High-rate lithiation-induced reactivation of mesoporous hollow spheres for long-lived lithium-ion batteries

Mechanical and chemical degradations of high-capacity anodes, resulting from lithiationinduced stress accumulation, volume expansion and pulverization, and unstable solid- electrolyte interface formation, represent major mechanisms of capacity fading, limiting the lifetime of electrodes for lithium-ion batteries. Here we report that the mechanical degradation on cycling can be deliberately controlled to finely tune mesoporous structure of the metal oxide sphere and optimize stable solid-electrolyte interface by high-rate lithiationinduced reactivation. The reactivated Co₃O₄ hollow sphere exhibits a reversible capacity above its theoretical value (924mAhg^-1 at 1.12 C), enhanced rate performance and a cycling stability without capacity fading after 7,000 cycles at a high rate of 5.62 C. In contrast to the conventional approach of mitigating mechanical degradation and capacity fading of anodes using nanostructured materials, high-rate lithiation-induced reactivation offers a new perspective in designing high-performance electrodes for long-lived lithium-ion batteries.