Ultra-high rapid-charging performance of 1D germanium anode materials for lithium-ion batteries

Abstract

The rapid-charging capability of lithium-ion batteries (LIBs) can effectively alleviate the load on new energy vehicles. The electrode material’s structure can be severely harmed by rapid charging and discharging, necessitating the use of electrode materials that exhibit excellent performance in fast-charging. In order to enhance the rapid charging capability of LIBs while maintaining a large capacity, we utilized nanotechnology and carbon coating to create Ge-CNFs, which are rod-shaped germanium/carbon nanofibers. These Ge-CNFs serve to mitigate the volume fluctuations of germanium. Ge-CNFs-(700) demonstrated remarkable electrochemical characteristics and durability, maintaining a 795.9 mAh∙g−1 capacity even after 100 cycles at 0.1 A∙g−1, a capacity of 281.6 mAh∙g−1 capacity after 5000 cycles at 5 A∙g−1, and achieved a Coulombic Efficiency of 99.76 %. Furthermore, the Ge-CNFs-(700)/LCO full cell achieving a discharge capacity of 124 mAh∙g−1 after 100 cycles when operated at a current density of 0.2 A∙g−1. The main reason for the excellent electrochemical performance was the ability of CNFs to reduce crushing by serving as a buffer to absorb mechanical stress resulting from volume changes when lithium ions are intercalated/deintercalated. The electrospinning technique used to create a rod-shaped structure, along with its outstanding electrochemical capabilities, showcases the promise of germanium-based materials for rapid charging in electric vehicles.