Battery safety: a real concern?

Transcription

1 Battery safety: a real concern? Hans Seifert Opportunities and challenges of batteries for energy storage in the EU; 19 October 2016, Brussels INSTITUTE FOR APPLIED MATERIALS APPLIED MATERIALS PHYSICS (IAM-AWP) KIT University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association

2 Increase of safety and reliability of lithium-ion batteries for smart grids, electromobility and all other applications Possible Safety Impacts Overheating Overcharge Overdischarge Short Circuit Accident For improving battery management system (BMS) and thermal management system (TMS) electrochemical and thermal behavior and materials of cells and batteries have to be thoroughly studied Aim: Improvement of TMS and BMS by determination of quantitative data using battery calorimetry in combination with modelling and simulation

3 Lithium Battery Safety Report Shmuel De-Leon Energy Ltd Danger of Lithium Batteries - Lithium batteries contain Wh/kg compared to 1375 Wh/kg in TNT - Lithium Thionyl Chloride D-size cell has 39 Wh of energy compared to an I.F.D. M26 hand grenade with 206 Wh (150g TNT) - If the energy of Lithium batteries is released at a fast, uncontrolled rate there is danger of potential hazards 5 x equivalent to Technische Daten Model: E R34615 D Size IEC ER34615 Lithium: System Lithium Thionyl Chloride Battery Einweg, Spannung 3,6 Volt Kapazität mah, Abmessungen 61,5x34mm, Zellengröße D Mono LR20, Gewicht 115Gramm, Standard Discharge Current: 2mA Capacity: 19.0Ah (@2.0m A Discharge Current to 2.0V Cut-off, +23 C), ISO9001 Certified, UL Certified MH20555 Maximum recommended current under continuous discharge: 230mA Maximum recommended current under pulse discharge: 500mA

4 Energy stored in a cell A cell has more energy than only electrical energy Stringfellow, R. et al. Lithium-Ion Battery Safety Field-Failure Mechanisms., 218 th ECS Meeting, Las Vegas, 2010.

5 Source: Shmuel De-Leon Energy, Ltd.

6 Future battery technologies affecting safety issues - Higher energy density and power density - High voltage cells - Fast charge and discharge - Fast response times - Use under extreme environmental conditions - Extended life time - Concepts to improve safety - Inherently safer design (materials, materials combination, ) - New concepts: Solid state electrolytes, improved separators, post-lithium, - Safety technologies design (vents, cooling, packing, ) - Improved cell and battery processing and quality control - Better measurements and analyses (in operando) - Better safety tests (adjusted to field conditions) - Improved Thermal Management Systems (TMS), Battery Management Systems (BMS) - Up-to-date norms, high quality standards, handling instructions - Training of customers and fire brigades in handling regular use, abuse and accident -

7 Quality: Six Sigma Management System 6-σ-Level with 3,4 DPMO (Defects Per Million Opportunities) Defective: % Not good enough for lithium batteries!

8 Thermal and Safety Studies for Batteries - Videos and pictures of tests and accidents showing venting, fire, flame, rupture and exploding batteries - On the bench and hot box tests are just pass - fail (empirical character) - However, too few quantitative experimental data available for - temperature behavior - heat generation, heat dissipation - inflammation - pressure development - gas and smoke compositions (battery failure) + integrated approach with modeling and simulation needed Regular use, abuse and accidents of interest for investigations

9 To be explored: Heat generation and dissipation of cells, batteries and packs during use, abuse and accidents Key data for thermal management and safety Conversion of thermal data (temperature, temperature rate) to heat (Joule) and power (Watt) with the aim of understanding of heat release to determine heat removal requirements for thermal management. To be measured: Specific heat capacity of the cell Heat transfer coefficient of the cell Reversible and irreversible heat rate Use of Calorimetry and Entropymetry

10 Accelerating Rate Calorimeters (ARC) EV+ ARC: Ø: 40 cm h: 44 cm ES-ARC: Ø: 10 cm h: 10 cm EV-ARC: Ø: 25 cm h: 50 cm ARC combined with internal or external cycler = Battery Calorimeter

11 Additional advanced methods of analysis Thermographic Cameras Analyses of: - Internal Pressures - Gas and fume Isothermal Battery Calorimeters Plus additional analysis methods: - Differential Scanning Calorimeters (DSC) - Simultaneous Thermal Analysis (STA, DTA + TGA) - X-ray diffraction, Neutron diffraction and tomography (in-operando techniques) - Electron Microscopy (SEM, TEM) - Focused Ion Beam methods (FIB) - Chemical Analysis (WDS, ICP-OES, Laser Ablation ICP-MS, RFA, ) - Raman-Spectroscopy -

12 Hazard Level Hazard Level Descriptoin Classifiaction Criteria & Effect 0 No effect No effect. No loss of functionality Heating Overcharge Deep discharge Short circuit (ext. / int.) Impact on LIB 1 Passive protection activated No defect; no leakage; no venting, fire or flame; no rupture; no explosion; no exothermic reaction or thermal runaway. Repair of protection device needed. 2 Defect / Damage No leakage; no venting, fire or flame; no rupture; no explosion; no exothermic reaction or thermal runaway. Cell irreversible damaged. Repair needed. 3 Leakage (Weight loss < 50%) No venting, fire or flame; no rupture; no explosion. Weight loss < 50% of electrolyte weight (solvent + salt). Intrusion 4 Venting (Weight loss > 50%) No fire or flame; no rupture; no explosion. Weight loss 50% of electrolyte weight (solvent + salt). 5 Fire or Flame No rupture; no explosion (i.e. flying parts). 6 Rupture No Explosion, but flying parts of the active mass. 7 Explosion Explosion (i.e. disintegration of the cell).

