Stable Li/Cu2O composite anodes enabled by a 3D conductive skeleton with lithiophilic nanowire arrays

Abstract

Lithium (Li) metal is an attractive anode for next-generation high-energy-density rechargeable batteries due to its high theoretical capacity and low redox potential. However, the uncontrolled growth of Li dendrites and infinite volume change during Li stripping/plating process lead to low coulombic efficiency and safety concern. To solve these critical issues, copper foam with Cu2O nanowire arrays (COCF) is rationally designed and used as three-dimensional (3D) conductive skeleton for compositing Li. Cu2O nanowire arrays structure with strong capillary forces and lithiophilicity is beneficial for the wetting of molten Li on surface and Li + nucleation. In addition, the 3D robust Cu skeleton with porous structure can reduce the local current density and regulate the distribution of Li+ flux on the electrode surface, leading to homogeneous nucleation and deposition of lithium, as well as mitigating the volume expansion. As a result, the COCF–Li composite lithium anode exhibits a prolonged cycling stability over 1000 h with a low over-potential of ∼50 mV at a current density of 1 mA∙cm−2 in a symmetric cell. Even at a current density of 4 mA∙cm−2 and deposition capacity of 4 mAh∙cm−2, it still delivers a stable cycling performance for 600 h.