二碲化钛的合成及隔膜修饰研究

Research on Synthesis and Diaphragm Modification of Titanium Ditelluride

多硫化物穿梭效应是阻碍锂硫电池实用化进程的诸多因素之一,隔膜修饰的方法可以有效抑制锂硫电池中多硫化物的穿梭效应,提高电池的循环稳定性。采用简单固相法制备二碲化钛,并用其对锂硫电池的隔膜进行修饰,进行了一系列物化表征和电池电化学性能测试。测试结果表明,在0.2 C的倍率下,二碲化钛修饰隔膜电池的首次放电比容量为1197 mAh·g^(-1),经100次循环后,放电比容量仍能保持到787 mAh·g^(-1),电池循环后金属锂表面腐蚀较弱,二碲化钛对多硫化物有一定的吸附和催化能力,可以有效阻挡多硫化物的穿梭效应,提升了电池的循环稳定性。希望为锂硫电池中隔膜修饰提供新思路。

The shuttle effect of polysulfides is one of the many factors that hinder the practical progress of lithiumsulfur batteries.The method of separator modification can effectively inhibit the shuttle effect of polysulfides in lithiumsulfur batteries and improve the cycle stability of batteries.Titanium ditelluride was prepared by a simple solid-phase method,and used to modify the diaphragm of lithium-sulfur battery.A series of physicochemical characterizations and battery electrochemical performance tests were carried out.The test results show that at a rate of 0.2 C,the initial discharge specific capacity of the titanium ditelluride modified diaphragm battery is 1197 mAh·g^(-1),and the discharge specific capacity can still be maintained to 787 mAh·g^(-1) after 100 cycles.After battery cycling,lithium surface corrosion is weak,and titanium ditelluride has certain adsorption and catalytic ability for polysulfides,which can effectively block the shuttle effect of polysulfides and improve the cycle stability of the battery.It is hoped that our work will provide new ideas for diaphragm modification in lithium-sulfur batteries.