High-Performance\nGa₂O₃ Anode for Lithium-Ion Batteries

Abstract

There\nis a great deal of interest in developing battery systems that can\nexhibit self-healing behavior, thus enhancing cyclability and stability.\nGiven that gallium (Ga) is a metal that melts near room temperature,\nwe wanted to test if it could be employed as a self-healing anode\nmaterial for lithium-ion batteries (LIBs). However, Ga nanoparticles\n(NPs), when directly applied, tended to aggregate upon charge/discharge\ncycling. To address this issue, we employed carbon-coated Ga₂O₃ NPs as an alternative. By controlling the pH of the\nprecursor solution, highly dispersed and ultrafine Ga₂O₃ NPs, embedded in carbon shells, could be synthesized through\na hydrothermal carbonization method. The particle size of the Ga₂O₃ NPs was 2.6 nm, with an extremely narrow size\ndistribution, as determined by high-resolution transmission electron\nmicroscopy and Brunauer–Emmett–Teller measurements.\nA lithium-ion battery anode based on this material exhibited stable\ncharging and discharging, with a capacity of 721 mAh/g after 200 cycles.\nThe high cyclability is due to not only the protective effects of\nthe carbon shell but also the formation of Ga⁰ during the\nlithiation process, as indicated by operando X-ray absorption near-edge\nspectroscopy.