Enhanced cyclic stability of Ga2O3@PDA-C nanospheres as pseudocapacitive anode materials for lithium-ion batteries

• Dopamine hydrochloride can self-polymerize along the surface of Ga 2 O 3 particles to form a uniform carbon layer. Nanomaterial Ga 2 O 3 @PDA-C was synthesized. • The Ga 2 O 3 @PDA-C electrode have high pseudocapacitance contribution. • The Ga 2 O 3 @PDA-C electrode exhibits 1059.7 mAh/g after 100 cycles. Ga 2 O 3 is widely used as anode material for lithium-ion batteries owing to its high theoretical capacity. However, Ga 2 O 3 has the disadvantages of limited electronic conductivity and severe volume expansion, which seriously restrict its application. Therefore, the Ga 2 O 3 nanospheres were coated with carbon using dopamine hydrochloride as the carbon source, which could self-polymerize along the surface of the Ga 2 O 3 particles, forming a uniform carbon coating layer, resulting in superior overall electrochemical performance. Moreover, this particular pomegranate-like morphology and carbon-coating treatment not only shorten the ion transmission path and improve the cycle stability but also provide abundant lithium-ion storage space inside the particle, which improves the pseudocapacitive storage characteristics. High capacitive contribution ratios were obtained for Ga 2 O 3 @PDA-C at different scan rates; these ratios were found to be much higher than those for Ga 2 O 3 electrode at different scan rates; the pseudocapacitance of Ga 2 O 3 @PDA-C increased to 69% and the more enormous capacitance contribution indicates its high capacity. Under the synergistic effect of multiple effects, the Ga 2 O 3 @PDA-C composite electrode exhibited excellent performance, with an initial capacity of 1863.9 mAh/g and maintained 1059.7 mAh/g after 100 cycles.