Nonaqueous electrolyte secondary battery porous layer
The present invention provides a nonaqueous electrolyte secondary battery porous layer which improves an initial battery characteristic immediately after initial charge and discharge of a nonaqueous electrolyte secondary battery. In the nonaqueous electrolyte secondary battery porous layer in accordance with an aspect of the present invention, a standard deviation of bursting strength is 0.6 or more and 11.0 or less.
1. A nonaqueous electrolyte secondary battery porous layer, wherein a standard deviation of bursting strength is 0.6 or more and 11.0 or less, the nonaqueous electrolyte secondary battery porous layer contains a resin and a filler, and the thickness of the nonaqueous electrolyte secondary battery porous layer is 5 μm or less.
2. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 1 , wherein the resin contains one or more resins selected from the group consisting of polyolefin, a (meth)acrylate resin, a fluorine-containing resin, a nitrogen-containing aromatic resin, a polyester resin, and a water-soluble polymer.
3. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 1 , wherein the resin comprises a nitrogen-containing aromatic resin.
4. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 2 , wherein the nitrogen-containing aromatic resin includes a polyamide resin.
5. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 4 , wherein the polyamide resin is an aramid resin.
6. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 5 , wherein the aramid resin is one or more aramid resins selected from the group consisting of poly(paraphenylene terephthalamide), poly(metaphenylene terephthalamide), and a paraphenylene terephthalamide/metaphenylene terephthalamide copolymer.
7. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 1 , wherein the filler is a heat-resistant filler.
8. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 7 , wherein the heat-resistant filler is an inorganic filler.
9. The nonaqueous electrolyte secondary battery porous layer as set forth in claim 8 , wherein the inorganic filler contains one or more inorganic substances selected from the group consisting of alumina, boehmite, aluminum hydroxide, magnesium hydroxide, magnesium oxide, titanium oxide, and silica.
10. A nonaqueous electrolyte secondary battery laminated separator, wherein a nonaqueous electrolyte secondary battery porous layer recited in claim 1 is stacked on one surface or both surfaces of a polyolefin porous film.
11. A nonaqueous electrolyte secondary battery comprising:
a nonaqueous electrolyte secondary battery porous layer recited in claim 1 .
12. A nonaqueous electrolyte secondary battery comprising:
a nonaqueous electrolyte secondary battery laminated separator recited in claim 10 .