A bio-inspired electrolyte with in situ repair of Zn surface cracks and regulation of Zn ion solvation chemistry to enable long life and deep-cycling zinc metal batteries

Abstract

Rechargeable aqueous Zn-ion batteries (ZIBs) have drawn incredible attention recently due to their high energy density, low cost, and intrinsic safety. However, water attacks that consistently corrode the Zn anode surface with the notorious dendrite growth, together with hydrogen evolution and inactive by-product formation seriously impede the practical applications of ZIBs. Here, we designed a bio-inspired electrolyte (DE) with a tetraethyl orthosilicate additive as a “healing agent” to repair the Zn surface wounds. The results revealed that the DE not only enabled an in situ formed zincophilic layer to promote the uniform Zn deposition, but also altered the Zn²⁺ solvation chemistry to suppress water-induced side reactions. Consequently, the Zn|Zn cells with DE harvested an ultralong life of 6000 h at 0.5 mA cm⁻² and 0.5 mA h cm⁻² and 830 h even at a high depth of discharge of 80%. Furthermore, the Zn/V₂O₅ battery retained 93.15% of the initial capacity after 1000 cycles at 1 A g⁻¹ with a low N/P ratio (2.0), lean electrolyte (20 μL mA h⁻¹), and a high-capacity cathode (2.9 mA h cm⁻²). This work presents a fresh strategy for the development of high-performance ZIBs.