid(IL)can be used for the formulation of ionogels.Such solid networks typically containing 80%of IL were produced,resulting in high ionic conductivity performances.The oligomer chain length was shown to affect IL fragility due to confinement and specific interactions of ions with the host polymer network.
基金supported by the Natural Science Foundation of Heilongjiang Province (No.LH2023E035)the Heilongjiang Provincial Postdoctoral Science Foundation (No.LBH-TZ0604)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices,South China University of Technology (No.2022-skllmd-08).
文摘Polymer ionogel(PIG)is a new type of flexible,stretchable,and ion-conductive material,which generally consists of two components(polymer matrix materials and ionic liquids/deep eutectic solvents).More and more attention has been received owing to its excellent properties,such as nonvolatility,good ionic conductivity,excellent thermal stability,high electrochemical stability,and transparency.In this review,the latest research and developments of PIGs are comprehensively reviewed according to different polymer matrices.Particularly,the development of novel structural designs,preparation methods,basic properties,and their advantages are respectively summarized.Furthermore,the typical applications of PIGs in flexible ionic skin,flexible electrochromic devices,flexible actuators,and flexible power supplies are reviewed.The novel working mechanism,device structure design strategies,and the unique functions of the PIG-based flexible ionic devices are briefly introduced.Finally,the perspectives on the current challenges and future directions of PIGs and their application are discussed.
基金research was made possible as a result of generous grants from the National Key Research and Development Program of China(grant no.2021YFB3200700)the Natural Science Foundation of China(grant nos.22175138,21875180,and 52203240)+4 种基金the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University(grant no.PY3A066)the China National Postdoctoral Program for Innovative Talents(grant no.BX2021231)the Fundamental Research Funds for the Central Universities(grant no.sxjh032021099)the China Postdoctoral Science Foundation(grant no.2021M692545)the Natural Science Foundation of Shaanxi Province(grant no.2021JQ-043).
文摘Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate smart sensors with high robustness,reliability,and visible readout.Herein,high-performance electrochromic(EC),electro-fluorochromic(EFC),and double-network ionogels with excellent transmissivity,high mechanical robustness,and ultrastable reversibility are prepared by combination of thienoviologen-containing ionic liquids with poly(ethyl acrylate)elastomer.The ionogels exhibit good mechanical properties(1000%stretchability and 3.2 kJ m^(−2) fracture energy).The ionogel-based EC devices have a significantly simplified device fabrication process as well as superior cycling stability in which 88%of the contract ratio is maintained at 88%at 500 cycles,even after being stored for 2 years under ambient atmosphere(relative humidity:30%∼40%,25°C).The conductivity of ionogels showed a fast and reproducible response to strain,and the conductivity decreased with increased strain.By virtue of the EC and EFC properties of the thienoviologen component,the EC and EFC efficiency decreased with the increased strain loaded on the ionogels,and almost no EC or EFC phenomena were observed when the strain was above 300%.This feasible strategy provides an opportunity for the development of visible strain sensors to monitor the body’s movements through color and fluorescence emission.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFA0703100)the National Natural Science Foundation of China (Grant No. 51733006)。
文摘Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels remains a significant challenge.Here, a nanocomposite ionogel with skin-like stretchability, high i-TE performance, thermostability and durability is prepared by hybridizing ionic liquid(IL) and Laponite nanosheets into waterborne polyurethane(WPU). With multiple H-bond, WPU can accommodate a higher content of IL, thereby improving its ionic conductivity. After cation exchange between IL and Laponite,the negatively charged Laponite sheets and released Na+can enhance the ionic Seebeck coefficient by enlarging thermophoretic mobility difference between the cations and anions in ionogel. Besides, incorporation of Laponite causes the decrease of thermal conductivity. Thus, the WPU-IL-Laponite ionogel exhibits a high ionic thermopower of 44.1 m V K-1, high ionic conductivity of 14.1 m S cm-1and low thermal conductivity of 0.43 W m-1K-1at a relative humidity of 90%. The corresponding ionic figure of merit of the ionogel is 1.90±0.27. Moreover, the ionogel demonstrates excellent durability during repeated stretching process.The stretchable ionogel can be fabricated into ionic thermoelectric capacitor to convert thermal energy from solar radiation into electricity.
基金financially supported by theNationalNatural Science Funds for Distinguished Young Scholar(no.21725401)the National Key R&D Program of China(grant no.2017YFA0207800)+2 种基金the China Postdoctoral Science Foundation(no.2019M650434)the National Natural Scientific Foundation of China(nos.21774004,22073094)the supports of Computing Center of Jilin Province and Computing Center of CIAC,CAS.
