Developing 50+ Wh static zinc-bromine battery enabled by simple architecture and dual bromine capturing agent strategy

초록

Aqueous batteries can be a viable option for grid scale energy storage systems (ESSs) because of the nonflammable nature, cost advantages and high-power density. Despite the successful development of aqueous batteries in lab-scale, the insufficient cell-level energy density arising from low active material ratio and areal capacity limits their potential. Here, we demonstrate the viability of a simple static zinc-bromine battery (ZBB) architecture that achieves large areal capacity with comparable active material ratio through thick electrode design. The large reaction polarization with thick electrode design was alleviated by utilizing dual bromine capturing additive (dBCA) strategy, while maintaining efficiency at high areal capacity of 50 mAh cm-2. Finally, the lab-scale cell performance (active area: 4.00 cm2) can be successfully scaled-up to a practical Wh-scale short stack (active area = 210.25 cm2), delivering 57.6 Wh of output energy over 600 cycles. This successful scale-up is attributed to the simple cell architecture and well-managed polarization with dBCA electrolyte. Economic analysis shows the design maintains projected costs of $70kWh-1andachieveslowlevelizedcostofenergystored(LCOES)of$0.01 kWh-1%- 1 cyc-1, positioning thick electrode design in simple static architectures as a viable pathway for practical aqueous battery systems.

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