Low-tortuosity, high-loading electrodes for fast-charging quasi-solid-state lithium metal batteries

Abstract

Structural design of electrodes is a widely adopted approach towards enhanced electrochemical performance in various battery systems. However, in quasi-solid-state lithium metal batteries, research has predominantly focused on developing gel polymer electrolytes (GPEs), with limited attention given to utilizing electrodes with specialized structural design. Herein, by exploiting the excellent wettability and permeability of the GPE, high-loading NMC-811 cathodes featuring aligned channels achieved through freeze-casting are integrated with in-situ UV-polymerized poly (butyl acrylate) (PBA). The aligned channels in the freeze-cast electrodes provide low-tortuosity pathways for smooth Li+ transport, facilitating rapid kinetics. Consequently, superior areal capacity can be delivered under high areal current density (e.g. 1 mAh cm−2 at 2 mA cm−2 and 0.7 mAh cm−2 at 3.8 mA cm−2), demonstrating the fast-charging capability of quasi-solid-state lithium metal batteries.