Effect of simple cubic, face-centered cubic, and body-centered cubic-electrodes on the electric double layer capacitance of supercapacitors

Ravi Nigam; Kamal K Kar

doi:10.1088/1361-6528/acf04d

Effect of simple cubic, face-centered cubic, and body-centered cubic-electrodes on the electric double layer capacitance of supercapacitors

Nanotechnology. 2023 Aug 31;34(46). doi: 10.1088/1361-6528/acf04d.

Authors

Ravi Nigam¹, Kamal K Kar^{1

2}

Affiliations

¹ Advanced Nanoengineering Materials Laboratory, Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur-208016, India.
² Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, India.

PMID: 37582342
DOI: 10.1088/1361-6528/acf04d

Abstract

The continuum theory has been used to analyze the polarization, ion crowding, and electrostatic forces of the electric double layer in the electrode materials having simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) morphologies. The study manifests the effect of thickness of electrodes, electrode's particle size, and porosity on electric double-layer specific capacitance (EDLC). Electrochemical interference and the specific capacitance depend on the packing factor. The larger particle size decreases the specific capacitance, but porosity increases due to more surface area. Due to symmetry, SC, BCC, and FCC morphologies have 1, 3, and 5 spheres in a unit cell. The number of unit cells is varied from 1 to 100 in model 1 to analyze the effect of electrode thickness. Model 2 has three unit cells to understand the effect of porosity, and only pore lengths are varied. The critical thickness of the electrodes is the integer multiples of 1.71μm in all the morphologies. The Stern layer-specific capacitance is 167.6μF cm^-2in all cases. The EDLC in BCC is around 5.6-7.6μF cm^-2in the steady state that is intermediate between SC and FCC morphologies. The more dense packing of carbon particles in a unit cell increases the energy storage capabilities of electrodes. The average electrode permittivity slightly decreases due to the combined effect of the high electric field, status of polarization, and electrode particle size. The least optical transmission of electrodes is 98.35%.

Keywords: critical thickness; electric fields; electrical properties; electrodes; electrolytes; layers; porosity.