Outer packaging material for power storage device, and power storage device

Provided is an outer packaging material for a power storage device, which has excellent processability and puncture resistance. The outer packaging material (1) for a power storage device comprises a base material layer (51), a barrier layer (52) laminated on the inner side of the base material layer (51), and a sealant layer (53) laminated on the inner side of the barrier layer (52). The base material layer (51) is composed of a polyamide film. The base material layer 51 has a TD hot-water shrinkage rate and an MD hot-water shrinkage rate of 2.0-5.0%, a difference between the TD hot-water shrinkage rate and the MD hot-water shrinkage rate of 1.5% or less, a TD elastic modulus and an MD elastic modulus of 1.5-3 GPa, and at least one of a TD breaking strength and an MD breaking strength of 320 MPa or more. 本发明提供加工性及耐刺穿性优异的蓄电设备用外包装材料。本发明以包含基材层51、层叠于基材层51的内侧的阻隔层52、层叠于阻隔层52的内侧的密封剂层53的蓄电设备用外包装材料1为对象。基材层51由聚酰胺膜构成。基材层51的TD的热水收缩率及MD的热水收缩率均为2.0％～5.0％，TD的热水收缩率与MD的热水收缩率之间的差为1.5％以下，TD的弹性模量及MD的弹性模量均为1.5GPa～3GPa，TD的断裂强度及MD