Single-crystalline metal germanate nanowire–carbon textiles as binder-free, self-supported anodes for high-performance lithium storage
Single-crystalline metal germanate nanowires, including SrGe4O9, BaGe4O9, and Zn2GeO4 were successfully grown on carbon textile via a simple low-cost hydrothermal method on a large scale. The as-grown germanate nanowires–carbon textiles were directly used as binder-free anodes for lithium-ion batteries, which exhibited highly reversible capacity in the range of 900–1000 mA h g−1 at 400 mA g−1, good cyclability (no obvious capacity decay even after 100 cycles), and excellent rate capability with a capacity of as high as 300 mA h g−1 even at 5 A g−1. Such excellent electrochemical performance can be ascribed to the three-dimensional interconnected conductive channels composed of the flexible carbon microfibers, which not only serve as the current collector but also buffer the volume change of the active material upon cycling. Additionally, the one-dimensional nanostructures grown directly on the carbon microfibers also ensure fast charge carrier (e− and Li+) transport, large surface areas, better permeabilities, and more active sites, which also contributed to the improved electrochemical performance.