Lithium (Li) metal is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical specific capacity of 3860 mAh g −1 and the low potential of −3.04 V versus the standard hydrogen electrode (SHE). However, these anodes rely on repeated plating and stripping of Li, which leads to consumption of Li inventory and the growth of dendrites that can lead to self-discharge and safety issues. To address these issues, as well as problems related to the volume change of these anodes, a number of different porous conductive scaffolds have been reported to create high surface area electrode on which Li can be plated reliably. While impressive results have been reported in literature, current processes typically rely on either expensive or poorly scalable techniques. Herein, we report a scalable fabrication method to create robust 3D Cu anodes using a one-step electrodeposition process. The areal loading, pore structure, and electrode thickness can be tuned by changing the electrodeposition parameters, and we show how standard mechanical calendering provides a way to further optimize electrode volume, capacity, and cycling stability. Optimized electrodes achieve high Coulombic efficiencies (CEs) of 99% during 800 cycles in half cells at a current density of 0.5 mA cm −2 with a total capacity of 0.5 mAh cm −2 . To the best of our knowledge, this is the highest value ever reported for a host for Li-metal anodes using lithium bis(trifluoromethanesulfonyl)imide LITFSI based electrolyte.

Abstract

Lithium‐metal anodes (LMAs) are desirable for next‐generation rechargeable batteries because of their high energy density. However, in practical applications they are hindered by inhomogeneous and uncontrolled lithium‐dendrite deposition during cycling. Herein, we propose a dual charge storage mechanism, using freestanding carbon‐fiber paper (CFP) with carbon fillers electrode. These CFP electrodes are manufactured at an industrial scale and act both as a host for lithium (Li) intercalation and as a conductive and porous 3D scaffold for Li plating/stripping. The CFP electrode exhibits excellent long‐term cycling stability, as evidenced by Coulombic efficiencies of over 99.5 % on the 250th cycle in CFP|Li half‐cells with a lithiation capacity of 1.5 mA h cm−2 and current density of 0.5 mA cm−2. We also demonstrate that the CFPs are sufficiently electrically conductive to operate in small pouch cells without metal foil current collectors, further improving the energy density of the proposed electrodes.