摘要
Potassium-ion hybrid capacitors(PIHCs)have been considered as promising potentials in mid-to large-scale storage system applications owing to their high energy and power density.However,the process involving the intercalation of K+into the carbonaceous anode is a sluggish reaction,while the adsorption of anions onto the cathode surface is relatively faster,resulting in an inability to exploit the advantage of high energy.To achieve a high-performance PIHC,it is critical to promote the K^+insertion/desertion in anodic materials and design suitable cathodic materials matching the anodes.In this study,we propose a facile“homologous strategy”to construct suitable anode and cathode for high-performance PIHCs,that is,unique multichannel carbon fiber(MCCF)-based anode and cathode materials are firstly prepared by electrospinning,and then followed by sulfur doping and KOH activation treatment,respectively.Owing to a multichannel structure with a large interlayer spacing for introducing S in the sulfur-doped multichannel carbon fiber(S-MCCF)composite,it presents high capacity,super rate capability,and long cycle stability as an anode in potassium-ion cells.The cathode composite of activated multichannel carbon fiber(aMCCF)has a considerably high specific surface area of 1445 m^2 g^−1 and exhibits outstanding capacitive performance.In particular,benefiting from advantages of the fabricated S-MCCF anode and aMCCF cathode by homologous strategy,PIHCs assembled with the unique MCCF-based anode and cathode show outstanding electrochemical performance,which can deliver high energy and power densities(100 Wh kg^−1 at 200 W kg^−1,and 58.3 Wh kg^−1 at 10,000 W kg^−1)and simultaneously exhibit superior cycling stability(90%capacity retention over 7000 cycles at 1.0 A g^−1).The excellent electrochemical performance of the MCCF-based composites for PIHC electrodes combined with their simple construction renders such materials attractive for further in-depth investigations of alkali-ion battery and capacitor applications.
基金
the National Natural Science Foundation of China(51971147,51971146,51671135)
the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-07-E00015)
Shanghai Outstanding Academic Leaders Plan,and the Program of Shanghai Subject Chief Scientist(17XD1403000).
