Synergetic enhancement of sodium storage in gallium-based heterostructures

Gallium chalcogenides, emerging as promising anode for sodium-ion batteries (SIBs), show high capacity utilization and self-healing ability but poor electrochemical performance owing to their inferior electrical conductivity and sluggish ion diffusion. Building heterostructures is regarded as a valid strategy to facilitate carrier transfer and boost sodium storage. Herein, we develop a controllable two-step approach to synthesize the Ga2O3@Ga2S3@C heterostructures. Serving as the anode for SIBs, it exhibits a reversible capacity of 680 mAh g(-1) at a current density of 0.1 A g(-1) after 100 cycles, as well as superior cyclic stability (410 mAh g(-1) at an ultrahigh current density of 20.0 A g(-1) over 4000 cycles). The mechanism for the enhanced sodium storage of Ga2O3@Ga2S3@C heterostructures is disclosed, which is mainly ascribed to the synergistic effect of built-in electric field and interfacial effect in p-n junctions, helping the sodium ions diffusion and the further conversion reactions.

Automated summary

The study presents a new method for synthesizing gallium sulfide heterostructures, which exhibit excellent performance as the anode for sodium-ion batteries. The experiments show that the heterostructures have good cyclic stability and reversible capacity, with the mechanism for enhanced sodium storage elucidated.