摘要
通过结合固相和液相包覆在Al掺杂LiCoO_(2)表面共包覆了钛酸锂(Li_(4)Ti_(5)O_(12))和聚吡咯(PPy)。这种双包覆方法不仅稳定了高电压下LiCoO_(2)的表面,还增强了材料的离子和电子电导率。电化学测试表明,当活性物质、导电剂和黏结剂的质量比为80∶10∶10时,在0.5C(1C=180 mA·g^(-1))电流下,循环300周后的容量保持率为76.9%,且在5C电流密度下可逆比容量为150 mAh·g^(-1);由于双包覆后LiCoO_(2)电子电导率大幅提高,当活性物质、导电剂和黏结剂的质量比为90∶3∶7时,在0.5C电流下,循环200周后的容量保持率为82.8%,且在5C电流密度下可逆比容量为130 mAh·g^(-1)。X射线光电子能谱测试表明,包覆层可以在循环中保持稳定且能抑制LiCoO_(2)材料在高电压下的表面副反应。
In this study,by using the solid and liquid coating method,LiCoO_(2) wasdual-coated by lithium titanate(Li_(4)Ti_(5)O_(12))and polypyrrole(PPy).The coating layers not only protect the surface of LiCoO_(2) at high voltage but also increase its ion conductivity and electronic conductivity.According to the result of the electrochemistry test,when the mass ratio of active material,conductive agent,and binder was 80∶10∶10,the capacity retention of the modified material after 300 cycles at 0.5C(1C=180 mA·g^(-1))was 76.9%.Its reversible capacity was 150 mAh·g^(-1) at 5C current density.Due to the improvement of electric conductive of dual-coated LiCoO_(2),when this mass ratio was 90∶3∶7,the capacity retention after 200 cycles at 0.5C was 82.8%.Its reversible capacity was 130 mAh·g^(-1) at 5C current density.As shown in X-ray photoelectron spectra,the coating layers can keep stability during cycling and prevent side reactions on the surface.
作者
邓昊天
王传伟
陈守潇
潘思宇
吕超
郭明佳
刘君珂
魏国祯
周尧
李君涛
DENG Hao-Tian;WANG Chuan-Wei;CHEN Shou-Xiao;PAN Si-Yu;LÜChao;GUO Ming-Jia;LIU Jun-Ke;WEI Guo-Zhen;ZHOU Yao;LI Jun-Tao(College of Energy,Xiamen University,Xiamen,Fujian 361102,China;College of Chemistry and Chemical Engineering,Xiamen University,Xiamen,Fujian 361005,China;XTC New Energy Materials(Xiamen)Co.,Ltd.,Xiamen,Fujian 361026,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2022年第8期1557-1566,共10页
Chinese Journal of Inorganic Chemistry
基金
厦门市重大科技项目(No.3502Z20201012)资助。
关键词
钴酸锂
钛酸锂
聚吡咯
双包覆
高能量密度
lithium cobalt oxide
lithium titanate
polypyrrole
dual-coating
high energy density
