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Updated: Jun 16, 2026
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Evaluating the Electrochemical Properties of Supercapacitors using the Three-Electrode System
Published on: January 7, 2022
Does Electrode Spacing Truly Control Capacitance and Energy Density in Graphene-Based Supercapacitors? A Molecular
Davi de Oliveira Guedes1, Henrique de Araujo Chagas1, Iuliia V Voroshylova2
1Instituto de Física, Universidade Federal de Goiás, Goiânia, Goiás 74690-900, Brazil.
ACS Omega
|June 15, 2026
Summary
Electrode spacing in supercapacitors minimally impacts capacitance and energy storage, even under nanoconfinement. Simulations show intrinsic performance remains stable despite changes in electric double-layer structure.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Electrode spacing is a key parameter in supercapacitor design.
- Its precise effect on capacitance and energy storage under nanoconfinement is not fully understood.
Purpose of the Study:
- To investigate the impact of electrode spacing on supercapacitor performance using molecular dynamics simulations.
- To analyze capacitance, energy storage, and electric double-layer structure in nanoconfined ionic liquid electrolytes.
Main Methods:
- Classical molecular dynamics simulations were employed.
- Graphene-based supercapacitors with ionic liquid [emim]-[ala] were modeled.
- Simulations covered electrode separations from 4-12 nm.
Main Results:
- Electric double layers (EDLs) formed at electrodes, with significant overlap at small separations.
- Total capacitance remained nearly constant (~2.40-2.58 μF/cm²) across all spacings.
- Areal energy density was also independent of spacing (~7.4-7.7 μJ/cm²).
- Gravimetric and volumetric energy densities decreased with increasing separation.
Conclusions:
- Electrode spacing influences EDL structure but has a weak effect on intrinsic capacitive performance.
- Supercapacitor performance is dominated by surface mechanisms, making it robust to spacing variations.
- Results highlight the importance of surface-dominated storage in nanoconfined supercapacitors.
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