Offices in ENGLAND, USA, CHINA, INDIA

Representation Worldwide





Ba

Thtt

e e

ry

A

R S

C a

® fe

B tayt ta

e n

r d

y Ba

Sy t

stte

e ry

m sPerformance

St

B u

atdtie

er s

y Safety, Efficiency, Lifecycle, Performance, Lithium Batteries & Heat...

Lithium batteries are recognised as hazardous - it is important to determine both the effect of heat on lithium batteries and the heat that results from their use and abuse.

ARC Calorimetry will give vital thermal data to areas of battery development, battery safety, battery performance efficiency and lifecycle.





Battery Safety and Battery Performance


The Accelerating Rate Calorimeter was devised by the Dow Chemical Company in the 1970’s and was commercialised in 1980. This technology was developed to simulate exothermic runaway reactions from hazardous and reactive chemicals safely in the laboratory. For such a simulation an Adiabatic Calorimeter is appropriate and ARC technology embodies the best adiabatic control. In operation, the calorimeter temperature is controlled to always track or follow the sample temperarture. Therefore as a sample self-heats and its temperature rises, so does the calorimeter temperature. Worst Case evaluation is made and a Real Life Scenario simulated. Pressure can also be measured and calorimeters can take very large batteries. In addition, the ARC will operate in isothermal mode with exceptional sensitivity and stability. The unique dynamic range allows for detection and measurement of very small heat release as well as the ability to quantify runaway explosive decompositions.

Such requirements are important for battery work.

Uniquely the ARC has robustness and ruggedness to 2

withstand damage should an explosive reaction occur and thus THT systems are designed to be safe in such circumstances.



Unrivalled Specification

The other key point necessary for many battery applications severe oxidation reactions occur between battery components is the size of the calorimeter. Five options are available; of and oxygen in the air. Because of the volume of the calorimeter it is simple to connect the battery to leads, allowing in-situ electrical those cylindrical in their internal shape, the smallest measurement. Also with large batteries it is possible to apply measures 10cm in diameter by 10cm in depth and is suitable multiple thermocouples to allow temperature distribution for testing battery components in metal holders, coin cells, measurement over the battery surface. Connecting the battery to small prismatic, 18650 and other smaller ‘domestic’ batteries.

an appropriate cycler or battery test system allows vital The largest 65cm by 50cm will take large battery modules and temperature and pressure data to be obtained under conditions of packs used, for example, in applications from power tools to charge, discharge (including of course the very fast discharge needed for automotive applications). Also successive cycling and satellite and automotive applications.

abuse testing such as short circuit, overvoltage and nail In use to detect heat release the system does not scan in penetration and crush (internal short circuit) can be performed temperature. Successive small heat steps are applied and within the ARC calorimeter. The ARC is therefore an ideal tool to evaluate both performance and safety aspects of lithium batteries, after a wait period for isothermal equilibration, there is a seek not forgetting its initial role in evaluating new battery chemistries.

period to detect heat release by temperature rise. When this occurs the system automatically switches to the Exotherm mode the world benchmark calorimeter for scientists and engineers and tracks the heat release, by accurately following the focusing in the area of chemical hazards. Today the latest temperature rise, storing Time-Temperature-Pressure data.

generation ESARC with large volume calorimeters is the No.1

choice for those researching battery safety and development Such studies are routine for groups studying battery components in order to develop chemistry that optimise life-cycle of those batteries.

But ARC technology can allow much more to be achieved.

Batteries like reactive chemicals or explosives will also release heat – they will react and decompose when heated, internal pressure may cause them to rupture and disintegrate.





M a i n H e a d i n g

ARC® Instrumentation





The ESARC


ARC key aspects are:


Excellent Adiabatic Control to 0.01°C

Ultimate Sensitivity to 0.002°C/min

Measurement of Pressure and Temperature

Choice of Calorimeter Size to 65cm by 50cm

Resultant Gas Collection facility

Ease of Use

Rapid Set Up; 10 Minutes

Intuitive Labview™ Software

1-3m 3 Working Volume





Versatile and Flexible Operation


Any Chemical / Battery Type

Many Battery Holders

Isothermal and Isoperibolic Modes

Air: Inert Gas Atmosphere, Vacuum

For safety studies and accurate detection the Heat-Wait- Seek protocol of the ARC and automatic

Multiple Built-In Safety Features

detection of exothermic reaction is shown below. For

Rugged Robust Construction

full details of the ESARC, its mode of operation data and analysis, please request the 28 page ARC

Explosion Proof Containment Vessel

brochure or visit www.thtuk.com, www.thtusa.com or

3mm Reinforced Steel

www.thtchina.com.

Proximity Switch Shut Down

Heat-Wait-Seek Protocol to Detect Self-Heating

Software Shut Down Facilities

120

120

Automated Fume Extraction

) 118

118

Fireproof and Explosion Containment

116

116

( ° C 114

114

R E 112

112

T U 110

Exotherm

110

R A 108

108

E P 106

106

M

Some Reaction, below sensitivity

104

104

T E 102

No reaction

102

100

100

200

250

300

350

400

450

500

T I M E ( m i n u t e s)

4





M a i n H e a d i n g

Cal m

o ain

rime theead

r C e

h r

oice

Batteries come in all shapes and sizes. Often it is necessary to BPC

test both small and large batteries.

