The large variability in energy-storage requirements for the wide spectrum of hybrid-vehicle architectures creates opportunities for multiple cell chemistries and system designs. In this session, automakers will present vehicle development and energy-storage requirements for micro, mild, and strong hybrid vehicles, and energy-storage developers will present the latest achievements in meeting the requirements of the various hybrid architectures.
Session Chairman: Frank Moebius, Head of R&D High Voltage Battery, BMW Group
Dr. Moebius studied mechanical engineering at the Stuttgart University, Germany. In 1990 he started his professional life as a Project Engineer in the technical section of Lufthansa German Airlines in Frankfurt. From 1992 until 1996 he conferred a doctorate at the chair of production automation at the Kaiserslautern University. In 1996 Dr. Moebius entered the BMW Group in Munich where he first was employed in the experimental vehicles department. After a 4 years side step into the HR division he started as a department manager the BMW pre-development activities of the inhouse-production of e-drive components. Between 2004 and 2013 he was responsible for manufacturing development and the prototype shop of high-voltage batteries and traction e-motors.
Since April 2014 Dr. Moebius is head of BMW R&D high-voltage battery department.
SESSION AGENDA
Advanced Lead-Acid Battery Technology for 12V Micro-hybrid Systems Scott McCaskey, Senior Application Engineer, Automotive Battery Division, East Penn Manufacturing Co.
The most cost-effective battery for 12V micro-hybrid systems is still a lead-acid battery. The most appropriate battery for a micro-hybrid system varies with duty cycle and position on the vehicle. Carbon enhanced EFBs (enhanced flooded batteries), Carbon enhanced AGM batteries (EPM trademark Synergy®) and small footprint auxiliary AGM batteries have been developed to fill various rolls on these vehicles. The capabilities of each technology will be compared with regards to performance, cycle life and how that ultimately relates to calendar life.
12V Dual Energy Storage Systems: System Performance Evaluation, Vehicle Integration, and Testing Daniel Le, Lead Systems Engineer, Johnson Controls, Inc.
Abstract
Increased fuel economy regulations continue to drive vehicle improvements and advancements in technologies to improve the energy utilization. Recovering energy through braking may help to increase vehicle fuel efficiency. Conversion of the vehicle’s kinetic energy and storing it in a battery as electrochemical energy and then using it to power the vehicle’s electrical systems can be a way to offset the energy consumption of the vehicle. In this paper, a Dual Energy Storage System (DESS) using a combination of lead-acid and lithium battery is investigated. Bench systems were tested to evaluate the power dynamics between systems using different lithium chemistries. Also, a vehicle test platform was developed to evaluate the performance of the DESS in an integrated environment. The results of these bench tests show that some lithium chemistries pair well with the lead-acid battery voltage and generate different power dynamics. The vehicle tests provide confirmation of the in-vehicle application of the DESS and validate fuel economy increases.
High-power Lithium-ion Battery Development for Start and Stop Application Kai Wu, Vice President of Research Institute, Amperex Technology Limited
Abstract
Global trends to enhance vehicle fuel efficiency and to reduce emissions are important to protect the environmental and meet regional regulations, especially in China. Vehicles being augmented with start-stop battery system has gained market acceptance in recent years. Start-stop system has better benefit ratio of vehicle system efficiency improvement over cost. Advanced lithium-ion battery with high-rate capability, long cycle life and calendar life, excellent balance between performance and cost, is one of the most promising electrochemistry system, especially for 48-V start-stop application. This presentation will high-light CATL‘s recent development in high-power prismatic hard-case cells based on NCM cathode chemistry, with cell capacities range from 6Ah to 18Ah. A recent CATL advanced cell design and development in VDA dimension has capacity 6.9Ah, and is capable to provide discharge output power density more than 4,000 W/kg at 50% state-of-charge (SOC). This advanced cell design at 25°C can adequately discharge 10 second, also capable to accept charge input power density more than 3,000W/kg. In terms of battery life, our results show more than 10,000 cycles at 3C/3C cycle at room temperature; while at accelerated life demonstrate more than 10-year calendar-life. Proprietary advanced cell design and processes are applied to ensure at the EOL having low increase in DCR and minimizing energy loss. CATL advanced power cell could be a good choice for start-stop application.
