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

Lithium-ion/sulfur (Li-ion/S) batteries consisting of metallic lithium-free anodes and sulfur cathodes are promising energy storage solutions. Anode prelithiation enables the Li-ion/S battery assembly with the extensively-developed sulfur cathodes. However, it’s...

This work reports a novel Ga-based material, NiGa2O4, which is typically used as a photocatalyst for water splitting, as an anode for Li-ion battery with a long cycle life. High-surface-area reduced graphene oxide (rGO) has been used as the conductive substrate to avoid the aggregation of NiGa2O4 nanoparticles (NPs). Because the size and shape of NiGa2O4 are very sensitive to the pH of the precursor, ethylene glycol has been employed as the solvent, as well as the reduction agent to reduce GO, to avoid using extra surfactants and also to avoid the variation of pH of the precursor. The obtained NiGa2O4/rGO composite possesses high capacity and long cycle life (2000 cycles, 2 A/g), with NiGa2O4 NPs around 3–4 nm that are uniformly distributed on the rGO surface. Full cell performance with LiCoO2 as cathode has also been studied, with the average loss of 0.04% per cycle after 100 cycles (C/2 of LiCoO2). The long cycle life of the composite was ascribed to the self-healing feature of Ga0 formed during charging.

The self-healing feature of gallium (Ga) is unique, making Ga-based materials attract attention for their potential to solve the anode pulverization issue of lithium ion batteries. In this work, a hierarchical two-dimensional (2D) Ga 2 O 3 /C structure has been synthesized by a facile NaCl template method. Ga 2 O 3 nanoparticles (3.8 nm) are uniformly embedded in 2D carbon nanosheets. The long horizontal length of the carbon nanosheets (10 μm) provides longrange electron conductivity, and the thin vertical thickness (75 nm) shortens the Li ion diffusion path. Benefited from the integrated 2D structure and the high electron conductivity, the obtained 2D Ga 2 O 3 /C nanosheets exhibit excellent overall performance, including high lithium storage capacity (1026 mAh g −1 at 0.5 A g −1 ), high rate capability (378 mAh g −1 at 10.0 A g −1 ), and high cyclability (500 cycles at 0.5 A g −1 ). The lithiation/delithiation mechanism of 2D Ga 2 O 3 /C has been further studied with combined electrochemical and ex situ Xray diffraction methods.