MOF-based ionic sieve interphase for regulated Zn2+ flux toward dendrite-free aqueous zinc-ion batteries

Abstract

Targeted at mitigating the inevitable dendrite growth and side reactions in zinc-ion batteries (ZIB), herein, a multifunctional protective strategy of Zn anode coating using zinc benzene tricarboxylate (Zn–BTC) is proposed in the Zn symmetric cell and MnO₂//Zn full cell. The rationally selected pores of Zn–BTC served as ionic sieves, accelerating the transport of Zn²⁺ while blocking the entrance of the electrolyte anions. The structural grids of Zn–BTC hindered the two-dimensional diffusion of Zn²⁺ and regulated the electric field at the anode, resulting in a uniform flux of Zn²⁺ and subsequently stable stripping/plating. The Zn–BTC layer also worked as an artificial solid/electrolyte interphase film, expelled the solvated water molecules and restricted the side reactions. As a result, ultra-long cycling stability was achieved, with a superior lifespan of 800 h in the Zn symmetric cell and outstanding capacity retention of 81.1% after 1000 cycles in the MnO₂//Zn battery at a high current density of 2 A g⁻¹.