Journal Article

Coupling of Adhesion and Anti-Freezing Properties in Hydrogel Electrolytes for Low-Temperature Aqueous-Based Hybrid Capacitors

Wang, Zihao, Chu, Fuxiang, Jiang, Jianchun, Sun, Yue, Yang, Fusheng, Zhu, Tianyu, Li, Yuxi, Zhang, Yijing, Wang, Chunpeng, Nan, Jingya, Wang, Chuchu, Wang, Dingkun

2024

Overview

HighlightsA class of hydrogel electrolytes that couple high adhesion and anti-freezing properties is developed.Zn/Li hybrid capacitors based on the hydrogel electrolyte can tolerate low temperatures and accommodate dynamic deformations across a temperature range of 25 to − 60 °C.This work highlights an advancement for promoting next-generation energy storage system with low-temperature capability and mechanical durability.Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety, mechanical and thermal stability and easy-to-direct stacking. Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness, high conductivity and intrinsic flexibility. However, the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors. Here, we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance. The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode. Meanwhile, the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures. More significantly, the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance, delivering high-energy density of 39 Wh kg−1 at −60 °C with capacity retention of 98.7% over 10,000 cycles. With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte, the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at −60 °C. This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.

• Publisher: Springer Nature B.V
• Subject: Adhesion / Aqueous electrolytes / Capacitors / Carbon nanotubes / Deformation / Electrodes / Electrolytes / Energy storage / Freezing / Hydrogels / Ion currents / Low temperature / Molten salt electrolytes / Solid electrolytes / Solid state / Solvation / Temperature / Thermal stability / Zinc chloride