Ga2O3 Quantum Dots with N-Doped Amorphous Carbon Fixed for Efficient Storage and Transfer of Lithium Ions by Introduction of Dopamine Hydrochloride.

Abstract

The Ga2O3 anode has great potential due to its self-healing and high theoretical capacity in lithium-ion batteries. Like anodes with other transition metal oxides, the Ga2O3 anode has the problems of structural change and low electrical conductivity. The electrochemical performance of the Ga2O3 anode still needs to be improved. In this work, we synthesized a Ga2O3 quantum dots@N-doped carbon (Ga2O3-QD@NC) composite by hydrothermal reaction with a carbon source of dopamine hydrochloride, in which Ga2O3 quantum dots were dispersed in the interior of the amorphous carbon. Such a special structure is conducive to the high-speed migration of lithium ions and electrons and effectively inhibits volume expansion and agglomeration. Smaller and more uniform quantum dots facilitate efficient repair of the structure. Due to these advantages, the Ga2O3-QD@NC electrode has great electrochemical performance. The Ga2O3-QD@NC electrode has an initial discharge capacity of 1580 mAh g-1 with a high first Coulombic efficiency of 62.8% and a cycling capacity of 953 mAh g-1 under 0.1 A g-1. It even has a capacity of 460 mAh g-1 at 1 A g-1 after 300 cycles. This strategy can provide a new direction for the Ga2O3 anode in lithium-ion batteries with high capacity.