A lithium battery packaging material of the present invention includes a laminate in which a substrate layer, a first adhesive layer, a metal foil layer, a corrosion prevention treatment layer, a second adhesive layer, and a sealant layer are laminated in this order. In the packaging material, the corrosion prevention treatment layer contains an rare-earth oxide, and 1 to 100 parts by mass of phosphoric acid or phosphate relative to 100 parts by mass of the rare-earth oxide, the second adhesive layer includes an adhesive composition containing an acid modified polyolefin resin and a polyfunctional isocyanate compound, and, in an infrared absorption spectrum of the second adhesive layer, a ratio (Y/X) between absorption (X) derived from C—H bending vibration of CH3 and absorption (Y) derived from N—H bending vibration of a biuret bond is 0.3 or less.