文献类型：会议

作　　者：严小艳 徐明 李灵均 朱华丽 段军飞 陈召勇

作者单位：长沙理工大学材料科学与工程学院&新能源动力电池研究所

会议文献：2016中国国际新能源材料及动力电池高峰论坛暨第八届中国储能与动力电池及其关键材料学术研讨与技术交流会摘要集

会议名称：2016中国国际新能源材料及动力电池高峰论坛暨第八届中国储能与动力电池及其关键材料学术研讨与技术交流会

会议日期：20160714

会议地点：中国广东广州

主办单位：中国仪表功能材料学会;中央企业电动车产业联盟;全国储能与动力电池及其材料专业委员会;国家仪表功能材料工程技术研究中心;中国汽车工业国际合作有限公司;广东省低碳化学与过程节能重点实验室

出版日期：20160700

学会名称：中国仪器仪表学会仪表功能材料分会

语　　种：中文

摘　　要：The flourishing development of lithium-ion batteries(LIBs)has accelerated the manufacturing of potable electric devices,electric vehicles(EVs)and hybrid electric vehicles(HEVs).Lithium-rich layered oxide(LLMO)cathode materials are receiving international attention because they can deliver an exceptionally high rechargeable capacity of 250 m Ah/g between 2.0 V-4.8 V.However,this high capacity cathode material still faces challenges,such as transition metal(TM)dissolution occurs at high electrode potentials(>4.5V vs.Li/Li+),and the evolution from layered structure to spinel-like upon cyling leads to the poor cycle life.Therefore,we have tried to synthesis LLMO cathode materials by sol-gel method and modify them via surface coating approach in this paper.The mechanisms and effects of three typical chelating agents,namely glucose,citric acid and sucrose on the sol-gel synthesis process,electrochemical degradation and structural evolution LLMO cathode materials are systematically compared.Electrochemical tests further prove that the LLMO material obtained from sucrose maintains 258.4 m Ah/g with 94.8%capacity retention after 100th cycle at 0.2 C.The superior electrochemical performance can be ascribed to the exceptional complexing mechanism of sucrose,compared to those of the glucose and citric acid.X-ray diffraction,scanning electron microscopy,X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy analysis indicate that the sample synthesized from sucrose owns well structure,homogenous distribution,low Ni3+concentration and good surface structural stability during cycling,respectively.This discovery is an important step towards understanding the selection criterion of chelating agents for sol-gel method,that chelating agent with excellent complexing capability is beneficial to the distribution,structural stability and electrochemical properties of advanced lithium-rich layered materials.Surface coating has been considered as the most promising method to protect cathode materials from t

关 键 词：正极材料

分 类 号：TB306[材料类] TM912]