Article Title
Graphene-nickel cobaltite nanocomposite asymmetrical supercapacitor with commercial level mass loading
Authors
Huanlei Wang, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Chris M. B. Holt, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Zhi Li, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Xuehai Tan, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Babak Shalchi Amirkhiz, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Zhanwei Xu, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Brian C. Olsen, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Tyler Stephenson, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
David Mitlin, Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
National Institute for Nanotechnology (NINT), National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
Keywords
Graphene, nickel cobaltite (NiCo2O4), supercapacitor, energy density, power density
Abstract
A high performance asymmetric electrochemical supercapacitor with a mass loading of 10 mg·cm–2 on each planar electrode has been fabricated by using a graphene–nickel cobaltite nanocomposite (GNCC) as a positive electrode and commercial activated carbon (AC) as a negative electrode. Due to the rich number of faradaic reactions on the nickel cobaltite, the GNCC positive electrode shows significantly higher capacitance (618 F·g–1) than graphene–Co3O4 (340 F∙g–1) and graphene–NiO (375 F∙g–1) nanocomposites synthesized under identical conditions. More importantly, graphene greatly enhances the conductivity of nickel cobaltite and allows the positive electrode to charge/discharge at scan rates similar to commercial AC negative electrodes. This improves both the energy density and power density of the asymmetric cell. The asymmetric cell composed of 10 mg GNCC and 30 mg AC displayed an energy density in the range of 19.5 Wh∙kg–1 with an operational voltage of 1.4 V. At high sweep rate, the system is capable of delivering an energy density of 7.6 Wh∙kg–1 at a power density of about 5600 W∙kg–1. Cycling results demonstrate that the capacitance of the cell increases to 116% of the original value after the first 1600 cycles due to a progressive activation of the electrode, and maintains 102% of the initial value after 10000 cycles.
Graphical Abstract
Publisher
Tsinghua University Press
Recommended Citation
Huanlei Wang,Chris M. B. Holt,Zhi Li,Xuehai Tan,Babak Shalchi Amirkhiz,Zhanwei Xu,Brian C. Olsen,Tyler Stephenson,David Mitlin, Graphene-nickel cobaltite nanocomposite asymmetrical supercapacitor with commercial level mass loading. NanoRes.2012, 5(9): 605–617
