Rational Design of a 3D Li-Metal Electrode for High-Energy Lithium Batteries

Abstract

Li metal is considered the ultimate electrode for lithium-ion batteries due to its high specific capacity (3860 mAh g–1) and density (0.534 g cm–3). Despite these advantages, the practical use of Li-metal electrodes is currently limited by uncontrollable Li-plating and stripping, which causes undesirable dendritic growth and severe volume changes during cycles. As a practical solution for the successful implementation of Li-metal electrodes, we propose herein a three-dimensional (3D) Li-metal electrode by integrating 3D Ni foam as a current collector via a molten Li impregnation process. Using both theoretical simulations and experiments, we demonstrate that our 3D Li-metal electrode creates a large contact area between active Li metal and the current collector, which is beneficial for improving the reversibility by reducing the overpotential for Li-plating and stripping and suppressing the dendritic growth of Li during cycles. Furthermore, dimensional changes of the Li-metal electrode are effectively minimized by the 3D Ni foam framework. For practical use, the feasibility of the 3D Li-metal electrode is examined in a full-cell compared to a conventional 2D Li-metal electrode. We believe that this work will provide insights into the design of advanced Li batteries configured with a Li-metal electrode.