The development of transition metal oxidebased electrode materials with proper controlled structures is highly desirable for high-performance supercapacitors.However,it remains a major challenge.Here,we present the fi...The development of transition metal oxidebased electrode materials with proper controlled structures is highly desirable for high-performance supercapacitors.However,it remains a major challenge.Here,we present the first synthesis of bowl-like Ni Co2O4nanosheet clusters through a simple soft template guided hydrothermal strategy.The resulting bowl-like clusters consist of numerous Ni Co2O4nanosheets with an average thickness of 19 nm and possess a mean diameter of 1μm along with a specific surface area of40 m2g^-1.Remarkably,serving as an electrode material in a three-electrode system,the bowl-like Ni Co2O4nanosheet clusters exhibit a high specific capacity of 1068 F g^-1at a current density of 1 A g^-1and excellent cycling stability with90%capacitance retention after 5000 charge-discharge cycles.Meanwhile,an asymmetric supercapacitor(ASC)assembled with the Ni Co2O4clusters and activated carbon(AC)as the two electrodes exhibits a high specific capacitance of 129 F g^-1at 1 A g^-1,along with a high energy density of 33 W h kg^-1at a power density of 0.66 k W kg^-1.Such performance is superior to those of many commercial supercapacitors.This study opens a new avenue for the construction of ordered complex particles with controlled architectures for energy storage and conversion applications.展开更多
基金supported by the National Natural Science Foundation of China(21774076,61774102 and 51573091)the National Key Research and Development Program of China(2017YFE0195800)+2 种基金the Program of the Shanghai Committee of Science and Technology(17JC1403200)the Program of Shanghai Academic Research Leader(19XD1421700)the Program of Distinguished Professor of Special Appointment at Shanghai Institutions of Higher Learning。
文摘The development of transition metal oxidebased electrode materials with proper controlled structures is highly desirable for high-performance supercapacitors.However,it remains a major challenge.Here,we present the first synthesis of bowl-like Ni Co2O4nanosheet clusters through a simple soft template guided hydrothermal strategy.The resulting bowl-like clusters consist of numerous Ni Co2O4nanosheets with an average thickness of 19 nm and possess a mean diameter of 1μm along with a specific surface area of40 m2g^-1.Remarkably,serving as an electrode material in a three-electrode system,the bowl-like Ni Co2O4nanosheet clusters exhibit a high specific capacity of 1068 F g^-1at a current density of 1 A g^-1and excellent cycling stability with90%capacitance retention after 5000 charge-discharge cycles.Meanwhile,an asymmetric supercapacitor(ASC)assembled with the Ni Co2O4clusters and activated carbon(AC)as the two electrodes exhibits a high specific capacitance of 129 F g^-1at 1 A g^-1,along with a high energy density of 33 W h kg^-1at a power density of 0.66 k W kg^-1.Such performance is superior to those of many commercial supercapacitors.This study opens a new avenue for the construction of ordered complex particles with controlled architectures for energy storage and conversion applications.
