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Metal-organic frameworks induced robust layered Co(OH)(2) nanostructures for ultra-high stability hybrid supercapacitor electrodes in aqueous electrolyte
Li, Xu1,2; Lu, Li3; Shen, Jun2; Li, Zhenhu1; Liu, Shuangyi1
2020-11-30
摘要Comparing with intensively studied alpha-Co(OH)(2) with applying on hybrid supercapacitors, alpha-Co(OH)(2) is believed to possess higher electrochemical energy storage performances because of its larger interlayer spacing. However, alpha-phase is always transforming to beta-phase when subject to successive charge-discharge processes with resulting in fast degradation in electrochemical performance. Here, by controlling ZIF-67 hydrolysis with appropriate pH regulating additives, the robust alpha-Co(OH)(2)-A nanostructures are obtained with excellent electrochemical energy storing performances, which present higher specific capacity of 87.1 mAh g(-1)- at 1 A g(-1), excellent rate capability of 77% capacity retention at 20 A g(-1)- and ultra-high cycle stability of over 100% capacity retention over 200, 000 charge-discharge cycles. Through detailed characterizations, such great enhancement is mainly due to the synergistically achieving interlayer crystal water and non-stoichiometric valence states with stable larger interlayer spacing on the robust layered nanostructures. Moreover, the present study also confirms that, instead of most understanding of H+ (de)intercalation, OH- ions significant contributing to pseudocapacitive storage through inserting and reacting with H+ of crystal water and alpha-Co(OH)(2). Thus, the present simple strategy with clear understanding to the energy storage mechanism is beneficial for designing and fabricating mass producible electrode materials of hybrid supercapacitors.
关键词Co(OH)(2) Interlayer spacing Cycle stability Pseudocapacitive behavior Hybrid supercapacitor
DOI10.1016/j.jpowsour.2020.228974
发表期刊JOURNAL OF POWER SOURCES
ISSN0378-7753
卷号477页码:9
通讯作者Li, Zhenhu(lizhenhu@cigit.ac.cn) ; Liu, Shuangyi(liushuangyi@cigit.ac.cn)
收录类别SCI
WOS记录号WOS:000582488600035
语种英语