Abstract
? 2022 Elsevier B.V.The proper N doping engineering and microstructure design are of essential importance to develop advanced carbon anodes for Li-ion batteries. Herein, a facile strategy was developed to fabricate hierarchical porous carbon with controllable pore structures, N doping content and configurations, which was easily realized via introducing zinc salt as recyclable activator and regulator in the precursors. The zinc salt could not only function as pore-forming agent to facilitate the formation of hierarchical porous defect-rich structure, but also act as N-confined reactor to preserve the N-containing intermediates and promote N doping in the carbon matrix during thermal conversion. Specifically, 21.7% N content (increased by 115%) which was mainly composed of pyridinic/pyrrolic N (88.6%) was achieved with the addition of Zn5(OH)6(CO3)2. Meanwhile, desirable mesopore-dominant hierarchical porous carbon with appropriate specific surface area was obtained. Benefiting from the unique microstructure and N functionalities, the NC-Zn5(OH)6(CO3)2 anode delivered a high reversible capacity of 564 mAh g?1 at 200 mA g?1 over 100 cycles, which was almost two times higher than those for NC, and remarkable long-term cycling stability with high coulombic efficiency around 100% after 1300 cycles at 1000 mA g?1. This work provides an intriguing and feasible avenue for the reasonable structure design of carbon material with superior electrochemical performance for sustainable energy storage.
NSTL
Elsevier