Session 2: Lithium-Ion Battery Safety and Reliability Enhancement and Validation
While battery performance and cost are receiving unprecedented attention, the safety, life, and reliability of the early installations will have the greatest impact on market acceptance for Li-Ion-powered advanced vehicles. In this session, we will discuss safety-enhancing technology and the validation of battery reliability and safety under ordinary and abusive conditions.
Session Chairman: Arno Perner, Head of Component Lead Engineering & Validation R&D Battery, BMW Peugeot Citroën Electrification
Dr. Perner worked for Varta Microbatteries for many years and has excellent knowledge of cells and chemistry. He joined BMW 3 years ago and was responsible for the 60Ah cell from SBL for the Mega City Vehicle (MCV). Six months ago, he became team leader for the "component lead engineers" (the technical project leaders) and the complete pack validation of all HV batteries. Dr. Perner possesses deep know-how in cell and pack development for PHEV and EV.
Validation of Safety and Reliability for Advanced EV Battery Arno Perner, Head of Component Lead Engineering & Validation R&D Battery, BMW Peugeot Citroën Electrification
A professional validation is essential for the reliability and safety improvement of EV-batteries. The presentation gives an overview of the validation strategy of BMW Peugeot Citroën Electrification.
The process is defined by mechanical, climatic, chemical, electrical and not to forget by legal requirements.
At BMW Peugeot Citroën Electrification validation is performed on four levels:
The presentation shows some examples of safety and environmental tests and also outlines measures to improve safety and reliability on cell and battery level.
Deep understanding in electric powertrain development and production is essential for BMW on its road to sustainable mobility.
Validation is determined by a wide range of requirements
FEM simulations are a fundamental part of our development
Several safety levels are fundamental part of our batteries
Validation on the shown four levels lead to a safe batteries
BPCE will be the center of competence for powertrain electrification for BMW Group and PSA.
Safe Batteries for a New Era of Automotive Mobility Markus Meiler, Manager Product Safety, Deutsche Accumotive
The Deutsche ACCUmotive GmbH & Co. KG is a joint venture of Daimler AG and Evonik Industries AG and was established in April 2009. The head office as well as the location for research and development is located in Kirchheim unter Teck/Nabern in Baden-Württemberg. In Kamenz near Dresden in Saxony the production site was constructed in April 2010.
The presentation starts with a short introduction to the company profile and continues with a survey of the products of Deutsche ACCUmotive GmbH & Co. KG. The main differences between power- and energy batteries and their technical data will be presented. A detailed explanation of the safety philosophy of the Deutsche ACCUmotive GmbH & Co. KG will be provided by the example of an energy battery for an electric vehicle.
The main focus of the presentation lies on the safety concept of EV batteries which is divided active, passive and cell intrinsic safety facts, in order to pursue the determined safety goals. In this context two examples of safety concepts for two different types of batteries will be shown during the presentation.
A concept for a safe design will be presented by a dense network of tests. These tests are split into a systematic and a thematic one and include all relevant aspects of a new era of batteries, too. During that part of the presentation a crush test at battery level and a vehicle crash test will be shown and explained.
Automotive LIBs - Recent Requirements and Test-Methods Detlef Hoffmann, Team Leader Product Management E-Mobility, SGS Germany
Today Lithium-ion batteries are the preferred solution for storing and providing energy for the drive train of electric vehicles. LIBs are improving their key-performance, namely energy density, power and durability, while their cost must be reduced. Besides this, also reliability remains a challenge in the automotive environment with its intense vibrations, shocks and extreme temperatures. These challenges concern the design and testing of packs. Quick charging, ageing, abuse, accidental situations lead to new discussions in the standardization groups on safety and approval requirements. More than ten years ago, test-methods have been developed for LIBs for portable consumer products. For automotive application, there are new draft standards from ISO, UN ECE, JIS, MIIT, SAC, VDA, SAE, IEC and others. Fast current rise times and new active and passive protection measures also have an impact on the test methodology. The descriptions in the existing standards often are insufficient to capture the relevant reaction of the battery under test in a comprehensive, reproducible and unambiguous way. Existing methods for reliability and life time testing for automotive components must be adapted to qualify battery systems and to allow for accelerated testing to reduce throughput time. So the test methods are moving as well. Therefore, the design of hardware and software of the test setup must be prepared for changes in requirements. The effort of testing battery packs depends a lot on the qualification concept, which should make use of the results of the risk analysis and the results of carefully selected preliminary cell-tests. The presentation will content:
What contributes to safety of a cell, module, battery-system?
