Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb₂O₅ electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li⁺. This electrode can reversibly cycle three lithiums per Nb₂O₅, corresponding to a capacity of 269 mAh g⁻¹ at 20 mA g⁻¹, and retains a capacity of 191 mAh g⁻¹ at a high rate of 1 A g⁻¹. It exhibits superb cycling stability with a capacity of 225 mAh g⁻¹ at 200 mA g⁻¹ for 400 cycles, and a Coulombic efficiency of 99.93%. We attribute the enhanced performance to the cubic rock-salt framework, which promotes low-energy migration paths. Our work suggests that inducing crystallization of amorphous nanomaterials through electrochemical cycling is a promising avenue for creating unconventional high-performance metal oxide electrode materials.

由于在低电压下镀锂的风险降低，插层型金属氧化物是用于安全可充电锂离子电池的有前途的负极材料。然而，它们较低的能量和功率密度以及循环不稳定性仍然是它们实施的瓶颈，特别是对于快速充电应用。在这里，我们报告了一种纳米结构的岩盐 Nb ₂ O _{5电极，该电极在与 Li} ⁺的重复电化学循环过程中通过无定形到晶体的转变而形成。_{该电极每 Nb 2} O ₅可以可逆地循环三个锂，对应于 269 mAh g ^-1在 20 mA g ^-1的容量，并保持 191 mAh g 的容量^{-1以 1 A g -1}的高速率。它表现出极好的循环稳定性，容量为 225 mAh g ^-1在 200 mA g ^-1下循环 400 次，库仑效率为 99.93%。我们将增强的性能归因于立方岩盐框架，它促进了低能迁移路径。我们的工作表明，通过电化学循环诱导非晶纳米材料的结晶是创造非常规高性能金属氧化物电极材料的有希望的途径。