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

Abstract

The Ga 2 O 3 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 Ga 2 O 3 anode has the problems of structural change and low electrical conductivity. The electrochemical performance of the Ga 2 O 3 anode still needs to be improved. In this work, we synthesized a Ga 2 O 3 quantum dots@N-doped carbon (Ga 2 O 3 -QD@NC) composite by hydrothermal reaction with a carbon source of dopamine hydrochloride, in which Ga 2 O 3 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 Ga 2 O 3 -QD@NC electrode has great electrochemical performance. The Ga 2 O 3 -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 Ga 2 O 3 anode in lithium-ion batteries with high capacity.

High-performance Si@C anode for lithium-ion batteries enabled by a novel structuring strategy

“…The primary Si characteristic peaks of Si and Si@FeNO@P are located at ∼500 cm −1 , which has weakened significantly after 50 cycles due to the low degree of crystallization of Si caused by the transition from the crystal to the amorphous structure after the cycles. 67 Moreover, the Raman peak of the pure Si electrode has a more significant downshift and a more increased full width at half-maximum than that of Si@FeNO@P after the cycles, indicating worse structural stability. 68 The chemical states of the Si and Si@FeNO@P electrodes before and after 50 cycles were further investigated, as revealed in Fig.…”

Construction of WS2/NC@C nanoflake composites as performance-enhanced anodes for sodium-ion batteries

“…Dopamine is rich in amino and catechol groups, and the surface of the W/NC precursor is covered by carbon via chelating and absorbing tungstate ions in alkaline aqueous solution. 31,32 The W/NC@PDA precursor is formed. Finally, the WS 2 /NC@C composite is prepared after the calcination and vulcanization treatment of the W/NC@PDA precursor at 700 °C in the presence of sublimated sulfur.…”

Low Barriers and Faster Electron/Ion Transport Rates through the Ga2O3/MnCO3 Anode with a Heterojunction Structure for Lithium-Ion Batteries

“…However, the wide band gap of about 4.8 eV seriously affects its conductivity. Besides, pure Ga 2 O 3 shows poor structure stability and performance in the electrochemical process . These require us to further design a reasonable structure and improve the synthesis process for advanced anodes.…”