FIBER ASSEMBLY, SEPARATOR FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND METHOD FOR MANUFACTURING FIBER ASSEMBLY

摘要

PROBLEM TO BE SOLVED: To provide a fiber assembly excellent in wettability with an electrolyte and capable of constituting a secondary battery excellent in long-term cycle stability when being used as a separator for a secondary battery.SOLUTION: A fiber assembly of the present invention includes: an aggregate of fibers including a polyolefin-based resin fiber; and a film layer covering at least a part of the surface of the polyolefin-based resin fiber and including a polymer of a polymerizable compound having two or more radical polymerizable functional groups in one molecule.