文摘Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),which show significant influence on the physicochemical properties of the ionogels,has been rarely studied.Herein,we elucidate a lower critical solution temperature(LCST)-type phase behavior of ionogels composed of polyacrylates and hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ILs.We systematically study the structural effects of ILs and monomers on the LCST of ionogels.Our work illustrates that the LCST of ionogels is primarily determined by the polarity of polymer side chains and the alkyl chain on cations of ILs.The oriented solvation between polymers and ILs caused by hydrogen-bonding effects and van der Waals interactions may serve as the driving force for the LCST phase behavior in our system.Furthermore,by varying the mixing ratio of two structurally similar ILs in their blends,the LCST of ionogels can be tuned to exhibit a linear variation within a wide temperature range(from subzero to over 200℃).Finally,thermoresponsive ionogels with desired patterns are prepared using photomasks.These nonvolatile ionogels with tunable LCST enriched the functionality of state-of-the-art ionogels,which provides insight into the design and fabrication of smart and flexible electronic/optical devices.
基金the UK Engineering and Physical Sciences Research Council(EPSRC)Standard Research(EP/V027131/1)EPSRC New Investigator Award(2018+6 种基金EP/R043272/1)Newton Advanced Fel owship(192097)for financial supportEPSRC New Investigator Award(EP/V002260/1)National Measurement System of the UK Department of Business,Energy&Industrial Strategythe China Scholarship Council(CSC,no.201808370197)for financial supportCSC(no.202007040033)for financial supportCSC(no.201908310074)for financial support
文摘Perovskite solar cells have emerged as a promising technology for renewable energy generation.However,the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and long-term stable photorechargeable systems remains a persistent challenge.Issues such as electrical mismatch and restricted integration levels contribute to elevated internal resistance,leading to suboptimal overall efficiency(η_(overall))within photorechargeable systems.Additionally,the compatibility of perovskite solar cells with electrolytes from energy storage devices poses another significant concern regarding their stability.To address these limitations,we demonstrate a highly integrated photorechargeable system that combines perovskite solar cells with a solid-state zinc-ion hybrid capacitor using a streamlined process.Our study employs a novel ultraviolet-cured ionogel electrolyte to prevent moisture-induced degradation of the perovskite layer in integrated photorechargeable system,enabling perovskite solar cells to achieve maximum power conversion efficiencies and facilitating the monolithic design of the system with minimal energy loss.By precisely matching voltages between the two modules and leveraging the superior energy storage efficiency,our integrated photorechargeable system achieves a remarkableηoverall of 10.01%while maintaining excellent cycling stability.This innovative design and the comprehensive investigations of the dynamic photocharging process in monolithic systems,not only offer a reliable and enduring power source but also provide guidelines for future development of self-power off-grid electronics.
基金supported by the National Natural Science Foundation of China(52273256)Beijing Municipal Natural Science Foundation(L223006)Beijing Institute of Technology Research Found Program for Young Scholars.
文摘Thermally chargeable supercapacitors can collect low-grade heat generated by the human body and convert it into electricity as a power supply unit for wearable electronics.However,the low Seebeck coefficient and heat-to-electricity conversion efficiency hinder further application.In this paper,we designed a high-performance thermally chargeable supercapacitor device composed of ZnMn_(2)O_(4)@Ti_(3)C_(2)T_(x)MXene composites(ZMO@Ti_(3)C_(2)T_(x) MXene)electrode and UIO-66 metal–organic framework doped multichannel polyvinylidene fluoridehexafluoro-propylene ionogel electrolyte,which realized the thermoelectric conversion and electrical energy storage at the same time.This thermally chargeable supercapacitor device exhibited a high Seebeck coefficient of 55.4 mV K^(−1),thermal voltage of 243 mV,and outstanding heat-to-electricity conversion efficiency of up to 6.48%at the temperature difference of 4.4 K.In addition,this device showed excellent charge–discharge cycling stability at high-temperature differences(3 K)and low-temperature differences(1 K),respectively.Connecting two thermally chargeable supercapacitor units in series,the generated output voltage of 500 mV further confirmed the stability of devices.When a single device was worn on the arm,a thermal voltage of 208.3 mV was obtained indicating the possibility of application in wearable electronics.
基金supported by the National Natural Science Foundation of China(32071715)Canada Research Chairs program of the Government of Canada,and National Science Foundation for Post-doctoral Scientists of China(2019M651050).
