posted on 2022-01-08, 15:29authored byGuang
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.