A Heterogeneous Host Intercalation-Customized Efficient Dual Electrode–Electrolyte Interphase for Self-Enhanced Aqueous Zinc Metal Batteries

The practical operation of aqueous zinc-ion batteries is greatly influenced by the microenvironment of the electrode–electrolyte interface, while the structural instability and sluggish interfacial reaction kinetics at both cathode and anode sides are still critical challenges. This work develops a heterocation intercalation approach to unlock a robust La3+/Ca2+–Na0.7MnO2.05 (LCNMO) cathode material, which enables simultaneously constructing an efficient cathode–electrolyte interphase (CEI) and a compressed double electric layer (EDL) interphase during the first few charging cycles. These in situ-formed interphases can simultaneously alleviate the interrelated adverse issues including cathode dissolution, uneven deposition, severe side reactions, and sluggish reaction kinetics. Benefiting from that, the constructed aqueous Zn||LCNMO system was demonstrated to exhibit self-enhanced electrochemical performance. Impressively, it can display a 6000-cycle lifespan with a 73.7% capacity retention even at a high current density of 10 A g–1. Besides, the corresponding pouch cell with a 10 mg cm–2 loading enables providing a high reversible capacity of 14.8 mAh at 1 A g–1 after 100 cycles. Such a heterogeneous intercalation paradigm creates a tandem effect to expand the regulatory area of guest cations, deepen the understanding of host intercalation chemistry, and boost the development of high-performance aqueous zinc-ion batteries.