Isotropy‐Induced Stress Relaxation and Strong‐Tolerance for High‐Rate and Long‐Duration Sodium Storage by Amorphous Structure Engineering

Abstract

AbstractHigh‐performance conversion‐reaction‐based electrodes have received enormous attention due to their high theoretical capacities, yet the poor structural stability and large stress accumulation induced from volume change are identified as major limiting factors for further utilization. Although viable strategies are exerted to acquire durable storage capacity, the controllable technology of inner stress is still required to explore. Herein, the amorphous structured GeS2 with 2D porous sheet morphology is designed for sodium‐ion batteries (SIBs). The differences in reaction mechanism and structure reversibility between amorphous and crystalline states are systematically investigated and unraveled. Notably, the amorphous matrix can ensure evenly distributed intermediate interface and alleviated aggregation of active materials, promoting the complete conversion reaction with decreased hysteresis. Furthermore, it provides more isotropic Na‐ion diffusion channels and active sites, effectively boosting the reaction kinetics. Meanwhile, it can fully relieve the volume expansion and restrain the inner stress of GeS2, resulting in excellent structural tolerance. As expected, it expresses prominent rate capability and cyclic life (512.8 mA h g−1 at a superhigh rate of 10 A g−1 after 1000 cycles) for SIBs. Therefore, amorphization engineering is a reliable strategy to obtain the robust framework and unimpeded diffusion channels for developing high‐performance conversion‐reaction‐based electrode materials.