可控合成锂离子电池分级微纳结构正极材料
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- 英文论文题名：Controllable Synthesis of Hierarchical Cathode for Lithium Ion Batteries
- 论文作者：李雨 ; 王辉 ; 刘露 ; 白莹 ; 吴川 ; 吴锋
- 英文论文作者：Yu Li ; Hui Wang ; Lu Liu ; Ying Bai ; Chuan Wu ; Feng Wu ; School of Materials Science and Engineering ; Beijing Institute of Technology
- 年：2016
- 作者机构：北京理工大学材料学院;
- 论文关键词：锂离子电池 ; 正极 ; 微纳结构 ; 富锂材料
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第三十分会：化学电源
- 语种：中文
- 分类号：TM912;TQ131.11
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第三十分会 ; 化学电源
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：229k
- 原文格式：D
- 会议级别：全国
摘要
富锂正极材料xLi_2MnO_3·(1-x)LiMO_2(M为过渡金属)是目前锂离子电池正极材料研究的热点之一,电压>4.5 V时首周放电容量可高达250 mAh g~(-1)~([1])。然而较高容量的释放引发材料主体由层状至尖晶石结构破坏,从而引发电压衰退,循环性能不佳等问题~([2])。可控合成分级微纳结构并使锂离子脱嵌活性晶面择优生长可有效解决上述问题。本文通过采用聚吡咯烷酮(PVP)辅助水热法合成富锂正极材料Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_2,其中对水热反应过程中最佳金属盐浓度、水热时间以及水热温度进行优化,得到不同形貌的电极材料。一次颗粒为纳米立方体构筑的微米球0.1C条件下首周放电容量可达298 mAh g~(-1),经200周循环后容量仍有243 mAh g~(-1)。调控反应条件,可得二次颗粒为纺锤形微米材料,由于其具备特殊的形貌,电压衰退得到有效遏制;除此之外,这一材料的Li~+脱嵌活性晶面(110)择优生长,倍率性能也得到显著改善。
Li-rich cathode materials for lithium ion batteries have attracted much attention in recent years,owing to their high capacity of over 250 mAh g~(-1) when charged to 4.5 V or higher.However,they have inherent issues such as voltage fade and poor cycle performance,which limits their industrialization.Herein,we adopted PVP-assisted hydrothermal method to controllably synthesize hierarchical micro/nano Li-rich materials Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_2.We optimized concentration of reactants,reaction temperature and time of hydrothermal process to prepare materials with different morphologies.The initial discharge capacity of microsphere with nanocubes was 298 mAh g~(-1) at 0.1C.After 200 cycles,the capacity of 243 mAh g~(-1) was still remained.To control synthesis condition,fusiform-like cathode was obtained.Depend on particular morphology,the voltage fade was efficiently suppressed.In addition,the rate performande was also improved due to preferential growth of the active(110) plane,which were favorable for ultrafast intercalation/de-intercalation kinetics.
Li-rich cathode materials for lithium ion batteries have attracted much attention in recent years,owing to their high capacity of over 250 mAh g~(-1) when charged to 4.5 V or higher.However,they have inherent issues such as voltage fade and poor cycle performance,which limits their industrialization.Herein,we adopted PVP-assisted hydrothermal method to controllably synthesize hierarchical micro/nano Li-rich materials Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_2.We optimized concentration of reactants,reaction temperature and time of hydrothermal process to prepare materials with different morphologies.The initial discharge capacity of microsphere with nanocubes was 298 mAh g~(-1) at 0.1C.After 200 cycles,the capacity of 243 mAh g~(-1) was still remained.To control synthesis condition,fusiform-like cathode was obtained.Depend on particular morphology,the voltage fade was efficiently suppressed.In addition,the rate performande was also improved due to preferential growth of the active(110) plane,which were favorable for ultrafast intercalation/de-intercalation kinetics.
引文
[1]Lu,Z.;Dahn,J.R.J.Electro.Soc.2002,149:A815.
[2]Gu,M.;Belharouak,I.;Zheng,J.M.et al.ACS nano 2013,7:760.
[2]Gu,M.;Belharouak,I.;Zheng,J.M.et al.ACS nano 2013,7:760.