摘要：Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and *** electrode materials combing the features of high specific capacitance,excellent rate performance,and outstanding mechanical stability is still a ***,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 *** 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.