Abstract: The present invention relates to a battery comprising a crosslinked intumescent layer selected from a coating and a self-supported film or sheet the layer being formed from a curable intumescent composition comprising: (a) a resin component comprising one or more oligomeric or polymeric compounds having a plurality of functional groups; (b) optionally a curing agent having a plurality of functional groups that are reactive with the functional groups of the oligomeric or polymeric compound of resin component (a); and (c) a compound providing an expansion gas upon thermal decomposition; wherein compounds (a) to (c) differ from each other, to an article comprising a battery, wherein the crosslinked intumescent layer is applied to a part of the article adjacent to the battery between the battery and the article, to methods to provide fire protection to a battery or an article comprising a battery or to reduce or prevent thermal runaway of a battery.