| 摘要 |
PROBLEM TO BE SOLVED: To provide an electricity storage element including a multilayer structured separator, which is capable of significantly improving transient degradation of output.SOLUTION: In an electricity storage element including a positive electrode plate and a negative electrode plate, which are insulated from each other with a separator 430 interposed therebetween, and a nonaqueous electrolyte, the separator 430 includes a base material layer 431 and a coating layer 432 disposed on at least one surface of the base material layer 431. The air permeability of the base material layer 431 is 25 (sec/100 cc) or more and 250 (sec/100 cc) or less, the porosity of the base material layer 431 is 45% or more, the air permeability of an interface 433 between the base material layer 431 and the coating layer 432 is 15 (sec/100 cc) or less, and the air permeability of the coating layer 432 is 15 (sec/100 cc) or less. |
