Few-layer bismuth selenide cathode for low-temperature quasi-solid-state aqueous zinc metal batteries

The performances of rechargeable batteries are strongly affected by the operating environmental temperature. In particular, low temperatures (e.g., <= 0 degrees C) are detrimental to efficient cell cycling. To circumvent this issue, we propose a few-layer Bi2Se3 (a topological insulator) as cathode material for Zn metal batteries. When the few-layer Bi2Se3 is used in combination with an anti-freeze hydrogel electrolyte, the capacity delivered by the cell at -20 degrees C and 1 A g(-1) is 1.3 larger than the capacity at 25 degrees C for the same specific current. Also, at 0 degrees C the Zn | |few-layer Bi2Se3 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 Bi2Se3 is higher at low temperatures, e.g., almost four Zn2+ at 25 degrees C and six Zn2+ at -20 degrees C. We demonstrate that the unusual performance improvements at low temperatures are only achievable with the few-layer Bi2Se3 rather than bulk Bi2Se3. We also show that the favourable low-temperature conductivity and ion diffusion capability of few-layer Bi2Se3 are linked with the presence of topological surface states and weaker lattice vibrations, respectively. The performances of rechargeable batteries are detrimentally affected by low temperatures (e.g., < 0 degrees C). Here, the authors report a few-layer Bi2Se3 material capable of improving battery cycling performances when operational temperatures are shifted from +25 degrees C to -20 degrees C.

Automated summary

The performances of rechargeable batteries are detrimentally affected by low temperatures (e.g., < 0 degrees C). Here, the authors report a few-layer Bi2Se3 material capable of improving battery cycling performances when operational temperatures are shifted from +25 degrees C to -20 degrees C.