Dendrite-free lithium metal anode enabled by ion/electron-conductive N-doped 3D carbon fiber interlayer

Lithium metal is considered as the ultimate anode candidate for next-generation high-energy storage systems due to its ultrahigh specific capacity and low reduction potential. However, the practical application of lithium metal anode is severely impeded by uncontrollable lithium dendrite growth. In this work, a three-dimensional (3D) N-doped carbon fiber (NCF) network with ion/electron-conductivity has been fabricated by electrospinning the polyacrylonitrile solution and subsequent thermal treatment. The 3D NCF as an interlayer covering on the lithium anode is used to regulate the lithium plating/stripping behavior, accommodating partially deposited Li to realize lithium dendrite-free deposition on the lithium anode. Benefiting from these, the symmetrical cell of Li anode protected by NCF (Li@NCF) delivers long duration time (>1200 h) with a low initial nucleation overpotential (30 mV) at the current density of 1 mA cm(-2) . In addition, the full cell of Li@NCF parallel to LiFePO4 exhibits excellent capacity retention of 114.6 mAh cm(-2) over 360 cycles at the current density of 1 C. This strategy contributes a step forward for dendrite-free lithium metal batteries.