Li_(2)AQ-Li_(2)S_(n)复合材料在锂硫电池中的研究

Study on Li_(2)AQ-Li_(2)S_(n) composite material in lithium-sulfur battery

多硫化物中间体的“穿梭效应”是抑制锂硫电池商业化应用的关键问题之一。基于此,引入一种添加剂通过锂化作用形成锂化蒽醌(Li_(2)AQ)和可溶性多硫化物(Li_(2)S_(n))结合,形成固态有机多硫化物复合物(Li_(2)AQ-Li_(2)S_(n)聚合物),进而将多硫化物固定在正极上。该复合物极大地限制了Li_(2)S_(n)的溶解,促进了硫物质的充分利用,提高了电极材料的电化学性能。使用Li_(2)AQ后,Li-S电池在0.1 C时表现出1316 mAh/g的大初始比容量,较不引入Li_(2)AQ添加剂的电池有了较大提升。1 C下1000次稳定循环,剩余比容量为421 mAh/g,具有优异的循环性能。

The shuttle effect of polysulfide intermediates is one of the key problems in the commercial application of simulated lithium sulfur batteries.Based on this,an additive was introduced to combine Li_(2)AQ with soluble polysulfide(Li_(2)S_(n))through lithiation to form solid organic polysulfide complex(Li_(2)AQ-Li_(2)S_(n) polymer),and then the polysulfide was fixed on the positive electrode.The dissolution of Li_(2)S_(n) was greatly limited by the full utilization of sulfur was promoted,and the electrochemical performance of the electrode material was improved.After using Li_(2)AQ,LI-S battery shows a large initial capacity of 1316 mAh/g under 0.1 C,which is significantly improved compared with the battery without Li_(2)AQ additive.1 C 1000 stable cycles,the remaining specific capacity is 421 mAh/g,it represents excellent cycle performance.