Fire Hazards of Lithium Ion Batteries

FEDERAL AVIATION ADMINISTRATION

Aviation Research Division

William J. Hughes Technical Center

Atlantic City International Airport, NJ 08405

*Department of Fire Protection Engineering,

University of Maryland, College Park

International Aircraft Systems Fire Protection Working Group Meeting

Atlantic City, New Jersey, October 21-22, 2015

WEB: www.fire.tc.faa.gov E-MAIL: richard.e.lyon@faa.gov

Richard E. Lyon, Richard N. Walters, Sean Crowley,

and *James G. Quintiere

Outline of Talk

Motivation: Safe Shipment of Batteries

Background: Lithium Ion Cells/Batteries

Methodologies

Findings

William J. Hughes Technical Center, Atlantic City, NJ

Fire Safety Research

Aircraft Fire Incidents Involving Li Batteries

• Fire erupted in a cargo plane that landed in Philadelphia on Feb. 7, 2006.

• A cargo plane with 81,000 lithium batteries caught fire and crashed after it left Dubai on Sept. 3, 2010.

• A cargo jet crashed into the East China Sea on July 28, 2011, after the crew reported a fire on board.

Objective: Measure Fire Hazards of LIBs

Passenger electronics

Typical

packaging

Bulk shipment as cargo

• Increasing applications

– More widely used

– Higher energy densities

• Modeling of Failure

(Thermal Runaway)

– Up to 6 decomposition

reactions

– CFD thermal-chemical-

electrical analyses

• Experimental Studies

– Component studies

– DSC, ARC studies

Applications and Industry Research

Electronics Cars

E-cigarettes

ARC

0

Lead-Acid

NI-Cd

Li-Titanate

NiMH

Li-Metal

(Non-rechargeble)

Zn-air (developmental)

Energ

y D

ensity,

kJ/c

m3

Specific Energy, kJ/g

Smaller

Lighter 0.5 1.0 1.5 2.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Energy Density and Cell Chemistry

Voluntary ban as cargo on

passenger flights by major airlines

Officially banned as cargo

on passenger aircraft by

FAA (2005) and

International Civil Aviation

Organization (ICAO) (2015)

Normal Discharge of Lithium Ion Cell

Copper Terminal

Graphite

Anode

Lithium Transition

Metal Oxide

Cathode

Aluminum Terminal

Electrolyte: Organic Ethers, Esters,Carbonates

(polymer = gel)

PE or PP

Membrane

Separator

Materials: Commercial 18650 LIB Cells

65 mm

18650 Rechargeable Cells ( 44 grams each)

18 mm

Causes of Battery Failure

• Electrical

– Overcharge

– Rapid discharge

• Mechanical

– Physical damage (puncture)

– Manufacturing defect or contaminant

• In Fires

– Separator melts due to high temperature causing internal short circuit that liberates heat.

– Contents mix, react and thermally decompose.

Thermal Runaway

• Auto-accelerating heat generation

• Rapid temperature increase

• Expulsion of flammable gases and liquids

< 1 second

Experimental Methods: Cell Charging

• Charge / Discharge 4 cells simultaneously

• Record: charge / discharge capacity

• Programmable for different states of charge

Electrical Properties of Tested Cells

LiMn2O4-LiNiCoO2

LiCoO2

LiNiCoAlO2

Unknown

Cathode

Maximum

Capacity,Qmax

(A-s)

11,700

9,400

5,400

18,000

Rated

11,200

8,300

5,000

3,600

Actual

Cell Potential,

(V) -∆G, Qmax

(kJ/cell)

41

31

19

13

3.6

3.7

3.7

3.7

Nominal

4.1

4.1

4.1

4.0

Max.

