Nanoporous carbon microspheres as anode material for enhanced capacity of lithium ion batteries

Abstract

Nanoporous carbon microspheres (NCMs) are prepared by a one-step carbonizing and activating resorcinol−formaldehyde polymer spheres (RFs) in inert and CO2 atmosphere for anode materials of lithium-ion batteries (LIBs). Compared with RFs carbon microspheres (RF-C), after activating with hot CO2, the NCMs with porous structure and high BET surface area of 2798.8 m2 g−1, which provides abundant lithium-ion storage site as well as stable lithium-ion transport channel. When RF-C and NCM are used to anode material for LIBs, at the same current density of 210 mA g−1, the initial specific discharge capacity are 482.4 and 2575.992 mA h g−1, respectively; after 50 cycles, the maintain capacity are 429.379 and 926.654 mA h g−1, respectively. The porous spherical structure of NCM possesses noticeably lithium-ion storage capability, which exhibits high discharge capacity and excellent cycling stability at different current density. The CO2 activating carbonaceous materials used in anode materials can tremendously enhance the capacity storage, which provides a promising modification strategy to improve the storage capacity and cyclic stability of carbonaceous anode materials for LIBs.