Study the Structure, Optical, and Electrochemical Properties of Germanium Oxide/Graphene Nanoplatelet Composite for Energy Storage Applications

Germanium oxide (GeO 2 ) nanoparticles exhibit a high theoretical discharge capacity of 2152 mAh g −1 , making them promising anode materials for lithium‐ion batteries. However, their practical application is hindered by severe volume expansion during charge/discharge cycles, leading to structural degradation and capacity fading. To address this challenge, GeO 2 /graphene nanoplatelet (GNP) composite is synthesized via a modified sonochemical technique. The structural, optical, thermal, and electrochemical properties of GeO 2 and GeO 2 /GNP composites are systematically investigated. The incorporation of GNP improves the structural integrity of GeO 2 by mitigating volume changes, enhancing electronic conductivity, and increasing thermal stability. Optical studies reveal a slight bandgap widening, while Fourier transform infrared spectroscopy analysis confirms strong interfacial interactions between GeO 2 and GNP. Electrochemical evaluation demonstrates that the composite retained a discharge capacity of 181 mAh g −1 after 100 cycles, significantly improving the cyclic stability of GeO 2 anodes. These findings highlight the potential of GeO 2 /GNP composites as high‐performance anode materials for energy storage applications.