TUT4: Managing and Understanding the Risks of Li-Ion Battery Safety
MONDAY, 13 JANUARY | 18:30 - 20:30 (DINNER PROVIDED)
ABOUT THIS TUTORIAL:
This tutorial provides insights regarding processes that lead to thermal runaway in Li-ion cells,
why all thermal runaway processes are not the same and how thermal runaway can be better
understood and managed. There are fundamental differences between how cells respond to
various stresses and, unfortunately, still too-common misunderstandings of the causes of
thermal runaway. These misunderstandings can seriously complicate battery safety
management. The tutorial continues to provide the basis for a clearer understanding of cell-
level processes that result in thermal runaway.
Increasingly, questions are arising regarding how thermal runaway in a single cell can lead to
propagation in other cells in a battery pack. Many battery engineers are considering the
viability of a “single-fault-tolerant” battery design as a realistic alternative (or at least a useful
“what-if”) to a battery that never experiences any cell safety failures. In a single fault tolerant
battery design, a single cell thermal runaway failure does not result in propagation of thermal
runaway failures in any other cells in the pack. Increasingly the question of how to proactively
design batteries that build in a single fault tolerance are arising.
As difficult as it can be to understand the different sides of thermal runaway for single cells, it is
even more complex to understand how propagation occurs and what means are available to
inhibit propagation. A larger array of factors is typically involved. Thermal runaway of an initial
single cell in a battery pack involves release of (a variable amount of) thermal energy in the
form of both gases and solids. These high temperature gases and ejecta, which can exhibit
considerable variability in their characteristics, can trigger subsequent thermal runaway of
other cells in a pack in a number of unexpected ways. Provision for safely managing these
effects are required. It’s important to understand the factors involved in limiting propagation
and to learn about some of the new tools being applied to this problem. The tutorial has added
coverage of these topics.
The design of a single-fault-tolerant battery is subject to a wide variety of engineering
considerations and can be very complicated, depending on the battery design options,
especially as higher energy density cells are employed. The tutorial has added consideration of
the factors that must be taken into account to limit propagation (or cascading) as well as to
obtain better data to support engineering of safer battery packs with respect to propagation.
Brian Barnett, PhD, President, Battery Perspectives LLC
Brian Barnett recently founded Battery Perspectives LLC, a company providing consulting services related to battery technology and battery safety. Dr. Barnett has extensive experience in assessment, development and commercialization of battery technology
and is recognized as both a technical and industry expert related to batteries and an expert in battery safety. He has directed a series of successful lab-based, highly multidisciplinary battery technology development programs that resulted in technology
licensing or sale.
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