Cu3Pt alloy-functionalized Cu mesh as current collector for dendritic-free anodes of potassium metal batteries

Potassium metal batteries are considered a promising type of batteries for next generation of energy storage systems due to the natural abundance and relatively low redox potential of potassium. However, similar to lithium metal anode, the practical application of potassium metal anode also suffers from issues induced by uncontrollable dendrite growth. To overcome this challenge, using three-dimensional (3D) porous current collectors to construct potassium metal anodes is an effective way to inhibit dendrite growth during the repeated charge/discharge processes. In this paper, the 3D Cu meshes with a layer of Cu3Pt are successfully functionalized in through a fast Galvanic replacement reaction. Compared to the bare Cu mesh, the obtained Cu3Pt-funtionalized Cu mesh (Cu3Pt-Cu mesh) has ultra-rough surface and quite-large surface area, which can provide uniform electrical field and ion flux distributions and reduce the localized current density. Moreover, density function theory calculations and experimental results both show that Cu3Pt has high affinity for potassium, which lowers the nucleation overpotential and induces uniform potassium deposition. Therefore, this Cu3Pt-Cu mesh can achieve long cycle life and high Coulombic efficiency in both half-cells and symmetric cells. A full potassium battery is developed by using prussian blue (KPB) as the cathode material. The full battery can deliver an ultra-long cycle life more than 250 cycles, revealing the great potential of the Cu3Pt-Cu mesh in practical application for potassium metal batteries.