Lithiophilic Cu-CuO-Ni Hybrid Structure: Advanced Current Collectors Toward Stable Lithium Metal Anodes

Abstract

Metallic lithium (Li) is a promising anode material for next-generation rechargeable batteries. However, the dendrite growth of Li and repeated formation of solid electrolyte interface during Li plating and stripping result in low Coulombic efficiency, internal short circuits, and capacity decay, hampering its practical application. In the development of stable Li metal anode, the current collector is recognized as a critical component to regulate Li plating. In this work, a lithiophilic Cu-CuO-Ni hybrid structure is synthesized as a current collector for Li metal anodes. The low overpotential of CuO for Li nucleation and the uniform Li⁺ ion flux induced by the formation of Cu nanowire arrays enable effective suppression of the growth of Li dendrites. Moreover, the surface Cu layer can act as a protective layer to enhance structural durability of the hybrid structure in long-term running. As a result, the Cu-CuO-Ni hybrid structure achieves a Coulombic efficiency above 95% for more than 250 cycles at a current density of 1 mA cm⁻² and 580 h (290 cycles) stable repeated Li plating and stripping in a symmetric cell.

A lithiophilic Cu-CuO-Ni hybrid structure is synthesized on Ni foam substrate as a current collector for lithium (Li) metal anodes. The collective effects of low overpotential of Cu-CuO-Ni hybrid structure for Li nucleation, nanowire array configuration, and the Cu buffer layer are demonstrated to be keys for achieving an outstanding overall performance of the current collector.

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