scholarly journals Introduction of Co3 O4 to MnO2 /activated carbon for high performance electrode materials toward electrochemical capacitor application

2018 ◽  
Vol 56 (4) ◽  
pp. 525-531
Author(s):  
Le Van Khu ◽  
Luong Thi Thu Thuy ◽  
Ngo Kim Chi
Author(s):  
Juan Yu ◽  
Xuyang Wang ◽  
Jiaxin Peng ◽  
Xuefeng Jia ◽  
Linbo Li ◽  
...  

Abstract Biomass-activated carbon materials are promising electrode materials for lithium-ion hybrid capacitors (LiCs) because of their natural hierarchical pore structure. The efficient utilization of structural pores in activated carbon is very important for their electrochemical performance. Herein, porous biomass-activated carbon (PAC) with large specific surface area was prepared using a one-step activation method with biomass waste as the carbon source and ZnCl2 as the activator. To further improve its pore structure utilization efficiency, the PAC was doped with nitrogen using urea as the nitrogen source. The experimental results confirmed that PAC-1 with a high nitrogen doping level of 4.66% exhibited the most efficient pore utilization among all the samples investigated in this study. PAC-1 exhibited 92% capacity retention after 8000 cycles, showing good cycling stability. Then, to maximize the utilization of high-efficiency energy storage devices, LiNi0.8Co0.15Al0.05O2 (NCA), a promising cathode material for lithium-ion batteries with high specific capacity, was compounded with PAC-1 in different ratios to obtain NCA@PC composites. The NCA@PC-9 composite exhibited excellent capacitance in LiCs and an energy density of 210.9 Wh kg-1 at a high power density of 13.3 kW kg-1. These results provide guidelines for the design of high-performance and low-cost energy storage devices.


2018 ◽  
Vol 6 (9) ◽  
pp. 11397-11407 ◽  
Author(s):  
Xiaodong Wang ◽  
Sining Yun ◽  
Wen Fang ◽  
Chen Zhang ◽  
Xu Liang ◽  
...  

2014 ◽  
Vol 627 ◽  
pp. 3-6 ◽  
Author(s):  
M.Y. Ho ◽  
Poi Sim Khiew ◽  
D. Isa ◽  
T.K. Tan ◽  
W.S. Chiu ◽  
...  

In this study, a symmetric electrochemical capacitor has been fabricated by adopting the lithiated compound (LiFePO4)-activated carbon (AC) composite as the core electrode materials. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (CV) in 1.0 M Na2SO3 solution. Experimental results reveal that the maximum specific capacitance of 112.41 F/g is obtained in 40 wt % LiFePO4 loading on AC electrode in comparison to that of pure AC electrode (76.24 F/g) in 1 M Na2SO3. The enhanced capacitive performance of the 40 wt % LiFeO4 –AC composite electrode is believed attributed to the contribution of synergistic effect of electric double layer capacitance (EDLC) on the surface of AC as well as pseudocapacitance via intercalation/extraction of Na+, SO32-and Li+ ions in LiFePO4 lattices. The composite electrodes can sustain a stable capacitive performance at least 1000 cycles with only ~5 % specific capacitance loss after 1000 cycles. Based on the findings above, 40 wt % LiFeO4 –AC composite electrodes which utilise low cost materials and environmental friendly electrolyte is worth being investigated in more details.


2020 ◽  
Vol 6 (2) ◽  
pp. 17
Author(s):  
Stefan Breitenbach ◽  
Alexander Lumetzberger ◽  
Mathias Andreas Hobisch ◽  
Christoph Unterweger ◽  
Stefan Spirk ◽  
...  

Viscose fibers were impregnated with different concentrations of diammonium hydrogen phosphate (DAHP), carbonized, activated, and tested as high-performance electrode materials for supercapacitors. The yield of these activated carbon fibers (ACFs) could be increased by a factor of 14 by using DAHP compared to ACF without impregnation. These specific activation procedures yielded a high specific surface area of more than 2700 m2·g−1 with a pore size distribution (PSD) suitable for use as a supercapacitor electrode. The electrode materials were implemented in symmetric supercapacitors using TEMA BF4 as electrolyte and cyclic voltammetry measurements showed high specific capacitances of up to 167 F·g−1. Furthermore, the devices showed high energy densities of up to 21.4 W·h·kg−1 and high-power densities of up to 8.7 kW·kg−1. The supercapacitors featured high capacity retention (96%) after 10,000 cycles. These results show that ACFs made of viscose fibers, previously impregnated with DAHP, can be used as high-performance electrodes in supercapacitors for energy storage applications.


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