The result of a Li-ion battery that has gone through what is known as “thermal runaway” is illustrated in this slide. Such an event could be non-violent where only outgassing occurs from pressure built inside the battery. However, pictures in this slide are from a controlled experiment where a violent runaway occurred from an internal short-circuit induced by a testing lab. Safety worthiness testing facilities such as UL or Intertek can help run a series of tests to help prevent or minimize safety concerns. It is highly recommended for engineers to select a battery cell(s) that is UL listed to avoid or prevent safety concerns at the cell level.