Ternary all-lithium-reactive AlGeP solid solution as an advanced anode material for lithium-ion batteries

Abstract

With the rapid development of portable electronic devices and electric vehicles, lithium-ion batteries (LIBs) are being used extensively as clean and efficient power sources. Among the various anode materials being explored for use in LIBs, Ge has attracted significant attention owing to its high theoretical specific capacity. However, low electronic conductivity, relative poor Li-ion mobility, large volume expansion impede its commercial application. Herein, we synthesize a single-phase AlGeP solid solution through a facile high-energy ball milling of the raw materials of Al, P and Ge. The ternary AlGeP exhibits superior Li-storage properties than the single-component phase of Ge in terms of longer cycling stability, and faster rate performance profiting from its faster electronic conductivity confirmed by electrochemical impedance spectra, and higher Li-ion mobility confirmed by galvanostatic intermittent titration technique measurements. Moreover, we further promote the electrochemical Li-storage properties of the ternary AlGeP through carbon modification which accommodate the volume expansion and improve the electronic conductivity. Broadly this work will stimulate more research interest on ternary all-lithium-reactive compounds in the energy storage field.