Session 3: Batteries for High-Voltage HEVs and PHEVs
In AABTAM’s third session major automakers, as well as HEV-battery developers, discussed the timeframe for Lithium Ion displacing NiMH in existing applications and discussed which cell and pack, out of the multiple designs already commercialized, might provide the best cost-performance, reliability, and safety trade-offs.
Mr. Minoru Noguchi is chief engineer of battery research and development division at Honda R&D Co., Ltd. Automobile R&D center. He joined Honda in 1985. He studied the material of a lithium ion battery and an ultra-capacitor. He developed the electric energy storage system which used the ultra-capacitor, and it contributed to improve the efficiency and in acceleration performance of FCX. He is engaged in development of the battery system for HEV or EV now.
Session Chairman: Ted J. Miller, Senior Manager of Energy Storage Strategy and Research, Ford
Ted Miller’s team is responsible for energy-storage strategy, research, development, and worldwide implementation of hybrid electric vehicles, plug-in hybrid electric vehicles, fuel cell hybrid electric vehicles, and battery electric vehicles. Mr. Miller is a member and Chairman of the United States Advanced Battery Consortium (USABC) Management Committee and past Chairman of the USABC Technical Advisory Committee. He is the principle investigator for Ford/University Research Alliance energy storage research programs at MIT and the University of Michigan.
SESSION AGENDA
Honda's Technology and Strategy Regarding HEV Koichi Shinmura, SeniorChief Engineer, Honda R&D Co., Ltd.
Honda developed three kinds of HEV systems so that it may meet social needs and the needs of a market.
He introduces the LIB cell adopted as these HEV systems and the feature of three HEV systems. Moreover, he speaks about the characteristic required of the battery for vehicles based on the environment used, what is expected in the future.
High-Energy Automotive Battery Safety Performance and Modeling Ted Miller, Senior Manager of Energy Storage Strategy and Research, Ford
Advanced lithium ion rechargeable energy storage systems (RESS) are critical to vehicle electrification. However, there are technology challenges which must be mastered in order to ensure RESS safety. Among key challenges are robust controls, active safety systems, and passive safety design. As well, RESS behavior in the event of a crash, or other such safety issues, must be fully comprehended and addressed in the vehicle system design. Finally, a means must exist to effectively assess the safety performance of RESS at the vehicle level. This talk will consider an approach to assessing RESS safety performance within the context of vehicle safety qualification, progress to date, and plans for safety performance modeling tools. The range of efforts undertaken by the Ford Energy Storage and Materials Research Team will be presented.
Key topics to be presented include:
RESS safety performance project status
RESS safety testing update
RESS safety performance project plans
Ford RESS safety research
RESS safety performance modeling
Energy-Storage Requirements and Solutions for Subaru's Hybrid Vehicles Kenji Inakoshi, Senior Engineer, Subaru Heavy Industies.Co.Ltd.
The high voltage battery system, which is installed in SUBARU XV CROSSTREK HYBRID, is presented. In this battery system, Ni-MH battery, which is superior in safety and durability, is adopted. Furthermore, the design and control management of this battery system are optimized to maximize vehicle performance.
The technologies about safety, reliability and control management are mainly presented.
Why we chose Ni-MH battery system?
Battery performance
Safety
Reliability
Packaging (weight, space, and other requirements)
Cost
SAE Standards for Li-Ion Batteries Monique Richard, Senior Principal Engineer, Materials Engineering Department, Toyota Technical Center
Safety. Performance. Cost. These are the key metrics to success of Li-ion batteries in xEV applications. Quantifying and understanding the performance of Li-batteries on the first 2 metrics is not trivial, in part because different methodologies are used to measure said performance.
Cost can be calculated based on design, but with so many designs in the market it is difficult to imagine how standardization, necessary for sufficient production to get economies of scale, will occur. This presentation will focus on efforts in the US, by the Society of Automotive Engineers (SAE), to address Safety, Performance and Standardization, as well as other initiatives. Key topics include:
Introduction of the SAE Battery Steering Committee and its activities
Status of the various battery committees
Battery System Design Approach to Reduce Cost and Weight Uwe Wiedemann, Senior Product Mangager, Global Competence Team, AVL List GmbH
As a result of the permanent search for further reduction measures in battery pack cost, AVL has developed a technological approach to significantly push down production costs and to reduce the weight and to improve the thermal cell management at the same time.
The basic idea is to embed cell stacks and consequently a complete battery pack into foam.
The foaming technology allows a part count that is minimized to the limit. The cells are covered, protected and isolated by foam. In addition the foam also carries mechanical load and provides a seal encapsulation to the ambient.
A typical example of a much cost sensitive application is a 48V Li ion battery pack for a modern mild hybrid powertrain system. AVL has developed such a battery.
It includes the following features, which are most cost relevant:
Use of cost effective pouch cells
Cell tab clinching
Foamed in battery cells and E/E components
Foam replaces housing and structural components
Simplified electrical safety concept (<60V)
A simple cell stack incorporates the cooling system and the BMS. Finally the battery pack is a compact foam block with only the main electrical terminals, the cooling air inlet and outlet and a LV connector as interfaces.
The pouch cells are well insulated against thermal cycling and are well protected from vibration load and external acceleration. The foam prevents the cells and live components from contact with cooling air and condensate.
Cell tab clinching, the AVL cell connection method is used to further reduce production costs. Both clinching and the foaming technology itself are very insensitive to production and assembly tolerances. That also allows low cost production tools.
Recycling aspects as well as possible cell venting events were considered in the design of the pack.
Next to the cost benefit, also the gravimetric and volumetric energy density is excellent due to the fact that the number of components was reduced to the bare minimum.
Optimizing Cell, Module, Pack and Controls Design with Comprehensive Simulation Sandeep Sovani, Director, Global Automotive Industry, ANSYS Inc.
Large format automotive propulsion batteries are made up of components at many different length scales - starting from electrode pairs at the small scale, and up through cells, modules, cooling system, and to the pack. The performance of these components is governed by widely different physical phenomena including electrochemistry, electric current fields, heat transfer, fluid flow, structural mechanics, and electromagnetics. In a battery pack, these physical aspects are tightly coupled with each other. Further, the performance of each component depends closely on those of others. Therefore, in creating and testing a virtual prototype of an advanced battery, it is necessary to use comprehensive simulation methods based on multiphysics and system integration of sub-component models.
This presentation discusses a comprehensive simulation methodology for an advanced automotive propulsion battery. In a single simulation platform, the methodology performs detailed simulations of all design aspects of the battery, starting from models of electrochemistry, cell current and thermal models, cooling system models, equivalent circuit models, bus bar models, controller models, crash crush vibration and fatigue models, and full pack models.
