Dynamic Dual‐Evolution of Heterostructure Catalysts in Li‐S Batteries

ABSTRACT It is greatly challenging to monitor real‐time dynamic evolution of pre‐catalysts in complicated redox reactions, and there is, therefore, still a lack of profound understanding into their behavior mechanisms. Herein, we reveal a dynamic dual‐evolution mechanism of Co‐CoO heterostructure catalyst in Li‐S batteries through combining a series of in situ characterization techniques. In situ phase transformation of partial CoO into CoS 2 couples with synchronous crystal‐plane slip, and the crystal‐plane slip induced by lattice distortion continuously exposes new active sites. The dynamic dual‐evolution of heterostructure catalysts broadens the catalytic selectivity toward sulfur redox reactions, establishes a unique bidirectional catalytic reaction pathway for sulfur conversion, and realizes controllable full‐range reaction kinetics manipulation in Li‐S batteries. Eventually, Li‐S batteries exhibit a low capacity decay of 0.035% per cycle for 1000 cycles at 1.0 C, and multilayered Li‐S pouch cells harvest an ultrahigh energy density of 362.7 W h kg −1 even under a high areal loading of 8.33 mg cm −2 . This work provides direct atomic‐level evidence to real‐time dynamic evolution of catalysts, deepens insights into the catalyst evolution mechanism, and inspires new design routes for developing low‐cost and high‐energy‐density Li‐S batteries.