The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to ta...The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to tackle the above-mentioned issues.The hollow cavity affords empty space to accommodate the volume variation of SnO_(2),while the C and TiO_(2)protecting shells strengthen the structural integrity and enhances the electrical conductivity.As a result,the three-layer structured SnO_(2)@C@TiO_(2)hollow spheres demonstrate enhanced Na storage performances.The SnO_(2)@C@TiO_(2)manifests a reversible capacity two times to that of pristine SnO_(2)hollow spheres.In addition,Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO_(2)@C@TiO_(2)hollow spheres.This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.展开更多
Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage sy...Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage systems.Na-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode material.But in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery performance.In this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray drying.By taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge processes.When coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.展开更多
Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electroch...Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electrochemical performance of Li2MnO_(3), also written as Li(Li1/3Mn2/3)O_(2), we propose a strategy to substitute Mn4+and Li+in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO_(3)by inhibiting the excessive oxidation of O_(2)-above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O_(2)with high interlayer Li vacancies, which presents a high capacity(290 m Ah/g at 10 m A/g) and stable cycling performance(84% over 60 cycles at 50 m A/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.展开更多
Main observation and conclusion The cathode material plays a crucial role in the performances of aqueous zinc-ion batteries(ZIBs).Herein,we report an ammonium vanadate(NH_(4)V_(4)O_(10)∙0.28H_(2)O,NHVO)aqueous ZIB cat...Main observation and conclusion The cathode material plays a crucial role in the performances of aqueous zinc-ion batteries(ZIBs).Herein,we report an ammonium vanadate(NH_(4)V_(4)O_(10)∙0.28H_(2)O,NHVO)aqueous ZIB cathode material.The obtained NHVO microflowers manifest high discharge capacity(410 mA·h∙g^(-1) at 0.2 A∙g^(-1)).展开更多
基金financially supported by Shenzhen Fundamental Research Program(JCYJ20190809114409397)
文摘The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to tackle the above-mentioned issues.The hollow cavity affords empty space to accommodate the volume variation of SnO_(2),while the C and TiO_(2)protecting shells strengthen the structural integrity and enhances the electrical conductivity.As a result,the three-layer structured SnO_(2)@C@TiO_(2)hollow spheres demonstrate enhanced Na storage performances.The SnO_(2)@C@TiO_(2)manifests a reversible capacity two times to that of pristine SnO_(2)hollow spheres.In addition,Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO_(2)@C@TiO_(2)hollow spheres.This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.
基金the National Natural Science Foundation of China(No.52102299)the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110059,2020A1515110250,and 2021B1515120041)+1 种基金the National Key Research and Development Program of China(No.2020YFA0715000)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(Grant No.2021JJLH0058).
文摘Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage systems.Na-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode material.But in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery performance.In this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray drying.By taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge processes.When coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.
基金financially supported by the National Natural Science Foundation of China (Nos. 51972258 and 22109186)Open Fund by Sanya Science and Education Innovation Park of Wuhan University of Technology (No. 2021KF0021)supported by 21C Innovation Laboratory,Contemporary Amperex Technology Ltd. by Project No. 21C-OP-202002。
文摘Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electrochemical performance of Li2MnO_(3), also written as Li(Li1/3Mn2/3)O_(2), we propose a strategy to substitute Mn4+and Li+in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO_(3)by inhibiting the excessive oxidation of O_(2)-above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O_(2)with high interlayer Li vacancies, which presents a high capacity(290 m Ah/g at 10 m A/g) and stable cycling performance(84% over 60 cycles at 50 m A/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.
基金This work was supported by the National Natural Science Foundation of China(21905218)the National Key Research and Development Program of China(2018YFB0104200)+2 种基金the China Postdoctoral Science Foundation(2020M682500,2020M682502)the Fundamental Research Funds for the Central Universities(WUT:203114001,2020IVA098)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHT2020-003).
文摘Main observation and conclusion The cathode material plays a crucial role in the performances of aqueous zinc-ion batteries(ZIBs).Herein,we report an ammonium vanadate(NH_(4)V_(4)O_(10)∙0.28H_(2)O,NHVO)aqueous ZIB cathode material.The obtained NHVO microflowers manifest high discharge capacity(410 mA·h∙g^(-1) at 0.2 A∙g^(-1)).
