A Stress-Cushioning Pocket-Cube-Like Structured Anode for Fast-Charging Lithium-Ion Batteries

Rational design of complex hollow architectures in conversion-type anode materials is critical for regulating mechanical stress and ion transport during battery operation. However, the fundamental relationship between the structural topology and its mechanical robustness remains insufficiently understood. Herein, guided by finite element analysis, a novel pocket-cube-like hollow composite consisting of porous N/S co-doped carbon matrix and highly dispersed CoS₂ (CoS₂/hPC-NSC) has been rationally designed as the active material. Ex situ and in situ characterizations further demonstrate that the pocket-cube-like hollow structure not only exhibits a higher density of active sites but also effectively alleviates volume expansion and delivers enhanced mechanical stability relative to traditional hollow structures. Accordingly, the as-designed CoS₂/hPC-NSC can deliver a high reversible specific capacity of 528 mAh g^-1 after 2000 cycles at a high current density of 5 A g^-1. This work establishes a viable strategy for designing mechanically robust transition metal sulfide-based anodes and promotes their practical application in LIBs.