General hybrid asymmetric capacitor model: validation with a commercial lithium ion capacitor

TL;DR

This paper develops and validates a physics-based model for Hybrid Asymmetric Capacitors, accurately simulating charge-discharge behavior in commercial lithium ion capacitors with minimal error.

Contribution

A general, simple Ohmic model for HACs is proposed and validated against real LIC data, capturing key electrochemical phenomena effectively.

Findings

Maximum mean relative error of 7.8% in simulations

Model accurately describes galvanostatic charge-discharge processes

Simplifies understanding of LIC electrochemical behavior

Abstract

Modelling and numerical simulations play a vital role in the design and optimization of electrochemical energy storage devices. In this study, a general physics-based model is developed to describe Hybrid Asymmetric Capacitors (HACs). A one-dimensional cell is constructed with one faradaic electrode, a separator and a capacitive electrode. The model is validated using a commercial Lithium Ion Capacitor (LIC). Galvanostatic charge and discharge processes are simulated with a maximum mean relative error of 7.8 %. This suggest that this simple Ohmic model captures the key electrochemical phenomena occurring inside the LIC cell.