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Enhancing Capacitance of Nickel Cobalt Chalcogenide via Interface Structural Design

Journal Article


Abstract


  • Spinel NiCo 2 X 4 (X = O or S), comprising two geometrical cobalt ions, Co 2+ in the tetrahedral site (Co 2+Td ) and Co 3+ in the octahedral site (Co 3+Oh ), has been widely evaluated as a promising pseudocapacitor electrode material. Previous literature mainly demonstrated that much higher specific capacitance of NiCo 2 S 4 than that of NiCo 2 O 4 was ascribed to the higher electronic conductivity. However, we argue that only a small amount of capacitance can be induced by the electronic conductivity, while the significance of electrochemical active species in these system has long been ignored. Here, we propose that geometrical-site-dependent pseudocapacitive activity will generate enhanced specific capacitance through the interface structural design. It reveals that specific capacitance of NiCo 2 S 4 (1862 F g -1 at 4 A g -1 ) is 50% higher than that of NiCo 2 O 4 (1230 F g -1 at 4 A g -1 ), which is derived from the designed increase of Co 2+Td ions (cobalt ions in the tetrahedral site) in NiCo 2 S 4 . These results have significant implications for the design and optimization of the electrochemical properties of transition-metal-based pseudocapacitors.

Publication Date


  • 2019

Citation


  • Lu, F., Zhou, M., Su, K., Ye, T., Yang, Y., Lam, T. D., . . . Wang, X. (2019). Enhancing Capacitance of Nickel Cobalt Chalcogenide via Interface Structural Design. ACS Applied Materials and Interfaces, 11(2), 2082-2092. doi:10.1021/acsami.8b19035

Scopus Eid


  • 2-s2.0-85059821478

Start Page


  • 2082

End Page


  • 2092

Volume


  • 11

Issue


  • 2

Place Of Publication


Abstract


  • Spinel NiCo 2 X 4 (X = O or S), comprising two geometrical cobalt ions, Co 2+ in the tetrahedral site (Co 2+Td ) and Co 3+ in the octahedral site (Co 3+Oh ), has been widely evaluated as a promising pseudocapacitor electrode material. Previous literature mainly demonstrated that much higher specific capacitance of NiCo 2 S 4 than that of NiCo 2 O 4 was ascribed to the higher electronic conductivity. However, we argue that only a small amount of capacitance can be induced by the electronic conductivity, while the significance of electrochemical active species in these system has long been ignored. Here, we propose that geometrical-site-dependent pseudocapacitive activity will generate enhanced specific capacitance through the interface structural design. It reveals that specific capacitance of NiCo 2 S 4 (1862 F g -1 at 4 A g -1 ) is 50% higher than that of NiCo 2 O 4 (1230 F g -1 at 4 A g -1 ), which is derived from the designed increase of Co 2+Td ions (cobalt ions in the tetrahedral site) in NiCo 2 S 4 . These results have significant implications for the design and optimization of the electrochemical properties of transition-metal-based pseudocapacitors.

Publication Date


  • 2019

Citation


  • Lu, F., Zhou, M., Su, K., Ye, T., Yang, Y., Lam, T. D., . . . Wang, X. (2019). Enhancing Capacitance of Nickel Cobalt Chalcogenide via Interface Structural Design. ACS Applied Materials and Interfaces, 11(2), 2082-2092. doi:10.1021/acsami.8b19035

Scopus Eid


  • 2-s2.0-85059821478

Start Page


  • 2082

End Page


  • 2092

Volume


  • 11

Issue


  • 2

Place Of Publication