Turning waste into treasure: biomass carbon derived from sunflower seed husks used as anode for lithium-ion batteries

In this paper, sunflower seed husks were used as raw materials to prepare porous biomass carbon through physical carbonization and chemical activation. Calcium chloride and pyromellitic acid were used as activators and processing assistant. The influences of activation temperature and processing additives on the activation mechanism of CaCl2 were analyzed. The results showed that activation temperature and processing aids act on the two competing mechanisms of micropore formation and pore expansion, respectively. The average pore diameter of the resulting sample was 9.75 nm, and the specific surface area was 404.215 m2 g−1. The sample was circulated 100 cycles at 0.2 C. The specific flow was 1100 mAh g−1 in the change rate test. The discharge specific capacity was 590 mAh g−1 after 450 cycles at 2 C rate. The structure of the sample collapsed after 250 cycles at 5 C, and the specific discharge capacity dropped to 390 mAh g−1 after 350 cycles.