Mathematical modelling of primary alkaline batteries

Johansen, Jonathan Frederick (2007) Mathematical modelling of primary alkaline batteries. PhD thesis, Queensland University of Technology.

Abstract

Three mathematical models, two of primary alkaline battery cathode discharge, and one of primary alkaline battery discharge, are developed, presented, solved and investigated in this thesis. The primary aim of this work is to improve our understanding of the complex, interrelated and nonlinear processes that occur within primary alkaline batteries during discharge.

We use perturbation techniques and Laplace transforms to analyse and simplify an existing model of primary alkaline battery cathode under galvanostatic discharge. The process highlights key phenomena, and removes those phenomena that have very little effect on discharge from the model. We find that electrolyte variation within Electrolytic Manganese Dioxide (EMD) particles is negligible, but proton diffusion within EMD crystals is important. The simplification process results in a significant reduction in the number of model equations, and greatly decreases the computational overhead of the numerical simulation software. In addition, the model results based on this simplified framework compare well with available experimental data.

The second model of the primary alkaline battery cathode discharge simulates step potential electrochemical spectroscopy discharges, and is used to improve our understanding of the multi-reaction nature of the reduction of EMD. We find that a single-reaction framework is able to simulate multi-reaction behaviour through the use of a nonlinear ion-ion interaction term.

The third model simulates the full primary alkaline battery system, and accounts for the precipitation of zinc oxide within the separator (and other regions), and subsequent internal short circuit through this phase. It was found that an internal short circuit is created at the beginning of discharge, and this self-discharge may be exacerbated by discharging the cell intermittently. We find that using a thicker separator paper is a very effective way of minimising self-discharge behaviour.

The equations describing the three models are solved numerically in MATLABR, using three pieces of numerical simulation software. They provide a flexible and powerful set of primary alkaline battery discharge prediction tools, that leverage the simplified model framework, allowing them to be easily run on a desktop PC.

Impact and interest:

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

Full-text downloads:

2,528 since deposited on 03 Dec 2008
332 in the past twelve months

Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.

ID Code: 16412
Item Type: QUT Thesis (PhD)
Supervisor: Farrell, Troy & Turner, Ian
Keywords: advection, anode, asymptotic analysis, BET surface area, binary electrolyte, boundary condition, Butler-Volmer equation, cathode, closed circuit voltage, concentration polarisation, control volume, current path, discretisation, diffusion, electrochemical reaction, electrode, electrolytic manganese dioxide, EMD crystals, EMD particles, exchange current density, geometric surface area, initial condition, linearisation, macrohomogeneous porous electrode theory, mathematical model, Nernst equation, ohmic losses, open circuit voltage, ordinary differential equation, overpotential, partial differential equation, perturbation techniques, potassium hydroxide, potassium zincate, precipitation reaction, primary battery, separator paper, simulation, step potential electrochemical spectroscopy, ternary electrolyte, theoretical capacity, utilisation, zinc, zinc oxide
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Past > Schools > Mathematical Sciences
Department: Faculty of Science
Institution: Queensland University of Technology
Copyright Owner: Copyright Jonathan Frederick Johansen
Deposited On: 03 Dec 2008 04:02
Last Modified: 28 Oct 2011 19:47

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page