© VIRTUAL VEHICLE - European Commission · 2018. 4. 6. · VIRTUAL VEHICLE Research Center is...

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VIRTUAL VEHICLE Research Center is funded within the COMET – Competence Centers for Excellent Technologies – programme by the Austrian Federal Ministry for Transport, Innovation and Technology (BMVIT), the Federal Ministry of Science, Research and Economy (BMWFW), the Austrian Research Promotion Agency (FFG), the province of Styria and the Styrian Business Promotion Agency (SFG). The COMET programme is administrated by FFG.

INITIATION OF THERMAL RUNAWAY WITH DIFFERENT HEATING DEVICES

Andrej GolubkovVIRTUAL VEHICLE Research CenterArial, 18

Motivation

Experimental

Simulation

Motivation

Experimental

Simulation

How to start TR of the initial cell for propagation certification, my opinion

08.03.2018 / Golubkov Initiation of thermal runaway propagation 5

How to start TR of the initial cell for propagation certification, my opinion

Motivation

Experimental

Simulation

Laboratory for thermal runaway experiments with large Li-ion cells

Reactor for

• cells up to 500 Wh• 30 Thermocouples• Feedthroughs for 400 A• Volume 120 l

Ventgas analysis

FTIR: Bruker Matrix MG01

For all ventgas-components (incl. HF) except H2

GC: Agilent microGC 3000

For CO2, CO, CH4, Hydrocarbons, H2

Sample holder

Space for the sample holder

Space for sample set-up

Sample holder for pouch cells

Springs to simulate mechanical force inside a module.

Tested cell before and after TR experiment

Test results: cell temperatures

Heating from both sides Heating from one side Heating with heater cardrige

Test results: cell temperatures, detail

5 sec10 sec

30 sec

Test results: gas pressure

4 sec 7 sec23 sec

Open the cell (inside fumehood!)

Put 3 thermocouples into the middle of the electrode stack

TR temperatures, including internal thermocouples

center

outerNeed to measure internal temperature to create a TR model

Why no put heater elements into cell?

• Heater wire put into jelly roll.• Tried to trigger TR by heating, wire fails before TR• Opened cell again, inserted new heater wire• Triggering TR with heater wire fails again• Instead triggering TR by sample holder heating• TR at already 100°C. Probably because of internal short.

TR of the damaged cell, already at 100°C

Direct transition to TR

External heating and possible internal short

Abrupt increase of temperatureDiscontinual curvatureTransition at 110°C

Even increase of temperatureContinual curvatureTransition at 200°C

Normal TR Probably internal short at 110°C of a damaged cell

Inser better heating wire devices into pouch cell.

Try other small heater devices, which could also fit into a battery moduleE.g: small silicon nitride ceramic heater, available in different sizes. Down to 3 x 7 mm

Motivation

Experimental

Simulation

Use LT-spice for thermal network simulation

Thermal network for a 3p2s module

Examples of simulation results

No propagation

smaller spacer thickness

Propagation occurs

Testing Openmodellica

No spacer between cells Spacer: 1mm mica sheet

What influences if TR-propagation takes place

• TR characteristics of the cell

• Starting temperature of the module

• What is initial cell (oustide vs. centre)

• Heat conduction between adjacent cells

• Other heat-capacities (mechanical structure, cooling liquid)

• Cooling power

Proposed next steps

Exchange LT-spice for Openmodellica (or Dymola)

Make Library for thermal elements

• Heat conductor, PCM, heat pipe,..

• Make individual cell models of TR from experiment (e.g. use internal

thermocouples)

• Measure heat conductivity and heat capacity of a failed cell

Industry can use this tools to find solutions for prevention of TR propagation.

Andrej Golubkov

VIRTUAL VEHICLE Research CenterAndrej.golubkov@v2c2.at

© VIRTUAL VEHICLE - European Commission · 2018. 4. 6. · VIRTUAL VEHICLE Research Center is...

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