导电聚合物包覆钴酸锂在水锂电池中的电化学性能

Electrochemical Performance of Conductive Polymer Coated Lithium Cobalt Oxide in Aqueous Lithium Ion Batteries

为了提高水系锂离子电池的电化学性能,以Co2O3和Li2CO3为原料,采用固相法合成了LiCoO2材料,并通过化学氧化法在LiCoO2材料表面包覆聚吡咯(PPy)和聚苯胺(PAn),作为水系锂离子电池的正极材料,并与作负极的活性炭组装成扣式电池,测定其电化学性能.结果表明PPy和PAn包覆之后,LiCoO2的比容量从65 mAh/g提高到了85 mAh/g,首次充放电效率从80%提高到88%以上;LiCoO2循环300次之后,比容量衰减为84%,经过包覆之后,在1000次循环之后比容量还可以保持在90%以上.PPy和PAn包覆LiCoO2不但提高了水系锂离子电池的比容量和首次充放电效率,而且大幅度提高了循环性能.

In order to improve the electrochemical performance of aqueous lithium ion battery,LiCoO2 material was synthesized by the solid phase method using Co2O3 and Li2CO3 as raw materials,and was coated with polypyrrole(PPy)and polyaniline(PAn)by chemical oxidation.The electrochemical properties were determined by means of a button cell with prepared materials as the positive electrode and the activated carbon as the negative electrode.It was found that after the coating of PPy and PAn,the specific capacity of LiCoO2 increases from 65mAh/g to 85mAh/g,and the first charging and discharging efficiency increases from 80% to 88%.The specific capacity of LiCoO2 decays to 84%after 300 cycles.After it is coated,the specific capacity can remain above 90%after 1000 cycles.The experimental results show that not only the specific capacity and the initial charge and discharge efficiency but also the cycling performance of aqueous lithium ion battery is greatly improved using the LiCoO2 coated with polypyrrole(PPy)and polyaniline(PAn)as the cathode material.