Super-Assembled Hierarchical and Stable N-Doped Carbon Nanotube Nanoarrays for Dendrite-Free Lithium Metal Batteries

Lithium (Li) has been widely studied as a promising anode material for secondary batteries because of its excellent performance. However, the severe issue of dendrites must be solved for manufacturing safe and sustainable batteries. The proper selection and design of three-dimensional (3D) current collectors are of great significance for regulating the formation of Li dendrites. Here, 3D stable lithium metal anodes were prepared by growing N-doped carbon nanotubes on the surface of carbon cloth (CC). Experimental results reveal that the presence of carbon nanotubes increases the specific surface area of carbon cloth, and the local current density is effectively reduced. Nitrogen doping significantly enhances the lithiophilicity of CC, which is conducive to reversible Li plating and stripping. The formation of dendrite can be greatly inhibited on the 3D Li composite electrodes, thus leading to steady voltage curves at current densities of 10 mA cm–2 and 3 mAh cm–2 for 300 h. Furthermore, a full cell assembled with this electrode and a commercial high-load (120 g m–2) LiFePO4 exhibits excellent cycle stability with a capacity retention rate of 83.4% after 650 cycles at 1 C and excellent rate performance. These results prove the potential for the commercialization of Li metal anodes.