High energy density lithium-ion capacitor enabled by nitrogen-doped amorphous carbon linked hierarchically porous Co3O4 nanofibers anode and porous carbon polyhedron cathode
Journal of Alloys and Compounds
School of Engineering
National Natural Science Foundation of China (No. 2213000238) YanKuang Group Co., Ltd. Technology Project (YKKJ2019AJ08JG-R63) Taishan Scholar Project (No. ts201712020)
Lithium-ion capacitors (LICs) are emerging as progressive energy storage systems with high energy density, high power output, and a long cycle life span. The key to constructing LICs with high performances is alleviating the dynamics mismatch between the faradic anode and capacitor-type cathode. Herein, nitrogen-doped amorphous carbon linked hierarchically porous Co3O4 nanofibers (NAC-L-Co3O4 NFs) were prepared by electrospinning strategy, where the amorphous carbon can mitigation the volume variation of Co3O4 during the lithiation/delithiation process, while the hierarchically porous structure provides effective channels and exposes more active sites for fast electron transfer and Li+ storage. The delicate structure endows NAC-L-Co3O4 NFs with remarkable rate capacity and robust cycling durability. Furthermore, nitrogen-doped carbon polyhedron (NPCP) is prepared for the cathode, displaying superior rate performances and cycling stability. As a result, by assembling the NAC-L-Co3O4//NPCP LICs, a high energy density of 296 Wh kg−1 and a high output of 11750 W kg−1 is delivered. Additionally, the LIC devices display excellent cycle lifespan (80% capacity retention after 10000 cycles at 1 A g−1).