“One-for-All” strategy to design oxygen-deficient triple-shelled MnO2and hollow Fe2O3microcubes for high energy density asymmetric supercapacitors

2019 ◽  
Vol 48 (24) ◽  
pp. 8623-8632 ◽  
Author(s):  
Henan Jia ◽  
Haoyan Liang ◽  
Zhaoyue Wang ◽  
Chun Li ◽  
Xiaohang Zheng ◽  
...  

Intrinsically poor conductivity, sluggish ion transfer kinetics, and limited specific area are the three main obstacles that confine the electrochemical performance of metal oxides in supercapacitors.

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.


2021 ◽  
Author(s):  
yajun JI ◽  
Fei Chen ◽  
Shufen Tan ◽  
Fuyong Ren

Abstract Transition metal oxides are generally designed as hybrid nanostructures with high performance for supercapacitors by enjoying the advantages of various electroactive materials. In this paper, a convenient and efficient route had been proposed to prepare hierarchical coral-like MnCo2O4.5@Co-Ni LDH composites on Ni foam, in which MnCo2O4.5 nanowires were enlaced with ultrathin Co-Ni layered double hydroxides nanosheets to achieve high capacity electrodes for supercapacitors. Due to the synergistic effect of shell Co-Ni LDH and core MnCo2O4.5, the outstanding electrochemical performance in three-electrode configuration was triggered (high area capacitance of 5.08 F/cm2 at 3 mA/cm2 and excellent rate capability of maintaining 61.69 % at 20 mA/cm2), which is superior to those of MnCo2O4.5, Co-Ni LDH and other metal oxides based composites reported. Meanwhile, the as-prepared hierarchical MnCo2O4.5@Co-Ni LDH electrode delivered improved electrical conductivity than that of pristine MnCo2O4.5. Furthermore, the as-constructed asymmetric supercapacitor using MnCo2O4.5@Co-Ni LDH as positive and activated carbon as negative electrode presented a rather high energy density of 220 μWh/cm2 at 2400 μW/cm2 and extraordinary cycling durability with the 100.0 % capacitance retention over 8000 cycles at 20 mA/cm2, demonstrating the best electrochemical performance compared to other asymmetric supercapacitors using metal oxides based composites as positive electrode material. It can be expected that the obtained MnCo2O4.5@Co-Ni LDH could be used as the high performance and cost-effective electrode in supercapacitors.


2017 ◽  
Vol 46 (38) ◽  
pp. 12876-12883 ◽  
Author(s):  
Saurabh Singh ◽  
Nanasaheb M. Shinde ◽  
Qi Xun Xia ◽  
Chandu V. V. M. Gopi ◽  
Je Moon Yun ◽  
...  

A NiCoMn-LDH (10%)//rGO asymmetric supercapacitor device with 574 Wh kg−1 energy density at 749.9 W kg−1 power density and 89.4% retention even after 2500 cycles has been explored.


2017 ◽  
Vol 322 ◽  
pp. 582-589 ◽  
Author(s):  
Mengyao Yao ◽  
Xin Zhao ◽  
Lei Jin ◽  
Fangyuan Zhao ◽  
Junxian Zhang ◽  
...  

2019 ◽  
Vol 6 (3) ◽  
pp. 659-670 ◽  
Author(s):  
Zhiqin Sun ◽  
Xue Yang ◽  
Huiming Lin ◽  
Feng Zhang ◽  
Qian Wang ◽  
...  

FeS2, prepared using a rapid microwave assisted method, exhibits excellent electrochemical performance for supercapacitor and OER applications.


2019 ◽  
Vol 7 (10) ◽  
pp. 5333-5343 ◽  
Author(s):  
Wen Lu ◽  
Ze Yuan ◽  
Chunyang Xu ◽  
Jiqiang Ning ◽  
Yijun Zhong ◽  
...  

A self-templating strategy was used to prepare novel mesoporous Cu-doped Co9S8 rectangular nanotube arrays (Cu-Co9S8 NTAs) as an advanced electrode for all-solid-state asymmetric supercapacitors, which deliver a high energy density of 71.93 W h kg−1 at a power density of 750 W kg−1.


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