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

Lithium metal is considered to be an ideal anode material due to its ultra-high theoretical capacity and extremely low electric potential. Unfortunately, the infinite volume expansion and unregulated formation of lithium dendrites in the plating/stripping process restrict its practical utilization. Herein, we designed a hollow Co3[Co(CN)6]2 (CoCoPBA) embedded high-conductivity carbon film as a three-dimensional (3D) lithiophilic current collector (h-CoCoPBAs@SWCNT). The interwoven carbon nanotubes with hollow nanoparticles can effectively promote electron transfer and reduce local current density, adapting to the huge volume expansion in long-term electrochemical cycling. At the same time, lithiophilic hollow CoCoPBA nanoparticles provide abundant active sites due to their large surface area, efficiently reducing nucleation overpotential and making lithium deposition easier and more uniform, both confirmed by theoretical calculation and experiment. Accordingly, compared with bare Cu electrodes, h-CoCoPBAs@SWCNT electrodes have a flat and uniform Li deposition morphology, which is beneficial to enhance the cycle life of lithium metal anodes. And the symmetrical cell assembled by h-CoCoPBAs@SWCNT shows stable cycling performance of more than 500 h 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.