Battery Testing Services
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Battery Testing Services For Performance & Safety Safety Tests Thermal Hazard Technology specializes in thermal analysis of lithium cells/modules in the areas of safety and performance. Testing is carried out in adiabatic calorimeter systems with additional options Performance Tests •Cell Heat Capacity: Measure from -30°C to maximum cell operating temperature. •Change/Discharge Heat Release: Quantify total thermal energy released from cell/module during different charge/discharge protocols. •Cycling with Multiple Thermocouple Measurement: Establish areas of greatest heat release across the cell surface. •Thermal Abuse: Determine the maximum safe operating temperature of the cell and self-heating rate versus cell temperature •Overcharge: Tests can be carried out at different temperature and charge rates. •Short Circuit: Cell is shorted through a low impedance. •Nail Penetration: Automated nail penetration of the cell. Penetration speed, distance and test temperature can be specified. •Temperature Ramp: Establish cell decomposition temperature. Temperature ramp at up to 5°Cmin All above tests can be carried out with: • Pressure measurement and [or gas collection for third party analysis] • Cell voltage monitored throughout, and multiple thermocouples positioned across the cell surface. • Video monitoring of the cell, including cell temperature synced with video frames to establish cell temperature at points of visual interest.
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Performance and safety testing
Transcript of Battery Testing Services
Battery Testing ServicesFor Performance & Safety
Safety Tests
Thermal Hazard Technology specializes in thermal analysis of lithiumcells/modules in the areas of safety and performance.
Testing is carried out in adiabatic calorimeter systems with additional options
Performance Tests
•Cell Heat Capacity: Measure from -30°C to maximum cell operating temperature.
•Change/Discharge Heat Release: Quantify total thermal energy released fromcell/module during different charge/discharge protocols.
•Cycling with Multiple Thermocouple Measurement: Establish areas of greatest heatrelease across the cell surface.
•Thermal Abuse: Determine the maximumsafe operating temperature of the cell andself-heating rate versus cell temperature
•Overcharge: Tests can be carried out atdifferent temperature and charge rates.
•Short Circuit: Cell is shorted through a lowimpedance.
•Nail Penetration: Automated nail penetrationof the cell. Penetration speed, distance and testtemperature can be specified.
•Temperature Ramp: Establish celldecomposition temperature. Temperature rampat up to 5°Cmin
All above tests can be carried out with: • Pressure measurement and [or gas collection for third party analysis] • Cell voltage monitored throughout, and multiple thermocouples positioned across the cell surface. • Video monitoring of the cell, including cell temperature synced with video frames to establish cell temperature at points of visual interest.
Anode, cathode, electrolyte materials, 2 or 3component mixtures, lithiated carbon, delithiatedoxide; particle size and shape variations. ARC testshave been reported from many groups showingdata aiding safer and improved battery chemistry.Data can be complex, work is often carried out byacademic groups.
The effect of heat on batteries, onset (stability),speed (kinetics) and quantity of heat release (safety).Variation with SoC, cell construction and age ofbattery. Batteries of size from coin cell to EV oraerospace modules. Quantify the heat and pressurerelease; ascertain likelihood of battery disintegrationor explosion.
External short circuit, over-voltage charging anddischarging; nail penetration, crush. The ability toconnect the battery to an external device to monitorvoltage, to short-circuit, to supply current, tocharge/discharge, to cycle. Allows abuse testing tobe carried out. Monitor temperature, voltage andpressure during the test, to determine if (e.g.) shortcircuit leads to a temperature rise large enough tocause disintegration.
Measure internal pressure with battery connectedto a fine tube leading to the pressure transducer.Determine pressure variation in use or during atemperature excursion. Measure externalpressure, the pressure rise during gas release andcollect gas for analysis.
Effect of Increasing Component Particle Size
Thermal Stability of an 18650 Battery
External Short Circuit Test
Pressure Determination & Off-Gas Collection
Battery Testing ServicesFor Performance & Safety
100 160 220 280 340
Temperature(°C)
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Stopped at 220°C(a) LiCoO2 (1)
(b) LiCoO2 (2)
(c) LiCoO2 (3)
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SEI ReactionAnode Reaction
Separator Melting
Cathode Reaction
BatteryDisintegration
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Battery Testing ServicesFor Performance & Safety
Over-voltage from Ambient Temperature
Variation in Temperature Rise over Surface
Heat Capacity of a Small Module
Thermal Effect of RepeatedCharge/Discharge Cycles
Use multiple thermocouples positioned over thesurface of the battery, module or pack to evaluatethe variation of heat release over the surface. Thisinformation allows knowledge of the location andamount of heat that must be removed. Thus aidingreliable thermal management
Evaluate larger cells, modules and small packs withlarger volume calorimeters. Using the larger sizecalorimeters (EV, EV+, BPC) to carry out all the testspreviously described; safety, stability, use, abuse.THT’s pioneering work over the past 10 years hasmade available the EV+ Calorimeter and the BatteryPerformance Calorimeter.
Determine the Heat Capacity of batteries andmodules. This knowledge allows conversion of thethermal data (temperature & temperature rate) toheat (Joules) and power (Watts). This allows a directunderstanding of heat release to determine heatremoval requirements for thermal management.Determine change in heat capacity with celltemperature.
Using a single channel cycler implement repeatedCC, CV cycles to quantify the heat release in chargeand discharge. Determine variation of heat releaseover voltage range and with batteries of variousages. Compare electrical energy input to thevariation of heat release to quantify efficiency andeffect of ageing. The heat release variation givesinsight into lifecycle.
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Time (min)
Top of Battery5mm from Top25mm from Top45mm from Top
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Electrical Calorimetric
U =77.76 W/m3K
A =452.39mm2
R =727m
Start of self heatingdue to charging
End ofcharging
ThermalRunaway
High power discharge from larger cells or modulesrequires special considerations. Cells or modulesmust be connected effectively to prevent heat beingproduced at the connectors. There is also the needto prevent heat loss from the battery along thick lowimpedance cables. THT has addressed these issueswith terminal clamps and thermal guarding.
In-built video camera captures images of cell duringabuse tests to establish points of physical change incells. Pictures are linked to cell temperature toestablish the temperature at which these changesoccur. For example, melting of cell parts, burst discrupture, gas release, ignition.
Visual evidence of physical cell changes
Charge Discharge Cycles
With all THT services we provide full report, rapid turn-around with confidentialityand a price conscious approach.
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Battery Testing ServicesFor Performance & Safety
Implementing charge/discharge on EV battery at
simply carried out with the ARC to gain informationon the battery’s heat release at driving temperature.This option allows the large THT calorimeters tooperate isothermally over this temperature range orto be thermally cycled or programmed over theseenvironmental temperatures. BPC includesintegrated refrigerated circulator for this.
Cycles at Varying Environmental Temperatures
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