**Are you an EPFL student looking for a semester project?**

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Concept# Butler–Volmer equation

Summary

In electrochemistry, the Butler–Volmer equation (named after John Alfred Valentine Butler and Max Volmer), also known as Erdey-Grúz–Volmer equation, is one of the most fundamental relationships in electrochemical kinetics. It describes how the electrical current through an electrode depends on the voltage difference between the electrode and the bulk electrolyte for a simple, unimolecular redox reaction, considering that both a cathodic and an anodic reaction occur on the same electrode:
The Butler–Volmer equation
The Butler–Volmer equation is:
: j = j_0 \cdot \left{ \exp \left[ \frac { \alpha_{\rm a} zF } {RT} (E - E_{\rm eq}) \right] - \exp \left[ - { \frac { \alpha_{\rm c} zF } {RT}} (E - E_{\rm eq}) \right] \right}
or in a more compact form:
:j= j_0 \cdot \left{ \exp \left[ \frac { \alpha_{\rm a} zF \eta} {RT} \right] - \exp \left[ - { \frac { \alpha_{\rm c} zF \eta} {RT}} \right] \right}
where:

- j: electrode current

Official source

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications

Loading

Related people

Loading

Related units

Loading

Related concepts

Loading

Related courses

Loading

Related lectures

Loading

Related people

No results

Related publications (1)

Loading

Related units

No results

Related concepts (4)

Tafel equation

The Tafel equation is an equation in electrochemical kinetics relating the rate of an electrochemical reaction to the overpotential. The Tafel equation was first deduced experimentally and was late

Nernst equation

In electrochemistry, the Nernst equation is a chemical thermodynamical relationship that permits the calculation of the reduction potential of a reaction (half-cell or full cell reaction) from the s

Voltammetry

Voltammetry is a category of electroanalytical methods used in analytical chemistry and various industrial processes. In voltammetry, information about an analyte is obtained by measuring the current

Véronique Amstutz, Alberto Battistel, Julien Léo Billeter, Dominique Bonvin, Timm Faulwasser, Hubert Girault, Heron Vrubel, Daniel Wrang

Vanadium Redox Flow Batteries (VRFB) can be used as energy storage device, for example to account for wind or solar power fluctuations. In VRFBs charge is stored in two tanks containing two different vanadium solutions. This approach decouples the storage capacity and the power supply which is dependent only on the number and size of the cells [1]. A control specific model of a VRFB is proposed, which captures the essential dynamic properties of the battery while ignoring all fluid mechanical elements. The model of the battery is a nonlinear DAE comprising a differential equation for the state of charge SoC and algebraic equations based on the Butler-Volmer equation for the current I and the voltage U, the power P = U∙I being set by the operator. The battery typically operates in constant power mode, but the control system limits its operating range by switching to a constant voltage when upper or lower voltage thresholds are reached. In addition, this VRFB contains a secondary flow circuit, where the electrolyte discharge reactions produce hydrogen and oxygen [2]. Model parameters are estimated by minimizing the difference between the measured and modeled SoC over time, the other states (I, U and P) being compared with measured data. The model is validated using independent measurements, which show good fits. Finally, the dynamic model will be used to formulate and numerically solve the problem of optimal battery operation in different scenarios. [1] C. Blanc, A. Rufer, Chapter 18, in Paths to Sustainable Energy, InTech, 2010 [2] V. Amstutz et al., Energy and Environmental Science 7, 2350-2358 (2014)

2016Related courses (2)

ChE-407: Electrochemical engineering

This course builds upon the underlying theory in thermodynamics, reaction kinetics, and transport and applies these methods to electrosynthesis, fuel cell, and battery applications. Special focus is placed on addressing current challenges in state-of-the-art energy storage and conversion devices.

MSE-311: Corrosion and protection of metals + Laboratory Work

Ce cours d'introduction à la corrosion veut familiariser l'étudiant avec les mécanismes réactionnels de la corrosion, avec les différentes formes de corrosion et avec les principes de la protection contre la corrosion.

Related lectures (11)