For battery performance studies and research of large format cells appropriate in the automotive and power tools industries, Standard esARC

THT has developed the battery performance calorimeter (BPC).

The standard ARC Calorimeter has an internal size of 10cm diameter by 10cm depth. This restricts use to battery The BPC is also likely to be the calorimeter of choice in areas of components and smaller batteries, from Coin Cells to AA and Stationary Applications; for storage and ‘peak shaving’. The BPC

18650 to 26650, prismatic and smaller lithium polymer is 65cm diameter by 50cm depth and is housed in the EV

batteries.

containment vessel ensuring maximum safety in operation. The BPC uses the same electronics hardware and software as other EV

THT ARC systems and can be acquired packaged together with To facilitate safety testing of large batteries, EV batteries and the other calorimeters – or as a multi calorimetry system.

modules, THT developed the large volume calorimeter, the EVARC. The internal size of this EV calorimeter is 25cm diameter and 50cm depth. Using all electronics and software of the ESARC, the EVARC can be operated with either the EV

calorimeter or the standard calorimeter allowing full functionality of both instruments.

EV+

The EV+ calorimeter has larger volume and is designed for safety and performance testing of EV cells and small modules.

It has been designed to fulfil requirements of SAND 2005-3123, SAE J2464. USABC / FeedomCAR, UN & UL tests.

The EV+ calorimeter is a low-pressure tight sealed unit. The lid to base seal is maintained by electromagnets. It is designed to vent with a modest over pressure, but this is unlikely as gas generation is led to collection facilities.

There is in built capability for gas collection, video monitoring, battery clamping, multifunction and cryogenic operation.

A THT Battery Test system; the ESARC,





EVARC Double System is shown


5





M a i n H e a d i n g

Battery Specific ARC Options

A range of options and kits are available to allow

Battery Abuse Tester (BSU)

testing for Battery Chemicals to Abuse tests and EV

battery modules. Many options are suitable for all The BSU allows abuse tests to

calorimeters, some are specific to particular be carried out such as over

calorimeters.

voltage

charging

and

discharging and short circuit

Options can be acquired with the unit or added at any testing. The options currently

later date.

requires manual operation but

links with ARC software for data

Battery Materials & Chemical Components Kit

analysis. Such tests can be

achieved in the standard and EV

To test effect of heat upon materials, the standard calorimeters.

(small size) calorimeter is typically used. Sample size may be 100mg to 5g. The kit contains appropriate

Battery Connection Kits

sample holders and modified pressure lines to facilitate such studies.

EV size cells and modules tested with high power discharge require low impedance cables and connections. THT supplies standard and customer specified connection kits to allow appropriate testing.

Heat Capacity Option (CPO)

Battery Safety Holders & Canisters

There is need to measure

THT have available a full range of battery holders.

heat capacity for ‘Thermal

There are suitable for all shapes and sizes from small Management’ studies. If the

coin cells, 1850 to prismatic to large format cells and battery overall heat capacity

modules. In addition THT provide pressure certified is known the temperature

canisters where cells can be isolated in smaller and temperature rate data

calorimeters, gas can be isolated and then taken for can be converted to units of

analysis.

heat in Enthalpy (Joules) and

heat release rate i.e Power

(Watts). The option can be

provided as semi or fully

automated form. To measure

the heat capacity two or

more cells are heated with a

‘heater mat’ by a precise power supply. In the fully automated form the power supply is integrated to the ARC system and the data is analysed with the ARCCal+ ARC software.

Integrated Battery Cycler - KSU Option

Surface Area Heat Measurement

THT, KSU option, is an integrated

Multipoint Option (MPO)

single channel battery cycler. The

voltage and current range are

Heat

release

for

user specified. Fully integrated

batteries is not uniform.

with appropriate software to give

Typically

heat

may

a single turn-key instrument to

conduct through metal

allow

rapid

charge/discharge

components or collector

cycling i.e tests under conditions

plates and appear at the

of battery use.

terminals.

For

applications such as

Further to this interfacing of other

Thermal Management

units to THT ARCs can be

there is the need to

requested or the user may implement other available understand the variation

cyclers and testers, loads and charges with stand 6

of heat release over

alone software.





batter surface.





The motorised option allows controlled speed nail

Surface Area Heat Measurement

penetration. This is needed in ‘standard test

Multipoint Option (MPO) - continued

methods’ and is valuable for larger batteries or modules when speed variation can give difference in THT provide both semi and fully automatic options to result. The controlled speed unit has been developed allow surface area heat measurement. 8, 16 and 24

for the EV+ calorimeter which is itself designed to thermocouple options are available.

carry out testing to standard methods.

The fully automated option integrates both with the ARC hardware and software. The same option is available for all THT battery calorimeters.

Cryogenic Operation





Video Monitoring


Video monitoring is standard in the EV+ calorimeter again fulfilling the need in ‘standard test methods’.

The high resolution camera is air cooled for close proximity filming. The special glass window used in the EV+ calorimeter allows a gas tight seal and easy cleaning.

