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 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 °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 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 °C and six Zn2+ at −20 °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.
Original language | English |
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Article number | 752 |
Journal | Nature Communications |
Volume | 13 |
Issue number | 1 |
Early online date | 8 Feb 2022 |
DOIs | |
Publication status | Published - Dec 2022 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2022, The Author(s).
Funding
This research was supported by the National Key R&D Program of China (no. 2019YFA0705104 (C.Z.)). The work was also partially sponsored by GRFs under Project CityU 11305218 (C.Z.), CityU 11212920 (C.Z.), and the Guangdong Innovative and Entrepreneurial Research Team Program (no. 2016ZT06G587 (W.L.)). The authors would like to thank Mr T. F. Hung for HRTEM analysis.