载硫纤维膜对锂硫电池储能性能影响研究

单质硫的低导电性是限制锂硫电池电化学性能及正极载硫量的重要原因。针对这个问题,本文通过引入负载有单质硫的玻璃纤维膜的方式在锂硫电池中引入与正极没有导电连接的单质硫。采用拉曼光谱分析电池循环后正极表面的生成物,发现玻璃纤维上的单质硫能转移到正极,并参与电化学反应为电池贡献容量。进一步研究了电池容量和隔膜硫含量与正极碳含量之间的关系,认为单质硫可以通过溶液路径转移到正极表面,而正极的电化学活性表面积对电池的容量有着重要影响。本研究为开发高载硫锂硫电池提供了新的思路。

Effect of sulfur-loaded sparator on performance of lithium-sulfur batteries

The inferior electrical conductivity of elemental sulfur was considered as the major reason that limit the sulfur loading amount in the cathode of lithium-sulfur batteries.In this work,isolated elemental sulfur was introduced in cathode using sulfur loaded glass fiber as an interlayer in Li-sulfur batteries.Electrochemical and the Raman spectra analysis were employed to study the composition of the cycled cathode.It is found that the isolated elemental sulfur can be transferred from the glass fiber to the cathode during discharging,which improves the capacity of the lithium-sulfur battery as well.Further,the cycling performance of batteries was investigated at different elemental sulfur content on glass fiber and the carbon loading amount in cathode.It is found that the electrochemical active surface area,determined by the carbon content,has significant influence on the capacity of Li-sulfur batteries.Our work put forward a new strategy for developing a high sulfur loading and high capacity lithium-sulfur battery.