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The Origin of Improved Electrical Double‐Layer Capacitance by Inclusion of Topological Defects and Dopants in Graphene for Supercapacitors |
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| Authors: | Jiafeng Chen Yulei Han Prof Xianghua Kong Xinzhou Deng Hyo Ju Park Yali Guo Song Jin Zhikai Qi Prof Zonghoon Lee Prof Zhenhua Qiao Prof Rodney S Ruoff Prof Hengxing Ji |
| Institution: | 1. Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, Hefei, Anhui, China;2. ICQD, Hefei National Laboratory for Physical Sciences at Microscale, Synergetic Innovation Center of Quantum Information and Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, China;3. School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei, Anhui, China;4. School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea;5. Center for Multidimensional Carbon Materials, Institute for Basic Science Center at UNIST Campus, Ulsan, Republic of Korea |
| Abstract: | Low‐energy density has long been the major limitation to the application of supercapacitors. Introducing topological defects and dopants in carbon‐based electrodes in a supercapacitor improves the performance by maximizing the gravimetric capacitance per mass of the electrode. However, the main mechanisms governing this capacitance improvement are still unclear. We fabricated planar electrodes from CVD‐derived single‐layer graphene with deliberately introduced topological defects and nitrogen dopants in controlled concentrations and of known configurations, to estimate the influence of these defects on the electrical double‐layer (EDL) capacitance. Our experimental study and theoretical calculations show that the increase in EDL capacitance due to either the topological defects or the nitrogen dopants has the same origin, yet these two factors improve the EDL capacitance in different ways. Our work provides a better understanding of the correlation between the atomic‐scale structure and the EDL capacitance and presents a new strategy for the development of experimental and theoretical models for understanding the EDL capacitance of carbon electrodes. |
| Keywords: | electrical double-layers nitrogen dopants quantum capacitance single-layer graphene topological defects |