High Energy Density in Combination with High Cycling Stability in Hybrid Supercapacitors
journal contributionposted on 2022-01-08, 15:29 authored by Guang Cong Zhang, Man Feng, Qing Li, Zhuang Wang, Zixun Fang, Zhimin Niu, Nianrui Qu, Xiaoyong Fan, Siheng Li, Jianmin Gu, Jidong Wang, Desong Wang
Hybrid supercapacitors are considered the next-generation energy storage equipment due to their superior performance. In hybrid supercapacitors, battery electrodes need to have large absolute capacities while displaying high cycling stability. However, enhancing areal capacity via decreasing the size of electrode materials results in reductions in cycling stability. To balance the capacity–stability trade-off, rationally designed proper electrode structures are in urgent need and still of great challenge. Here we report a high-capacity and high cycling stability electrode material by developing a nickel phosphate lamination structure with ultrathin nanosheets as building blocks. The nickel phosphate lamination electrode material exhibits a large specific capacity of 473.9 C g–1 (131.6 mAh g–1, 1053 F g–1) at 2.0 A g–1 and only about 21% capacity loss at 15 A g–1 (375 C g–1, 104.2 mAh g–1, 833.3 F g–1) in 6.0 M KOH. Furthermore, hybrid supercapacitors are constructed with nickel phosphate lamination and activated carbon (AC), possessing high energy density (42.1 Wh kg–1 at 160 W kg–1) as well as long cycle life (almost 100% capacity retention after 1000 cycles and 94% retention after 8000 cycles). The electrochemical performance of the nickel phosphate lamination structure not only is commensurate with the nanostructure or ultrathin materials carefully designed in supercapacitors but also has a longer cycling lifespan than them. The encouraging results show the great potential of this material for energy storage device applications.
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nickel phosphate laminationlong cycle lifelarge absolute capacitiesencouraging results showelectrode materials results160 w kg1 wh kglonger cycling lifespan9 c g375 c g3 f gbattery electrodes need8000 cycles ).high energy densitylarge specific capacity6 mah g2 mah ghigh cycling stabilitycycling stabilityurgent need1000 cyclesultrathin nanosheetssuperior performancegreat potentialgreat challengeelectrochemical performancecapacity lossbuilding blocksalmost 100activated carbon