Rb4Li2TiOGe4O12: a novel high-performance titanyl germanate anode for Li-ion batteries

Abstract

The design of high-performance anode materials is the key to improving the performance of lithium-ion batteries. Here, a new high-performance titanyl germanate anode, Rb₄Li₂TiOGe₄O₁₂ (RLTG), was investigated for lithium-ion storage properties for the first time. Thanks to the multi-electron reactions of Ti and Ge and the polyanion framework, RLTG exhibits a high discharge specific capacity of 786.2 mA h g⁻¹ and decent capacity retention performance of 84%. In addition, RLTG shows a good rate capability in the range of 0.05–2.5 A g⁻¹. Furthermore, the discharge/charge behaviors were explored in depth by a cyclic voltammetry test, galvanostatic intermittent titration technique, X-ray absorption near-edge spectroscopy and electrochemical impedance spectroscopy, combined with first-principles calculations.