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Electro-Thermal Analysis of Lithium Ion Batteries: Experimental and Numerical study. Gad A. Pinhasi . The Israeli Fuel Cell and Batteries Center (IFCBC) Conference 26 January 2011, Tel Aviv University. Outline. The Objective The Project Background Internal Resistance Heat Generation
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Electro-Thermal Analysis of Lithium Ion Batteries: Experimental and Numerical study Gad A. Pinhasi The Israeli Fuel Cell and Batteries Center (IFCBC) Conference 26 January 2011, Tel Aviv University
Outline • The Objective • The Project • Background • Internal Resistance • Heat Generation • The Study • Experimental Setup • Calorimeter • Models • Lumped heat model • CFC model • Results • Cell • Battery • Pack 4 • Conclusions • Summery
The Objective • Thermal Analysis and Design of a Large Battery Pack. • To evaluate the heat generation and temperature field under various electrical loads and design specifications. • Safety: Thermal Runaway • Max. Temperature restriction: • “Passive cooling” solutions
The Project • Evaluation of Heat Generation: • Source term • Experimentally • Calculation of the Temperature Field • Numerically • Cell, Battery, Packs : 4, 92
Introduction • Evaluation of Heat Generation • Experimentally • Calculation of the temperature field • Numerically • Model Approaches • Thermal characterization • Battery Internal Resistance
Model Approaches • Fundamental models • physical foundations principles • Transport Phenomena • Phenomenological models • Equivalent circuit models
Thermal characterization • The heat produced due to: • Joule heat of the electrical resistance • Polarization heat • Reaction heat • initially exothermic during discharge • reversible
Battery Internal Resistance • The cell voltage under load is : • Open circuit voltage • Internal Ohmic resistance • “Concentration polarization” • “Charge transfer polarization” • Methods for Determining the Internal Resistance • Ohm’s Law • Joule’s Law • AC Resistance • Electrochemical Impedance Spectroscopy (EIS)
Internal Resistance Dependence • Temperature • Decreasing with Temperature • State of Charge (SoC) • State of Health (SoH) Yurkovich et al. (2009)
Joule heat of the electrical resistance Open circuit voltage Internal Resistance and Heat Generation
Experimental Setup Liquid Bath Dewar: Calorimeter FLUKE: Data Acquisition Cell/ Battery/ Pack Charge/ Load Charge Load Temperature Data logger Silicone Fluid Dow Corning DC‑200/100 cSt
Calorimeter: • Batch / Continuous Flow (SHC) Calorimeter Tw,out Tw,in Toil,in
Computational Fluid Dynamics (CFD) Partial differential equations (PDEs) solvers: Fluid Mechanics Heat Transfer Mass Transfer (Diffusion) Chemical reactions COMSOL Multiphysics Batteries & Fuel Cells Module ANSYS CFX FLUENT ToolsNumerical Study:
T T1 Cell T3 T2 q”’ 24 U3 q”’ U23 U12 Battery 91 The Lumped Model • Cells • Battery Medium • Pack Medium • Heat Transfer Mechanisms
Results • Cell • Temperature history • Heat Generation and SOC • Battery • The Pack • Electrical resistance • Open-circuit voltage • Heat Generation
Samsung 18650 • ICR18650-26C 2600m Li-ion 3.7v Battery • Brand :Samsung • Nominal voltage : 3.7V • Capacity: 2.6Ahr • Size 18mm x 65.0mm • Weight : 48g/pcs • Made in JAPAN
Cell Heat Generation and SOC 2.6A 1A
YT-600 4 Batteries 2791 4P Voltage: 16.8 Volts Capacity: 57.6Ahr Pack 4
Current: 32A Temperature Battery inside Battery Gap Surrounding water Electrical voltage Electrical Power Heat Power Pack 4 zeros
Experiment vs. Simulation Medium Effect: air/oil Pack 4: Simulation
Experiment vs. Simulation • Points: • Battery inside • Battery Gap Experiment Simulation 0.6W/cell
Experiment vs. Simple model • Points: • Battery inside • Battery Gap 0.6W/cell 24
Oil Air Pack 4: Medium Effect: 32A100min Tmax: 51ºC Tmax: 96ºC
Summary • The heat generation and temperature field for battery packs were evaluated theoretically and experimentally • Internal resistance of a cell was determined by current step methods and thermal loss methods. • Future Work: • Heat generation Correlation • Dynamic models • Fundamental models
People • Dr. Gad Pinhasi • Department of Chemical Engineering and Biotechnology • Dr. Alon Kuperman • Department of Electrical Engineering • Neria Roth • (M.Sc. Student) Experimental Study • Itshak Shtainbach • (M.Sc. Student) Numerical Study
Acknowledgment The research is supported by the ISRAEL Ministry of Defense : MAFAT
Roth, N., Shtainbach, T., Kuperman, A. and Pinhasi, G.A., "Electro-thermal Analysis of Lithium Ion Batteries: Experimental and Numerical study”, The 31st Israeli Conference on Mechanical Engineering - ICME 2010 , Dan Panorama Hotel, Tel-Aviv 2-3 June 2010. The 47th annual meeting of the IIChE, 2010. The Israeli Fuel Cell and Batteries Center (IFCBC) Conference, 2011 Conferences