导电碳修饰隔膜在高硫载量锂硫电池中的作用

Conductive carbon-coated separator for high sulfur-loading lithium sulfur batteries

研究了分别以乙炔黑、科琴黑、Super P、气相生长碳纤维、石墨烯、碳纳米管、XE-2为正极侧修饰层的隔膜对高硫载量(5.4 mg/cm^2)锂硫电池电性能的影响。XE-2、Super P、石墨烯、科琴黑、气相生长碳纤维涂覆隔膜有助于提高隔膜正极侧的保液能力和导电能力;石墨烯、Super P涂层对多硫化锂有很好的阻挡、吸附作用。涂覆石墨烯的隔膜装配的电池的首次放电比容量可达1007 m A·h/g,远远高于采用空白隔膜的电池(340m A·h/g),循环100次后放电比容量为539 m A·h/g,仍然高于采用空白隔膜的电池(399 m A·h/g)。

The effects of separators consisting of cathode-side functional layers separately composed of acetylene black, Ketjen black, Super P, vapor-grown carbon fiber, graphene, carbon nano-tube and XE-2, on high sulfur-loading （5.4 mg/ cm2） lithium sulfur batteries have been investigated. The separators coated by XE-2, Super P, graphene, ketjen black, vapor-grown carbon fiber can improve the electrolyte adsorbility and electrical conductivity of cathode side. Besides, the separators coated by Super P and graphene can obstruct and adsorb lithium polysulfide. The battery with separator coated by graphene delivers a specific capacity as high as 1007 mA- h/ g, much higher than that of untreated separator （340 mA- h/ g）. After 100 cycles, the battery with separator coated by graphene can still maintain a specific discharge capacity of 539 mA- h/ g, still higher than that of untreated separator （399 mA- h/ g）.