kth.sePublications
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Discrete element modelling of the mechanical behaviour of lithium-ion battery electrode layers
KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics, Solid Mechanics.ORCID iD: 0009-0001-4912-7091
2024 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Since their introduction in the late 20th century, lithium-ion batteries have become the leading battery technology for portable devices and electric vehicles due to their high energy density and rechargeability. However, the increasing demand for a longer battery life span is hindered by the fading of the battery’s charge capacity over prolonged use. This reduction in charge capacity stems from electrochemical and mechanical degradation of the battery cells. The main research focus in the literature has been on the chemical degradation of battery cells. However, the mechanical degradation also substantially contributes to the battery’s capacity degradation. Therefore, it is crucial to understand the mechanical properties of the battery cells to be able to mitigate mechanical degradation. The battery’s mechanical degradation stems from the electrode layers’ constituents. This thesis aims to model the positive electrode’s mechanical properties by recreating its granular microstructure using the discrete element method.

In Papers 1 and 2, a discrete element method modelling framework is developed, which can reconstruct a positive electrode layer of a lithium-ion battery, simulate manufacturing processing steps, and determine the mechanical properties of the electrode layer. The framework uses two contact models, representing the positive electrode material in the form of particles and a binder agent, which gives the electrode layer its structural integrity. The framework is used to link the mechanical behaviour of the electrode particles and the binder agent to the mechanical behaviour of the entire electrode layer. The framework is able to capture the layer’s pressure sensitivity and relaxation behaviour, properties which have been displayed in the literature through experimental testing.

Abstract [sv]

Sedan de introducerades i slutet av 1900-talet har litiumjonbatterier blivit den ledande batteriteknologin för portabla enheter samt elfordon på grund av deras höga energidensitet och återladdningförmåga. Den ökade efterfrågan på utökade batterilivslängder är dock hämmad av reduceringen av uppladdningskapacitet över längre användningstider. Denna reducering av laddningskapacitet kommer från elektrokemisk och mekanisk degradering av battericellerna. Det största forskningsintresset i litteraturen har varit på den kemiska degraderingen av battericellerna. Dock ger den mekaniska degraderingen ett betydande bidrag till batteriets kapacitetsdegradering. Därför är det viktigt att förstå battericellens mekaniska egenskaper för att kunna förhindra mekaniskdegradering. Batteriets mekaniska degradering beror på elektrodlagrets beståndsdelar. Denna avhandlings målsättning är att modellera den positiva elektrodens mekaniska egenskaper genom att återskapa dess granulära mikrostruktur med hjälp av diskret elementmetodik.

I Artikel 1 och 2 utvecklades ett ramverk för modellering med användning av diskreta elementmetoden, vilket kan återskapa det aktiva lagret för en positiv elektrod, simulera tillverkningsprocesser, samt fastställa elektrodlagrets mekaniska egenskaper. Ramverket använder två kontaktmodeller som representerar det positiva elektrodmaterialet i form av partiklar samt ett bindemedel, som ger elektrodlagret dess strukturella integritet. Ramverket används för att undersöka hur de mekaniska egenskaperna för det hela elektrodlagret beror på egenskaperna för de aktiva partiklarna samt bindemedlet. Ramverket kan fånga lagrets tryckkänslighet samt dess relaxering, egenskaper som har påvisats i litteraturen genom experimentell provning. 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2024.
Series
TRITA-SCI-FOU ; 2024:12
Keywords [en]
Lithium-ion batteries, mechanical characterisation, simulations, contact mechanics, discrete element method
Keywords [sv]
Litiumjonbatterier, mekanisk karakterisering, simuleringar, kontaktmekanik, diskret elementmetod
National Category
Applied Mechanics
Research subject
Engineering Mechanics; Solid Mechanics
Identifiers
URN: urn:nbn:se:kth:diva-344632ISBN: 978-91-8040-855-4 (print)OAI: oai:DiVA.org:kth-344632DiVA, id: diva2:1846438
Presentation
2024-04-19, 4303, seminarierummet, Teknikringen 8, Stockholm, 13:00 (English)
Opponent
Supervisors
Funder
Swedish Energy Agency, 46558-1
Note

Qc240322

Available from: 2024-03-22 Created: 2024-03-22 Last updated: 2024-04-03Bibliographically approved
List of papers
1. A discrete element analysis of the mechanical behaviour of a lithium-ion battery electrode active layer
Open this publication in new window or tab >>A discrete element analysis of the mechanical behaviour of a lithium-ion battery electrode active layer
2023 (English)In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 425, article id 118574Article in journal (Refereed) Published
Abstract [en]

Lithium-ion batteries experience charge capacity loss during their lifecycle caused by mechanical phenomena. In this study, a discrete element method (DEM) simulation model, to link the local mechanical behaviour in the positive electrode active layer to its global mechanical properties, was developed. DEM is a suitable method to use as the electrode active layer has a granular structure and the model includes contact formulations for the active particles and the binder domain. Simulations of the calendering process and the measurement of the active layer's global mechanical properties is possible with the framework. The model developed can capture the pressure sensitivity of the active layer, which has been observed in experiments.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Lithium -ion batteries, Discrete element method, Bonded contact model, Simulation, Calendering, Mechanical characterisation
National Category
Applied Mechanics
Identifiers
urn:nbn:se:kth:diva-328280 (URN)10.1016/j.powtec.2023.118574 (DOI)000988002100001 ()2-s2.0-85153253764 (Scopus ID)
Note

QC 20230607

Available from: 2023-06-07 Created: 2023-06-07 Last updated: 2024-03-22Bibliographically approved
2. Discrete element modelling of the elastic-plastic and viscoelastic properties of a lithium-ion battery electrode layer
Open this publication in new window or tab >>Discrete element modelling of the elastic-plastic and viscoelastic properties of a lithium-ion battery electrode layer
(English)Manuscript (preprint) (Other academic)
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:kth:diva-343439 (URN)
Note

QC 20240215

Available from: 2024-02-14 Created: 2024-02-14 Last updated: 2024-03-22Bibliographically approved

Open Access in DiVA

Kappa(442 kB)61 downloads
File information
File name FULLTEXT01.pdfFile size 442 kBChecksum SHA-512
e84b6c211ff5e3cde4dd68fd0bfd305651d4c17f8a7fe51fe8936a684b173864a8f621efbfc4b99a080cff11345224d3f852652626d4342a884ff70ece07e155
Type fulltextMimetype application/pdf

Authority records

Lundkvist, Axel

Search in DiVA

By author/editor
Lundkvist, Axel
By organisation
Solid Mechanics
Applied Mechanics

Search outside of DiVA

GoogleGoogle Scholar
Total: 61 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 377 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf