3D Cu Pyramid Array Grown on Planar Cu Foil for Stable and Dendrite-free Lithium Deposition

Abstract

Lithium metal is recognized as the anticipated anode for rechargeable batteries because of its inherent physicochemical properties. Unfortunately, the industrialization of Li metal anodes (LMAs) has been entangled in some intractable problems stemming from the uncontrollable growth of Li dendrites, which could result in the issue of short-circuit, thereby leading to cell failure. Here, a three-dimensional structured Cu pyramid array (CPA@CF) is constructed on planar Cu foil (CF) by the simple electrodeposition method. Owing to the features of large surface area and 3D porous structure, the proposed CPA@CF not only can promote Li-ion diffusion and charge transfer, but also effectively slow down the volume change of Li. Consequently, an even and steady Li plating/stripping process up to 360 h is realized using such a CPA@CF current collector. The Li@CPA@CF|LiFePO4 full cell achieves an excellent Coulombic efficiency (CE) of 99.3 % for 160 cycles at 0.3 C with a superior capacity retention of 84.2 %.