Patent ID: 8497032

Claim:
A rectangular bag-like separator produced in the form of a bag by thermo-bonding of peripheral portions of a resin film, wherein the rectangular bag-like separator defines four separator sides including two adjacent first and second bonding sides each including a bonding section therein and two adjacent first and second insertion opening sides defining an insertion opening through which an electrode is allowed to be inserted, wherein said first insertion opening side has a bonding section therein, said first insertion opening side is adjacent to said first bonding side, wherein the bonding section of said first insertion opening side defines a first side that opposes said second insertion opening side, and the bonding section of said first bonding side defines a second side that opposes said second insertion opening side, wherein said first side is located farther from said first bonding side than said second side, and wherein a distance from said first side to said second insertion opening side is within 50% to 99% of a whole length of said first insertion opening side.