Lithium-ion batteries are found in devices such as mobile phones, laptops etc. However, these devices can occasionally catch fire. Unfortunately, adding a flame retardant to the electrolyte makes the battery less efficient.
Scientists have now come up with fibres, containing a flame retardant inside a plastic shell, which can be added to the electrolyte. If the battery heats up too much, the plastic melts and the flame retardant escapes.