Vertically aligned carbon nanotubular structure for guiding uniform lithium deposition via capillary pressure as stable metallic lithium anodes

Abstract

Metallic lithium anodes hold the key for next-generation high-energy batteries. However, the safety issues and poor Coulombic efficiency induced by dendritic growth of lithium hinder their commercialization. We address these limitations with vertically aligned nanoporous carbon tubes (VNPCT) as a high performing, stable host for lithium. The designed carbon structure can efficiently direct Li deposition inside the tubular structure through uniform lithium flux and capillary force. Furthermore, the tubular host can greatly reduce the effective current density to eliminate the dendrite formation even at 5 mA cm−2. A high areal lithium deposition of 2 mAh cm−2 can be plated efficiently on the designed structure without any dendritic morphology. Additionally, the engineered lithium metal host exhibited a stable cycle life and higher Coulombic efficiency of 96% over 200 cycles at a current density of 0.5 mA cm−2, which is superior to conventional 2D planar hosts. A full cell performance of lithiated VNPCT (VNPCT@Li) and LiFePO4 cathode was demonstrated.