Separator with heat resistant insulation layer
View Patent ↗A separator with a heat resistant insulation layer includes a porous substrate layer and a heat resistant insulation layer formed on one surface or both surfaces of the porous substrate layer and containing inorganic particles and a binder. The ratio of tensile strength in MD direction×fracture strain in MD direction to the tensile strength in TD direction×fracture strain in RD direction is in a range from 0.3 to 20. A ratio of the unit mass of the heat resistant insulation layer to the unit mass of the porous substrate layer is in a range from 0.5 to 2.5. Accordingly, the separator with a heat resistant insulation layer can have improved resistance to an internal short-circuit (shorting resistance).
1. A separator with a heat resistant insulation layer consisting of:
a porous substrate layer; and
a heat resistant insulation layer placed on both surfaces of the porous substrate layer and containing inorganic particles and a binder, wherein the separator has R in a range from 0.3 to 20 and a ratio of a unit mass of the heat resistant insulation layer to a unit mass of the porous substrate layer is in a range from 0.5 to 2.5, and wherein R is defined as:
R
=
Tensile
Strength
in
MD
Direction
×
Fracture
Strain
in
MD
Direction
Tensile
Strength
in
TD
Direction
×
Fracture
Strain
in
TD
Direction
.
2. The separator with the heat resistant insulation layer according to claim 1 , wherein R is in the range from 0.5 to 10, and
the ratio of the unit mass of the heat resistant insulation layer to the unit mass of the porous substrate layer is in the range from 0.7 to 2.2.
3. The separator with the heat resistant insulation layer according to claim 1 , wherein R is in the range from 0.7 to 5, and
the ratio of the unit mass of the heat resistant insulation layer to the unit mass of the porous substrate layer is in the range from 0.9 to 1.3.
4. The separator with the heat resistant insulation layer according to claim 1 , wherein the porous substrate layer contains resin having a melting temperature in a range from 120° C. to 200° C.
5. The separator with the heat resistant insulation layer according to claim 1 , wherein the inorganic particles contain at least one material selected from the group consisting of an oxide, a nitride and a hydroxide of silicon, aluminum, zirconium or titanium, and a complex of the oxide, the hydroxide and the nitride.
6. The separator with the heat resistant insulation layer according to claim 1 , wherein the porous substrate layer contains at least one material selected from the group consisting of polyethylene, polypropylene, and an ethylene-propylene copolymer.
7. The separator with a heat resistant insulation layer according to claim 1 , wherein the porous substrate layer contains a microporous film.
8. The separator with a heat resistant insulation layer according to claim 1 , wherein a content of the binder in the heat resistant insulation layer is in a range from 2% by mass to 20% by mass with respect to 100% by mass of the heat resistant insulation layer.
9. A separator with a heat resistant insulation layer consisting of:
a porous substrate layer; and
a heat resistant insulation layer placed on only one surface of the porous substrate layer and containing inorganic particles and a binder, wherein the separator has R in a range from 0.3 to 20, and a ratio of an unit mass of the heat resistant insulation layer to an unit mass of the porous substrate layer is in a range from 0.5 to 2.5, and R is defined as:
R
=
Tensile
Strength
in
MD
Direction
×
Fracture
Strain
in
MD
Direction
Tensile
Strength
in
TD
Direction
×
Fracture
Strain
in
TD
Direction
.
10. The separator with the heat resistant insulation layer according to claim 9 , wherein a content of the binder in the heat resistant insulation layer is in a range from 2% by mass to 20% by mass with respect to 100% by mass of the heat resistant insulation layer.
11. An electric device comprising the separator with a heat resistant insulation layer according to claim 1 .
12. The separator with a heat resistant insulation layer according to claim 1 , wherein a porosity of the porous substrate layer is 50% or more.
13. The separator with a heat resistant insulation layer according to claim 1 , wherein a porosity of the porous substrate layer is 55% or more to 60% or less.
14. The separator with a heat resistant insulation layer according to claim 1 , wherein the binder contains at least one material selected from the group consisting of carboxymethyl cellulose, polyacrylonitrile, cellulose, an ethylene-vinyl acetate copolymer, polyvinyl chloride, styrene butadiene rubber, isoprene rubber, butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride and methyl acrylate.
15. The separator with a heat resistant insulation layer according to claim 1 , wherein the binder contains at least one material selected from the group consisting of carboxymethyl cellulose, methyl acrylate and polyvinylidene fluoride.
16. The separator with a heat resistant insulation layer according to claim 9 , wherein a porosity of the porous substrate layer is 50% or more.
17. The separator with a heat resistant insulation layer according to claim 9 , wherein a porosity of the porous substrate layer is 55% or more to 60% or less.
18. The separator with a heat resistant insulation layer according to claim 9 , wherein the binder contains at least one material selected from the group consisting of carboxymethyl cellulose, polyacrylonitrile, cellulose, an ethylene-vinyl acetate copolymer, polyvinyl chloride, styrene butadiene rubber, isoprene rubber, butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride and methyl acrylate.
19. The separator with a heat resistant insulation layer according to claim 9 , wherein the binder contains at least one material selected from the group consisting of carboxymethyl cellulose, methyl acrylate and polyvinylidene fluoride.