Sulfur Immobilization by Chemical Anchor to Suppress the Diffusion of Polysulfides in Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) battery is considered to be one of the most promising contenders for the next generation high-energy storages due to their high theoretical energy density (approximate to 2600 Wh kg(-1)), which is nearly five times higher than that of the commercial LiCoO2/graphite batteries. However, a series of issues especially for the dissolution of lithium polysulfides (LiPSs) and their shuttle effect greatly limit their widely commercial applications. Starting from a brief overview of conventional methods to solve these problems, the achievements spotlighted in this review mainly show that the diffusion of LiPSs can be effectively suppressed by forming strong chemical anchor between LiPSs and host materials. The synthetic methods and characterization techniques are reviewed according to different types of chemical bonding between LiPSs and the host materials. Theoretical calculation methods are also summarized here to further understanding the role of these chemical anchors. Proposing with some perspectives and future research efforts, this review is hoped to provide an in-depth understanding and offer avenues in the rational design of Li-S batteries with long cycle life and high energy/power density in the near future.