Dendrite-Free Lithium Deposition via Flexible-Rigid Coupling Composite Network for LiNi_0.5Mn_1.5O₄/Li Metal Batteries

Notorious lithium dendrite causes severe capacity fade and harsh safety issues of lithium metal batteries, which hinder the practical applications of lithium metal electrodes in higher energy rechargeable batteries. Here, a kind of 3D-cross-linked composite network is successfully employed as a flexible-rigid coupling protective layer on a lithium metal electrode. During the plating/stripping process, the composite protective layer would enable uniform distribution of lithium ions in the adjacent regions of the lithium electrode, resulting in a dendrite-free deposition at a current density of 2 mA cm⁻². The LiNi_0.5Mn_1.5O₄-based lithium metal battery presents an excellent cycling stability at a voltage range of 3.5–5.0 V with the induction of 3D-cross-linked composite protective layer. From an industrial field application of view, thin lithium metal electrodes (40 µm, with 4 times excess lithium) can be used in LiNi_0.5Mn_1.5O₄ (with industrially significant loading of 18 mg cm⁻² and 2.6 mAh cm⁻²)-based lithium metal batteries, which reveals a promising opportunity for practical applicability in high energy lithium metal batteries.