▎ 摘　　要

NOVELTY - Thermal shielding device comprises: (i) a first metal layer (12); (ii) a second metal layer (14); and (iii) a polymeric core layer (16) interposed between the first metal layer and the second metal layer, where the thermal shielding device has a thermal conductivity of 0.05-4 W/mK, and upon heating to a temperature of ≥ 100° C, the polymeric core layer causes a separation distance between the first and second metal layers to increase in at least one region and a thickness of the thermal shielding device to increase by ≥ 15% in the region. USE - The device is useful for battery cover for a plug-in electric vehicle (claimed) and reducing and/or delaying heating of a region near a heat source. ADVANTAGE - The device: provides reduced flow of heat through the device, reduced thermal conductivity of the device, reduced weight, ability to expand in thickness more than from thermal expansion coefficient, ability to absorb thermal energy due to an endothermic reaction, ability to retard a flame, and ability to reduce sound transmission; reduces or minimizes the heat flow through the device; and is designed so that the spacing between the metal layers that may increase when the device is exposed to high temperatures, e.g. during an extreme thermal event. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: a battery cover for a plug-in electric vehicle comprising a thermal shielding device; and a system comprising the battery cover, an electric motor for driving at least one wheel of a vehicle, and at least one battery cell for providing power to the electric motor, where the battery cover is arranged over at least one of the battery cell, the battery cover is generally horizontal, optionally the battery cover is attached to a container that holds at least one battery cell and/or the battery cover is attached to a vehicle body and arranged below a passenger compartment, optionally the system includes a gap above or below the battery cover for allowing a separation of the first and second metal layers to increase. DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional side view of the composite material, through the thickness of the composite material, in a thermal shielding device. 10Composite material 12First metal layer 14Second metal layer 16Polymeric core layer