High‐Performance Sodium‐Ion Hybrid Supercapacitor Based on Nb2O5@Carbon Core–Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites |
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| Authors: | Eunho Lim Changshin Jo Min Su Kim Mok‐Hwa Kim Jinyoung Chun Haegyeom Kim Jongnam Park Kwang Chul Roh Kisuk Kang Songhun Yoon Jinwoo Lee |
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| Institution: | 1. School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea;2. Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea;3. Energy and Environmental Division, Korea Institute of Ceramic Engineering and Technology (KICET), Jinju, Gyeongnam, Republic of Korea;4. Department of Materials Science and Engineering, Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul, Republic of Korea;5. School of Energy and Chemical Engineering, Ulsan National Institute of Science andTechnology (UNIST), Ulsan, Republic of Korea;6. Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul National University, Seoul, Republic of Korea;7. Department of Integrative Engineering, Chung‐Ang University, Seoul, Republic of Korea |
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| Abstract: | Sodium‐ion hybrid supercapacitors (Na‐HSCs) have potential for mid‐ to large‐scale energy storage applications because of their high energy/power densities, long cycle life, and the low cost of sodium. However, one of the obstacles to developing Na‐HSCs is the imbalance of kinetics from different charge storage mechanisms between the sluggish faradaic anode and the rapid non‐faradaic capacitive cathode. Thus, to develop high‐power Na‐HSC anode materials, this paper presents the facile synthesis of nanocomposites comprising Nb2O5@Carbon core–shell nanoparticles (Nb2O5@C NPs) and reduced graphene oxide (rGO), and an analysis of their electrochemical performance with respect to various weight ratios of Nb2O5@C NPs to rGO (e.g., Nb2O5@C, Nb2O5@C/rGO‐70, ‐50, and ‐30). In a Na half‐cell configuration, the Nb2O5@C/rGO‐50 shows highly reversible capacity of ≈285 mA h g?1 at 0.025 A g?1 in the potential range of 0.01–3.0 V (vs Na/Na+). In addition, the Na‐HSC using the Nb2O5@C/rGO‐50 anode and activated carbon (MSP‐20) cathode delivers high energy/power densities (≈76 W h kg?1 and ≈20 800 W kg?1) with a stable cycle life in the potential range of 1.0–4.3 V. The energy and power densities of the Na‐HSC developed in this study are higher than those of similar Li‐ and Na‐HSCs previously reported. |
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| Keywords: | core– shell nanoparticles Nb2O5 reduced graphene oxide sodium‐ion hybrid supercapacitors ultracapacitors |
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