文摘With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we report a facile strategy of using the green choline chloride-acrylamide deep eutectic solvent(CC-AM DES)to guide the in-situ ring-opening polymerization ofα-lipoic acid(LA),leading to the successful development of a stretchable ionogel material.The as-prepared ionogel from CC-AM DES system exhibits multifunctional merits including the super stretchability(>9000%),100%UV-blocking ability,tunable adhesiveness(29-414 kPa),high ionic conductivity(4.45×10^(-4) S/cm),and ideal anti-freezing(-27℃).In addition,this outstanding ionogel can be readily coated on various material substrates with designable shapes and patterns.Owning to these promising properties and performances,a scalable flexible strain sensor is assembled from the ionogel and exhibits stable resistance variations(R/R_(0))towards multiple external mechanical stimulus.This study provides a green,cost effective,and scalable strategy to fabricate ionogel materials and multifunctional flexible strain sensors,showing a great potential in the fast-emerging highly stretchable wearable/flexible electronics.
基金funding from the Research Grants Council of the Hong Kong SAR Government(GRF#16302723 and ECS#26201323).
文摘Neurological injuries and disorders have a significant impact on individuals’quality of life,often resulting in motor and sensory loss.To assess motor performance and monitor neurological disorders,non-invasive techniques such as electroencephalography(EEG)and electromyography(EMG)are commonly used.Traditionally employed wet electrodes with conductive gels are limited by lengthy skin preparation time and allergic reactions.Although dry electrodes and hydrogel-based electrodes can mitigate these issues,their applicability for long-term monitoring is limited.Dry electrodes are susceptible to motion artifacts,whereas hydrogel-based electrodes face challenges related to water-induced instability.Recently,ionogels and eutectogels derived from ionic liquids and deep eutectic solvents have gained immense popularity due to their non-volatility,ionic conductivity,thermal stability,and tunability.Eutectogels,in particular,exhibit superior biocompatibility.These characteristics make them suitable alternatives for the development of safer,robust,and reliable EEG and EMG electrodes.However,research specifically focused on their application for EEG and EMG signal acquisition remains limited.This article explores the electrode requirements and material advancements in EEG and EMG sensing,with a focus on highlighting the benefits that ionogels and eutectogels offer over conventional materials.It sheds light on the current limitations of these materials and proposes areas for further improvement in this field.The potential of these gel-based materials to achieve a seamless interface for high-quality and long-term electrophysiological signal acquisition is emphasized.Leveraging the unique properties of ionogels and eutectogels holds promise for future advancements in EEG and EMG electrode materials,leading to improved monitoring systems and enhanced patient outcomes.
基金This work is supported by the National Natural Science Foundation of China(No.51972132.51772116 and 52002141)the Program for HUST Academic Frontier Youth Team(2016QYTD04).The authors thank the Analytical and Testing Center of HUST for DMA,TGA measurements,etc.
文摘New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.
基金financial support by the National Natural Science Foundation of China(No.51873033 and No.52073057)the Fundamental Research Funds for the Central Universities(2232020A-01 and 2232019A3-02)+3 种基金DHU Distinguished Young Professor Program(LZB2019002)Shanghai Rising-Star Program(20QA1400300)the Fundamental Research Funds for the Central University and Graduate Student Innovation Fund of Donghua University(CUSFDH-D-2020033)State Key Laboratory for Space Power Sources Technology(No.YF07050117F0768)。
文摘Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment on the electrodes.Although the urgent demand of energy conversion-storage(ECS)has emerged in the field of wearable electronic,achieving the integrated bi-functional device remains challenge due to the different mechanisms of electrical transportation and storage.Here,we report an ionic thermoelectric supercapacitor that relies on the synergistic functions of thermoelectricity and supercapacitor in the thermoelectric ionogel electrolyte and high-performance hydrogel electrodes to enhance the ECS performance under a thermal gradient.The thermoelectric electrolyte is composed of polyacrylamide hydrogel and sodium carboxymethyl cellulose(PMSC),possessing cross-linked network with excellent cation selectivity,while the ionic thermoelectric properties are further improved in the presence of NaCl.The corresponding Seebeck coefficient and ionic conductivity of the NaCl–PMSC electrolyte reach 17.1 mV K^(-1)and 26.8 mS cm^(-1),respectively.Owing to good stretchability of both gel-based electrolyte and electrode,the fullstretchable integrated ECS device,termed ionic thermoelectric supercapacitor,presents promising thermal-charge storage capability(~1.3 mC,ΔT≈10 K),thus holds promise for wearable energy harvesting.
基金supported by the National Key Research and Development Program of China(2021YFC2101800,2021YFC2400802)the National Natural Science Foundation of China(52173117,21991123)+1 种基金the Ningbo 2025 Science and Technology Major Project(2019B10068)the Science and Technology Commission of Shanghai(20DZ2254900,20DZ2270800)。
文摘Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.