Isothermal, Thermal Management, Multipoint and Heat Capacity testing is often needed over the full range of ambient temperature - this could possible be to -40°C. To facilitate such tests THT provide a manual cooling option for the EV and EV+. The option Gas Collection

using liquid nitrogen allows rapid cooling and short Gas collection is achieved in the standard and EV

term cryogenic isothermal stability.

calorimeters by use of sealed canisters. These are placed internally within the calorimeter. The canister allow for cables and thermocouples to pass through

Nail Penetration & Crush Option

via sealed ports. Other ports allow for inerting the THT provide Nail Penetration & Crush option for atmosphere, pressure measurement and gas differing requirements; smaller and larger batteries.

collection. The versatility of this approach means that For the standard and EV calorimeter the option is a variety of external collection methods are possible pneumatic abd has capabilities to crush 18650 cells.

(cylinders or bags). This method eliminates the need The interchangeable nail and crush head can be for closed battery holders. Closed holders were selected and easily replaced. A range of size and originally used but explosion of holders with shapes are possible.

associated hazard is common with this approach.

Manual Nail Penetration and Crush can be carried out The EV+ calorimeter is of sealed construction but with simply with all calorimeters but can be hazardous to a 5cm port integrated for gas collection. As standard the operator and gas release to the environment is the unit is supplied with gas collection bags though possible.

alternative configurations can be simply made. The EV+ is designed to facilitate gas measurement and THT offer two options; pneumatic and motorised: The collection with the gas being taken for external pneumatic system has been designed to automate analysis and fulfil the requirements of standard test Nail Penetration and Crush with smaller batteries.

methods

This option does not have controlled speed but can give high power. When the batteries are small, speed variation gives little difference in result. Small batteries (e.g. 18650) may be very rigid and this pneumatic method will give nail penetration and appropriate crush. This option is available for the standard and EV calorimeters.

7





M a i n H e a d i n g

Battery & Battery Components Testing





Battery Components


Evaluation of battery components to study new battery chemistries is key to enhanced battery performance and safety. Also heat capacity of batteries of any size can be measured - this is uniquely available with THT ARC technology.

The application of the ARC to lithium batteries may be categorised into six groups:





1


Battery components testing and development of new battery chemistries; a research area where much work has been done within University & Academic environments

It is the reaction or an





2


Complete batteries and packs for safety studies; interaction

between

testing and for performance and safety; typically components that can lead to

carried out by battery manufacturers and bulk reaction is decomposition of





3


Battery heat output under normal conditions of SEI surface layers, anode

use for heat output; cycling for heat release reaction

then

internal

release of oxygen from

studies; testing carried out in academic or

electrolyte or cathode that

industrial laboratories

can self-heat or violently react with the lithiated anode.





4


Fast discharge, battery performance studies

Pressure measurement is important, disintegration of important for EV, HEV , PHEV , battery packs & modules where the temperature distribution over

)

THT has worked with battery companies to develop the battery varies, typically MultiPoint

i n

the technology and application in this area. The measurement important for power tools and

m /

automotive applications

‘Battery Component Kit’ contains low mass silver tubes and these can connect to a ‘side branch 5

Battery heat output under abuse conditions;

t ( ° C

pr dessure tube’. In this way ‘low

’ testing with

implementing tests where the battery is subjected

/

measurement of pressure can be achieved using to misuse and quantifying heat output (shorting & sm

d T all quantities of battery component material. Of overvoltage); again typically carried out by g

course where large quantities are available, the ARC

L o

can be used without modification using standard ‘ARC





6


Stationary applications; important in storage and Bombs’.



peak shaving. These are typically with very large batteries that are potentially subjected to a full range of tests; and is of value to power generator, Effect of Increasing Component Particle Size LiCoO2 (a), (b), (c)



and municipalities.

10

(a), LiCoO2(1)

There may be the need to measure pressure and 1

Stoppedat 220°C

collect resulting gas for analysis; this is possible 0.1

for all batteries. Also there is ability to measure i n )

10

heat capacity of batteries of any size. This is uniquely available with THT ARC technology.

C / m

(b), LiCoO2(2)

1

0.1

10

d T / d t ( °

(c), LiCoO2(3)

1

0.1

120

160

200

240

280

320

T E M P E R A T U R E ( ° C )

8





M a i n H e a d i n g

main header





Safety Testing of Batteries


To facilitate pressure measurement THT has developed tanks that will accommodate the battery and be gas tight. These still Batteries of varying shape and size may be tested in the ARC; allow for thermal and electrical measurement. The chamber they may be accommodated by suspension from the lid section (as is usual) or may be supported directly in the base of the measurement of pressure it is possible after the test to sample calorimeter. The simplest test is effect of heat upon the battery. It gas for analysis. If connected to external analytical is possible to test batteries at any State of Charge, or age, and it is possible to connect cables to the battery terminals to measure time gas analysis.

voltage during the test. Open or closed sample holders are available – but as with all samples that undergo significant

The exothermic reactions shown from a fully charged 18650

gas generation, rupture of a closed holder might occur.

battery are typically SEI, anode, separator (endotherm) and cathode reacting with electrolyte – as shown. Above 200°C the A key difference between chemicals and batteries is that battery may disintegrate or the reaction may go to completion batteries have their own ‘holder’. Also initial pressure generation without disintegration of the battery.

is contained. THT offer two possibilities to study pressure associated with batteries, internal pressure measurement or the Batteries at different States of Charge or different age will give pressure

upon gas

release

from battery after disk

rupture or disintegration.

that batteries will retain their voltage until well into exothermic decomposition as illustrated.

