Nitrogen-doped cotton stalk porous carbon composite as anode material for Lithium-ion battery

In this study, the raw material of cotton stalks, N source of urea, and activator of ZnCl2 were used to prepare high N-doped cotton stalk activated carbon (N-AC) and exploring the synergistic mechanism of activator and dopant on electrochemical performance improvement. Addition of ZnCl2 promoted the formation of mesopores, but urea inhibited the development of pore structures. In addition, the development of pore structure was the basis for excellent electrochemical performance. The co-modification promotes the retention of heteroatoms and the expansion of interlayer spacing on the basis of retaining the three-dimensional pore structure, which is also the main reason to obtain the higher electrochemical performance. N-AC, an LIB anode material, still maintained a specific capacity of 504.1 mAhg−1 after 100 cycles at current density of 0.1 Ag−1. Under the high current density of 2 Ag−1, N-AC showed a specific capacity of 250.32 mAhg−1, which had good cycle performance and rate performance. This study discussed the mechanism of two modification methods to improve electrochemical performance, which provided a theoretical basis for future research.