Abstract
Potassium-ion hybrid capacitors(PIHCs)are widely regarded as highly promising energy storage devi-ces,due to their exceptional energy density,impressive power density,and abundant potassium resources.Unfor-tunately,restricted by the inherent capacitive storage mechanism,the carbon cathodes possess a much lower specific capacity than battery-type anodes.Therefore,designing high-performance carbon cathodes is extremely urgent for the development of PIHCs.Herein,N,O co-doped porous carbon(NOPC)was fabricated through the NaCl hard template method and combined KOH/melamine chemical activation technique,displaying the characteris-tics of abundant N/O content(4.7 at％/16.9 at％),ultrahigh specific surface area(3092 m2·g-1)and hierarchical pore network.The designed NOPC cathode delivers a high specific capacity(164.4 mAh·g-1 at 0.05 A·g-1)and superior cyclability(95.1％retention ratio at 2 A·g-1 over 2500 cycles).Notably,the adjustable ratio of micropores to mesopores facilitates the achievement of the optimal bal-ance between capacity and rate capability.Moreover,the pseudocapacitance can be further augmented through the incorporation of N/O functional groups.As expected,the graphite//NOPC based PIHC possesses a high energy density of 113Wh·kg-1 at 747 W·kg-1 and excellent capacity retention of 84.4％after 4000 cycles at 1.0 A·g-1.This work introduces a novel strategy for designing carbon cathodes that enhances the electrochemical performance of PIHCs.
基金项目
National Natural Science Foundation of China(22179123)
National Natural Science Foundation of China(52002138)
Taishan Scholar Program of Shandong Province,China(tsqn202211048)
Fundamental Research Funds for the Central Universities(202262010)
Fundamental Research Funds for the Central Universities(862201013190)
NETL
NSTL
万方数据