Synergistic effects of microwave irradiation and CeF3 surface coating of lithium titanate for stable, high-capacity, and high-rate lithium-ion batteries

Abstract

The low theoretical specific capacity and rapid capacity degradation, especially during long cycling, have been the key challenges to the practical application of lithium titanate (Li₄Ti₅O₁₂) as an anode material for stable, high-energy and high-power density lithium-ion batteries (LIBs). This study reports a novel strategy of the synergy of surface lattice plane engineering by microwave irradiation and CeF₃ surface coating to synthesize a high-specific-capacity, high-rate and durable LTO–CeF₃–mw anode material for LIBs. The innovative anode material shows outstanding specific capacity, rate capability and long-term cycle stability. It is of interest to note that the LTO–CeF₃–mw anode material has a specific capacity of 191.1 mAh g⁻¹ at 175 mA g⁻¹ (1C), which is greater than the theoretical specific capacity of LTO (175 mAh g⁻¹). Furthermore, LTO–CeF₃–mw has specific capacities of 168.3 and 119.9 mAh g⁻¹ at 875 mA g⁻¹ (5C) and 1750 mA g⁻¹ (10C), respectively. Remarkably, it shows a specific capacity of 166.5 mAh g⁻¹ after 1000 cycles at 5C and a capacity retention of 98.9%. This notable electrochemical performance of LTO–CeF₃–mw is attributed to the synergy of surface lattice plane engineering by microwave irradiation and CeF₃ surface coating that transformed the surface lattice plane (111) of LTO to (220) and (310) in LTO–CeF₃–mw, resulting in high surface area which significantly improved mass transport. Therefore, the unique structure of the LTO–CeF₃–mw anode material is a key development for achieving safe, durable, high-energy and high-power lithium-ion batteries, with potential applications in large-scale energy storage.