Glass-Ceramic-Like Vanadate Cathodes for High-Rate Lithium-Ion Batteries

Abstract

Nanostructured electrode materials are good candidates in batteries especially for high-rate applications, yet they often suffer from extensive side reactions due to anomalously large surface areas. While micrometer-size materials provide better stability, the lattice diffusivity is often too slow for lithium ion intercalation over the same length scale in a short time. Herein, a simple method to synthesize glass-ceramic-like vanadate cathodes for lithium-ion batteries with abundant internal boundaries that allow fast lithium ion diffusion while maintaining a small surface area that thus minimize the contact and side reactions with organic electrolyte, is reported. Such samples heat-treated under optimized conditions can deliver an impressive high-rate capacity of 103 mAh g(-1) at 4000 mA g(-1) over 500 cycles, which has better kinetics and cycling stability than similar vanadate-based materials. A striking grain-size refinement effect accompanied by a low-temperature growth-controlled phase transition, can be achieved by fine tuning the heat-treatment process. It is believed that the findings are general for other transition metal oxides for energy applications.