13 Qualifying Standards, Norms can be behind the technical state-of-the-art UN38.3 Recommendations on the transport of dangerous goods; Manual of Tests and Criteria DIN EN 62427:2006 Secondary cells and batteries for solar photovoltaic energy systems - general requirements and methods of test DIN EN Akkumulatoren und Batterien mit alkalischen oder anderen nichtsäurehaltigen Elektrolyten DIN EN Sicherheitsanforderungen an Batterien und Batterieanlagen Stationäre Batterien DIN EN Akkumulatoren und Batterien mit alkalischen oder anderen nicht säurehaltigen Elektrolyten - Sicherheitsanforderungen für Lithium- Akkumulatoren und -Batterien für die Verwendung in industriellen Anwendungen (IEC 21A/529/CD: )

14 Frequently quoted procedures for abuse testing by SAE International, Sandia National Laboratories and NREL SAE J2464 EV & HEV Rechargeable Energy Storage System (RESS) Safety and Abuse Testing Procedure, Daniel H. Doughty, , Published 04/12/2010 SAE International, SURFACE VEHICLE RECOMMENDED PRACTICE J2464 NOV2009 Issued , Revised , Superseding J2464 MAR1999 (R) Electric and Hybrid Electric Vehicle Rechargeable Energy Storage System (RESS) Safety and Abuse Testing SANDIA REPORT, SAND , Unlimited Release, Printed August 2006, FreedomCAR Electrical Energy Storage System and Abuse Test Manual for Electric and Hybrid Electric Vehicle Applications Daniel H. Doughty and Chris C. Crafts NREL, National Renewable Energy Laboratory, Vehicle Battery Safety Roadmap Guidance, Daniel H. Doughty, Ph.D., Ahmad A. Pesaran, Ph.D. Subcontract Report NREL/SR October 2012

15 Excerpt from NREL, National Renewable Energy Laboratory, Vehicle Battery Safety Roadmap Guidance, Daniel H. Doughty, Ph.D., Ahmad A. Pesaran, Ph.D. Subcontract Report NREL/SR October 2012

16 Excerpt from NREL, National Renewable Energy Laboratory, Vehicle Battery Safety Roadmap Guidance, Daniel H. Doughty, Ph.D., Ahmad A. Pesaran, Ph.D. Subcontract Report NREL/SR October 2012

17 Back-up slides

18 Source: Shmuel De-Leon Energy, Ltd.

19 Temperature in C Thermal Runaway: different cathode materials Samsung_NMC Sony_LMO A123_LFP Time in min 80<T<130 C: low rate reaction, between 0.02 und 0.05 C/min: exothermic decomposition of the solid electrolyt interface (SEI) Temperature Rate in C/min ,1 0,01 1E-3 Temperature in C Samsung_NMC Sony_LMO A123_LFP 130<T<200 C: medium rate reaction, between 0.05 and 25 C/min: solvent reaction, exothermic reaction between embedded Lithium ions and electrolyte => reduction of electrolyte at negative electrode T > 200 C: high rate reaction, higher than 25 C/min: Exothermic reaction between active positive material and electrolyte at positive electrode => rapid generation of oxygen

20 Temperature and heat dissipation rate during cycling T env = 60 C, C/2 Charge, C/2 Discharge Manufacturer B

21 Worst Case-Bedingungen: Zelle im Pack umgeben von anderen Zellen ohne aktive Kühlung Adiabatische Messungen T st = 23 C (RT) Ladeparameter: - Methode: constant current, constant voltage (CCCV) - U max = 4,1V - I = 5A C/8-Rate - I min = 0,5A Entladeparameter: - Methode: constant current (CC) - U min = 3,0V - I = 5A C/8-Rate

22 Interne Druckmessung beim Thermal Runaway - Röntgentomographieaufnahme einer Zelle Zellaufbau ohne Dorn, zentraler Hohlraum mit 4 mm Durchmesser

23 Interne Druckmessung beim Thermal Runaway

24 Interne Druckmessung beim Thermal Runaway

25 Druckmessungen beim Thermal Runaway

26 Materials - Thermodynamics, - Phase Diagrams, - Kinetics Micro- and Nanomaterials Crystal structures, Crystal chemistry, Microstructure, Reactivity Electrochemical performance and safety of cells / batteries