Aside from onset, the ARC test will determine self heating at all temperatures – and thus gives much more information than Hot Internal pressure measurement is simply achieved by attaching contain pressure or to disintegrate in such an event is important; shown here indicates pressure increase to 4bar prior to the exothermic decomposition commencing. As decomposition lithium reacts with air and the release of potentially toxic smoke.

proceeds the internal pressure increases and it is not until above 12 bar that the battery disintegrates and there is gas release.

Battery Thermal Stability Test





Voltage Against Time Graph


600


4.2

/ )

4.15

( ° C 500

Voltage against Time

T E

4.1

)

400

R A

4.05

( V

R E 300

4

G EA

T U

T

A

3.95

200

O LV

E R

3.9

P 100

M

3.85

T E 0

3.8

0

500

1000

1500

0

500

1000

1500

T I M E ( m i n )

T I M E ( m i n )

T I M E ( m i n )

The Exotherm Portion has Overlapping Reactions Internal Pressure During Test

) 100

450

16

i n

400

Temperature

/ m

Thermal Stability Testing

Batery Disintegration

/)

14

of a Charged18650 Batery

C

PR

( ° C

10

350

Pressure

(°

12

E

T E

E

S

300

10

S

Cathode Reaction

R

R A

U

U

1

T

R

250

8

R E

A

E

R



T U

E

(

200

6

b

P

a

R A 0.1

SEI Reaction

M

r

E

Separator Melting

E 150

4

)

P

T

M

Anode Reaction

100

2

T E 0.01

9

80

100

120

140

160

180

200

1000

1100

1200

1300

1400

1500

1600

1700

1800

T E M P E R A T U R E ( ° C )

T I M E ( m i n )

)

) ( ° C

( ° C T E

T E R A

R A R E

R E T U

T U R A

R A E

E P

P M

M T E

T E

M a i n H e a d i n g

Use & Abuse Testing of Lithium Batteries

Testing of Batteries under Abuse conditions

The result shown is from a fully charged battery and shorting leads to a temperature rise of 100°C and then Lithium batteries can fail dramatically when to disintegration. This will not happen for all battery overvoltage charged or when physically abused. Many chemistries and does not happen for this battery type such abuse tests have been proposed and several are if it is fully discharged. In the discharged state, a detailed as standard tests required by regulating temperature rise of 30°C occurs. This temperature authorities. Prescribed tests typically give an empirical rise is not sufficient to lead to runaway and Heat-Wait-pass or fail answer. The ARC has potential here to Seek steps occur.

accomplish a range of tests in which abuse conditions are simulated, generating quantitative thermal External Short Circuit

information. Such tests may be carried out with smaller 600

batteries in the standard

ESARC

system or

/ )

with large batteries in the EVARC system.

500

( ° C

Several esoteric tests have been achieved within an 400

R E

ARC calorimeter, for example water immersion.

T U 300

However here overvoltage, external short circuit and R A

nail penetration are illustrated.

E 200

P

Options are available from THT to allow either manual M 100

or automated (computer controlled) abuse tests on T E

0

batteries to be carried out within the ARC calorimeter.

0

10

20

30

40

50

60

70

80

90

100

T I M E ( m i n )

Lithium batteries if overcharged are known to self heat and can lead to disintegration. The

battery here

As battery development has progressed; variation in was overcharged. The battery was subjected to chemistry has led to batteries that are thermally stable charging at 450mA on a 20V supply. After 200

to higher temperatures and undergo much smaller minutes the battery voltage increased above 4V with exothermic reactions i.e. giving less heat release.

associated temperature rise. After 500 minutes there These batteries are SAFER, it is naive to say they are was rapid temperature rise (and cycler shut down). he SAFE! Data shown for Generation 1 to 5 of cathode exothermic reactions continued and increased until material has been published by Dr E. Peter Roth at battery disintegration occurred.

Sandia National Laboratories and is shown with his permission.

Overvoltage Test

) 25

500

300

Comparison of Cathode Materials and Reduction in Heat Output

E ( V

T

250

E

G 20

400

M

A

P

500

TL

200

E

ARC

EC:PC:DMC 1.2M LiPF6

O

R A

LiCoO2: 1.20Ah

V 15

300

) 400

T

100% SDC

150

U

i n

LiNi0.8Co0.15Al0.05O2: 0.93Ah

( A )

R E

T 10

200

/ m 300

100

(

E N

º C

Li

( C

1.1(Ni1/3Co1/3Mn1/3:)0.9O2 0.90Ah

R

)

5

100

R

50

T E 200

LiFePO4: 1.18Ah

C U

R A 100

0

0

0

LiMn2O4: 0.65Ah

0

100

200

300

400

500

600

0

T I M E ( m i n s )

0

100

200

300

400

External shorting of a battery within the ARC is simply T E M P E R A T U R E ( º C )

achieved by joining two low impedance wires

)

connected to the battery terminals. The test is rapid (1-2

in

5

EC:PC:DMC 1.2M LiPF6

Gen2: LiNi

/m

0.8Co0.15Al0.05O2

hours) and carried out with the instrument in an 4

(C

100% SDC

Gen3: Li

isothermal mode.

1.1(Ni1/3Co1/3Mn1/3:)0.9O2

TEA 3

R

LiMn2O4

D

Shorting gives heat output that is tracked by the E

2

LiCoO

IZ

2

calorimeter and the amount of heat released can be LA

LiFePO4

quantified together with an understanding that this M

1

RO

temperature rise can lead to battery disintegration.

