In order to improve the electrochemical performance of polyoxomolybdate Na3[AlMo6O24H6]（NAM） as the cathode material of lithium ion battery, the NAM materials with small particle size were synthesized by elevatingth...In order to improve the electrochemical performance of polyoxomolybdate Na3[AlMo6O24H6]（NAM） as the cathode material of lithium ion battery, the NAM materials with small particle size were synthesized by elevatingthe synthesistemperaturein the solution.The as-prepared NAM materials were investigated by FT-IR, XRD, SEM and EIS. Their discharge-charge and cycle performance were also tested. The resultsshowthat the particle size decreasesto less than10μm at the temperature ofhigher than 40℃.When synthesized at 80℃,the NAMwiththe smallest particle size （-3μm）exhibitsthe best electrochemical performance such ashigh initial discharge capacity of 409 mA·h/gandcoulombic efficiency of 95% in the first cycle at 0.04C.展开更多
For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capac...For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.展开更多
The Li Ni1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coated with Ni3(PO4)2particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are inv...The Li Ni1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coated with Ni3(PO4)2particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are investigated by electrochemical impedance spectroscopy and galvanostatic measurements. The element ratio of Ni:Mn:Co is tested by inductively-coupled plasma spectrometer(ICP) analysis and it testified to be 1:1:1. It is indicated that Ni3(PO4)2-coated Li Ni1/3Co1/3Mn1/3O2 has an outstanding capacity retention, where 99% capacity retention is maintained after 10 cycles at 5C discharge rate between 2.7 V and 4.6 V. The electrochemical impedance spectroscopy(EIS) results show that the current exchange density i0 of the coated sample is higher than that of Li Ni1/3Co1/3Mn1/3O2, which is beneficial to its electrochemical performances. All the conclusions show that the Ni3(PO4)2coating can prominently enhance the high rate performance of the Li Ni1/3Co1/3Mn1/3O2, especially at high cut-off voltage.展开更多
Na-ion batteries(NIBs)have attracted significant attention owing to Na being an abundant resource that is uniformly distributed in the Earth's crust.Several 3d transition metal(TM)ions have been thoroughly investi...Na-ion batteries(NIBs)have attracted significant attention owing to Na being an abundant resource that is uniformly distributed in the Earth's crust.Several 3d transition metal(TM)ions have been thoroughly investigated as charge compensators in single or multiple composition systems to enhance the electrochemical performance of cathodes for the practical applications.In this review,the composition-structure-property relationship of Ni-based cathodes has been reviewed as a design perspective for NIB'S cathodes.The typical Ni-based cathode materials have bee n systematically summarized and comparatively analyzed,and it is dem on strated that Ni io ns can be used to provide charge compensation.Moreover,Ni-based cathodes present