二氧化钛-聚萘/硫正电极的制备及其电化学性能

以3,4,9,10-二萘嵌苯(PTCDA)为原料成功合成聚萘(PPN),然后利用硫代硫酸钠为硫源,通过化学还原法制备聚萘/硫(PPN/S)复合材料,接着在PPN/S外表面包覆一层二氧化钛(TiO₂),最后制备出二氧化钛-聚萘/硫(TiO₂-PPN/S)复合材料.采用扫描电镜、X-射线衍射和热重分析对复合材料TiO₂-PPN/S进行表征; 采用充放电测试系统和电化学工作站对TiO₂-PPN/S电极的电化学性能进行测试.结果表明:PPN/S复合材料表面被TiO₂成功包覆,制得一种新型TiO₂-PPN/S复合材料; TiO₂-PPN/S电极具有良好的循环稳定性,在电流密度为400 mA·g^-1时,首次放电容量达到1 334.8 mA·h·g^-1,循环150次后,放电容量仍保持在691.4 mA·g^-1; 与含硫量相当的PPN/S电极相比,TiO₂-PPN/S电极具有更佳的电化学性能.

The Preparation and Electrochemical Performance of Titanium Dioxide-Polyperinaphthalene/Sulfur Cathode Material for Lithium-Sulfur Battery

Poly-peri-naphthalene has been prepared by 3,4,9,10-perylenetetracarboxylic acid ahydride,sodium thiosulfate was as sulfur source,and poly-peri-naphthalene/sulfur was prepared,then poly-peri-naphthalene/sulfur was wrapped by titanium dioxide.At last,TiO₂-PPN/S was synthesized.The TiO₂-PPN/S composite material was characterized by SEM,XRD and TGA.The electrode of TiO₂-PPN/S was tested by charge and discharge system and electrochemical workstation.The results show TiO₂-PPN/S composite material was successfully synthesized.The electrode of TiO₂-PPN/S has a good cycle property,the first discharge specific capacity is 1 334.8mA·h·g^-1 at 400 mA·h·g^-1,after 150 cycles,the discharge special capacity still maintain 691.4 mA·g^-1.To comparative sulfur content of PPN/S electrode,the electrode TiO₂-PPN/S is better.