N

0

10

0

100

200

300

400

T E M P E R A T U R E ( º C )





M a i n H e a d i n g

main header

Nail penetration testing considers the effect of such where rapid and large discharge is needed, this can abuse and of internal short circuit. This test can be result in a much greater heat release and done within the ARC in a manual or automatic mode.

temperature rise.

The battery is held on a support and the nail, on the end The KSU Option for the ARC is a single channel cycler of a rod is driven through the battery, the thermal effect and several versions are available with differing is measured. Of key importance is to know if the voltage and current ranges. This may be used or battery temperature will be raised to initiate a testing can be achieved with a stand-alone disintegration reaction. In the example shown nail customer supplied cycler. In the latter case there penetration results in a temperature rise of near 100°C

will be two sets of data that need to be synchronised.

and there was further temperature rise that led slowly to battery disintegration.

Often in cycling tests, the battery within the ARC is surrounded by a jacket of insulation. This reduces Nail Penetration

heat loss and better data can be obtained from tests

) C 500

carried out either isothermally or adiabatically.

( ° 450

T E 400

Repeated cycling is often implemented. Tests may 350

R A

be carried out with a few cycles in the ARC (when the 300

R E

battery is fresh), the battery removed and repeated 250

T U

cycling performed outside the ARC. Then the test is 200

R A 150

repeated (with the aged battery) inside the ARC. The E P 100

change in thermal effect and speed of charge M

50

T E

discharge will give a measure of capacity change with 0

200

6040



10080



200

140120



180160



220

240

T I M E ( m i n )

and lifetime characteristics of the battery are determined.

Such tests are illustrated here with ‘model’ 18650

batteries. These are often the choice in development The data below illustrates, left, two cycles of a fresh studies. However using the

EVARC and BPC

18650 battery and, right, several cycles of an aged calorimeters these same tests can be carried out with battery. The associated thermal change, shows larger, indeed very large battery packs and modules.

charging to be

endothermic

and

discharging

To facilitate these tests Battery Abuse Kits for manual exothermic. However the overall trend is for a operation and the Battery Safety Unit (BSU Option) for temperature increase, the magnitude of this relates automated operation are available.

to the internal resistance of the battery.





Battery Cycling


600


4.2

3.9

-250

)

4.1

-200

( V 400

3.8

e ( V )

4

G E

150

A 200

T

3.9

3.7

100

o l t a g

V

O L

0

3.8

O

V

400

450

500

550

600

650

700

750

800

850

900

V

50

L

3.7

3.6

-200

) &

TA

) &

3.6

0

A

G

A -400

E

3.5

3.5



-50

( m

T ( m

T -600

3.4

N

-100

3.4

E N

E

3.3

-800

R

R

-150

R

3.2

R

-1000

C U

3.1

C U

-200

45

50

80

)

40

45

75

T

( ° C

E ( ° C )

e

E

m

R

R



35

40

p

70



T U

T U

B

A

a

Testing of Batteries under Use Conditions A

t

R

t

E

E R 30

35

e

65



P

P

r y

M

Quantifying the heat generated by lithium batteries T E

T E M 25

30

60

during conditions of use allows for an understanding 55

20

25

400

500

600

700

800

900

0

500

1000

1500

2000

2500

3000

T I M E ( m i n )

T I M E ( m i n )

of their efficiency and gives information that is Again such application can be realised not just with important in determining their use and any thermal or smaller (e.g. 18650) batteries but with large batteries, safety issues that may result during normal packs and modules. Cycle life is one key advantage operation. Variation in heat release from batteries as of lithium batteries over different chemistries; cycle they age will indicate life cycle.

life is important in satellite and space application Heat release relates to internal resistance and where there may be a day – night charge – discharge rotation; it is similarly important in stationary applications where discharge is slow and gradual, in 11

applications designed for peak shaving and storage.

applications such as electric vehicles or power tools





M a i n H e a d i n g

Calorimeter Choice

EV+

EV+ Calorimeter

The calorimeter is ready for addition of further options:-

The EV+ Calorimeter has been designed for EV cells and small modules and to make the needs of testing Sub Ambient Operation, Cryogenic Option necessary with EV batteries.





Calorimeter Ready.


Pressure tight ports provided in calorimeter which can be Many prescribed ‘standard’ tests call for Calorimetry blanked off or used if cryogenic (LNFO) option is available and also call for use of abuse testing (eg SAND, SAE).

operates to -50°C.

Tests call for video monitoring, gas detection/analysis, Heat Capacity Measurement Cp Option

nail penetration and crush under controlled conditions.





Calorimeter Ready


The EV+ calorimeter from THT has been designed to Pressure tight ports provided in calorimeter which can be accommodate many of these tests - and more whilst blanked off or used if Heat Capacity Option (CPO) is gaining quality information on heat release.

available.

Surface Area Heat Distribution, Multipoint Option





Calorimeter Ready


Pressure tight ports provided in calorimeter which can be blanked off or used if either the 8 thermocouple, 16

thermocouple or 24 thermocouple Multipoint Option (MPO) is available.

Controlled Speed Nail Penetration & Crush Option





Calorimeter Ready


Pressure tight ports provided in calorimeter which can be blanked off or used if the NP option is available.

The latest THT Nail Penetration option allows functionality to SAND 2005-3123 & SAE J2464 specification. (EC-CS-NPCO). The NP option is pressure tight to the calorimeter (it allows in operation in situ gas collection and video monitoring). The NP option allows for nail penetration at controlled speed and crush with movement stop at voltage drop.

