Exfoliation and Reassembly Routes to a Ge/RuO₂ Nanocomposite as an Anode for Advanced Lithium-Ion Batteries

Ge/RuO₂ nanocomposites were successfully fabricated as anode materials for lithium-ion batteries using RuO₂ nanosheets and Ge/GeO₂ nanoparticles (NPs). X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) analyses showed that elemental Ge nanoparticles were distributed onto the rutile-type RuO₂. Transmission electron microscopy images showed well-dispersed Ge nanoparticles embedded in rutile-type RuO₂. The Ge/RuO₂ nanocomposite maintained higher discharge capacities (471 mA h g⁻¹) after the 90th cycle at 0.1 A g⁻¹ than that (211 mA h g⁻¹) of Ge/GeO₂ nanoparticles. The Ge/RuO₂ nanocomposite exhibited a higher capacity retention than Ge/GeO₂ NPs. These results suggest that the well-dispersed Ge nanoparticles within RuO₂ matrices enhance the cycle stability and capacity retention of the anode material.