Fire Hazards of Lithium Ion Batteries

International Aircraft Systems Fire Protection Working Group Meeting
Dresden, Germany, May 12-13, 2015

Fire Hazards of Lithium Ion Batteries

Richard E. Lyon, Richard N. Walters, Sean Crowley,
and *James G. Quintiere

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

WEB: www.fire.tc.faa.gov E-MAIL: [email protected]

Objective: Measure Fire Hazards of LIBs

Typical
packaging

Typical bulk shipment as cargo

Passenger electronics

Causes of Battery Failure

• Thermal < 1 second
– Separator melts due to high
temperature causing All lead to auto-accelerating heat
internal short circuit that generation and rapid temperature
releases heat. increase (Thermal Runaway) leading
– Contents mix, react and
thermally decompose. to fire and/or explosion

• Electrical
– Overcharge
– Rapid discharge

• Mechanical
– Physical damage (puncture)
– Manufacturing defect or
contaminant

Materials: Commercial 18650 LIB Cells

18650 Rechargeable Cells ( 44 grams each)

65 mm

18 mm

Electrical Properties of Tested Cells

Maximum Cell Potential, -∆G, Qmax

Capacity,Qmax  (V) (kJ/cell)
(A-s)
Nominal Max. 41
Cathode Rated Actual 31
3.6 4.1 19
LiMn2O4-LiNiCoO2 11,700 11,200 3.7 4.1 13
LiCoO2 3.7 4.1
LiNiCoAlO2 9,400 8,300 3.7 4.0
Unknown
5,400 5,000

18,000 3,600

Chemical Energy Available to Do Useful Work (Free Energy), ∆G = -Q
State-of-Charge, SOC = Q/Qmax

Experimental Methods: Cell Charging

• Charge / Discharge 4 cells simultaneously
• Record: charge / discharge capacity
• Programmable for different states of charge

Methods: Hazard Measurements

Energetics of Cell Failure

ASTM D 5865-14, Standard Test Method for
Gross Calorific Value of Coal and Coke

Thermal Effects of Cell Failure

Purpose-Built Thermal Capacitance
(Slug) Calorimeter

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)

• 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

Experimental Setup

Bomb and other components
for 18650 battery tests

Thermodynamics of Cell Failure

Depends on
cell chemistry

UTotal  Urxn  Q

Total energy Electrochemical (Free) energy release
released at cell (Calculable from cell potential (V) and

failure charge Q (A-s))

 (measured in bomb)

Energy released by mixing, chemical
reaction and thermal decomposition

of cell components.

Analysis of Bomb Calorimeter Data

18650 Cell Chemistry

Unknown LiNiCoAlO2 LiCoO2 LiMn2O4-LiNiCoO2

Energy Release at Failure (kJ/cell) 80 Total Energy Energy of Mixing, Reaction
70 (∆Utotal)
60 and Decomposition, ∆Urxn
50
40 ∆Urxn  90% of Q
30
20 Free Energy, ∆G (Q)
10
500 1000 1500 2000 2500 3000 3500
0 Charge, Q (mAh)
0

Energetics of Individual Cell Failure

Energy Release at Failure (kJ/cell) 80 LiMn2O4-LiNiCoO2 ∆Utotal 60 LiCoO2 ∆Utotal
50
70

60 40
50 30
40
30 20
∆Urxn
10
20 ∆Urxn 0
10

0 -10
0 10 20 30 40 50 60 0 5 10 15 20 25 30 35 40

40 LiNiCoAlO2 ∆Utotal 30 Unknown ∆Utotal
∆Urxn
30 25
20
10 20

0 ∆Urxn 15
10

5

0

-10 5 10 15 20 25 -5
0 0 5 10 15 20

Electrochemical Free Energy, Q (kJ/cell)

State-of-Charge is Not a Good Predictor of Energetics for
Different Chemistries and Cell Potentials

50 StoredFree Energy, Q (kJ/cell) LiMn2O4- 80 Total LiMn2O4-
Electrochemical LiNiCoO2 Energy LiNiCoO2
Total Energy, ∆Utotal (kJ/cell)
Energy (Q) LiCoO2 70 (∆Utotal) LiCoO2
60
40 LiNiCoAlO2
Unknown 50
30
40
20
LiNiCoAlO2
10
30