In built safety features are standard to the EV+ calorimeter and it is housed within the THT ‘EV Containment Vessel’.

Multiple shut down features add to the fail safe mode of operation.

The EV+ links to THT hardware and software to allow Key features of the EV+ are its size and its ability to:-

modulating and upgrade possibilities at moderate cost.



Have good calorimetric performance

Gas analysis options can be supplied by THT or THT can Incorporate the range of appropriate options advise on specific options for gas analysis; real-time MS or GC-MS.

The EV+ is an cylindrical calorimeter 40cm in diameter and 44cm depth. Unlike other THT adiabatic calorimeters the lid seals to the base unit. This seal is restricted to below 1 bar and is maintained by electromagnets. This allows for inertion of the environment and the ability to collect products of battery disintegration. A gas collection line (leading to gas collection bag) is standard.

Also standard on the EV+ calorimeter are:-

Integrated cables for current & voltage measurement

Video camera (with light)

Ability for battery pressure and temperature measurement

Ability for purging, evaluation, inerting

12





M a i n H e a d i n g

m

C a

alin

o he

rim a

e d

t e

e r

r Choice

BPC & IBC

The Battery Performance Calorimeter (BPC) The BPC used with THT ARC software and electronics can be Thermal Management, Efficiency & Lifecycle Studies.

used within the adiabatic isothermal or isoperibolic modes. The choice of mode relates to the studies undertaken.

The Battery Performance Calorimeter (BPC) is a large volume calorimeter developed for research studies of larger (EV) cells Key options used with the BPC are the surface area (multipoint) and modules. The BPC utilise ARC electronics and software and option and the heat capacity option. The BPC complements the is modular with the standed, EV and EV+ calorimeters. It can be other calorimeters available from THT.

housed in the standard THT EV containment vessel.

The Isothermal Battery Calorimeters (IBC)

THT have a range of isothermal battery calorimeters. These complement the ARC-based calorimeters however they do not use ARC electronics or software.

The need for true isothermal calorimeters is when charge discharge or self discharge isothermal testing is appropriate.

The isothermal battery calorimeters are fully described in their

specific brochure.

The BPC is designed to quantify heat changes during charge Isothermal calorimeters have higher sensitivity that adiabatic and discharge – at conditions that simulate use of the battery.

calorimeters but have a limited range of applications. Their The BPC is not appropriate for stability, safety and abuse studies temperature range is limited and they are not appropriate for where battery disintegration is possible. The BPC has an upper safety abuse testing when battery disintegration or high temperature limit of 200°C but operates down to -40°C.

temperatures may result.

Cryogenic operation is possible by linking to a refrigerated The THT range of

circulating bath.

isothermal calorimeters

A key and unique feature of the BPC is the ‘Thermal Diode’

includes size specific

heating system that allows current flow through the calorimeter.

calorimeters that have

This eliminates need for conductive leads or cables to carry built in cycler capacity.

current. At high power operation such loads do come major heat The high sensitivity of

loss and data error in calorimeters with no ‘thermal guard’. (The these units allows the

EV+ uniquely does have thermally guarded leads and these do measurement of small

minimise error)

coin cells. The IBC for

prismatic batteries can

The calorimeter has a depth of 50cm but its cross section is oval have

integrated

(50-65cm) maximising useful volume for large batteries.

multipoint heat measurement. This allows the variation of heat With heat detection sensitivity at 0.005°C/min the BPC has release over the surface area of the battery to be measured.

stable specific detection for heat release. In conjunction with the High sensitivity self-discharge calorimeters (IBC-SD) are THT surface area (multipoint) heat measurement option, the available. The chamber size (typically Double-D) means that a BPC at well below 1 w/g detection, is ideally suited for gaining wide variety of small cell may be accommodated. Accelerated information appropriate for Thermal Management.

self-discharge tests may be accomplished of long shelf-life batteries. Special build multi-well (4 sample) self discharge calorimeter (IBC-SD4) are available with chamber size being cell specific.





M a i n H e a d i n g

EV+ Options: Sub-Ambient Testing

& Thermal Distribution

EV+ Calorimeter

Multipoint data is illustrated for a small battery (18650).





Cycler Data


Larger batteries and batteries / modules / packs have application requirements that extend from the 3000

4.5

)

application of smaller batteries.

2000

A

V

4

1000

O L

With large batteries there is still the need stability and ( m

0

T

T

3.5

safety testing, use and abuse testing however larger

-1000

N

AG E

batteries applications often need high power. This E -2000

Current

3

R

maybe discharge of 10-100°C and potentially charge in

-3000

Voltage



R

( V

minutes rather than hours. The applications focus on

-4000

2.5

C U

)

destructive abuse and thermal management under use

-5000

scenarios. The size of the batteries and applications has

-6000

2

115

120

125

130

led to the need to devise additional application options.

T I M E ( m i n )

Cryogenic Applications





Spatial Temperature of Battery


There is the need to evaluate battery performance and

) 80

thermal aspects of its operation at all environmental Top of Batery

70

( ° C

temperatures. These may be to a temperature of -30°C

5mm fromTop

or below. Temperatures where electrodes could freeze!