high reversible capacity owing to the multi-electron redox reactions and suitable redox pote ntial of Ni-ions redox.However,con sidering the abundan ce,cost,and hygroscopic properties of Ni eleme nt,the content of 0.15-0.35 per formula can be optimal for enhancing the performance of cathodes.Lastly,further perspectives on designing Ni?containing cathodes,including Ni-rich layered cathodes,have been discussed,which could promote the practical applications of NIBs for grid-scale energy storage in future.展开更多
超高镍层状材料LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(简称NCM92)因其具有较高的能量密度和价格优势,已成为锂离子电池重要的正极材料来源之一。然而,由于该材料的界面不稳定和不可逆相变,商业应用面临特别是在高截止电压下快速的容量衰...超高镍层状材料LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(简称NCM92)因其具有较高的能量密度和价格优势,已成为锂离子电池重要的正极材料来源之一。然而,由于该材料的界面不稳定和不可逆相变,商业应用面临特别是在高截止电压下快速的容量衰落和严重的结构退化的问题。本研究设计了一种ZrO_(2)/Li_(2)ZrO_(3)双包覆层改性超高镍单晶正极材料,同时材料表面均匀掺杂有Zr元素,通过双包覆层协同策略显著增强了正极的高压性能和结构稳定性。研究结果表明,ZrO_(2)/Li_(2)ZrO_(3)双包覆层可以有效缓解超高镍正极材料H2-H3相变的不可逆性,提高力学稳定性和界面稳定性,同时表面Zr掺杂进入晶体结构中的TM层与Li位抑制Li/Ni混排并扩宽了晶格间距,ZrO_(2)/Li_(2)ZrO_(3)双包覆层与Zr掺杂改性的材料(NCM92-Zr)展现出优异的电化学性能,在0.5 C(200 mA·g^(-1))电流密度下,2.75~4.4 V电压范围内循环150圈后仍有155.2 mA h g^(-1)的放电比容量,容量保持率高达75.5%。此研究为在高截止电压下超高镍正极的复杂机制和改进的结构稳定性提供了新的思路。展开更多
锂硒电池因其可观的体积比容量(3254 m A·h/cm3),已经引起了国内外研究学者们的广泛关注。本文在介绍锂硒电池硒/碳正极材料的基础上,指出了锂硒电池目前存在的主要问题,并提出了可能的解决方案,最后对未来锂硒电池的研究方向做出...锂硒电池因其可观的体积比容量(3254 m A·h/cm3),已经引起了国内外研究学者们的广泛关注。本文在介绍锂硒电池硒/碳正极材料的基础上,指出了锂硒电池目前存在的主要问题,并提出了可能的解决方案,最后对未来锂硒电池的研究方向做出了展望。展开更多
高能、长循环寿命和高充放电速率的阴极材料是限制发展静态稳定电能存储和动力电源用先进锂电池的关键材料问题。基于脱嵌锂过程的层状锂过渡金属氧化物、过渡金属磷酸锂和富锂氧化物的阴极材料的容量发展遇到了瓶颈,因此探索基于新电...高能、长循环寿命和高充放电速率的阴极材料是限制发展静态稳定电能存储和动力电源用先进锂电池的关键材料问题。基于脱嵌锂过程的层状锂过渡金属氧化物、过渡金属磷酸锂和富锂氧化物的阴极材料的容量发展遇到了瓶颈,因此探索基于新电化学过程的新型高容量阴极材料的研究非常重要。基于硫(S)和Li2S的阴极材料具有高的理论容量(1673mA h g-1和1166mA h g-1),成为发展高容量和高能锂离子电池阴极材料研究的重点。综述了解决硫阴极材料面临的电子和锂离子传导能力差、充放电过程中可溶性硫的溶解及体积变化等关键科学问题的新思路和新方法,为发展新型硫阴极材料提供参考和启发。展开更多
文摘In order to improve the electrochemical performance of polyoxomolybdate Na3[AlMo6O24H6]（NAM） as the cathode material of lithium ion battery, the NAM materials with small particle size were synthesized by elevatingthe synthesistemperaturein the solution.The as-prepared NAM materials were investigated by FT-IR, XRD, SEM and EIS. Their discharge-charge and cycle performance were also tested. The resultsshowthat the particle size decreasesto less than10μm at the temperature ofhigher than 40℃.When synthesized at 80℃,the NAMwiththe smallest particle size （-3μm）exhibitsthe best electrochemical performance such ashigh initial discharge capacity of 409 mA·h/gandcoulombic efficiency of 95% in the first cycle at 0.04C.
基金supported by the Nature Science Foundations of Hebei Province (B2016210071, B2016210111)the Natural Science Foundation of Hebei Education Department (QN2016057, ZD2015082, ZC2016045)+3 种基金the National College Students’ Innovative Entrepreneurial Training Project of Chinasupported by the Chinese National 973 Program (2015CB251106)the Joint Funds of the National Natural Science Foundation of China (U1564206)Major achievements Transformation Project for Central University in Beijing
文摘For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.
