Trisodium citrate as a modulation additive to increase the cycling capability of a Bi 2 S 3 cathode in a zinc-ion battery.

3D Bi ₂ S ₃ materials were prepared by the trisodium citrate (Na ₃ Cit)-assisted solvothermal method and applied to aqueous zinc ion batteries (AZIBs) to explore the effect of the electrode material morphology on the electrochemical performance. As the concentration of Na ₃ Cit increases, the 3D assembly morphology evolves from coral-like to sphere-like to snowflake-like structures. The electrochemical test results show that the electrode materials of various morphologies possess excellent cycle life, but the specific capacity varies greatly depending on the morphology. Impressively, the Bi ₂ S ₃ -1.2 electrode has the best electrochemical performance, with a capacity of 203.5 mA h g ^-1 after 4000 charge/discharge cycles at 0.5 A g ^-1 . Furthermore, the Bi ₂ S ₃ -1.2 electrode delivers an ultralong lifetime of over 10 000 cycles with a capacity of 150.2 mA h g ^-1 at 1 A g ^-1 . This work demonstrates a feasible route to prepare ultra-long cycle life AZIBs.