25mm from Top

60

R E

45mm from Top

Base of Batery

T U 50

The THT CryoCool option to accommodate such testing at modest cost. The CryoCool option simply allows R A 40

E

testing to begin at sub-zero temperatures by cooling P 30

with a flow of ultra cold nitrogen / liquid nitrogen. The M

CryoCool option ‘plugs in’ to the EV or EV+ calorimeter.

20

T E

170

175

180

185

190

195

200

205

210

Surface Area Heat Determination - MultiPoint Option T I M E ( m i n )

For larger batteries and modules it is key to determine Control TemperatuTr I M

e E

as (

a m

F i n

un )





ction of Time


where heat release under use or abuse is focused –

) 80

how the temperature rise varies through the unit.

70

( ° C

The MultiPoint option provides a multiple thermocouple 60

R E

facility to achieve measurement of thermal distribution T U 50

over the surface of the battery, pack or module. The MultiPoint is available with 8,16 or 24 thermocouples to R A 40

E

be positioned where appropriate. The temperature at all P 30

points is recorded and control can be at any of these M

positions.

20

T E

170

175

180

185

190

195

200

205

210

T I M E ( m i n )

MultiPoint calorimeter tests

obtain data more accurately

than open bench tests. In the

Note the time scale of the test, the speed of heat release calorimeter the environment

and temperature increase – and that this is primarily at the is controlled and unknown

anode collector. The speed of battery thermal equilibration and un-quantified heat loss is

is illustrated. The discharge profile is shown and also the minimised. Conditions are

calorimeter temperature, controlled by the ‘average battery temperature’.

equilibrated

battery

temperature is recorded. Heat effects using such With a single large

calorimeters are carefully quantified.

pouch cell the data

might be more complex.

Data here illustrates a

100

amp

discharge

experiment.

14





M a i n H e a d i n g

EV+ Options: Heat Capacity, Thermal

Management & Abuse Testing

Heat Capacity





Thermal management of EV Batteries


A value for the overall heat capacity of the battery is Utilising the THT EV options, key information is available needed to allow conversion of standard calorimeter data to for thermal management of EV batteries. The battery may react with units of joules (heat) and watts (power or speed be subjected to EV use conditions by charge/discharge of heat release).

with an EV test system (eg Bitrode XXX, dSpace coupled to high power charge and load units or stand alone high There are many methods by which heat capacity can be power change and load units). The test system might apply determined through typically these involve an additional repeated charge-discharge cycles or a prescribed drive heater. The heater is in contact with 1 or more batteries, scenario.

power is supplied and the temperature rise of the battery relate to the heat capacity.

The ARC/EV+ calorimeter equipped with Multipoint and Heat Capacity options will give the thermal management The THT Heat Capacity Option is supplied with heaters information. Initially the specific heat capacity must be appropriate for batteries of the size to be measured. The available. This value is simply put in to a MultiPoint Test unit utilises aluminium reference samples. The method is allowing for generation of Enthalpy and Power graphs.

automatic and leads directly to determination of the

‘overall’ heat capacity.

The THT ARC data analysis software has ability to take in sample heat capacity and generate automatically Enthalpy and Power graphs.

Software Set Up for MultiPoint

Screen Display During Test

Enthalpy at One Point

Power at One Point

Battery pack wrapped in aluminium

Nail penetration and crush – controlled speed tape suspended within the calorimeter

Tests call for nail penetration at defined speed and crush to be terminated at voltage drop. This presents challenges though the THT option fulfils all requirements. The THT

NPCO can be added to the EV or EV+ calorimeter.

The raw data is shown in above.

THT has a Wizard to calculate the

specific heat and heat capacity at

any temperature (or over any

temperature range). Taking the

value for the temperature rate (at

Data from a nail penetration test, shown above. Initially the system was held or averaged over a temperate

isothermally before nail penetration commenced. Following the penetration range), and with knowledge the

the cell led into complete thermal disintegration (in fully adiabatic conditions).

mass of the battery pack and the

voltage and current supplied to

the heater, we can then calculate

the Cp value and heat capacity

using the heat capacity wizard

software.

15

From this test the wizard calculated an average (mean) Cp value over the entire temperature range of the experiment of 0.83 J/gK.





M a i n H e a d i n g

History / Users





History


The focus on safety at this time was crucial due to applications in cell phones and laptop computers – and The Accelerating Rate Calorimeter has a long history of well documented incidents that let to hugely expensive being the favoured technology to study lithium batteries.

‘recalls’. The manufactures were predominately Japanese Clearly this is down to the ARC’s...

companies.

Ability to accommodate large samples

From the year 2000 application areas expanded rapidly; Rugged and Robust construction

large format (prismatic and pouch cells) appeared. The Possibility to connect cables in-situ to allow potential to use the ARC to study cells and small modules charge and discharge

in situ under a variety of use and abuse conditions was Quality adiabatic control

realised. Within the period of 2000 - 2010 THT worked with organisations around the world to implement the options Lithium and sulphur dioxide batteries where being described in this brochure.

investigated over 30 years ago – the first publication known to THT being Eber W. B & Ernst D. W, Power Sources From 2005 and until today large format cells have become Symposium June 1982; Safety Studies of the Li/SO2

more established for high power applications. This led to system using Accelerating Rate Calorimetry. The Li/SO2

challenges that THT has met with the large format battery being a primary cell considered for defence calorimeters EV+ and BPC.

applications.

