金属锡辅助阻隔多硫化锂实现锂硫电池长循环稳定性

Metal tin assists in blocking lithium polysulfide to achieve long-cycle stability of lithium-sulfur batteries

用碳修饰隔膜抑制锂硫电池中的飞梭效应并改善其电化学性能是一种简单有效的方式.然而,碳材料与多硫化锂之间弱的相互作用影响了修饰隔膜的作用.因此,提出将金属锡注入到多孔碳中制备了金属锡/碳复合物(C@Sn),并将其涂敷在常规的聚丙烯(PP)隔膜上用作锂硫电池的隔膜(C@Sn-PP).氮气吸附发现,金属锡注入减小了多孔碳的孔尺寸,增强了其阻隔多硫化锂的能力.此外,自身快速的锂离子传输速率有利于氧化还原反应动力学.这些优势实现了锂硫电池高的倍率性能(2 C容量为749.2 mAh/g),同时可以稳定循环300个周期.这个策略为碳修饰隔膜在锂硫电池中的应用提出了新思路.

It is a simple and effective way to modify separator with carbon to suppress the shuttle effect in lithium-sulfur batteries and improve its electrochemical performance.However,the weak interaction between carbon materials and lithium polysulfide restricts the effect of modifying the separator.Therefore,metallic tin was inject into porous carbon to prepare metallic tin/carbon composite(C@Sn),and it was coated on a conventional polypropylene(PP)separator to be used as a lithium-sulfur battery diaphragm(C@Sn-PP).Nitrogen adsorption found that metal tin injection reduced the pore size of porous carbon and enhanced its ability to block lithium polysulfide.In addition,the rapid lithium ion transmission rate is beneficial to the kinetics of redox reactions.These advantages make the lithium-sulfur battery achieved high rate performance(2C capacity is 749.2 mAh/g),and realized 300 times stable cycles.This strategy provides a new idea for the application of carbon-modified separator in lithium-sulfur batteries.