State-of-Charge, SOC = Q/Qmax

Chemical Energy Available to Do Useful Work (Free Energy), ∆G = -Q

Methods: Hazard Measurements

Thermal Effects of Cell Failure Purpose-Built Thermal Capacitance

(Slug) Calorimeter

Energetics of Cell Failure ASTM D 5865-14, Standard Test Method for

Gross Calorific Value of Coal and Coke

Fire Behavior of Lithium Cells (ASTM E 1354, Standard Test Method for Heat and Visible

Smoke Release Rates for Materials and Products Using an

Oxygen Consumption Calorimeter)

Bomb Calorimeter (ASTM D 5865)

• Standard Test Method for Gross Calorific Value of Coal and Coke

• Parr Instruments Model 1341 Plain Jacket Oxygen Bomb Calorimeter

• Resistance heating to force thermal runaway of LIBs

• Nitrogen blanket (1 Atm) to prevent oxidation of contents after failure

• Temperature, voltage and current logged for all tests

Bomb and other components

for 18650 battery tests

Experimental Setup

Cell Thermodynamics (see Paper)

Energy released by mixing, chemical

reaction and thermal decomposition

of cell components.

UTotal Urxn Q

Total energy

released at cell

failure

(measured in bomb)

Electrochemical (Free) energy, ∆G

(Equal to cell potential (V) times

charge Q (A-s))

Depends on

cell chemistry

Baseline-Corrected Temperature History In Bomb

0

1

2

3

4

5

6

500 1000 1500 2000 2500 3000

Tem

pera

ture

Ris

e (C

)

Time (seconds)

100% 80%

50%

20%

0%

SOC

Generalized Energetics of Cell Failure

0

10

20

30

40

50

60

70

80

0 500 1000 1500 2000 2500 3000 3500 Energ

y R

ele

ase a

t F

ailu

re (

kJ/c

ell)

Charge, Q (mAh)

Free Energy, ∆G (Q)

Total Energy

(∆Utotal) Energy of Mixing, Reaction

and Decomposition, ∆Urxn

∆Urxn Q

LiMn2O4-LiNiCoO2 LiCoO2 LiNiCoAlO2 Unknown

18650 Cell Chemistry

80

70

60

50

40

30

20

10

0 0 10 20 30 40 50 60

LiMn2O4-LiNiCoO2

En

erg

y R

ele

ase

at F

ailu

re (

kJ/c

ell)

60

50

40

30

20

10

0

-10 0 5 10 15 20 25 30 35 40

LiCoO2

40

30

20

10

0

-10 0 5 10 15 20 25

LiNiCoAlO2

Electrochemical Free Energy, Q (kJ/cell)

30

25

20

15

10

5

0

-5 0 5 10 15 20

Unknown

∆Utotal

∆Urxn

Energetics of Individual Cell Failure

∆Utotal

∆Urxn

∆Utotal

∆Urxn

∆Utotal

∆Urxn

Fre

e E

nerg

y,

Q (

kJ/c

ell)

State of Charge, Q/Qmax (%)

LiMn2O4-

LiNiCoO2

LiCoO2

LiNiCoAlO2

Unknown

0

10

20

30

40

50

60

70

80

0 20 40 60 80 100 0

10

20

30

40

50

0 20 40 60 80 100

State of Charge, Q/Qmax (%)

Stored

Electrochemical

Energy (Q)

Total

Energy

(∆Utotal)

LiMn2O4-

LiNiCoO2

LiCoO2

LiNiCoAlO2

Unknown

Tota

l E

nerg

y, ∆

Uto

tal (

kJ/c

ell)

SOC is a Poor Predictor of Energy Release for

Different Chemistries (and Cell Potentials)

Li-Ion 18650 Batteries - Post Test

Zero Charge 50% Charged 100% Charged

Gravimetric Analysis for Volatile Yield

0

1

2

3

4

5

6

0 10 20 30 40 50

Vola

tile

Yie

ld,

g/c

ell

Electrochemical (Free) Energy, Q (kJ/cell)

• Bomb weighed before and after venting

• Volatiles are combustible

• Yield Q

LiMn2O4-LiNiCoO2

LiCoO2

LiNiCoAlO2

Unknown

Infrared Spectra of Gaseous Decomposition Products

LiMn2O4-

LiNiCoO2

LiCoO2

LiNiCoAlO2

Unknown

Thermal Effects of Cell Failure

J.G. Quintiere & S.B. Crowley, Thermal Dynamics of 18650 Li-ion Batteries, The

Seventh Triennial International Fire & Cabin Safety Research Conference,

Philadelphia, PA, 2013.