Lead Acid, Lithium Ion or Ultracapacitors; A Stand-Alone or Combination Solution? Michael Everett, Chief Technical Officer, Maxwell Technologies
Abstract
Automakers continue to labor over the decision of how to best implement energy storage in 14V architectures to the best cost and performance advantages of the vehicle. The main choices of PbA, LiB and/or UCAP certainly justify this laboring. With three main technologies available, the 6 options are all enticing in their own way. With 6 configurations, there is real requirement to take the time to fully assess the attributes of each of those options. Many automakers have begun to assemble very competent and well developed energy storage laboratories just to aid in their decision making by understanding these technologies at the fundamental level. And these labs are staffed by experts in the energy storage fields. There is too much at stake to make a decision based on passive knowledge, the OEMs realize that practical knowledge is required to make the right choice.
This paper will illustrate the best ways to implement the ultracapacitor energy storage either alone or in combination with lead acid or lithium ion in a 14V system emphasizing the strengths and weaknesses of the respective systems. The discussion will center on the most important aspects of the system including:
The technology roadmap of ultracapacitors which make them the right choice now alone or in combination with other technology.
In the end, there is likely no perfect solution. The complex landscape lends itself to deeper and deeper understanding necessary to implement a system which is optimized and provides the competitive performance advantages sought by the aggressive OEMs in this pivotal exciting time. The decisions made now will influence the automotive architectures for years to come.
System Design Solutions for 48V Lithium-Ion Batteries Jeff Kessen, Vice President of Corporate Strategy, A123 Systems
Abstract
As ever-tightening regulations drive fuel efficiency and emissions improvements globally, vehicle manufacturers are steadily considering methods to achieve greater brake energy recuperation in addition to lightweighting and other powertrain efficiency initiatives. In recent years, considerable effort has been spent developing 48V electrical systems as a means to cost effectively enhance vehicle efficiency. As of today, the requirements for 48V batteries vary greatly around the world and even among OEMs in the same region. To promote the open discussion of 48V battery design alternatives, this presentation will provide a case study of a specific program and explain why certain design decisions were made.
Analysis of global variation in 48V requirements
Vehicle features which drive battery requirements
Market outlook for 48V systems
Elements of a cost effective system design
Cell selection
Thermal management
System integration
Introduction of a 48V production design
The Survey of Battery Deterioration for Hybrid Vehicles in the Field Shinishi Hamasaki, Battery Material Engineering Division, Toyota Motor Corporation
Abstract
In 1997, Toyota Motor Co. released the first production hybrid vehicle in the world (1st gen Prius). Since then, Toyota has been a world leader in the development of hybrid technology, and launched Prius alpha incorporating Li-ion battery in 2011. With Li-ion battery, Prius alpha has wide cargo space and keeps high fuel efficiency. After launched Prius alpha, we have been continued long distance driving test with Prius alpha, to investigate performance of Li-ion battery. This presentation will discuss the deterioration of Li-ion battery for Prius alpha in the field, including the survey and analysis for safety and reliability.
Introduction of the Prius alpha and the traction battery
Power and reliability design concept for Li-ion battery
Life, safety and reliability of Li-ion battery in the field
Analysis to deterioration of Li-ion cell
Next Generation GM Li-Ion Power Battery System Andrew Oury, Global Lead for GM Power Battery Packs, General Motors
Abstract
Building on the knowledge and experience of GM’s experience in Li-Ion power battery systems the next generation battery system shows significant improvement in power, mass and volume, compared to earlier systems. The presentation will highlight the key design elements including:
