Jong Hun Ryu, Jaehyun Park, Jeongwoo Park, Jinhong Mun, Eunmi Im, Hojeong Lee, Sung You Hong, Kwangjin An, Geunsik Lee, Youngsik Kim, Pil Sung Ho, Seok Ju Kang
Energy Storage Materials, 45 (2022) 281-290 (Website link)
Seawater batteries consisting of Na anode, Na super-ionic conductor separators, and seawater catholytes have received wide attention because of their theoretical specific capacity of 1160 mAh g−1 and cost-effective Na anode in comparison to rare-earth Li. However, large overpotential during charge and discharge caused by parasitic reactions limits their practical applications. In this work, we employ the bifunctional Pt-Co alloy electrocatalysts produced by carbothermal shock (CTS) method to improve the oxygen evolution and reduction reaction activities of seawater batteries. The CTS induced Pt-Co alloy nanoparticles are well synthesized and dispersed on a carbon current collector within a few s, resulting in improved overpotential and cycle endurance of seawater batteries compared to pristine carbon cathode. In particular, the cell can operate for over 500 h in a seawater catholyte at a fixed capacity of 0.25 mA cm−2 without significant performance degradation. Furthermore, CTS can be readily applied to large-area prismatic seawater battery cells. We observe excellent cyclability in a large-scale seawater battery, suggesting that bifunctional Pt-Co alloy electrocatalysts produced by CTS are viable for use in seawater batteries.