A Mineral‐Biopolymer Synergistic Quasi‐Solid‐State Electrolyte for Long‐Lasting Zinc Metal Batteries

ABSTRACT Combining the high ionic conductivity of inorganic filler with the robust strength of organic matrix is a valid strategy to boost the ion transport and interface stability of composite solid electrolyte, which effectively inhibits dendrite growth of zinc anode and active material dissolution of cathode for zinc metal batteries (ZMBs). Herein, DLM@SA@Zn quasi‐solid‐state electrolytes (QSSEs) are constructed by sodium alginate (SA) and dolomite (DLM) through self‐assembly film technology, and delivers wide operating voltage window (3.08 V), high ionic conductivity (2.22 mS cm −1 ), and high Zn 2+ transference number (0.84). For the Zn//AC@I 2 cells in DLM@SA@Zn electrolyte, a high‐capacity retention ratio of 82.48% is achieved after 22 000 cycles at 1 A g −1 , and a high reversible capacity of 162.7 mAh g −1 is maintained after 250 cycles at 0.5 A g −1 under high temperature of 60°C. These outstanding performances can be attributed to the low zinc diffusion energy barriers, superior structural stability, and strong polyiodide adsorption capability, consequently guaranteeing uniform Zn deposition, ignorable iodine dissolution, and polyiodide shuttle‐free behavior. Furthermore, Zn//NH 4 V 4 O 10 cells also exhibit a high‐capacity retention ratio of 81% after 200 cycles at 0.5 A g −1 in DLM@SA@Zn electrolyte, highlighting its promising application potential in ZMBs, and providing new insights for the rational design of QSSEs.