Perhaps another application is insulation of batteries. You want good thermal conductivity when the battery is in active use at high power draw to sink heat to

Perhaps another application is insulation of batteries. You want good thermal conductivity when the battery is in active use at high power draw to sink heat to the environment, but also you may want to insulate it when it's idle and freezing outside, to reduce how much self-discharge is needed to maintain its minimum temperature. However, it might be simpler to do this with moving parts or phase-change materials, etc