Bonding Synergy in In2TiO5 Enables High-Capacity Fast Lithium Storage

The growing need for lithium-ion batteries offering elevated energy density and rapid charging capabilities motivates the exploration of innovative high-capacity and high-rate anode materials. In this study, In2TiO5 anode is developed by merging the substantial lithium uptake from conversion-alloying processes of In2O3 with the rapid ion kinetics from insertion process of TiO2via strategic octahedral reconfiguration. By capitalizing on the bonding synergy where longer In-O bonds enable efficient and large Li storage and shorter Ti-O bonds provide robust framework and fluent ion pathways, the Ti-O frameworks can effectively confine and stabilize the volume change of In species during (de)alloying processes. Leveraging the functionalities of Ti-O and In-O bonds, the In2TiO5 anode shows a stable capacity of 550 mAh g-1 with capacity retention of 82.1% after 600 cycles at 0.1 A g-1, far exceeding In2O3 (290 mAh g-1 after 260 cycles). Even at high current density of 10 A g-1, it maintains 160 mAh g-1 with 80% retention after 1000 cycles. In situ and ex situ characterizations uncover that the LixTiO2 effectively confine the (de)alloying process of In species which enables high structural integrity during (de)lithiation. This bonding synergy strategy by unit-scale hybridization approach paves the way for engineering high-capacity and high-rate lithium-ion battery anodes.