Immunizing Aqueous Zn Batteries against Dendrite Formation and Side Reactions at Various Temperatures via Electrolyte Additives

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 17; no. 42; pp. e2103195 - n/a
• Main Authors: Feng, Doudou, Cao, Faqing, Hou, Lei, Li, Tianyu, Jiao, Yucong, Wu, Peiyi
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-10-2021
• Subjects: Additives; Basal plane; dendrite‐free; Dendritic structure; Dimethyl sulfoxide; Electrolytes; Freezing; Hydrogen bonds; Immunization; Ion currents; Manganese dioxide; Melting points; Nanotechnology; nucleation basal plane; Solvation; Subzero temperature; Zn 2+ solvation; Zn‐ion batteries
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202103195

Aqueous Zn‐ion batteries own great potential on next generation wearable batteries due to the high safety and low cost. However, the uncontrollable dendrites growth and the negligible subzero temperature performance impede the batteries practical applications. Herein, it is demonstrated that dimethyl sulfoxide (DMSO) is an effective additive in ZnSO4 electrolyte for side reactions and dendrites suppression by regulating the Zn‐ion solvation structure and inducing the Zn2+ to form the more electrochemical stable (002) basal plane, via the higher absorption energy of DMSO with Zn2+ and (002) plane. Moreover, the stable reconstructed hydrogen bonds between DMSO and H2O dramatically lower the freezing point of the electrolyte, which significantly increases the ionic conductivity and cycling performance of the aqueous batteries at subzero temperatures. As a consequence, the symmetrical Zn/Zn cell can be kept stable for more than 2100 h at 20 °C and 1200 h at −20 °C without dendrite and by‐products formation. The Zn/MnO2 batteries can perform steadily for more than 3000 cycles at 20 °C and 300 cycles at −20 °C. This work provides a facile and feasible strategy on designing high performance and dendrite free aqueous Zn‐ion batteries for various temperatures.
The dimethyl sulfoxide (DMSO) molecule can help to optimize the Zn2+ deposition behavior by inducing the fine‐grained Zn nucleation with higher overpotential, and texturing the growth of the electrochemically stable hexagonal (002) plane. In addition, the reconstructed strong hydrogen bonds between DMSO and H2O further alleviate side reactions and endow the battery subzero temperature performance.