KxNayH(2-x-y)Ti2O5 for High-Performance Lithium-Ion Battery Anode with Li Dendrites-Free Mechanism, Zero-Strain Characteristic

Conventional Li-ion batteries equipped with graphite anodes suffer from poor rate performance and the risk of lithium dendrites, which constrain scale-up applications. Among the promising candidates, spinel-type Li4Ti5O12 is still subjected to low theoretical specific capacity, high working potential, and poor diffusion properties. Herein the KxNayH(2-x-y)Ti2O5 product is provided by reconstructing the chemical bonding idea, which exhibits enhanced specific capacity (323 mAh g(-1)), lower working potential (major capacity contribution < 1.5 V vs Li+/Li), higher diffusion coefficient (10(-8.5)-10(-5) cm(2 )s(-1)), and long cycle stability. Further in/ex situ studies show that these excellent properties can be attributed to the combination of high capacitive contribution, unique "switching mechanism" to avoid lithium dendrite generation, and the zero-strain properties. The findings provide new ideas and opportunities for the development of next generation titanate anode materials with desirable electrochemical properties.