Ionothermal Synthesis of Graphene-Based Hierarchically Porous Carbon for High-Energy Supercapacitors with Ionic Liquid Electrolyte

2017 ◽  
Vol 241 ◽  
pp. 124-131 ◽  
Author(s):  
Xiao-Feng Hao ◽  
Yang Yan ◽  
Li-Guo Gao ◽  
Wen-Sheng Mu ◽  
Ce Hao
2017 ◽  
Vol 241 ◽  
pp. 202-209 ◽  
Author(s):  
Dong Zhou ◽  
Huanlei Wang ◽  
Nan Mao ◽  
Yanran Chen ◽  
Ying Zhou ◽  
...  

2020 ◽  
Author(s):  
Urbi Pal ◽  
Fangfang Chen ◽  
Derick Gyabang ◽  
Thushan Pathirana ◽  
Binayak Roy ◽  
...  

We explore a novel ether aided superconcentrated ionic liquid electrolyte; a combination of ionic liquid, <i>N</i>-propyl-<i>N</i>-methylpyrrolidinium bis(fluorosulfonyl)imide (C<sub>3</sub>mpyrFSI) and ether solvent, <i>1,2</i> dimethoxy ethane (DME) with 3.2 mol/kg LiFSI salt, which offers an alternative ion-transport mechanism and improves the overall fluidity of the electrolyte. The molecular dynamics (MD) study reveals that the coordination environment of lithium in the ether aided ionic liquid system offers a coexistence of both the ether DME and FSI anion simultaneously and the absence of ‘free’, uncoordinated DME solvent. These structures lead to very fast kinetics and improved current density for lithium deposition-dissolution processes. Hence the electrolyte is used in a lithium metal battery against a high mass loading (~12 mg/cm<sup>2</sup>) LFP cathode which was cycled at a relatively high current rate of 1mA/cm<sup>2</sup> for 350 cycles without capacity fading and offered an overall coulombic efficiency of >99.8 %. Additionally, the rate performance demonstrated that this electrolyte is capable of passing current density as high as 7mA/cm<sup>2</sup> without any electrolytic decomposition and offers a superior capacity retention. We have also demonstrated an ‘anode free’ LFP-Cu cell which was cycled over 50 cycles and achieved an average coulombic efficiency of 98.74%. The coordination chemistry and (electro)chemical understanding as well as the excellent cycling stability collectively leads toward a breakthrough in realizing the practical applicability of this ether aided ionic liquid electrolytes in lithium metal battery applications, while delivering high energy density in a prototype cell.


Ionics ◽  
2019 ◽  
Vol 25 (9) ◽  
pp. 4351-4360 ◽  
Author(s):  
Zhongliang Yu ◽  
Jiahe Zhang ◽  
Chunxian Xing ◽  
Lei Hu ◽  
Lili Wang ◽  
...  

2019 ◽  
Vol 7 (44) ◽  
pp. 25297-25304 ◽  
Author(s):  
Yang Yan ◽  
Xiao-Feng Hao ◽  
Li-guo Gao ◽  
Si-si Lin ◽  
Nan Cui ◽  
...  

The graphene-based hierarchical porous carbon GGI has high surface area, dual-doping, micro/meso-pores and exhibits good compatibility with the ionic liquid electrolyte EmimTFSI.


RSC Advances ◽  
2017 ◽  
Vol 7 (88) ◽  
pp. 55702-55708 ◽  
Author(s):  
Duck-Jae You ◽  
Zhenxing Yin ◽  
Yong-keon Ahn ◽  
Seong-Hun Lee ◽  
Jeeyoung Yoo ◽  
...  

A bimodal redox-active ionic liquid electrolyte for high energy density supercapacitors was fabricated by the redox reaction of halide ions and size variation of ions.


2021 ◽  
Author(s):  
Thushan Pathirana ◽  
Dmitrii Rakov ◽  
Fangfang Chen ◽  
Maria Forsyth ◽  
Robert Kerr ◽  
...  

<p>ABSTRACT </p><p>Cell formation of lithium-ion cells impacts the evolution of the solid electrolyte interphase (SEI) and the cell cycle stability. Lithium metal anodes are an important step in the development of high energy density batteries owing to the high theoretical specific capacity of lithium metal. However, most lithium metal battery research has used a conventional lithium-ion formation protocol; this is time consuming, costly and does not account for the different properties of the lithium metal electrode. Here, we have used a recently reported promising phosphonium bis(fluorosulfonyl)imide ionic liquid electrolyte coupled with an NMC622 high areal capacity cathode (>3.5 mAh/cm2) to investigate the effect of cell formation rates. A faster formation protocol comprised of a pulsed 1.25C current decreased the formation time by 56 % and gave a 38 % greater capacity retention after 50 cycles when compared to formation at C/20. Electrochemical impedance spectroscopy measurements showed that the fast formation gave rise to a lower-resistance SEI. Column-like lithium deposits with reduced porous lithium domains between the particles were observed using scanning electron microscope imaging. To underline the excellent performance of these high energy-density cells, a 56 % greater stack specific energy was achieved compared to the analogous graphite-based lithium-ion cell chemistries. </p>


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