Outer casing material for battery and lithium secondary battery

摘要

An outer casing material for a battery is provided which is constituted by laminating an outer layer that includes a heat-resistant resin film, a metal foil layer, and an inner layer that includes a thermoplastic resin film, wherein a melt flow rate of the inner layer is in a range of greater than or equal to 1 and less than 10.

主权项

1. An outer casing material for a battery, wherein the casing material is formed by laminating an outer layer which includes a heat-resistant resin film, a metal foil layer and an inner layer which includes a thermoplastic resin film, wherein:
the melting point of the heat-resistant resin film constituting the outer layer is higher than the melting point of the thermoplastic resin film constituting the inner layer; an adhesive layer for dry lamination having a thickness in a range of 0.1 μm to 10 μm between the outer layer and the metal foil layer and between the inner layer and the metal foil layer, and the adhesive layer is made with at least one selected from: a urethane-based adhesive, an acid-modified polyolefin adhesive, a styrene elastomer adhesive, an acrylic adhesive, a silicone-based adhesive, an ether-based adhesive and an ethylene-vinyl acetate-based adhesive; the inner layer consists of an intermediate layer and a pair of covering layers laminated on both sides in the thickness direction of the intermediate layer so that the intermediate layer is sandwiched by the covering layers; a melt flow rate of the covering layer is higher than a melt flow rate of the intermediate layer; and the melt flow rate of the inner layer is greater than or equal to 1 and less than or equal to 4 g/10 min as the average of melt flow rate of the three layers included in the inner layer.