SiO₂–GeO₂ Glass–Ceramic Flakes as an Anode Material for High‐Performance Lithium‐Ion Batteries

Abstract

The preparation of a flake‐like glass–ceramic anode material comprised of SiO 2 and GeO 2 for Li‐ion batteries (LIBs) is demonstrated. The precursor glass material is prepared via a traditional melt quenching technique. Flake‐like glass particles are obtained by compression in the liquid phase via ball milling. A subsequent heat treatment induces crystallization of Ge x Si y O 6 domains inside the vitreous SiO 2 –GeO 2 matrix. This novel glass‐ceramic material is applied as an anode material for LIBs and shows a stable reversible capacity of 520 mAh g −1 at 0.2 C combined with good capacity retention of 87% after 100 cycles. This cycling stability can be attributed to the synergistic effects of having nanocrystalline domains embedded in the glass matrix: The open glass network can withstand the volume change and stress caused by the lithium insertion during cycling, while the nanocrystals act as active sites for the electrochemical conversion and alloying reactions. The glass–ceramic anode material exhibits superior electrochemical properties compared to its pure glass counterparts.