Few-layer bismuth selenide cathode for low-temperature quasi-solid-state aqueous zinc metal batteries
Yuwei Zhao, Yue Lu, Huiping Li, Yongbin Zhu, You Meng, Na Li, Donghong Wang, Feng Jiang, Funian Mo, Changbai Long, Ying Guo, Xinliang Li, Zhaodong Huang, Qing Li, Johnny C. Ho, Jun Fan, Manling Sui, Fu‐Rong Chen, Wenguang Zhu, Weishu Liu, Chunyi Zhi
Abstract
Abstract The performances of rechargeable batteries are strongly affected by the operating environmental temperature. In particular, low temperatures (e.g., ≤0 °C) are detrimental to efficient cell cycling. To circumvent this issue, we propose a few-layer Bi 2 Se 3 (a topological insulator) as cathode material for Zn metal batteries. When the few-layer Bi 2 Se 3 is used in combination with an anti-freeze hydrogel electrolyte, the capacity delivered by the cell at −20 °C and 1 A g −1 is 1.3 larger than the capacity at 25 °C for the same specific current. Also, at 0 °C the Zn | |few-layer Bi 2 Se 3 cell shows capacity retention of 94.6% after 2000 cycles at 1 A g −1 . This behaviour is related to the fact that the Zn-ion uptake in the few-layer Bi 2 Se 3 is higher at low temperatures, e.g., almost four Zn 2+ at 25 °C and six Zn 2+ at −20 °C. We demonstrate that the unusual performance improvements at low temperatures are only achievable with the few-layer Bi 2 Se 3 rather than bulk Bi 2 Se 3 . We also show that the favourable low-temperature conductivity and ion diffusion capability of few-layer Bi 2 Se 3 are linked with the presence of topological surface states and weaker lattice vibrations, respectively.