新型锂电池正极材料多硫代聚苯胺的制备和电化学性能

Preparation and Electrochemical Performance of a Novel Lithium Battery Cathode Material Polysulfurpolyaniline

通过聚苯胺合成了多氯代聚苯胺以及锂电池正极材料多硫代聚苯胺, 利用元素分析、红外光谱、 X射线光电子能谱和扫描电镜对反应产物多氯代聚苯胺和多硫代聚苯胺进行了化学结构和形貌分析. XPS结果表明, 多硫代聚苯胺没有明显的π-π*电子离域现象. 多硫代聚苯胺的主链聚苯胺对侧链S-S未发现有明显的电化学催化作用. 多硫代聚苯胺的充放电曲线及其微分曲线表明, 其在充放电过程中可能存在3个连续的氧化还原反应过程, 在2.07 V处有一个明显的放电电位平台. 放电比容量在30次循环中能够维持在181～187 mA·h/g之间, 循环效率达到94%.

A novel cathode material containing S-S side group on the main polyaniline chain backbone was obtained for lithium secondary battery. Polychloropolyaniline and polysulfurpolyaniline were prepared successively by the reactions of polyaniline with chloride monosulfur catalyzed by AlCl3 and with Na2S5, respectively. The resultants were both analyzed by elemental analysis, IR spectroscopy, X-ray electron spectroscopy （XPS） and SEM. XPS data suggested that electrons were more localized in the monomers of the main polyaniline chain structure of polysulfurpolyaniline. The polyaniline chain structure of polysulfurpolyaniline couldn＇t effectively catalyze the electrochemical reaction of side group S-S. The charge-discharge profile and the corresponding differential profile indicated that the charge-discharge process maybe contained three successive redox reactions, and there was an obvious discharge voltage plateau at 2.07 V. The discharge specific capacity of polysulfurpolyaniline was in the range of 181-187 mA · h/g and the efficiency was up to 94% for 30 charge-discharge cycles.