Battery cover having one or more quenching media

A battery includes a case having an interior holding an electrolyte activating one or more anodes and one or more cathodes. A cover is positioned on the case. The cover includes one or more quenching media that each has a phase transition that occurs at a temperature above a failure temperature of the battery and below a failure temperature of the battery. The failure temperature is the temperature at which a chain reaction associated with thermal runaway is initiated. The failure temperature of the battery is the temperature of the battery at which the thermal runaway causes failure of the battery.