Unknown

20

10

0 0
0 20 40 60 80 100 0 20 40 60 80 100

State of Charge, Q/Qmax (%) State of Charge, Q/Qmax (%)

Li-Ion 18650 Batteries - Post Test

Zero Charge 50% Charged 100% Charged

Volatile Yield, g/cellGravimetric Analysis for Volatile Yield

• Bomb weighed before and after venting
to atmosphere to determine volatile yield

• Volatiles are combustible

• Yield  Q

LiMn2O4-LiNiCoO2

6 LiCoO2
5
4 LiNiCoAlO2
3 Unknown
2
1
0

0 10 20 30 40 50

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

Infrared Spectra of Gaseous Decomposition Products

LiNiCoAlO2
LiCoO2
LiMn2O4-
LiNiCoO2
Unknown

Thermal Effects of Cell Failure

Separator 20 g
Melts (150C) 2s

Venting (200C)
Failure (250C)

600C

2s

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.

Thermal Energy Release (qb)  Free Energy (Q)

Implies chemical reactions of electrolytes
(∆Urxn) take place outside of cell when
contents are ejected

Thermal Energy qb, kJ/cell 50 1
40 1
30 50
20 10 20 30 40
10
Stored Free Energy, Q (kJ/cell)
0
0

Adiabatic (Surface) Temperature Rise

Tmax  Tf  Utotal  Tf  Urxn  Q
m cp m cp
m cp

 250C  Urxn  Qmax * SOC

mcp mcp 100


Maximum Cell Surface 1400
Temperature, Tmax (C)
1200  Contents
1000
Ejected,
800 ∆Urxn  0,
600 Tmeas < Tcalc

400

200

0
0 20 40 60 80 100

State of Charge/SOC (%)

Fire Calorimeter Testing of Lithium Cells

Standard ASTM E 1354 Operation

Special holder designed to
prevent rocketing of cell at failure

Heat Release Rate in Cone Calorimeter

Failure is so rapid that HRR must be HRR Corrected for 3-
corrected for cone calorimeter response second Response Time of

6 Failure Cone Calorimeter
(Deconvoluted)
5 Venting 5s

HRR, kW/cell 4 5s 5s

3

2 Original Data

1

0
80 90 100 110 120 130 140 150

Elapsed Time, seconds

Fire and Thermal Hazards of 18650 Cell

Discharge of Stored Total  103 kJ/cell = 2.3 kJ/g  1/20 jet fuel
Electrochemical Energy
By Internal Short Circuit Flaming
Combustion of
(14 kJ/cell) Cell Contents

(75 kJ/cell)

qv = 75 kJ/cell
6.62 x 10-5 m3/
cell

= 109 J/m3

Decomposition LiCoO2 Cell at 50% SOC
Reactions
(14 kJ/cell)

Analytic Model of 18650 Cargo Fire Growth

L(t)
Combustion

Volume at time t,
L(t) V(t ) = L(t )3

L(t)

Effective Length of 18650, L  (18mm)(65mm)  34mm

Constant linear fire growth rate, L0  L  L2  3x104 m / s

 mc/ 

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



HRR (t )  qv dV  qv dL(t )3  3qv (L0)3t 2
dt dt

Model Versus Full Scale Test Data

Class E
Main Deck

Cargo

Heat Release Rate, HRR (kW) Full-Scale Test (Before) Full-Scale Test (After)

1200

1000 Battery Fire t 2 Model
800 (LiCoO2 18650, 50% SOC)

600 Full Scale Test Data
400
200 LiCoO2 18650, 50% SOC
(from O2 consumption)
0 H. Webster, May 2013
0
10 20 30 40 50 60 70
Time After First Ignition, minutes

Summary

State-of-charge is a poor predictor of fire hazard for
different batteries and cell chemistries.

Total energy at failure of Li Ion cells/batteries (LIB), ∆Utotal

is almost twice the stored electrochemical energy Q for

the 18650 cell chemistries of this study.