A Trifunctional Electrolyte Enables Aqueous Zinc Ion Batteries with Long Cycling Performance

Abstract

Aqueous zinc ion batteries hold promise as alternative systems to lithium-based batteries. However, practical development faces critical challenges due to parasitic side reactions and dendrite growth in zinc anodes. While introducing electrolyte additives is promising, monofunctional additives offer limited protection to the zinc anode from a single aspect. Herein, a disodium succinate additive is presented to establish a hydrophobic and zincophilic dual electric layer structure on the Zn surface, regulate the solvation structure of Zn2+, and act as a pH buffer during cycling. As a result, the symmetrical cell with an electrolyte containing 0.2 m SADS shows a durable life of over 2200 h, and the Zn||MnO2 full cell still maintains an 80% capacity retention after 1000 cycles. In addition, SADS both show wide applicability in the match with NVO and I2 cathode. This work provides a low-cost and multifunctional electrolyte additive, facilitating the development of high-performance aqueous zinc ion batteries.