LithiumLithium‐‐ion Battery Manufacturingion Battery Manufacturingy f gy f g

S. Jack S. Jack HuHu

Department of Mechanical EngineeringDepartment of Mechanical Engineering

The University of MichiganThe University of MichiganThe University of MichiganThe University of Michigan

Backgrounds Backgrounds 

Rechargeable batteriesSmall sized cells for portable d i ( bil t l h

Attractiveness of lithium‐ion batteries

devices (e.g., mobile telephones, notebooks, etc.)Large sized cells for battery electric vehicles including EV

High power & energy densityHigh energy efficiency Long cycle durability  (>1000 cycles)L lf di h t ( t telectric vehicles including EV, 

HEV and PHEVLow self‐discharge rate (up to ten years)Low toxicitycamera

Lighter weight

cell phonelaptop

Smaller sizeEV

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor

[http://www.mpoweruk.com/chemistries.htm]

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Hierarchy of Automotive LiHierarchy of Automotive Li‐‐I Battery PacksI Battery Packs

Battery Pack

Cell Level Module Level Pack Level

Electrodes‐to‐Tab

Module‐to‐Module

Case(Sealing)

Cell‐to‐Cell

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor 2

Assembly Technologies for Battery Modules/PacksAssembly Technologies for Battery Modules/Packs

Battery module/pack assembly procedure

Module assembly

Loading cells from feeder/container

I ti &Assembly actions:

Stacking 

Inspection & Sorting cells • Loading

• Sorting• Stacking• Inserting

(http://www.technologyreview.com/video/?vid=308)

gcomponents

Clamping/J i i

• Joining

Joining

Battery Module

Connection between modules & control

Pack assembly

Loading & Stacking

Battery Pack

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor 3

Cell/pack configurations and Joining MethodsCell/pack configurations and Joining Methods

Cell types Lithium‐ion Batteries 

Li‐TecA123

GS YUASA

Cylindrical  Prismatic (container) Prismatic (pouch)

LG Chem

A123

EnerDel AES

JCSSanyo

EnerDel AES

J i i th d (i ldi h i l j i i )Department of Mechanical EngineeringThe University of Michigan, Ann Arbor

Joining methods (i.e., welding or mechanical joining)

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Cell/pack configurations and Joining MethodsCell/pack configurations and Joining Methods

Implication to joining methodsCylindrical  Prismatic (container) Prismatic (pouch)

•Very flexible•Resistance, laser, ultrasonic welding or mechanical j i i

•Flat tabs & bolted tabs•Resistance, laser welding or mechanical joining

•Much more rigid than pouch type

•Mostly mechanical joining ( i ldi ) joining(sometimes welding)

Bolt joining Welding 

Bolt joining RSWMechanical joining

Projection Welding

Welding 

Welding 

`

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor 5

Joining Technologies in Battery ManufacturingJoining Technologies in Battery Manufacturing

Ultrasonic weldingSolid‐state welding W k ll f di i il

Battery applicationsJoining of electrode layers El t d t t b j i iWorks well for dissimilar 

materials and multiple sheetsGood weld for highly conductive materials (e g Cu Al)

Electrode‐to‐tab joiningTab‐to‐tab/ tab‐to‐busbar joining (pouch type)

Ni tab‐to‐Cu foil (M lti l ldi )Al tab to Al foilmaterials (e.g., Cu, Al)

A limitation in joint thicknessSensitivity to product/process variations

(Multi‐layer welding)Al tab‐to‐Al foil

variations

[http://www.asia.ru/en/ProductInfo/1277137.html]

Current collector‐to‐tab welding

Cu‐Al tab welding (dissimilar materials)

tab welding

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor

[Bella et al., 2009]

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[Patent, US 6641027] [AmTech](dissimilar materials)

ReManufacturingReManufacturing IssuesIssues

Disassembly

Reversible joining methods

Logistics

Department of Mechanical EngineeringThe University of Michigan, Ann Arbor 7