Exploring enhanced capacity in lithium-ion battery anodes: Synthesis and electrochemical evaluation of Zn2GeO4 encapsulated in porous carbon balls via carbonization

초록

Germanium-based materials, such as Zn2GeO4, have recently been attracting attention as anode materials that can be used as an alternative to graphite. However, Zn2GeO4 suffers from critical disadvantages-such as low electrical conductivity and volume expansion-during lithiation/de-lithiation processes, which lead to reduced cycling stability and low specific capacity. In this study, we proposed the concept of porous carbon ball- encapsulated Zn2GeO4. The porous carbon balls were synthesized using heat treatment to be used as a buffer, with the effectively mitigating the volume expansion of Zn2GeO4. We investigated the electrochemical properties and mechanisms of Zn2GeO4 during cycling using ex-situ XRD analysis. The final product (H-C@ZGO) demonstrated enhanced cycling stability, with capacities ranging from 550 to 660 mAhg- 1 at 0.1 Ag- 1. We also examined the improved diffusion pathways facilitated by the encapsulated carbon balls as well as the porous structure formed by heat treatment.

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