Bottom-Up Lithium Growth Triggered by Interfacial Activity Gradient on Porous Framework for Lithium-Metal Anode

Three-dimensional (3D) porous frameworks have attracted considerable interest as lithium-metal electrodes for next-generation rechargeable batteries. The high surface areas and large pore volumes of 3D frameworks are beneficial for reducing local current densities and suppressing volume changes. However, uneven Li plating on top of the framework electrode (top growth) has yet to be resolved. To enable the bottom-up Li growth while suppressing the top growth, herein, we propose a rational design of 3D framework electrodes with an interfacial activity gradient (IAG) based on a kinetics-based mechanistic analysis. A simulation demonstrates that an IAG design promotes the bottom-up Li growth, which is experimentally proven using model architectures. The IAG-Cu framework shows considerable improvements in morphological stability and reversibility during high-capacity Li storage, compared to the Cu framework with a uniform interfacial activity. This work provides fundamental insight into the design of 3D frameworks to boost the cycling stability of Li-metal batteries.