The interfacial stability of zinc anodes depends primarily upon the electrical double layer (EDL) environment and interfacial electric field (IEF) in repeated Zn plating/stripping processes. Herein, a high-entropy electrolyte (HEE) with over 68 types of Zn2+ solvation configurations is proposed to modulate the EDL and IEF of Zn anode/electrolyte interface, achieving the improved electrochemical stability and low freezing point. The formation of multiple and water-poor Zn2+ solvation configurations facilitates the ion transport dynamics and the desolvation process in the inner Helmholtz plane (IHP), inducing the formation of an organic-inorganic hybrid solid electrolyte interphase (SEI) layer and synergistically guiding the preferential growth of the Zn (100) and (101) crystal planes with compact and dendrite-free deposition morphology. Consequently, the Zn//Cu asymmetric cells with this HEE demonstrate a high average Coulombic efficiency (ACE) of 99.6% for over 3700 cycles (7390 h) at 25 °C and a high ACE of 99.7% for over 4600 cycles (9100 h) at -20 °C. The Zn//Zn symmetric cells also achieve stable operation for more than 3300 and 6900 h at 25 °C and -20 °C, respectively. The Zn//PANI cells exhibit 82.0% capacity retention after 2000 cycles at 1.0 A g-1 at 25 °C and ∼100% capacity retention after 7000 cycles at 0.5 A g-1 at -20 °C. This work provides an in-depth insight into the design of HEEs for tailoring the EDL and IEF to enhance the stability of Zn-based batteries.
Liu et al. (Sat,) studied this question.