Characterization of the Ge@GeO2-C Composite Anode Synthesized Using a Simple High-Energy Ball-Milling Process for Li-Ion Batteries

To address the limitations of the current anodes of Li⁺-ion batteries (LIBs), a Ge/GeO₂/carbon (Ge@GeO₂-C) composite was designed by introducing a high-energy ball-milling process for advanced LIBs. Ge@GeO₂-C is prepared and characterized by XPS, XRD, SEM, and TEM, which facilitate synthesis and provide controllability with respect to milling time. Interestingly, as the ball-milling time increased, the proportion of metallic Ge increased during the carbon thermal reduction reaction. The electrochemical characteristics of Ge@GeO₂-C are assessed using differential capacity analysis (dQ/dV) and galvanostatic charge–discharge techniques to confirm its viability as an anode material in LIBs. The results demonstrate decent initial and secondary capacities of approximately 1800 mAh g⁻¹ (for the first cycle) and 838 mAh g⁻¹ (for the second cycle) at a rate of C/60 by the reaction between Ge and the Li–Ge complex. Furthermore, post-mortem characterization was performed to gain an understanding of the material, suggesting future prospects for advanced LIBs.