▎ 摘　　要

After research, it is found that CoGa2O4, a gallium-based material with a dual energy storage mechanism, as the anode of a lithium-ion capacitor, has a good cycle stability. However, the nanoparticle CoGa2O4 is easy to agglomerate, which will affect its electrochemical performance. This article reports a CoGa2O4/RGO composite material acquired by an uncomplicated hydrothermal method. The agglomerations of CoGa2O4 nanoparticles were avoided by using RGO with high specific surface area. Here, the easily available distilled water is used as the solvent to avoid the use of additional surfactants. The prepared CoGa2O4/RGO composite material has a higher capacity and a longer cycle life, which is 4 times higher than the pure CoGa2O4. A device with activated carbon as the cathode was assembled to study its LIC performance, and after 10,000 cycles, the capacity retention rate of the assembled device can reach 89% and the coulomb efficiency can reach 100%.