Integrated electrolyte regulation strategy: Trace trifunctional tranexamic acid additive for highly reversible Zn metal anode and stable aqueous zinc ion battery

Abstract

Aqueous zinc ion batteries (AZIBs) are appealing increasing attention for large-scale energy storage systems (ESS) due to their intrinsic safety, low cost, and scalability. Unfortunately, the Zn metal anode suffers from chaotic side reactions, rampant dendrite growth and continuous hydrogen evolution, severely hampering the application of AZIBs. Herein, the trifunctional tranexamic acid (TXA) is introduced into aqueous electrolyte to form unique anode/electrolyte interface, enhance steric effect and regulate Zn2+ solvation structure. Theoretical calculations first illustrate the mechanism of TXA additive on Zn metal anode and electrolyte. Experimental results and molecular dynamic simulations further demonstrate the vital role of TXA in simultaneously regulating the anode interface chemistry and electrolyte environment. Consequently, Zn//Zn symmetric cells deliver a durable lifespan of over 2000 h at 1 mA cm–2, and a high cumulative capacity at 5 mA cm–2. A highly reversible Zn plating/stripping processes for over 1000 cycles in Zn//Cu asymmetric cells are also achieved. Moreover, the assembled Zn//NiCo-MnO2 and Zn//NH4V4O10 full cells exhibit stable cycling performance and high capacity retentions. This work proposes a novel and facile integrated electrolyte regulation strategy to realize dendrite-free Zn anodes and stable full cells, which is favorable for advanced AZIBs and beyond.