Graphene-based hybrid electrodes for high performance supercapacitors

13^th International Conference on Electrochemistry

May 27-28, 2019 | Barcelona, Spain

Syeda Wishal Bokhari, Ahmad Hassan Siddique, Shenmin Zhu and Wei Gao

University of Auckland, New Zealand
School of Materials Science and Engineering, Shanghai Jiao tong University, P. R. China
Chinese Academy of Sciences, Ningbo Institute of Materials Technology and Engineering, P. R. China

Scientific Tracks Abstracts: J Biosens Bioelectron

Abstract :

The high power density, long life cycle and very short charging time make supercapaictor a desirable energy stirage system.1 One of the limitations, however, is their low energy density as compared to the batteries.2 The best approach so far to overcome this problem is to design hybrid electrodes by comibining the capacitor type and battery type materials.3 Such hybrid electrodes use carbon materials as a conductive backbone and the transition metal oxides as an electroactive components.4 As a result, a synergistically high performance is obtained which originates from the high conductivity and long life cycle of carbon materials and the high specific capacitance of TMOs.5 Herein, we report two hybrid ternary electrode systems by using graphene-CNTs and graphene-CNCs as conductive matrix and combining them with bimorph Akaganeite (β-FeOOH) and Manganese dioxide (α-MnO2) nanoparticles respectively via a simple hydothermal self assembly method. When used as electrode in symmetirc and asymmetric spercapacitors (2V) in an aqeous electrolyte system, the hybrid electrodes gave an excellent energypower profile, high specific capaictance and remarkable cylic stability of upto 99.8% after 10,000 galvanostatic chargedischarge cycles. This high performance is attibuted to a dominant capacitive charge storage mechanism and the well-structuring of the hybrid electrodes. This system approcah can be useful in desiging high performance electrodes for long life supercapacitor systems with high energy and power desnsities.

References

1. Salanne, M.; Rotenberg, B.; Naoi, K.; Kaneko, K.; Taberna, P.-L.; Grey, C. P.; Dunn, B.; Simon, P., Efficient storage mechanisms for building better supercapacitors. Nature Energy 2016, 1 (6), 16070.

2. Mao, S.; Lu, G.; Chen, J., Three-dimensional graphene-based composites for energy applications. Nanoscale 2015, 7 (16), 6924-6943.

3. Peng, L.; Fang, Z.; Zhu, Y.; Yan, C.; Yu, G., Holey 2D nanomaterials for electrochemical energy storage. Advanced Energy Materials 2018, 8 (9), 1702179.

4. Bokhari, S. W.; Siddique, A.; Pan, H.; Li, Y.; Imtiaz, M.; Chen, Z.; Zhu, S.; Zhang, D., Nitrogen doping in the carbon matrix for Li-ion hybrid supercapacitors: state of the art, challenges and future prospective. RSC Advances 2017, 7 (31), 18926-18936.

5. Geng, P.; Zheng, S.; Tang, H.; Zhu, R.; Zhang, L.; Cao, S.; Xue, H.; Pang, H., Transition metal sulfides based on graphene for electrochemical energy storage. Advanced Energy Materials 2018, 8 (15), 1703259.

6. Bokhari, S. W.; Pan, H.; Siddique, A. H.; Imtiaz, M.; Chen, Z.; Li, Y.; Zhu, S., Self-assembly of β-FeOOH/ rGO/CNT for a high-performance supercapacitor. Materials Letters 2018, 220, 140143.

Biography :

Syeda Wishal Bokhari graduated from Shanghai Jiao Tong University with an MS degree in Materials Science and Engineering. She was awarded the prestigious Excellent International Student Award (2016-17) and Outstanding MS dissertation Award (2018) of SJTU based on her excellent academic and research performance. She was offered many prestigious fully funded scholarships from the University of Manchester, University of Alberta, University of Melbourne, University of Auckland and the Tsinghua University. She has 10 peer-reviewed journal articles under her belt. Her research focuses on the development of graphene-based composites, transition metal oxides, 2D materials with applications in electrochemistry and energy storage.