Copper Oxide Decorated Carbon Nanofiber Skeleton for Dendrite‐Free Lithium‐Metal Anodes

Copper on carbon: In this article, we prepared a 3D lithium metal composite anode (CuO-CNF−Li). The 3D structure based on carbon nanofibers provides sufficient space and a stable frame structure for lithium ion plating, The copper oxide nanoparticles loaded on the CNF can be used as the active sites for Li nucleation, which can guide the orderly and uniform plating/stripping of lithium to achieve dendrite-free.

Abstract

Lithium metal, possessing a high theoretical capacity, holds great promise as a desirable anode candidate for the next-generation high energy density lithium batteries. However, the practical implementation of lithium metal faces significant challenges, including dendrite growth and volume expansion. Herein, a carbon nanofiber (CNF) three-dimensional (3D) current collector was developed, complemented by the addition of copper oxide nanoparticles to the CNF framework, resulting in the creation of a lithiophilic 3D current collector known as CuO-CNF. Subsequently, a 3D lithium metal composite anode (CuO-CNF−Li) was fabricated through an electrochemical plating process. The utilization of a 3D structure based on carbon nanofibers provides sufficient space and a stable framework for lithium ion plating, effectively accommodating the substantial volume changes that occur during repetitive Li plating and stripping. The copper oxide nanoparticles loaded onto the CNF serve as active sites for lithium nucleation, facilitating an ordered and uniform plating/stripping process of lithium ions, thereby preventing dendrite formation. Consequently, the CuO-CNF current collector enables dendrite-free Li plating/stripping with an average Coulomb efficiency of up to 99 % and a low nucleation overpotential of only 15 mV. Moreover, symmetric cell tests demonstrated an extended lifespan of 2700 h at 2 mA cm⁻² for the CuO-CNF−Li composite anode.

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