20 g

2 s

600C

2 s

Separator

Melts (150C)

Venting (200C)

Failure (250C)

Mass Loss

Temp. Rise

Maxim

um

Cell

Surf

ace

Tem

pera

ture

, T

ma

x (C

)

Tmax Tf Utotal

mcp

Adiabatic (Surface) Temperature Rise

0

200

400

600

800

1000

1200

1400

0 10 20 30 40 50 60

(R = 0.99528)

∆Utotal (kJ/cell)

LiCoO2 Cell

Fire Calorimeter Testing of Lithium Cells

Special holder designed to

prevent rocketing of cell at failure

Standard ASTM E 1354 Operation

0

1

2

3

4

5

6

80 90 100 110 120 130 140 150

HR

R, kW

/cell

Elapsed Time, sec

Original Data

Corrected Data

HRR of 18650 LiCoO2 Cell in Cone

3 s

Venting Failure

HRR corrected for response time of cone calorimeter

3 s

Mass L

oss (

g/c

ell)

State of Charge, Q/Qmax (%)

Mass Loss of 18650 Cell in Fire Calorimeter Test

0

5

10

15

20

0 20 40 60 80 100

Gases Only

(from bomb calorimeter)

Gases + Liquids + Solids

(from fire calorimeter)

LiCoO2

Qmax = 2600 mAh

3.7V (nominal)

0

5

10

15

0 20 40 60 80 100

PH

RR

(kW

/cell)

or

HO

C (

kJ/g

-gas)

State-of-Charge/SOC (%)

Heat of Combustion

of Gases/HOC, kJ/g

Peak Heat Release

Rate/PHRR, kW/cell

PHRR and HOC for LiCoO2 18650 Cell

Flaming

Combustion of

Cell Contents

(75 kJ/cell)

Decomposition

Reactions

(14 kJ/cell)

Stored Electrochemical

Energy (14 kJ/cell)

LiCoO2 Cell at 50% SOC

Fire and Thermal Hazards of 18650 Cell

Total 103 kJ/cell = 2.3 kJ/g 1/20 jet fuel

= 109 J/m3

75 kJ/cell

6.62 x 10-5 m3/ cell qv =

HRR (t ) qv

dV

dt qv

dL(t )3

dt 3qv (L0

)3t 2

Analytic Model of LIB Cargo Fire Growth

L(t)

L(t)

L(t)

Combustion

Volume at time t,

V(t ) = L(t )3

L (18mm)(65mm) 34mmEffective Length of 18650,

Constant linear fire growth rate,

L 0 L

L 2

mc / 3x104 m /s

Heat Release in Flaming Combustion, qv = 109 J/m3

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60 70

Heat R

ele

ase R

ate

, H

RR

(kW

)

Time After First Ignition, minutes

Battery Fire Model

(LiCoO2 18650, 50% SOC)

Full Scale Test Data

LiCoO2 18650, 50% SOC

(from O2 consumption)

H. Webster, May 2013

Full-Scale Test (Before) Full-Scale Test (After)

Model Versus Full Scale Test Data

Class E

Main Deck

Cargo

Thermal Energy Released at Cell Failure of 18650 LIBs

(∆Utotal) is:

• Dependent on cell chemistry (voltage and capacity)

• Equal parts electrical (Q) and chemical (∆Urxn)

• Responsible for fire propagation

• Half of total fire hazard when combustion of contents is

included combustion.

Summary