Objective of Task

Task 10’s goal was to advance the state-of-the-art of battery and capacitor science and address issues related to their use in vehicles. The Task accomplished this goal by facilitating information exchange among technical experts from the electrochemical power sources field.

Working Method

The Task addressed selected topics through the use of focused working groups. Each working group met once or twice to discuss a specific topic. Products from the working groups varied depending upon the nature of the discussions and included documents distributed to the participants and summaries published in the Annual Reports. Each working group had unique members; attendees were individuals interested in the specific topic.

Results

Task 10 sponsored ten working group meetings between 2006 and 2016:

1. Attendance at a given workshop varied from about 18 to 40 individuals.
2. Total attendance for all of the workshops was about 250 people.
   • Some individuals attended more than one workshop, but many experts came to only one workshop on a topic of specific interest to them.
   • Attendees came from about 19 different countries.
3. Workshops were held in four member countries: Belgium, Canada, France, and the United States.
4. Attendees came from a range of organizations, including the following: Universities, Government agencies, National laboratories, Battery materials manufacturers/suppliers, Cell and battery manufacturers, Automotive manufacturers, Defense agencies, Recycling industry, and Independent R&D organisations.

A list of the Workshops with brief conclusions are given here:

Safety and Abusive Testing of Batteries, Parts 1 & 2

• Safety tests are complex and can be manipulated.
• Although many standard safety testing procedures and protocols address similar issues, there can be significant differences in the results depending upon subtle differences. For example, some procedures “test to failure” to identify failure mechanisms and “worst case” scenarios; other procedures only “test to a pass/fail point.” In these procedures, if a cell or battery reaches the defined “pass” criteria, no further testing is done.

The World’s Supply of Lithium

• There is an ample supply of lithium, but some sources of lithium are more expensive to process than others. Production of lithium from brines is normally less expensive than production from ores.

Accelerated Life Testing of Batteries (Especially Lithium-ion Batteries) for Vehicles

• It’s not easy, but it can be done.
• As a result of this working group meeting, a new, independent task focusing on Life Testing of Batteries was established.

Government Support for Vehicle Battery Manufacturing Facilities

• Government support can help build an industry, but there will be issues and “failures”.
• Several countries had programs to encourage the battery industry.
• No other country had, at the time of this workshop in September 2010, made the same type of large, focused investment that the U.S. had under the Recovery Act.

Battery Recycling (With an Emphasis on Lithium-ion Batteries)

• Most recycling systems in actual use destroy the cell either thermally or physically. What is actually recovered and how it is used is a function of the recycling technology used.
• Recycling is most attractive financially for cobalt systems, because of the value of the recovered cobalt.
• Many materials in a “recycled” battery end up in a slag or waste stream. Some of these slags do have commercial value. For example, the lithium/aluminum oxides in the slag from thermal treatment processes are of value as an additive to cement.
• Recovering “high value” components such as cathode active materials that can be used in new batteries with a minimum of processing is a challenge. Processes that can accomplish this goal are under development, but none were in commercial operation at the time of the workshop in September 2011.

Batteries under Extreme Temperature Conditions

• Cold hurts performance. Some of the suggested methods of extending battery operation in cold weather, such as wearing a very heavy coat and not using the car’s heater would not be acceptable to all users.
• Heat hurts battery life.

Safety of Batteries in Electric Drive Vehicles

• The battery is sometimes blamed unfairly.
• Often the problem is poor pack design or poor pack assembly.
• Some battery incidents have involved very complex, multi-step failure scenarios.
• Internal short circuits are a big concern that will be hard to “fix”.
• Electrical energy “stranded” in a damaged battery is of significant concern.

Fast Charging of Batteries in Plug-In Electric Vehicles (Joint with Task 20)

• Current versions of “Fast charging” are not that fast.
• Current versions of “Fast charging” should not damage batteries.
• No single standard for charging technology and connection to the vehicle has emerged as dominant.
• The logistical barriers (such as codes, standards, and permitting) to installing a fast charger can be significant.

Suppression of Battery Fires (Joint with the Battery Safety Council)

1. Battery fires are hard to put out, but water will keep them from spreading.
   • In some cases, a battery fire which was “suppressed” with water or another firefighting agent would “reignite” after a passage of time. In many cases, a battery fire was finally “extinguished” only after all reactive materials in the battery had been consumed – i.e., the battery “burned itself out.”
   • In some events, a battery failure propagated through multiple cells in one or more modules but did not spread to adjacent modules. This situation was characterised by the statement, “The car burned up, but much of the battery survived.”
2. A car fire is of small concern compared to a fire on an airplane at altitude.
3. The firefighting community is concerned about proposals to install multimegawatt hour batteries on an upper floor in high-rise buildings.