Preinserted Li metal porous carbon nanotubes with high Coulombic efficiency for lithium-ion battery anodes

Recently, many efforts have been devoted to enhance the capacity performance of porous carbon materials for lithium-ion battery (LIB)anodes. However, the low initial Coulombic efficiency (ICE)caused by the formation of solid electrolyte interphase (SEI)still remains unresolved. Here, we develop a facile and effective prelithiation strategy to compensate for the large irreversible capacity loss due to the formation of SEI. By this strategy, we not only obtain the high surface area and high active-porous carbon nanotubes (PCNTs)from polypyrrole nanotube (PPyNT)precusors, but also simultaneously achieve the satisfactory prelithiation for the PCNTs in which Li metal particles are well preinserted on its surface. This preinserted Li metal porous carbon nanotube (PCNTs@Li), as an anode material, shows a remarkably high ICE of 96% which is much larger than of the pure PCNTs (53%), and meanwhile delivers a high reversible capacity of 932 mAh g⁻¹ at a current density of 20 mA g⁻¹. Furthermore, it also possesses a desirable rate capability and cycling performance. That is, even at a large current density of 200 mA g⁻¹ (namely 1 mA cm⁻²), the reversible capacity is still as high as 530 mAh g⁻¹ after 230 cycles. With these distinguishing performance, the prepared PCNTs@Li is a promising anode material for LIBs.