posted on 2024-04-23, 18:40authored byQiu Zhang, Yong Lu, Xiaomeng Liu, Weiwei Xie, Jun Chen
Aqueous
batteries, with the advantages of high safety and low cost,
are highly promising for large-scale energy storage. However, freezing
of the aqueous electrolyte limits the low-temperature operation. Here,
we propose and achieve a highly dispersed solvation structure in the
electrolyte by coupling nonaggregated Cl– anions,
which reduces the water cluster size and prevents the solidification
of the aqueous electrolyte until −136.3 °C. The low-temperature
LiCl electrolyte exhibits a high ionic conductivity (1.0 mS cm–1) at −80 °C and enables a stable low-temperature
Ag/AgCl reference electrode at −50 °C. Moreover, the polyaniline-based
battery can work at an extremely low temperature of −100 °C
and shows superior cycling performance of 4000 cycles at −40
°C with 95.7% capacity retention. This work elucidates the correlation
between the anion effect and the thermodynamic transition of the electrolyte,
offering a novel approach for designing low-temperature electrolytes.