An aqueous zinc‐ion battery working at −50°C enabled by low‐concentration perchlorate‐based chaotropic salt electrolyte

Abstract

Rechargeable aqueous zinc-ion batteries (ZIBs) have been considered as a promising candidate for the large-scale energy storage device owing to their low cost and high safety. However, the practical application of aqueous ZIBs at low temperature environment is hindered by the freezing aqueous electrolytes, which leads to a sharp drop in ionic conductivity, and thereby a rapid deterioration of battery performance. Herein, a chaotropic salt electrolyte based on low concentration aqueous Zn(ClO 4 ) 2 with superior ionic conductivity under low temperature (4.23 mS/cm at À50 C) is reported. The anti-freezing methodology introduced here is completely different from conventional freezeresistant design of using "water-in-salt" electrolyte, cosolvents, or anti-freezing agent additives strategy. Experimental analysis and molecular dynamics simulations reveal that the as-prepared Zn(ClO 4 ) 2 electrolyte possesses faster ionic migration compared with other commonly used Zn-based salts (i.e., Zn (CF 3 SO 3 ) 2 and ZnSO 4 ) electrolyte. It is found that Zn(ClO 4 ) 2 electrolyte can suppress the ice crystal construction by forming more hydrogen bonds between solute ClO 4 À and solvent H 2 O molecules, thus leading to a superior anti-freezing property. The fabricated ZIBs using this aqueous electrolyte exhibits a dramatically enhanced specific capacity, remarkable rate capability, and great cycling stability over a wide temperature range, from À50 to 25 C. The aqueous ZIBs also exhibit an outstanding energy density of Guoshen Yang, Jialei Huang, and Xuhao Wan contributed equally to this work.

Boosting Low-Temperature Resistance of Energy Storage Devices by Photothermal Conversion Effects

“…The gel electrolyte was sandwiched between two pieces of electrodes to finish a SC device. 27,28 2.4. Characterization.…”

“…Activated carbon, conductive carbon black, and tetrafluoroethylene are mixed at a ratio of 8:1:1, which was further coated on carbon cloths as electrodes. The gel electrolyte was sandwiched between two pieces of electrodes to finish a SC device. , …”

Applying Classical, Ab Initio, and Machine-Learning Molecular Dynamics Simulations to the Liquid Electrolyte for Rechargeable Batteries

“…In addition, H 2 O molecules can connect to each other and form a network through H bonds. The H 2 O–H 2 O interaction network will be disrupted upon the addition of salts or organic solvents, which can be attributed to the additional interaction of H 2 O with anions or solvent molecules. − For instance, Chang et al proposed an aqueous hybrid electrolyte containing ethylene glycol (EG) solvents. EG can not only interact with Zn 2+ but also form the H bond with H 2 O to weaken the Zn 2+ –H 2 O interaction, affording the electrolyte with a low freezing point and reversible Zn deposition/stripping …”

Antifreezing Proton Zwitterionic Hydrogel Electrolyte via Ionic Hopping and Grotthuss Transport Mechanism toward Solid Supercapacitor Working at −50 °C

“…One is by using salts as inhibitors of water freezing. [8][9][10][11][12] In these systems, only high concentration of salts can reduce the freezing point. For example, 30 wt% CaCl 2 can reduce the freezing point of the hydrogel system to −57 °C, and the low salt concentration (10 wt% CaCl 2 ) is only reduced to −7 °C.…”