Etching‐Assisted Crumpled Graphene Wrapped Spiky Iron Oxide Particles for High‐Performance Li‐Ion Hybrid Supercapacitor |
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| Authors: | Eunji Kim Hyeri Kim Byung‐Jun Park Young‐Hee Han Jong Hyuk Park Jinhan Cho Sang‐Soo Lee Jeong Gon Son |
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| Affiliation: | 1. Photo‐Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea;2. Department of Chemical and Biological Engineering, Korea University, Seoul, Republic of Korea;3. Korea Electric Power Research Institute, Daejeon, Republic of Korea;4. Division of Energy and Environment Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea |
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| Abstract: | From graphene oxide wrapped iron oxide particles with etching/reduction process, high‐performance anode and cathode materials of lithium‐ion hybrid supercapacitors are obtained in the same process with different etching conditions, which consist of partially etched crumpled graphene (CG) wrapped spiky iron oxide particles (CG@SF) for a battery‐type anode, and fully etched CG for a capacitive‐type cathode. The CG is formed along the shape of spikily etched particles, resulting in high specific surface area and electrical conductivity, thus the CG‐based cathode exhibits remarkable capacitive performance of 210 F g?1 and excellent rate capabilities. The CG@SF can also be ideal anode materials owing to spiky and porous morphology of the particles and tightly attached crumpled graphene onto the spiky particles, which provides structural stability and low contact resistance during repetitive lithiation/delithiation processes. The CG@SF anode shows a particularly high capacitive performance of 1420 mAh g?1 after 270 cycles, continuously increases capacity beyond the 270th cycle, and also maintains a high capacity of 170 mAh g?1 at extremely high speeds of 100 C. The full‐cell exhibits a higher energy density up to 121 Wh kg?1 and maintains high energy density of 60.1 Wh kg?1 at 18.0 kW kg?1. This system could thus be a practical energy storage system to fill the gap between batteries and supercapacitors. |
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| Keywords: | crumpled graphene Li‐ion hybrid supercapacitors partially etched iron oxide spiky iron oxide particles supercapacitors |
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