All 3D printing lithium metal batteries with hierarchically and conductively porous skeleton for ultrahigh areal energy density

Abstract

The revival of Li metal batteries (LMBs) is revolutionizing current Li-ion battery technology. However, their practical applications are prevented by the bottlenecks like Li dendrite growth, low Coulombic efficiency, and mismatched cathodes with limited mass loading and sluggish kinetics, resulting in poor cyclability and low energy density. Here, 3D printed conductive Ti3C2Tx MXene scaffolds and porous LiFePO4 lattices are proposed to construct high-mass-loading LMBs with prolonged lifespan and high energy density. The exceptional lithiophilic feature of Ti3C2Tx regulates the uniform deposition of metallic Li, allowing the stable MXene scaffold to achieve an outstanding areal capacity of 30 mAh/cm2 at 30 mA/cm2 and ultralong cycle lifespan of 4800 h. The full battery is assembled by rationally matching this dendrite-free MXene based Li anode with a hierarchically conductive LiFePO4 framework at an ultrahigh mass loading of 171 mg/cm2. The as-assembled LMBs deliver unprecedented areal capacity of 25.3 mAh/cm2, record-high areal energy density of 81.6 mWh/cm2 and improved cycling stability of 500 cycles, breaking through the limitation of thick-film cathodes. Thereby, this work offers a viable strategy for the reasonable fabrication of advanced LMBs.