| abstract |
A separator for a rechargeable battery pack includes a porous substrate and an adhesive layer disposed on at least one surface of the porous substrate, wherein the adhesive layer includes a first adhesive, a second adhesive, and a filler, No. A binder comprising structural units derived from vinylidene fluoride and structural units derived from hexafluoropropylene, the content of structural units derived from hexafluoropropylene is not greater than about 10% by weight based on the total amount of the first binder , the weight average molecular weight of the first binder is in the range of about 800,000 to about 1,500,000, the second binder comprises a structural unit derived from vinylidene fluoride and a structural unit derived from hexafluoropropylene, and a structural unit derived from hexafluoropropylene The structural unit is present in an amount of not greater than about 10% by weight based on the total amount of the second binder, the second binder has a weight average molecular weight of not greater than about 600,000, and the rechargeable lithium battery includes a separator. Separators for rechargeable batteries have improved heat resistance, wet adhesion, and dry adhesion. |