High Energy Density in Combination with High Cycling Stability in Hybrid Supercapacitors

Abstract

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.

Engineering Oxygen Vacancies on Mixed-Valent Mesoporous α-MnO2 for High-Performance Asymmetric Supercapacitors

“…The last peaks at 533.2 eV were ascribed to adsorbed H−O−H. 42 In fact, the lower binding energy of O binding modes of Mn−O−Mn was defined as lattice oxygen (labeled as O lat ), while other higher binding energies were classified as adsorbed oxygen species (labeled as O ads ). 33 The adsorbed oxygen species can be related with oxygen vacancy.…”

Recent Progress in Carbonaceous and Redox‐Active Nanoarchitectures for Hybrid Supercapacitors: Performance Evaluation, Challenges, and Future Prospects

“…al. [208] developed Ni 3 (PO 4 ) 2 as an electrode material for HSC with high specific NiF and Ni 3 S 2 @NiF composites. Reproduced with permission.…”

Impact of oxygen‐defects induced electrochemical properties of three‐dimensional flower‐like CoMoO 4 nanoarchitecture for supercapacitor applications

“…3,4 However, the major bottleneck for practical applications of SCs is to boost their energy density without sacrificing power density and life cycle to meet the increasing energy demands. 3,4 The energy density (ED) of the SCs can be considerably enhanced by increasing the specific capacity/capacitance (C) and/or the voltage (V) of the device based on the E ¼ 1 2 CV 2 expression. 5,6 Consequently, the development of hybrid SCs (HSCs) is emerging as a feasible strategy by integrating appropriate capacitive-type (nagatrode) and battery-type (positrode) electrode materials to boost the energy density and expand the operating voltage window of SCs.…”

“…The exploration of promising, high efficient, and green energy storage systems (ESS) have attracted considerable research interest and actively sought by the technological and scientific communities due to the ever‐growing energy demands for the developing society 1,2 . Supercapacitors (SCs) have drawn extensive research interest as one class of indispensable ESS on account of their distinct advantages such as large power performance, quick charging/discharging ability, substantially long cycling lifetime, excellent reliability, environmental benignity, and safe configuration relative to its competitive counterpart like secondary batteries 3,4 . However, the major bottleneck for practical applications of SCs is to boost their energy density without sacrificing power density and life cycle to meet the increasing energy demands 3,4 .…”

“…Supercapacitors (SCs) have drawn extensive research interest as one class of indispensable ESS on account of their distinct advantages such as large power performance, quick charging/discharging ability, substantially long cycling lifetime, excellent reliability, environmental benignity, and safe configuration relative to its competitive counterpart like secondary batteries 3,4 . However, the major bottleneck for practical applications of SCs is to boost their energy density without sacrificing power density and life cycle to meet the increasing energy demands 3,4 . The energy density (ED) of the SCs can be considerably enhanced by increasing the specific capacity/capacitance (C) and/or the voltage (V) of the device based on the expression 5,6 .…”