MOF-Derived Hollow Dodecahedral Carbon Structures with Abundant N Sites and Co Nanoparticle-Modified Cu Foil for Dendrite-Free Lithium Metal Battery

In this work, hollow dodecahedral carbon structures with abundant N-doping sites and metal nanoparticles (NC-Co-CNTs) based on MOF-derivative materials were designed and prepared as host materials for lithium metal to ensure uniform lithium deposition on a Cu current collector. NC-Co-CNTs have good electrical conductivity, which ensures fast electron transport and Li+ transfer. The carbon nanotubes catalytically derived by Co can promote the uniform distribution of Li+ along the hollow dodecahedral carbon surface and deposition inside the cavity, and the larger electronegativity of N-doped sites and lithophilic sites such as Co nanoparticles can effectively adsorb lithium, inducing the Li+ to be deposited in the form of spherical lithium in a dendrite-free state, inhibiting the growth of dendritic lithium and improving the electrochemical performance of the lithium metal battery. Based on the above advantages, the electrodes of NC-Co-CNT-based symmetric cells present superior cycling performance for more than 1100 h with low overpotential at 1 mAh cm−2/1 mAh·cm−2. Even cycling at high current density of 5 mA cm−2 and high deposition parameters of 5 mAh cm−2, it still cycles for up to 800 h at a relatively low overpotential.