A Janus-Type Quasi-Solid-State Electrolyte Enabling Dual-Ion Relay for Long Lifespan of Nonaqueous Zinc Batteries†

Abstract

Quasi-solid-state or solid-state electrolytes are promising to address the long-standing challenges in zinc batteries, such as Zn dendrite formation and inevitable side reactions. Herein, we report an anhydrous Janus quasi-solid-state electrolyte that enables superior long-cycle performance of zinc batteries via a dual-ion relay mechanism. The spontaneously formed built-in electric field between PVDF-HFP and PMMA polymer layers induces an ionic double layer (IDL), which effectively addresses the inherent limitations in ionic transport kinetics within solid-state anhydrous systems operating under low-salt-concentration conditions. Benefiting from the electrolyte-constructed IDL and the derived organic outer-inorganic inner gradient SEI, effective ion rectification and transport have been achieved. Thus, Zn||Zn symmetric cells exhibited highly reversible Zn2+ plating/stripping without dendrite growth, achieving cycle lifetimes exceeding 13,300 h at 25 °C and 3,000 h at 60 °C. A full battery with a polyaniline cathode demonstrated exceptional stability (>10,000 cycles) and reliable operation from 25 °C to 80 °C. This innovative strategy significantly advances solid-state electrolyte design for zinc batteries and establishes a new paradigm for high-performance, safe, and durable energy storage systems.