To provide a laminate which has a heat sealing property, a barrier property and mechanical strength, of which elution of impurities from the surface to be in contact with a chemical solution is suppressed, and of which peeling and the like hardly occur at the sealed portion of a bag and at the interfaces between the layers of the laminate when exposed to high temperature, a bag using it and a lithium ion battery.
A laminate 10 comprising a first layer 12 containing a fluororesin, a second layer 14 containing a barrier material, a third layer 16 containing a fluororesin and a fourth layer 18 containing a polyamide in this order, wherein each of the fluororesin in the first layer 12 and the fluororesin in the third layer 16 is a fluororesin having a melting point of from 160 to 230° C. and having adhesive functional groups.