Copper Activation Enabling Reversible Aqueous Cu−ZnS Battery Chemistry

Abstract

The aqueous metal-sulfide batteries (AMSBs) have attracted research interest due to their high capacity, environmentally friendly qualities, and the accessibility of raw materials. However, the design strategies for metal-sulfide cathode have rarely been reported. Here, the copperactivated sphalerite in which Zn 2 + is substituted by Cu 2 + through ion exchange has been introduced for the first time as cathode for aqueous Cu/ZnS batteries. After sphalerite transformed to CuS, a two-step conversion of CuS!Cu 7 S 4 ! Cu 2 S storage mechanism has been proposed. At 0.7 A g À 1 current density, the capacity can reach 532.4 mAh g À 1 after 100 cycles. When cycled once at a current density of 35 mA g À 1 , the initial reversible capacity can reach 461 mAh g À 1 under 1 A g À 1 . Furthermore, the assembled Zn// ZnS hybrid ion cell delivers an energy of up to 460 Wh kg À 1 , which is better than for many AMSBs.

Aqueous copper batteries for future energy storage

“…由于高倍率和长循环性能对大规模储能尤为重要，这类体系将是未来水系铜电池的重要发展方向. 其 他硫族化合物如Ag 2 S [40] 和ZnS [41] 也在铜电池中得到了研究，但目前还存在着成本和性能的系列问题. 当然，硫 族化合物储铜时存在输出电压低的问题，此问题可以通过将Cu-S(或者Cu-CuSe)电池与Zn-Cu电池耦合来解 A c c e p t e d https://engine.scichina.com/doi/10.1360/TB-2024-0336 决 [42] .…”