THT is the Original Company for ARC & Battery

• pioneered ARC for over 20 years

• Pioneered Li Battery for over 10 years

Sales, service, support worldwide

THT is the Original Company for ARC & Battery

• pioneered ARC for over 20 years

• Pioneered Li Battery for over 10 years

Sales, service, support worldwide

Thermal Hazard TechnologyThermal Hazard Technology

Worldwide – Major Users

• Sony, Sanyo, Toshiba, Mitsubishi, Panasonic, GS Battery, BAK, Lishen, ATL

• Samsung, LG

• NASA, Penn State Univ, GM-Delphi, Motorola, Sandia National Labs, Duracell

• Nokia, SAFT, Ultralife, Varta, Valence

Worldwide – Major Users

• Sony, Sanyo, Toshiba, Mitsubishi, Panasonic, GS Battery, BAK, Lishen, ATL

• Samsung, LG

• NASA, Penn State Univ, GM-Delphi, Motorola, Sandia National Labs, Duracell

• Nokia, SAFT, Ultralife, Varta, Valence

Li BatterLi Battery Companies with THT ARCy Companies with THT ARC

Thermal properties;

• effect of heat on batteries

• effect of heat produced by batteries

Well known – temperature exposure,

overcharge / discharge, shorting

Heard details of such safety details, reference to in-house empirical tests, DSC, UL 150C Hot box,

and some ARC data

Thermal properties;

• effect of heat on batteries

• effect of heat produced by batteries

Well known – temperature exposure,

overcharge / discharge, shorting

Heard details of such safety details, reference to in-house empirical tests, DSC, UL 150C Hot box,

and some ARC data

Safety Issues with Li BatteriesSafety Issues with Li Batteries

The Accelerating Rate Calorimeter has become accepted as a key instrument for assessing the

thermal hazard potential of Li Batteries

Unlike other tests… it is not empirical

•Quantifies the thermal effect

•Gives a ‘worst case’ assessment

•Can test batteries of ‘any size’

•Different labs anywhere can compare data

The Accelerating Rate Calorimeter has become accepted as a key instrument for assessing the

thermal hazard potential of Li Batteries

Unlike other tests… it is not empirical

•Quantifies the thermal effect

•Gives a ‘worst case’ assessment

•Can test batteries of ‘any size’

•Different labs anywhere can compare data

Safety Issues with Li BatteriesSafety Issues with Li Batteries

•Evaluate the reactions in any type of battery component, for their stability and safety

•Evaluate made batteries under any state of charge, for their stability and safety

•Evaluate effect of abuse testing on battery safety, shorting over-voltage testing

•Evaluate batteries when charged, discharged, cycled for their thermal properties, to get life cycle and electrothermal efficiency information

•Evaluate the reactions in any type of battery component, for their stability and safety

•Evaluate made batteries under any state of charge, for their stability and safety

•Evaluate effect of abuse testing on battery safety, shorting over-voltage testing

•Evaluate batteries when charged, discharged, cycled for their thermal properties, to get life cycle and electrothermal efficiency information

Safety Issues with Li BatteriesSafety Issues with Li Batteries

Bomb Sensor

Top Sensor

Middle Sensor

Bottom Sensor

PressureSensor

Cartridge Heater Radiant Heater

Principle of ARC

Using the ARC with Battery Materials

• anode

• cathode

• electrolyte

• SEI……

fresh or after making / charging / cycling….

as per the work of Jeff Dahn

Using the ARC with Battery Materials

• anode

• cathode

• electrolyte

• SEI……

fresh or after making / charging / cycling….

as per the work of Jeff Dahn

Data shows onset and temperature and pressure increase under worst case conditions

Data shows onset and temperature and pressure increase under worst case conditions

Data shows onset, heat generation at every Data shows onset, heat generation at every temperature, temp rise is proportional to heat of temperature, temp rise is proportional to heat of reaction, slope is proportional to activation energy, reaction, slope is proportional to activation energy, shows complexity of decomposition, all under worst shows complexity of decomposition, all under worst case conditionscase conditions

Data shows onset, heat generation at every Data shows onset, heat generation at every temperature, temp rise is proportional to heat of temperature, temp rise is proportional to heat of reaction, slope is proportional to activation energy, reaction, slope is proportional to activation energy, shows complexity of decomposition, all under worst shows complexity of decomposition, all under worst case conditionscase conditions

Data varies with charge / age. Three regions of exothermicity, interface, anode and cathode reactions – but an 18650 will progress to explosion

Data varies with charge / age. Three regions of exothermicity, interface, anode and cathode reactions – but an 18650 will progress to explosion

Reaction Sequence in Li-Ion Battery exothermicity

1st reaction – SEI

2nd reaction – Anode (MCMB)

3rd reaction – cathode (Li Spinel)

Electrolyte – decomposition from 80oC

Electrolyte – very flammable

Lithiated MCMB –air flammable hazard

Delithiated spinel – shock sensitive explosive hazard

Li-Ion 18650 – Battery Safety

Onset of Exothermic Reaction

Overdischarged (2.0V) Onset = 110-120oC

Fully Discharged (2.6V) Onset = 110-120oC

Partially Charged (3.6) Onset = 90-100oC

Fully Charged (4.2V) Onset = 70-90oC

Overcharged (4.8V) Onset = 30-50oC

Overcharged (>5V) Onset = ambient

Mobile phone Li-ion prismaticShorting leads runaway

Mobile phone Li-ion prismaticShorting leads runaway

Lithium Iron Disulphide AA sizeShorting does not lead to runaway – note gap in data

Lithium Iron Disulphide AA sizeShorting does not lead to runaway – note gap in data

Temperature test 3.7V

Overcharging of Li-Polymer Battery

20 30 40 50 60 70 800

1

2

3

4

5

Voltage

Vol

tage

(V

)

Time (min)

20 30 40 50 60 70 800

500

1000

1500

2000

Separator Breakdown

Cycler Shutdown

Start of Charge

ARCCal:

Voltage and Current as a Function of Time

Cu

rrent (m

A)

Current

40 50 60 70

50

100

150

200

250

Separator breakdown

Tem

pera

ture

(°C

)

Time (min)

Start of Heat-up due to Charging

Thermal Runaway

ARCCal:

Temperature as a Function of Time

Overcharging of Li-Polymer Battery

4/5A Li-ion battery4/5A Li-ion battery

DET

CETi

100 Gibbs free energy efficiencyGibbs free energy efficiency

TmfIVfG

IVfG

REE

EECET ,,2

,0

0

TmfIVfG

IVfG

REE

EEDET ,,32

,0

0

m

AQ

ET

Si

Battery performance factorBattery performance factor

Q – charge capacityQ – charge capacityA – surface areaA – surface aream - massm - mass

Cycle Process ET ET (%)

2 Discharge 0.7865 42.5

3 Charge 0.3341  

4 Discharge 0.7926 41.8

5 Charge 0.3316  

6 Discharge 0.8055 41.1

7 Charge 0.3311  

Battery performance and Gibbs free energy efficiency results

Battery performance and Gibbs free energy efficiency results

Gateway Notebook Battery PackGateway Notebook Battery Pack