Facile simulation of carbon with wide pore size distribution for electric double-layer capacitance based on Helmholtz models

2015 ◽  
Vol 3 (32) ◽  
pp. 16535-16543 ◽  
Author(s):  
Wei Hsieh ◽  
Tzyy-Leng Allen Horng ◽  
Hsin-Chieh Huang ◽  
Hsisheng Teng

Incorporation of surface-based capacitances (C/S) simulated by Helmholtz models with pore size distribution obtained from the non-local density functional theory precisely predicts the double-layer capacitance of distinct forms of carbon.

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1492
Author(s):  
Carlos A. Guerrero-Fajardo ◽  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján

In this work, the textural parameters of graphene oxide (GO) and graphite (Gr) samples were determined. The non-local density functional theory (NLDFT) and quenched solid density functional theory (QSDFT) kernels were used to evaluate the pore size distribution (PSD) by modeling the pores as slit, cylinder and slit-cylinder. The PSD results were compared with the immersion enthalpies obtained using molecules with different kinetic diameter (between 0.272 nm and 1.50 nm). Determination of immersion enthalpy showed to track PSD for GO and graphite (Gr), which was used as a comparison solid. Additionally, the functional groups of Gr and GO were determined by the Boehm method. Donor number (DN) Gutmann was used as criteria to establish the relationship between the immersion enthalpy and the parameter of the probe molecules. It was found that according to the Gutmann DN the immersion enthalpy presented different values that were a function of the chemical groups of the materials. Finally, the experimental and modeling results were critically discussed.


2005 ◽  
Vol 50 (5) ◽  
pp. 1197-1206 ◽  
Author(s):  
Grażyna Gryglewicz ◽  
Jacek Machnikowski ◽  
Ewa Lorenc-Grabowska ◽  
Grzegorz Lota ◽  
Elzbieta Frackowiak

2017 ◽  
Vol 13 ◽  
pp. 341-347 ◽  
Author(s):  
Dmitry S. Muratov ◽  
Sergey Gromov

Two types of multi-wall carbon nanotubes (MWCNT) were studied by low temperature nitrogen adsorption method. Pore size distribution was calculated using non local density functional theory (NLDFT) and Barrett-Joyner-Halenda (BJH) models. The peaks on pore size distribution were attributed to MWCNT with different diameters. Maximum hydrogen uptake by weight was evaluated for both samples and do not exceed 5 % even for the sample with higher specific surface area.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Kangyu Zou ◽  
Peng Cai ◽  
Baowei Wang ◽  
Cheng Liu ◽  
Jiayang Li ◽  
...  

AbstractThe lack of methods to modulate intrinsic textures of carbon cathode has seriously hindered the revelation of in-depth relationship between inherent natures and capacitive behaviors, limiting the advancement of lithium ion capacitors (LICs). Here, an orientated-designed pore size distribution (range from 0.5 to 200 nm) and graphitization engineering strategy of carbon materials through regulating molar ratios of Zn/Co ions has been proposed, which provides an effective platform to deeply evaluate the capacitive behaviors of carbon cathode. Significantly, after the systematical analysis cooperating with experimental result and density functional theory calculation, it is uncovered that the size of solvated PF6− ion is about 1.5 nm. Moreover, the capacitive behaviors of carbon cathode could be enhanced attributed to the controlled pore size of 1.5–3 nm. Triggered with synergistic effect of graphitization and appropriate pore size distribution, optimized carbon cathode (Zn90Co10-APC) displays excellent capacitive performances with a reversible specific capacity of ~ 50 mAh g−1 at a current density of 5 A g−1. Furthermore, the assembly pre-lithiated graphite (PLG)//Zn90Co10-APC LIC could deliver a large energy density of 108 Wh kg−1 and a high power density of 150,000 W kg−1 as well as excellent long-term ability with 10,000 cycles. This elaborate work might shed light on the intensive understanding of the improved capacitive behavior in LiPF6 electrolyte and provide a feasible principle for elaborate fabrication of carbon cathodes for LIC systems.


Sign in / Sign up

Export Citation Format

Share Document