Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and storage.Designing electrode materials combing the features of high specific capacitance,...Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and storage.Designing electrode materials combing the features of high specific capacitance,excellent rate performance,and outstanding mechanical stability is still a challenge.Herein,a facile partial sulfurization strategy has been developed to modulate the electronic structure and crystalline texture of cobalt hydroxide nanosheets(denoted as Co(OH)2)at room temperature.The resultant cobalt hydroxysulfide nanosheet(denoted as Co SOH)electrode with abundant low-valence cobalt species and amorphous structure,exhibits a high specific capacitance of 2110 F g^-1at1 A g^-1with an excellent capability retention rate of 92.1%at10 A g^-1,which is much larger than that of Co(OH)2 precursor(916 F g^-1at 1 A g^-1 and 80%retention at 10 A g^-1).Furthermore,the fabricated asymmetric supercapacitor device constructed with Co SOH and active carbon displays a considerable high energy density of 44.9 W h kg^-1at a power density of 400 W kg^-1,and exceptional stability after 8000cycles.展开更多
基金surpported by the National Natural Science Foundation of China(21902108,21975163 and 51902204)China Postdoctoral Science Foundation(2019M663035)。
文摘Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and storage.Designing electrode materials combing the features of high specific capacitance,excellent rate performance,and outstanding mechanical stability is still a challenge.Herein,a facile partial sulfurization strategy has been developed to modulate the electronic structure and crystalline texture of cobalt hydroxide nanosheets(denoted as Co(OH)2)at room temperature.The resultant cobalt hydroxysulfide nanosheet(denoted as Co SOH)electrode with abundant low-valence cobalt species and amorphous structure,exhibits a high specific capacitance of 2110 F g^-1at1 A g^-1with an excellent capability retention rate of 92.1%at10 A g^-1,which is much larger than that of Co(OH)2 precursor(916 F g^-1at 1 A g^-1 and 80%retention at 10 A g^-1).Furthermore,the fabricated asymmetric supercapacitor device constructed with Co SOH and active carbon displays a considerable high energy density of 44.9 W h kg^-1at a power density of 400 W kg^-1,and exceptional stability after 8000cycles.
