Amorphous Germanium Nanomaterials as High-Performance Anode for Lithium and Sodium-Ion Batteries

Amorphous germanium (a-Ge) is a promising anode material for lithium and sodium-ion batteries (LIBs and SIBs) due to its higher capacity than traditional graphite materials. Herein, a method to prepare the a-Ge nano-materials with a particle size approximate to 10 nm is proposed by decomposing the CaGe Zintl phase at room temperature. For LIBs, a-Ge has a high-capacity retention of 80% even after 180 cycles (1375 mAh g(-1)). When employed as the anode for SIBs, two-dimensional composites with the a-Ge supported on the graphite nanosheets (a-Ge@GNS) is configured, and a high reversible capacity of 526 mAh g(-1) after 120 cycles is achieved. The preparation of such high-performance amorphous Ge nanomaterials demonstrated in this work is low-cost and environmentally-friendly, and compared with other methods it is especially suitable for scaling-up or mass production.

Automated summary

A method to prepare amorphous germanium (a-Ge) nanomaterials with a particle size approximate to 10 nm is proposed by decomposing the CaGe Zintl phase. As an anode material for lithium and sodium-ion batteries, a-Ge exhibits a higher capacity than traditional graphite materials. For lithium-ion batteries, a-Ge retains 80% of its capacity even after 180 cycles (1375 mAh g(-1)). When used as the anode for sodium-ion batteries, a two-dimensional composite of a-Ge supported on graphite nanosheets (a-Ge@GNS) achieves a high reversible capacity of 526 mAh g(-1) after 120 cycles. This work demonstrates a low-cost and environmentally-friendly method for preparing high-performance amorphous Ge nanomaterials, particularly suitable for scaling-up or mass production.