Unique Structural Design and Strategies for Germanium-Based Anode Materials Toward Enhanced Lithium Storage

Germanium-based materials are arousing increasing interest as anodes for lithium-ion batteries, stemming from the intrinsic physical and chemical advantages of germanium. This progress report provides a brief review on the current development of germanium-based materials in lithium storage. The state-of-the-art strategies to achieve enhanced electrochemical properties are highlighted, with their main aim being to resolve the trickiest issue: vast volume changes in germanium during cycling. These strategies include structural modification, modification by surface coating, forming germanium-based alloys, and forming binary or ternary germanium-based composites. The recent work on a novel composite of germanium and tin particles encapsulated in double-concentric carbon hollow spheres is also presented here, with an emphasis on the relationship between structural design and improved performance.