Lithiophilic Hollow Co3[Co(Cn)6]2 Embedded Carbon Nanotube Film for Dendrite-Free Lithium Metal Anodes

Abstract

Lithium metal is considered to be an ideal anode material due to its ultra-high theoretical capacity and extremely low electric potential. However, the unlimited volume expansion and uncontrollable growth of lithium dendrites during the plating/stripping process hinder its practical application. Here, we designed a hollow CoCoPBA penetrated self-supporting carbon film as a three-dimensional (3D) lithiophilic current collector (h-CoCoPABs@SWCNT). The interwoven carbon nanotubes with hollow nanoparticles can effectively promote electron transfer and reduce local current density, adapting to the huge volume changes during long-term electrochemical cycling. At the same time, lithiophilic hollow CoCoPBA nanoparticles provide abundant active sites due to their large surface area, which can effectively reduce nucleation overpotential to make lithium deposition easier and more uniform, both confirmed by theoretical calculation and experiment. Compared with bare copper electrodes, h-CoCoPABs@SWCNT electrodes have a flat and uniform Li deposition morphology, which is beneficial to improve the cycle life of lithium metal anodes. And the symmetrical cell assembled by h-CoCoPBAs@SWCNT exhibits stable cycling performance over 500 hours at 2 mA cm -2 with 1 mAh cm -2 . Besides, the assembled lithium-sulfur full cell also has higher cycle stability and rate performance.

Keywords: Hollow Co3[Co(CN)6]2, Film, Dendrite-Free, Lithium metal anode