Zn-ion ultrafluidity via bioinspired ion channel for ultralong lifespan Zn-ion battery

Abstract

Rechargeable aqueous Zn-ion batteries have been deemed a promising energy storage device. However, the dendrite growth and side reactions have hindered their practical application. Herein, inspired by the ultrafluidic and K⁺ ion-sieving flux through enzyme-gated potassium channels (KcsA) in biological plasma membranes, a metal-organic-framework (MOF-5) grafted with -ClO₄ groups (MOF-ClO₄) as functional enzymes is fabricated to mimic the ultrafluidic lipid-bilayer structure for gating Zn²⁺ 'on' and anions 'off' states. The MOF-ClO₄ achieved perfect Zn²⁺/SO₄ ^2- selectivity (∼10), enhanced Zn²⁺ transfer number ([Formula: see text]) and the ultrafluidic Zn²⁺ flux (1.9 × 10^-3 vs. 1.67 mmol m^-2 s^-1 for KcsA). The symmetric cells based on MOF-ClO₄ achieve a lifespan of over 5400 h at 10 mA cm^-2/20 mAh cm^-2. Specifically, the performance of the PMCl-Zn//V₂O₅ pouch cell keeps 81% capacity after 2000 cycles at 1 A g^-1. The regulated ion transport, by learning from a biological plasma membrane, opens a new avenue towards ultralong lifespan aqueous batteries.