基金Supported by the National Natural Science Foundation of China(51074096)
文摘The Li Ni1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coated with Ni3(PO4)2particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are investigated by electrochemical impedance spectroscopy and galvanostatic measurements. The element ratio of Ni:Mn:Co is tested by inductively-coupled plasma spectrometer(ICP) analysis and it testified to be 1:1:1. It is indicated that Ni3(PO4)2-coated Li Ni1/3Co1/3Mn1/3O2 has an outstanding capacity retention, where 99% capacity retention is maintained after 10 cycles at 5C discharge rate between 2.7 V and 4.6 V. The electrochemical impedance spectroscopy(EIS) results show that the current exchange density i0 of the coated sample is higher than that of Li Ni1/3Co1/3Mn1/3O2, which is beneficial to its electrochemical performances. All the conclusions show that the Ni3(PO4)2coating can prominently enhance the high rate performance of the Li Ni1/3Co1/3Mn1/3O2, especially at high cut-off voltage.
基金This work was supported by the National Key R&D Program of China(No.2016YFB0901500)the National Natural Science Foundation of China(Nos.51725206 and 51421002)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21070500)Beijing Natural Science Fund-Haidian Original Innovation Joint Fund(No.L182056)Beijing Municipal Science and Technology Commission(No.Z181100004718008)C.L.Z.also thanks to the State Scholarship Fund of China Scholarship Council(CSC).
文摘Na-ion batteries(NIBs)have attracted significant attention owing to Na being an abundant resource that is uniformly distributed in the Earth's crust.Several 3d transition metal(TM)ions have been thoroughly investigated as charge compensators in single or multiple composition systems to enhance the electrochemical performance of cathodes for the practical applications.In this review,the composition-structure-property relationship of Ni-based cathodes has been reviewed as a design perspective for NIB'S cathodes.The typical Ni-based cathode materials have bee n systematically summarized and comparatively analyzed,and it is dem on strated that Ni io ns can be used to provide charge compensation.Moreover,Ni-based cathodes present high reversible capacity owing to the multi-electron redox reactions and suitable redox pote ntial of Ni-ions redox.However,con sidering the abundan ce,cost,and hygroscopic properties of Ni eleme nt,the content of 0.15-0.35 per formula can be optimal for enhancing the performance of cathodes.Lastly,further perspectives on designing Ni?containing cathodes,including Ni-rich layered cathodes,have been discussed,which could promote the practical applications of NIBs for grid-scale energy storage in future.
文摘超高镍层状材料LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(简称NCM92)因其具有较高的能量密度和价格优势,已成为锂离子电池重要的正极材料来源之一。然而,由于该材料的界面不稳定和不可逆相变,商业应用面临特别是在高截止电压下快速的容量衰落和严重的结构退化的问题。本研究设计了一种ZrO_(2)/Li_(2)ZrO_(3)双包覆层改性超高镍单晶正极材料,同时材料表面均匀掺杂有Zr元素,通过双包覆层协同策略显著增强了正极的高压性能和结构稳定性。研究结果表明,ZrO_(2)/Li_(2)ZrO_(3)双包覆层可以有效缓解超高镍正极材料H2-H3相变的不可逆性,提高力学稳定性和界面稳定性,同时表面Zr掺杂进入晶体结构中的TM层与Li位抑制Li/Ni混排并扩宽了晶格间距,ZrO_(2)/Li_(2)ZrO_(3)双包覆层与Zr掺杂改性的材料(NCM92-Zr)展现出优异的电化学性能,在0.5 C(200 mA·g^(-1))电流密度下,2.75~4.4 V电压范围内循环150圈后仍有155.2 mA h g^(-1)的放电比容量,容量保持率高达75.5%。此研究为在高截止电压下超高镍正极的复杂机制和改进的结构稳定性提供了新的思路。
文摘高能、长循环寿命和高充放电速率的阴极材料是限制发展静态稳定电能存储和动力电源用先进锂电池的关键材料问题。基于脱嵌锂过程的层状锂过渡金属氧化物、过渡金属磷酸锂和富锂氧化物的阴极材料的容量发展遇到了瓶颈,因此探索基于新电化学过程的新型高容量阴极材料的研究非常重要。基于硫(S)和Li2S的阴极材料具有高的理论容量(1673mA h g-1和1166mA h g-1),成为发展高容量和高能锂离子电池阴极材料研究的重点。综述了解决硫阴极材料面临的电子和锂离子传导能力差、充放电过程中可溶性硫的溶解及体积变化等关键科学问题的新思路和新方法,为发展新型硫阴极材料提供参考和启发。
