HEAT INSULATION SHEET FOR ASSEMBLED BATTERIES AND ASSEMBLED BATTERY

A heat-insulating sheet for a battery pack, ensuring that an excellent heat-insulating performance may be obtained in a wide temperature range from a temperature during normal use of a battery to a high temperature of 500°C or more and preferably, even when the compressive stress on the heat-insulating sheet for a battery pack is increased, the excellent heat-insulating performance may be maintained, and a battery pack in which the heat-insulating sheet for a battery pack is interposed between battery cells are provided. A heat-insulating sheet 10 of the present invention is a heat-insulating sheet for a battery pack, the heat-insulating sheet being interposed between battery cells of the battery pack in which the battery cells are connected in series or in parallel, in which the heat-insulating sheet for the battery pack contains a first particle 21 made from a silica nanoparticle and a second particle 22 made from a metal oxide, and in which a content of the first particle 21 is 60 mass% or more and 95 mass% or less relative to a total mass of the first particle 21 and the second particle 22.