Effect of Deep Cryogenic Activated Treatment on Hemp Stem-Derived Carbon Used as Anode for Lithium-Ion Batteries

The cryogenic process has been widely applied in various fields, but it has rarely been reported in the preparation of anode materials for lithium-ion battery. In this paper, activated carbon derived from hemp stems was prepared by carbonization and activation; then, it was subjected to cryogenic treatment to obtain cryogenic activated carbon. The characterization results show that the cryogenic activated carbon (CAC) has a richer pore structure than the activated carbon (AC) without cryogenic treatment, and its specific surface area is 1727.96 m²/g. The porous carbon had an excellent reversible capacity of 756.8 mAh/g after 100 cycles at 0.2 C as anode of lithium-ion battery, in which the electrochemical performance of CAC was remarkably improved due to its good pore structure. This provides a new idea for the preparation of anode materials for high-capacity lithium-ion batteries.