Regulating Li-ion flux via engineering oxidized ZIF-8/polyacrylonitrile fiber interlayer for Li metal batteries with high performance

Abstract

It is a huge challenge to develop safe and stable lithium metal batteries with high energy density owing to the growth of Li dendrites. Herein, for the first time, an oxidized ZIF-8/polyacrylonitrile (OZPAN) fiber film is designed as a multifunctional interlayer for constructing a novel Li metal battery with superior performance. The excellent lithophilicity and uniform porous structure of the OZPAN interlayer could anchor and regulate Li-ion flux with high ionic conductivity (2.22 mS cm⁻¹), high Li⁺ transference number (0.78) and homogeneous Li deposition. Therefore, the Li//Li symmetric cell exhibits ultralow overpotential (11 mV) with long-term cycling stability and dendrite-free Li deposition. Moreover, Li//LiFePO₄ (LFP) full cell has an extremely high capacity (162 mA h g⁻¹ at 1C, close to the theoretical specific capacity of LFP), outstanding rate performance and high coulombic efficiency (more than 94%) during 500 cycles. This study demonstrates a promising interlayer strategy for developing high-performance Li metal batteries.