B-incorporated, N-doped hierarchically porous carbon nanosheets as anodes for boosted potassium storage capability

Carbonaceous nanomaterials with porous structure have become the highly promising anode materials for potassium-ion batteries (PIBs) due to their abundant resources, low-cost, and excellent conductivity. Nevertheless, the sluggish reaction kinetics and inferior cycling life caused by the large radius of K ions severely restrict their commercial development. Herein, B,N co-doped hierarchically porous carbon nanosheets (BNPC) are achieved via a facile template-assisted route, followed by a simple one-step carbonization process. The resultant BNPC possesses a unique porous structure, large surface area, and high-level B,N co-doping. The structural features endows it with remarkable potassium storage performances, which delivers a high reversible capacity (242.2 mAh/g at 100 mA/g after 100 cycles), and long cycling stability (123.1 mAh/g at 2000 mA/g and 62.9 mAh/g at 5000 mA/g after 2000 cycles, respectively). Theoretical simulations further validate that the rich B doping into N-modified carbon configuration can greatly boost the potassium storage capability of the BNPC anode.