碳基材料修饰聚烯烃隔膜提高锂硫电池性能研究

Owing to their great theoretical energy density (2600 Wh•kg^-1), lithium-sulfur (Li-S) batteries are one of the most promising candidates of the next generation energy storage devices. Moreover, the high theoretical specific capacity (1675 mAh•g^-1), good eco-friendliness, abundant natural resource and low cost of cathode sulfur are also good for the cheap cost and low environmental pollution of Li-S batteries. However, the practical applications of Li-S batteries are severely impeded by several key challenges, such as the low practical specific capacities, low coulomb efficiencies and fast capacity decay, which resulting from the poor electronic conductivity of sulfur and final products Li₂S₂ / Li₂S, the shuttle effects of lithium polysulfides and the growth of lithium dendrite during the electrochemical cycling. It is noted that the modification of the polyolefin separators is one of the effective methods to obviously improve the performances of Li-S batteries. In particular, various carbons and their composites are widely used materials for separator modification because of their unique properties, also, many advancements have been achieved. Herein, the research progresses of the various carbons and their composites for separator modification are reviewed, which will provide guidance for the future research on improving the performance of Li-S batteries by separator modification method.