Enhanced and evenly-distributed Li+ transport in well-aligned nanochannels enables stable lithium metal anode

Abstract

The high theoretical capacity of lithium (Li) has sparkled its intensive research as the anode for Li batteries. However, the dendritic growth due to the uneven Li deposition causes premature cell failure and dramatically restricts the application of Li anode. Herein, inspired by the pore sizes effects of anodized aluminum oxide (AAO) membranes on Li+ transport performance, 20 nm aperture membrane (AAO-20) with enhanced Li+ transport can achieve higher Li+ concentration near the deposition substrate, possibly preventing rapid Li+ depletion compared to other aperture sizes. Subsequently, smaller Li nucleation overpotential and larger exchange current density in AAO-20 reveal the enhanced kinetics at deposition interface, which is derived from the enhanced Li+ transport in nanochannels, leading to a superior Li deposition. With AAO-20 which can stabilize Li anode, Li-Cu, Li-Li, and Li-LiFePO4 cells demonstrate high Coulombic efficiency, superior cycling stability, and excellent capacity retention, respectively. Such findings can be helpful for the development of high-energy Li metal batteries.