What are the recent requirements for Automotive LIBs?
Tests setups and methods:
Transportation, Safety, Abuse
Vibration and Shock
Summary and Outlook
Aluminum Pouch Film for Large Li-Ion Batteries Yuji Minamibori, Researcher of R&D center, Showa Denko Packaging Co.
This presentation outlines the Performance of Aluminum Pouch Film for Large Lithium ion batteries. The contents are as below.
Introduction of Aluminum Pouch Film
History of Aluminum Pouch Film for LIB
The Kind of Aluminum Pouch Film
Aluminum Pouch Film-Layer construction
Production method of Aluminum Pouch Film
Advantage of Aluminum Pouch Film against to Metal Can
Features of Showa Denko Packaging’s Pouch Film
Performance of Aluminum Pouch Film
Moisture Barrier property
Rubbing and Wipping Test
The Aluminum Pouch film made by Showa Denko Packaging is used for LIB as mobile applications from 1998.
Showa Denko Packaging is the only supplier that puts Dry laminate type AL Pouch Film with special adhesive for Large Lithium ion batteries onto the battery material market. There are 2 production method in AL Pouch Film, Dry-lamination and Heat-lamination. AL Pouch Film made by Heat-lamination has started to use for automotive batteries.
Dry laminated film has a high degree of moisture barrier and electrolyte resistance properties, therefore it is suitable for Large Lithium ion batteries.
Dry laminated film has the advantage of Insulation property, forming property and cost-performance than Heat laminated film. Now, we are working toward improvement of the Dry laminated film.
We recommend large lithium ion battery manufacturers to switch from Metal can to our products due to the advantages of AL Pouch Film.
Root Causes of a Thermal Runaway in Lithium Batteries Pascal Gouérec, Energy Project Leader, Serma Technologies
SERMA Technologies, a well-renowned laboratory in electronics with an important portfolio of clients from many industry sectors (including automotive), has recently extended its domain of expertise to battery testing and analyses.
Through its major partnerships with components manufacturers, equipment suppliers and car manufacturers, SERMA has a complete range of expertise on EV and HEV power train: batteries, power electronics, signal electronics, motors.
During this event, case studies will be presented relative to identification of root causes on lithium batteries after a thermal runaway. Other examples will be also shown.
The post-mortem analyses developed by our labs for identifying the root causes for failures are composed by different levels of analyses:
Non-destructive: Electrochemical tests, X-ray 3D (1st level)
Destructive : Visual inspection of components (1st level)
Optical characterization and chemical analyses (2nd level)
It is also suitable for application with other battery technologies: Lead Acid batteries, NiMH, ultracapacities.
Concept for Enhanced Failure Detection in Traction Batteries Georg Fauser, Research Engineer, Energy Storage Systems, Fraunhofer-Institut für Keramische Technologien und Systeme
Since aging and failure modes of Li ion batteries are still not completely understood, the batteries are usually overdimensioned and their full capacity is not utilised. The possibilities for reactions from conventional BMS upon any detected fault or abuse condition are limited to derating the load current and increasing the battery cooling. This presentation is adressing those issues by presenting an approach for advanced online battery diagnostics. First theoretical considerations are put foward:
the problematic nature of the safe operation window
introduction to accelerated aging due to operating conditions
propagation of cell error states from accelerated aging to cell failure on the example of low temperature charging
Second a case study is shown:
accelerated aging due to overcharging
investigating the caused cell aging by using impedance spectroscopy
Also the methodical approach using FMEA will be described. In the conclusion key benefits as well as an outlook on this ongoing reasearch projet will be discussed.