Dynamic evolution of electrocatalytic materials for Li–S batteries

Abstract

Incorporating highly efficient electrocatalysts into sulfur cathodes is a promising strategy to alleviate the detrimental shuttle effect and sluggish conversion kinetics of lithium polysulfides for lithium–sulfur (Li–S) batteries. Although fruitful progress in the electronic structure modulation of electrocatalysts has been achieved, little attention has been paid to the dynamic evolution of electrocatalysts during real electrochemical reaction conditions. Subsequently, the evolution of original electrocatalysts, mainly pertaining to dynamic transformations in phase, composition, and structure, makes it necessary to reexamine the intrinsic structure–property relationship, which helps to establish an explicit direction in the rational design of efficient electrocatalysts based on self-adaptation. Therefore, it is of paramount significance to identify the actual electrocatalytic sites and understand the electrocatalyst evolution. In this review, a full description of electrocatalyst evolution with a focus on its occurrence, mechanism, and applications is provided. Specifically, the latest representative strategies for regulating the dynamic evolution of electrocatalysts under serving conditions are systematically scrutinized, classified, and summarized, in conjunction with a discussion of the closely related advanced characterization to recognize the dynamic evolution and thus decipher the electrocatalytic mechanism. Finally, future research directions and prospects of the dynamic evolution of electrocatalysts are comprehensively elucidated, aiming in essence to offer insights into the development of highly efficient electrocatalysts in the Li–S realm.