Perovskite with in situ exsolved cobalt nanometal heterostructures for high rate and stable lithium-sulfur batteries

In order to solve the fundamental problem of polysulfide shuttle and slow reaction kinetics in lithium-sulfur batteries, we designed a novel adsorption-catalysis bifunctional heterostructure of strontium titanate perovskite and cobalt nanometal (STO@Co) prepared by in situ exsolution. Heterostructure can effectively adsorb polysulfides, which takes advantage of the ferroelectric effect of perovskite. After the in situ exsolution of Co nanometals, the exsolution of conductive metals enhance the conductivity of the heterostructure, while the in situ exsolved Co nanometal has excellent electrocatalytic activity and stability. Because of the superior interface compatibility between the in situ exsolved Co nanometal and perovskite, promote the synergy of adsorption-catalysis performance. The STO@Co electrode delivers higher specific capacity, better long-cycle stability, and rate capability compared to metal-impregnated perovskite heterostructure (STO/Co). This study proposes a new method of in situ exsolution for the preparation of heterostructures, which guides designing efficient battery materials.