层状六边形Co_(1-x)S修饰氮掺杂碳纳米管用于锂硫电池的硫载体

Layered Hexagonal Co_(1-x)S Decorating N-Doped Carbon Nanotubes as a Sulfur Host for Li-S Batteries

通过纳米结构材料的设计和组装来改善锂硫电池的电化学性能。在本工作中,成功合成了六边形Co_(1-x)S纳米片修饰的氮掺杂碳纳米管(Co_(1-x)S⁃CNT)复合材料,并将其用作锂硫电池(LSBs)的硫正极载体。在Co_(1-x)S⁃CNT/S中,极性六方Co_(1-x)S纳米片可以化学吸附多硫化锂,同时CNT可以为电极材料提供高导电网络。基于物理限域和化学吸附的协同作用,Co_(1-x)S⁃CNT/S正极表现出优异的电化学循环性能。在0.5C倍率下循环170次,电极仍可保持405.6 mAh·g^(-1)的放电比容量,同时具有超过99.2%的稳定库仑效率。

The design and assembly of nanostructured materials are devoted to improving the electrochemical prop⁃erties of the Li⁃S batteries(LSBs)by synergistic effect.In this work,a composite of hexagonal Co_(1-x)S nanosheets decorating N⁃doped carbon nanotube(Co_(1-x)S⁃CNT)was successfully synthesized and used as a sulfur host for Li⁃S batteries(LSBs).In Co_(1-x)S⁃CNT/S,the polar hexagonal Co_(1-x)S nanosheets can absorb the lithium polysulfide through chemisorption,at the same time,the CNT can provide a highly conductive network.Based on the synergy of physical encapsulating and chemical trapping,the Co_(1-x)S⁃CNT/S cathode exhibited excellent electrochemical performance,especially the superior cycle performance.After 170 cycles,the Co_(1-x)S⁃CNT/S can maintain a discharge capacity of 405.6 mAh·g^(-1) at 0.5C,with a stable Coulombic efficiency(over 99.2%).