Advanced Hybrid Supercapacitor Based on a Mesoporous Niobium Pentoxide/Carbon as High-Performance Anode

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• 作者：Eunho Lim ; Haegyeom Kim ; Changshin Jo ; Jinyoung Chun ; Kyojin Ku ; Seongseop Kim ; Hyung Ik Lee ; In-Sik Nam ; Songhun Yoon ; Kisuk Kang ; Jinwoo Lee
• 刊名：ACS Nano
• 出版年：2014
• 出版时间：September 23, 2014
• 年：2014
• 卷：8
• 期：9
• 页码：8968-8978
• 全文大小：704K
• ISSN：1936-086X

文摘

Recently, hybrid supercapacitors (HSCs), which combine the use of battery and supercapacitor, have been extensively studied in order to satisfy increasing demands for large energy density and high power capability in energy-storage devices. For this purpose, the requirement for anode materials that provide enhanced charge storage sites (high capacity) and accommodate fast charge transport (high rate capability) has increased. Herein, therefore, a preparation of nanocomposite as anode material is presented and an advanced HSC using it is thoroughly analyzed. The HSC comprises a mesoporous Nb₂O₅/carbon (m-Nb₂O₅鈥揅) nanocomposite anode synthesized by a simple one-pot method using a block copolymer assisted self-assembly and commercial activated carbon (MSP-20) cathode under organic electrolyte. The m-Nb₂O₅鈥揅 anode provides high specific capacity with outstanding rate performance and cyclability, mainly stemming from its enhanced pseudocapacitive behavior through introduction of a carbon-coated mesostructure within a voltage range from 3.0 to 1.1 V (vs Li/Li⁺). The HSC using the m-Nb₂O₅鈥揅 anode and MSP-20 cathode exhibits excellent energy and power densities (74 W h kg^鈥? and 18鈥?10 W kg^鈥?), with advanced cycle life (capacity retention: 鈭?0% at 1000 mA g^鈥? after 1000 cycles) within potential range from 1.0 to 3.5 V. In particular, we note that the highest power density (18鈥?10 W kg^鈥?) of HSC is achieved at 15 W h kg^鈥?, which is the highest level among similar HSC systems previously reported. With further study, the HSCs developed in this work could be a next-generation energy-storage device, bridging the performance gap between conventional batteries and supercapacitors.

Keywords:

hybrid supercapacitors; Nb₂O₅; pseudocapacitive properties; mesoporous materials; block copolymer-assisted self-assembly