scholarly journals Valorization of lignin waste: high electrochemical capacitance of lignin-derived carbons in aqueous and ionic liquid electrolytes

2018 ◽  
Vol 6 (38) ◽  
pp. 18701-18711 ◽  
Author(s):  
Wantana Sangchoom ◽  
Darren A. Walsh ◽  
Robert Mokaya

Valorisation of waste lignin generates porous carbons with attractive properties as high-energy/high-power electrode materials for electric double layer capacitors (EDLCs), achieving an energy density of 25 W h kg−1at a power density of 500 W kg−1in ionic liquid electrolytes.

2016 ◽  
Vol 4 (38) ◽  
pp. 14586-14594 ◽  
Author(s):  
Helena Matabosch Coromina ◽  
Beatrice Adeniran ◽  
Robert Mokaya ◽  
Darren A. Walsh

The energy/power density of EDLCs containing high surface area carbon nanotube-based electrodes bridges the performance gap between conventional EDLCs and batteries.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Chen Li ◽  
Xiong Zhang ◽  
Kai Wang ◽  
Xianzhong Sun ◽  
Yanan Xu ◽  
...  

AbstractLithium-ion capacitors are envisaged as promising energy-storage devices to simultaneously achieve a large energy density and high-power output at quick charge and discharge rates. However, the mismatched kinetics between capacitive cathodes and faradaic anodes still hinder their practical application for high-power purposes. To tackle this problem, the electron and ion transport of both electrodes should be substantially improved by targeted structural design and controllable chemical doping. Herein, nitrogen-enriched graphene frameworks are prepared via a large-scale and ultrafast magnesiothermic combustion synthesis using CO2 and melamine as precursors, which exhibit a crosslinked porous structure, abundant functional groups and high electrical conductivity (10524 S m−1). The material essentially delivers upgraded kinetics due to enhanced ion diffusion and electron transport. Excellent capacities of 1361 mA h g−1 and 827 mA h g−1 can be achieved at current densities of 0.1 A g−1 and 3 A g−1, respectively, demonstrating its outstanding lithium storage performance at both low and high rates. Moreover, the lithium-ion capacitor based on these nitrogen-enriched graphene frameworks displays a high energy density of 151 Wh kg−1, and still retains 86 Wh kg−1 even at an ultrahigh power output of 49 kW kg−1. This study reveals an effective pathway to achieve synergistic kinetics in carbon electrode materials for achieving high-power lithium-ion capacitors.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3586
Author(s):  
Qi An ◽  
Xingru Zhao ◽  
Shuangfu Suo ◽  
Yuzhu Bai

Lithium-ion capacitors (LICs) have been widely explored for energy storage. Nevertheless, achieving good energy density, satisfactory power density, and stable cycle life is still challenging. For this study, we fabricated a novel LIC with a NiO-rGO composite as a negative material and commercial activated carbon (AC) as a positive material for energy storage. The NiO-rGO//AC system utilizes NiO nanoparticles uniformly distributed in rGO to achieve a high specific capacity (with a current density of 0.5 A g−1 and a charge capacity of 945.8 mA h g−1) and uses AC to provide a large specific surface area and adjustable pore structure, thereby achieving excellent electrochemical performance. In detail, the NiO-rGO//AC system (with a mass ratio of 1:3) can achieve a high energy density (98.15 W h kg−1), a high power density (10.94 kW kg−1), and a long cycle life (with 72.1% capacity retention after 10,000 cycles). This study outlines a new option for the manufacture of LIC devices that feature both high energy and high power densities.


Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 229 ◽  
Author(s):  
Jacob D. Huffstutler ◽  
Milinda Wasala ◽  
Julianna Richie ◽  
John Barron ◽  
Andrew Winchester ◽  
...  

There are several advantages to developing electrochemical double-layer capacitors (EDLC) or supercapacitors with high specific energy densities, for example, these can be used in applications related to quality power generation, voltage stabilization, and frequency regulation. In this regard, ionic liquids capable of providing a higher voltage window of operations compared to an aqueous and/or polymer electrolyte can significantly enhance the specific energy densities of EDLCs. Here we demonstrate that EDLCs fabricated using ionic liquid 1-butyl-1-methylpyrrolidinium tris (pentafluoroethyl) trifluorophosphate (BMP-FAP) as an electrolyte and few layer liquid-phase exfoliated graphene as electrodes show remarkable performance compared to EDLC devices fabricated with aqueous potassium hydroxide (6M) as well as widely used ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6). We found that graphene EDLC’s with BMP-FAP as an electrolyte possess a high specific energy density of ≈25 Wh/kg along with specific capacitance values as high as 200 F/g and having an operating voltage windows of >5 volts with a rapid charge transfer response. These findings strongly indicate the suitability of BMP-FAP as a good choice of electrolyte for high energy density EDLC devices.


2017 ◽  
Vol 5 (37) ◽  
pp. 19703-19713 ◽  
Author(s):  
Ruiqi Na ◽  
Ching-Wen Su ◽  
Yi-Han Su ◽  
Yu-Chun Chen ◽  
Yen-Ming Chen ◽  
...  

Capitalizing on ether groups, solvent-free synthesis produces ionic liquid integrated solid electrolytes for flexible capacitors delivering high energy and power.


2015 ◽  
Vol 51 (67) ◽  
pp. 13233-13236 ◽  
Author(s):  
Chang Yu ◽  
Changtai Zhao ◽  
Shaohong Liu ◽  
Xiaoming Fan ◽  
Juan Yang ◽  
...  

Polystyrene sphere-mediated ultrathin graphene sheet-assembled aerogels were configured, exhibiting high energy density and power density for Li–O2 batteries.


2015 ◽  
Vol 3 (38) ◽  
pp. 19545-19555 ◽  
Author(s):  
Huan Yi ◽  
Huanwen Wang ◽  
Yuting Jing ◽  
Tianquan Peng ◽  
Yiran Wang ◽  
...  

Asymmetric supercapacitors with CNT@nickel hydroxide nanosheet composites and 3-D graphene networks demonstrated a high energy density (∼44.0 W h kg−1) and high power density (∼16 kW kg−1) in aqueous KOH electrolyte.


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