BATTERY SYSTEM, ELECTRIC VEHICLE EQUIPPED WITH BATTERY SYSTEM, AND ELECTRICITY STORAGE DEVICE

In order to prevent induction of thermal runaway with a simple structure, a battery system incudes battery stack () formed by stacking a plurality of battery cells () and cooling plate () thermally coupled to battery cell () of battery stack (). Heat insulating material () is disposed between battery cells () of battery stack (), which are adjacent to each other, and heat insulating material () insulates heat between battery cells () adjacent to each other. In addition, cooling plate () cools battery cell (), is used in combination with an endothermic material having heat capacity to absorb thermal runaway energy of battery cell (), and prevents induction of thermal runaway.