Member for nonaqueous electrolyte batteries

A non-aqueous electrolyte battery comprising a member, wherein

• the member is configured to prevent a leakage of liquid or gas of the non-aqueous electrolyte battery or an intrusion of liquid or gas from outside of the non-aqueous electrolyte battery,
• the member is compressively deformed at a compressive deformation rate of 10% or more,
• the member comprises a copolymer containing a tetrafluoroethylene unit and a perfluoro (propyl vinyl ether) unit,
• the number of functional groups per 106 carbon atoms of a main chain of the copolymer is 100 or less, and a melt flow rate of the copolymer is 20 to 30 g/10 minutes, and
• the number of functional groups is a total number of —CF═CF2, —CF2H, —COF, —COOH, —COOCH3, —CONH2, and —CH2OH.