Key users of THT arc systems now are Tier 1 automotive However the major impetus for Lithium battery use was OEM’s, their suppliers and specifiers.

triggered by the advent of the Li-ion secondary 18650 cells pioneered from the mid 1990’s by Sony. Sony was the first Going into the 2010’s it seems likely that most application company to buy a THT ARC system for battery studies.

areas have been addressed though in the future new challenges will no doubt arise where THT will aim to fulfil.

Initial studies were using 18650 cells and centred on stability and safety – and improvements to stability with changes in chemistry. This work either at cell level or at component level was the primary work carried out in the later 1990’s and early 2000’s.





Users of THT ARC


4 Key Tangible Benefits from THT

Sony





ITRI


Latest Hardware and latest Labview Software

Nokia





Samsung


Highest Sensitivity, Widest Performance Features NREL





Panasonic


Large Volume EVARC and BPC Calorimeters

Mitsubishi





Lishen


Integrated Cycler & Battery Abuse Options NASA

BAK

Sandia National Labs

Lion Cell

4 Key Intangible Benefits

ATL





All Cell


Largest Global Customer Base


CEA


Hyundai - Kia


Most Experienced Technical Personnel

LG





Shin Kobe


Lifetime FREE Phone & -E-Mail Support

Worldwide Offices & Support

Nissan

Kokam

Sanyo

Tianjin Institute of Power





Sources


16





M a i n H e a d i n g

m

S a

p in

ec ih

fi e

c a

atdie

o r

n

ARC Common Components





Standard Calorimeter


Safety; 1-3 cubic meter containment vessels (allows Fully compliant to ASTM E1981 E27

options); reinforced 3mm steel; proximity switch, door Calorimeter design to Dow Patents of 1980 and 1984

interlock.

10cm diameter 10cm depth calorimeter

Temperature range 0-600°C

Electronics 3kVA or 7kVA power supply system (-40°C with cryogenic system)

Sensitivity: 0.002°C/min to 200°C,

Workstation with Microsoft Windows and NI 0.005°C/min to 400°C; 0.010°C/min to 500°C

Tracking Rate to 20°C/min

Gas Collection via canister

Slotted base for thermally guarded cables

change and full control; remote operation

Pneumatic Nail Abuse Testing

Remote User; ability to transfer operation of system to Fast Tracking

any allowed PC over network or internet

Designed for Vent Sizing Applications, not appropriate for abuse Battery work

Virtual Technician; ability to set up multiple tests in one method

10cm diameter 10cm depth calorimeter

Temperature range 0-400°C (-40°C with cryogenic system) Modes; Adiabatic; quasi Isothermal; true Isothermal; Sensitivity 0.02°C/min

Isoperibolic, Ramping

Tracking rate to 150°C/min

Size and shape similar to standard calorimeter Operation in air, vacuum, inert gas, reactive gas, EV Calorimeter

Adiabatic control to 0.01°C



25cm diameter 50cm depth

Pressure resolution 0.005bar; precision 0.02%; Temperature range 0-400°C (-60°C with cryogenic system) accuracy 0.05%



Sensitivity 0.02°C/min



Gas collection via canister

Sample holders; ARC Bombs, low phi holders, tube Collar for abuse testing

bombs, special open or closed holders for any battery Thermally guarded cable insert

type



Pneumatic or Control Speed Nail Penetration Crush option Data Analysis software in Labview with ability that includes

EV+



• Graphical and tabulation of raw data including Phi Corrected tmr plots



40cm diameter 44cm depth



• Data Conversion to Enthalpy, Power, Gas Generation Temperature range 0-300°C (-60°C with cryogenic system)



• Kinetic Modelling for thermodynamic and kinetic data Sealed lid designed for integral gas collection (Tedlar bags analysis

or cylinder)



• Phi Correction through kinetic modelling



Automatic electronic safe lid lift



• Report generation in Microsoft Word, Excel, html Sealed lid pressure limits 0-2 bar



• Analysis of 9 data sets; 3 analyses on each data set, Integrated video monitor



5 merge datasets



Integrated Inert gas purging facility



Integrated Battery Cable Connectors

Temperature resolution 0.001°C; precision 0.01%; thermocouples external and internal





BPC


Not designed for Vent Sizing Applications, abuse Battery work Vacuum to 200 bar pressure range (10-2000 bar with alternative transducers)



40x60 elliptical x 40cm depth



Temperature range -35 -200°C (with refrigerated Lifetime email and phone support, 1 Year warranty circulating bath)



Sensitivity 0.01°C/min

CE, UL, VCCI, CSA test certification



Integrated Battery Cables

© Thermal Hazard Technology 2012 All rights reserved.





HEAD OFFICE


1 North House, Bond Avenue,

Bletchley, MK1 1SW, England.

Tel: +44 1908 646800

Fax: +44 1908 645209

Email: info@thtuk.com

Web: www.thtuk.com





US OFFICE


Tel: +1 317 222 1904

Fax: +1 317 660 2092

Email: info@thtusa.com

Web: www.thtusa.com





CHINA OFFICE


Tel: +86 21 5836 2582

Fax: +86 21 5836 2581

Email: info@thtchina.com

Web: www.thtchina.com





INDIA OFFICE


Tel: +91 9560 655 626

Email: info@thtindia.com

Web: www.thtindia.com

Offices in ENGLAND, USA, CHINA, INDIA

Representation Worldwide