基金supported by the National Natural Science Foundation of China(grant No.22004117 and 21675146)Chinese Academy of Sciences for Special Research Assistant Grant.
文摘Developing the high biosafety,effective and wearable devices for fast wound healing is highly desired but remains a challenge.Here,we propose a“win–win co-operation”strategy to potentiate effective skin wound healing at the wound site by constructing robust and ecofriendly composite patch under opto-electric stimulation.The wearable patch is composed of ionic gel doped with Ti3C2Tx(MXene),which possesses good photothermal response to kill the bacteria via effective inhibition of the expression of inflammatory factors,preventing wound infection.Importantly,the composite ionogel patch is capable of providing green and on-demand electrical stimulation for wound site,guiding cell migration and proliferation by improved bioenergy and expression up-regulation of growth factor.In mice wound models,the treatment group healed~31%more rapidly.Mechanistically,the wearable devices could enable visual and real-time supervising treatment effect due to their good transmittance.The proposed strategy would be promising for future clinical treatment of wound healing.
基金supported by the National Key Research and Development Program from Ministry of Science and Technology of China(No.2021YFB3200300)the National Natural Science Foundation of China(No.62174115)+1 种基金the Suzhou Science and Technology Development Planning Project:Key Industrial Technology Innovation(No.SYG202009)This work was also supported by the Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.
文摘The rapid development of wearable electronic products brings challenges to corresponding power supplies.In this work,a thermally stable and stretchable ionogel-based triboelectric nanogenerator(SI-TENG)for biomechanical energy collection is proposed.The ionic conductivity of the ionogel increased to 0.53 S·m^(−1) through optimal regulation of the amount of aminoterminated hyperbranched polyamide(NH2-HBP),which also has high strain of 812%,excellent stretch recovery,and wide operating temperature range of−80 to 250°C.The SI-TENG with this ionogel as electrode and silicone rubber both as the triboelectric layer and encapsulation layer exhibits high temperature stability,stretchability,and washability.By adding appropriate amount of nano SiO2 to triboelectric layer,the output performance is further improved by 93%.Operating in singleelectrode mode at 1.5 Hz,the outputs of a SI-TENG with an area of 3 cm×3 cm are 247 V,11.7μA,78 nC,and 3.2 W·m^(−2),respectively.It was used as a self-charging power supply to charge a 22μF capacitor to 1.6 V in 167 s with the palm patting and then to power the electronic calculator.Furthermore,the SI-TENG can also be used as a self-powered motion sensor to detect the amplitude and frequency of finger bending,human swallowing,nodding,and shaking of the head motion changes through the analysis of the output voltage.
基金supported by the National Natural Science Foundation of China(Nos.21875268 and 51276009)National Research Fund for Fundamental Key Projects(Nos.2013CB933000 and 2012CB933800)+3 种基金the Key Research Program of the Chinese Academy of Sciences(Nos.KJZD-EW-M01 and KJZD-EW-M03)the 111 project(No.B14009)Youth Innovation Promotion Association,CAS(No.2016026)the China Postdoctoral Science Foundation(No.2019M650435).
文摘Human skin can function steadily regardless of surrounding circumstarices(dry or wet),while it is still a challenge for artificial ionic skins,which tend to release solvents in dry air and leach electrolytes in wetted state.Herein,a series of hierarchically crosslinked ionogels containing hydrophobic ionic liquids(ILs)is fabricated by combining a crystalline fluorinated copolymer with hydrophobic ILs.With a reasonable combination of nonvolatility,transparency,stretchablility,and sensitivity,such ionogels can work as reliable sensors for real-time monitoring huma n motions and operate steadily in complex environments as human skin does,which can contribute to the developme nt of durable sen sing devices with a simple design.
基金supported by the National Natural Science Foundation of China(NSFC grant nos.21935004 and 21774049).
文摘Highly durable and stretchable ionic conductors are indispensable components of flexible electronics.However,fabricating such ionic conductors that are also non-toxic and biodegradable remains a challenge.In this study,highly stretchable,elastic,healable,and ultra-durable ionic conductors capable of non-hazardous disposal are conveniently fabricated by complexation of vanillin-grafted polyvinyl alcohol(VPVA)and ionic liquids(ILs)(denoted as VPVA-IL).
基金This work was supported by the National Natural Science Foundation of China(21991123 and 52073049)the Natural Science Foundation of Shanghai(20ZR1402500 and 18ZR1401900)+5 种基金Shanghai Rising-Star Program(20520741000)Belt&Road Young Scientist Exchanges Project of Science and Technology Commission Foundation of Shanghai(20520741000)the Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials(Donghua University)(18520750400)the Fundamental Research Funds for the Central Universities(2232021G-02)DHU Distinguished Young Professor Program(LZA2019001)the Science and Technology Commission of Shanghai(17DZ2260100).
