Synthesis of large mesoporous carbon from cotton stalk for use as an anode for lithium-ion batteries

There has been increasing attention to the method of preparing anode materials for lithium-ion batteries from biomass resources which can more effectively use agricultural waste as resources. In this paper, cotton stalks are used as the precursor and ZnCl2 is used as the activator. A simple one-step carbonization technique is used to prepare porous carbon with high electrochemical performance. We found that the increase of ZnCl2 content is conducive to the development of large mesopore structure (>6 nm), and high content of ZnCl2 facilitates the retention of heteroatoms. The pore size distribution is the most important factor in all kinds of physical structures. Moreover, it can be concluded that physical structure is more important than chemical structure. Cotton stalk: ZnCl2 = 1:4 prepared porous carbon has the best electrochemical performance. After being cycled for 100 times at a current density of 0.1 Ag-1, it still maintains a specific capacity of 328.3 mAhg−1. In addition, compared with graphite, the above-mentioned carbon sample exhibits excellent high-power performance.