THT Battery Newsletter September 2018

Offices in ENGLAND, USA, CHINA, INDIA Representation Worldwide

World BatteryBenchmark Safety and Battery Calorimetry Performance Studies

News

RT Instruments visit THT During June, Dennis Roche and Tito Rivas from RT Instruments (RTI) visited THT for product training. Dennis recently joined RTI having previously worked as a field services engineer at Netzsch His appointment further strengthens our service capability in North America. RTI act as exclusive THT representatives with direct sales personnel based in locations around the USA - RTI’s proven service team now allow local support for THT products.

Contact RT Instruments by email info@rtinstruments.com or telephone +1 530-419-7033

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News TST-China This summer we also welcomed our Chinese distributors from Thermal Safety Technology.

Harry Li, Laven Liu and Wang Hao provide sales and service support for all THT products from their Shanghai office.

ARC IR Camera THT has developed an integrated IR camera replacing the standard optical camera that is supplied with the EV+ calorimeter. The IR camera shows the special temperature distribution across the battery surface. In cycling tests this could help determine the areas of significant heat generation (the tabs for example)

The user may choose to move the plot cursor in order to analyse the image frame by frame. As the cursor moves, the indicators “Test Temperature” and “Test Time” as well as the thermal image and rendering plot will be updated.

The information displayed on the 3D plot is the variation of temperature within the image. The X and Y axis correspond to each pixel of the image (in this case, because the camera used had a resolution of 60x80 we observe two arrays of data: on the X axis from 0 to 79 and on the Y axis from 0 to 59). The Z axis corresponds to the absolute temperature identified within the image.

The IR camera will be retro-attachable to existing EV+ system and can be purchased as an option with new systems.

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ARC Short Circuit Option (SCO).

SCO allows remote shorting of cells in the ARC. The short is carried out through a low impedance contactor box. The short circuit current can be independently measured at high frequency via a current transducer to verify the severity of the shorting current.

Use of ARC for QC A method to test multiple cells simultaneously in the ARC is being developed at THT. Using the MPO (multipoint option) individual cell temperatures are recorded. Voltage from each cell can also be measured. An aluminium shied limits interference between cells (prototype form shown below). An aluminium plate is used for bomb thermocouple connector.

4 cells

Aluminium Plate Voltage connections

The short circuit is triggered using a simple mechanical switch. The switch is designed to carry a load of up to 2750A for 10 seconds

Aluminium shield 200 190

The switch is located outside of the ARC blast box so it can be safely triggered while the ARC is running.

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150 140 120 360

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Time (min)

60 40 20 0 0

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Time (min) LFP

Shorting leads to temperature rise of 100°C. After charge is depleted battery continues to self-heat until disintegration occurs

NMC #1

NMC #2

NMC #3

ARC

LFP cell did not undergo thermal runaway.

NMC#3 cell exhibited significant self-heating from 140ºC, NMC#1 from 150ºC and NMC#2 from 160ºC. The technique could be applied for QC assessment of differences within batch cells.

Any variations, even small, would be shown.

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News 2nd Annual IBCC

ARC Latest Papers Since our last newsletter we are pleased to see more papers published by THT ARC users.

USTC, Hefei China investigate the thermal stability of pouch cells with standard and composite safety electrolyte under adiabatic conditions. The group also collaborated with University of Warwick, UK to publish ARC data for validation of a newly developed electrothermal model.

The 2nd International Forum on the Safety of Lithium Ion Batteries took place in Beijing from 8-10 June. The event was co-sponsored by the Department Of Automotive Engineering at Tsinghua University and THT. More than 200 delegates attended over 25 technical talks covering Li-ion battery design, safety testing protocols and novel thermal management technologies.

KIT: Special Report In a recent article Dr Carlos Ziebert of The Battery Safety Center at the Karlsruhe Institute of Technology’s (KIT) outlines how research and testing in calorimeters helps to improve the performance and safety of batteries. Read the article in full here. KIT is Europe’s largest battery calorimeter centre and is home to six ARCs from THT.

• Electrochemical performance and thermal stability analysis of LiNixCoyMnzO2 cathode based on a composite safety electrolyte Journal of Hazardous Materials 351 (2018) 260–269

• Modelling electro-thermal response of lithium-ion batteries from normal to abuse conditions Applied Energy 205 (2017) 1327–1344

UTAR, Malaysia present specific heat capacity data along with battery surface temperature under various charge / discharge C-rates in the ARC. • Novel thermal management system using mist cooling for lithium-ion battery packs Applied Energy 223 (2018) 146–158

CIDETEC, Spain study thermal runaway of several Li-ion batteries • A comparative study of thermal runaway of commercial lithium ion cells Energy 159 (2018) 547-557

Tsinghua University, China, use ARC data as a basis for a model-based thermal runaway prediction.

• Model-based thermal runaway prediction of lithium-ion batteries from kinetics analysis of cell components Applied Energy 228 (2018) 633–644

Exhibitions THT will be exhibiting at the following events.

• September 11-13 The Battery Show, North America Suburban Collection Showplace, Novi, MI • October 16-18 AABC Asia - Advanced Automotive Battery Conference Hyatt Regency, Osaka, Japan 4

© Thermal Hazard Technology 2018 All rights reserved.

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