Free-standing hollow carbon nanofibers scaffold with spherical nanocavities and lithiophilic N/ZnO heteroatoms as stable dendrite-free lithium metal anode

Abstract

Metallic Li as substitutional anode materials for high specific capacity lithium-ion batteries (LIBs) has been attached great importance. However, two major problems including serve Li dendrites growth and large volume change need to be settled before it can be commercialized. Herein, a 3D porous hollow carbon nanofibers (MC@HCNFs) with high electron transport rate and low regional current density polarization are designed, which are comprised of MOF-derived N/ZnO co-doped carbon frameworks and embedded carbon nanotubes. The spherical cavities within MC@HCNFs formed by the high-temperature decomposition of MOFs nanoparticles can provide abundant active space for Li metal nucleation and deposition to alleviate the infinite volume expansion, and more importantly regulate homogenous Li ions flow and preferential Li metal deposition to suppress the Li dendrites growth due to the presence of lithiophilic N/ZnO heteroatoms on the surface. As a Li metal carrier, MC@HCNFs displays stable Li platting/stripping for ultralong life spans of 2000 h with lower overpotentials at 1.0 mA cm−2 respectively, which also demonstrate excellent cycle and rate performances when used in LiFePO4-based full cells.