Hybrid supercapacitors combine the advantages of lithium-ion batteries and electrochemical capacitors to achieve both high energy density and power density. However, the overall energy density is limited by the low capacity of the carbon-based positive electrodes. We have been trying to improve the energy density of the carbon-based positive electrodes by incorporating surface reactions into nanocarbon materials, including carbon nanotube and graphene. Recently, we have demonstrated the redox-active carbon positive electrodes by coating functional polymers on the surface of carbon nanotubes.^1,2 This presentation introduces shape-controlled carbon materials with significantly enhanced charge storage performance. We also demonstrate high-performance hybrid supercapacitors by combining the redox-active carbon positive electrode with the battery-type negative electrode.

References

1. J. C. Bachman, R. Kavian, D. J. Graham, D. Y. Kim, S. Noda, D. G. Nocera, Y. Shao-Horn and S. W. Lee, Nature Communications, 6:7040 (2015).
2. T. Liu, K. C. Kim, B. Lee, Z. Chen, S. Noda, S. S. Jang and S. W. Lee, Energy & Environmental Science, 10, 205 (2017).