文摘Ionogels with high transparency,stretchability and self-healing capability show great potential for wearable electronics.Here,a kind of highly transparent,stretchable and self-healable ionogels are designed using double physical cross-linking including hydrogen bonding and dipole–dipole interaction.Owing to the dynamic and reversible nature of the ion–dipole interaction and hydrogen bonds of polymeric chains,the ionogel possesses good self-healing capability.The multifunctional sensors for strain and temperature are fabricated based on ionogel.The ionogel can serve as strain sensor that exhibited high sensitivity[gauge factor(GF)=3.06]and durability(1000 cycles)to a wide range of strains(0–300%).Meanwhile,the ionogel shows rapid response to temperature,due to the temperature dependence of its ionic conductivity.Furthermore,the ionogel fbers with excellent antifreezing(−20°C)capability are fabricated,and the fbers show the good sensing performance to human motions and temperature.Importantly,the antifreezing ionogel-based triboelectric nanogenerator(ITENG)is assembled for efcient energy harvesting.The ITENG shows a short circuit current(ISC)of 6.1μA,open circuit voltage(VOC)of 115 V,and instantaneous peak power density of 334 mW m−2.This work provides a new strategy to design ionogels for the advancement of wearable electronics.
基金the financial support of the National Science Foundation of China(Nos.51605109 and 61804103)the Guangxi Natural Science Foundation(Nos.2018GXNSFBA281052 and 2018GXNSFAA281296)China Postdoctoral Science Foundation(Nos.2017M610346 and 2021T140494)。
文摘A flexible and stable power supply is essential to the rapid development of wearable electronic devices.In this work,a transparent,flexible,temperature-stable and ionogel electrode-based self-healing triboelectric nanogenerator(IS-TENG)was developed.The ionogel with excellent stretchability(1,012%),high ionic conductivity(0.3 S·m^(−1))and high-temperature stability(temperature range of−77 to 250℃)was used as the electrode of the IS-TENG.The IS-TENG exhibited excellent transparency(92.1%)and stability.The output performance did not decrease when placed in a 60℃oven for 48 h.In addition,the IS-TENG behaved like a stable output in the range of−20 to 60℃.More importantly,the IS-TENG could also achieve self-healing of electrical performance at temperatures between−20 and 60℃and its output can be restored to its original state after healing.When the single-electrode IS-TENG with an area of 3 cm×3 cm was conducted under the working frequency of 1.5 Hz,the output values for open-circuit voltage,short-circuit current,short-circuit transferred charge,and maximum peak power density were 189 V,6.2μA,57 nC,and 2.17 W·m^(−2),respectively.The IS-TENG enables to harvest biomechanical energy,and drive electronic devices.Furthermore,the application of IS-TENGs as self-driven sensors for detecting human behavior was also demonstrated,showing good application prospects in the field of wearable power technology and self-driven sensing.
文摘Orthorhombic niobium pentoxide （T-Nb2O5）/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2Os nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb205 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5 nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g^-1. Additionally, non-aqueous asymmetric supercapacitors （ASCs） were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg^-1 at 715.2 W·kg^-1. The working potential could be further enhanced to 4 V when a polymer ionogel separator （PVDF-HFP/LiTFSI/EMIMBF4） and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60℃ and delivered a maximum energy density of 70 Wh·kg^-1 at 1 kW·kg^-1.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0100204)the National Natural Science Foundation of China(No.51772030)+2 种基金the Joint Funds of the National Natural Science Foundation of China(No.U1564206)the Major Achievements Transformation Project for Central University in Beijingthe Science and Technology Project of State Grid Corporation of China(No.15-JS-191)
文摘In order to avoid leakage problem caused by liquid electrolyte, a new ionogel electrolyte was developed by in situ immobilizing organosilicon-functionalized ionic liquid within a nanoporous silica matrix. The ionic liquid evenly coats on the surface of porous silica and fills in the silica framework pores with no strong chemical interaction. The ionogel electrolyte has the dual advantages of a silica solid support and a wide electrochemical stability window of ionic liquid （4.87 V vs. Li^＋/Li）. The half-cells assembled with this electrolyte and LiFePO4 electrode have excellent performance at room temperature and 60 ℃. The Li/SiO2-IGE/LiFePO4 cell displays a discharge capacity of 129.1 mAh·g^-1 after 200 charge/discharge cycles at room temperature.
