Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and electric power system
Provided is a separator including: a substrate; and a surface layer formed on at least one surface of the substrate, and having a higher porosity than that of the substrate. It is preferable that the surface layer includes: a first layer having convexities and concavities existing as cavities; and a second layer formed between the first layer and the separator, and the second layer has a higher porosity than that of the substrate, and the first layer has a higher porosity than that of the second layer. In this case, it is preferable that the porosity of the substrate is from 25% to 40%, the porosity of the first layer is from 60% to 90%, and the porosity of the second layer is from 40% to 65%.
1. A battery comprising:
an electrode assembly having a positive electrode and a negative electrode arranged to face each other with a separator being interposed therebetween; and
an electrolyte,
wherein the separator includes:
a substrate; and
a surface layer formed on at least one surface of the substrate,
wherein the surface layer includes a first layer and a second layer formed between the first layer and the substrate,
the second layer has a higher porosity than that of the substrate, and
the first layer has a higher porosity than that of the second layer,
wherein the surface layer contains particles and a resin material, and the particles are in a state of being dispersed in the surface layer, and
wherein the surface layer has a concavo-convex shape, and the concavo-convex shape is formed as a result of uneven distribution of the particles and the resin material, and
wherein the porosity of the substrate is from 25% to 40%; the porosity of the first layer is from 60% to 90%; and the porosity of the second layer is from 40% to 65%.
2. The battery according to claim 1 , wherein the first layer has convexities and concavities existing as cavities.
3. The battery according to claim 1 , wherein the first layer is formed to have a thickness equivalent to the thickness of the second layer, or to have a thickness thicker than the thickness of the second layer.
4. The battery according to claim 1 , wherein the surface layer is formed such that the particles are dispersed and supported on the resin material formed in a three-dimensional network structure.
5. The battery according to claim 1 , wherein the particles contain at least one selected from aluminum oxide, boehmite, yttrium oxide, titanium oxide, magnesium oxide, zirconium oxide, silicon oxide, zinc oxide, aluminum nitride, boron nitride, silicon nitride, titanium nitride, silicon carbide, boron carbide, barium titanate, strontium titanate, barium sulfate, a porous aluminosilicate, a layered silicate, Li 2 O 4 , Li 3 PO 4 , LiF, aluminum hydroxide, graphite, carbon nanotube, and diamond.
6. The battery according to claim 1 , wherein the resin material includes polyvinylidene fluoride or aramid.
7. The battery according to claim 2 , wherein the porosity of the first layer represents a proportion of a total of pores contained in the convexities and the cavities of the concavities with respect to entirety of the first layer.
8. The battery according to claim 1 , wherein a negative electrode active material included in the negative electrode is formed from a material containing at least one of a metal element and a semimetal element as a constituent element.
9. A battery pack comprising:
the battery according to claim 1 ;
a control unit controlling the battery; and
an exterior material enclosing the battery.
10. An electronic apparatus comprising the battery according to claim 1 , and
configured to receive supply of electric power from the battery.
11. An electric vehicle comprising:
the battery according to claim 1 ,
a conversion device receiving supply of electric power from the battery and converting the electric power to the driving force for the vehicle; and
a control device performing information processing in connection with vehicle control, based on information on the battery.
12. A power storage device comprising the battery according to claim 1 , and
configured to supply electric power to an electronic apparatus connected to the battery.
13. The power storage device according to claim 12 ,
further comprising an electric power information control device configured to transmit and receive a signal to and from another apparatus through a network, and
performing charge-discharge control of the battery based on information received by the electric power information control device.
14. An electric power system receiving supply of electric power from the battery according to claim 1 , or supplying electric power from an electric power generation device or an electric power network to the battery.
15. The battery according to claim 1 , wherein the surface layer is formed on both surfaces of the substrate.
16. The battery according to claim 1 , wherein the porosity of the substrate is from 25% to 35%.
17. The battery according to claim 1 , wherein the concavo-convex shape includes one or more of a mottled (crater) pattern, a lattice (waffle) pattern, a dotted (pillar) pattern, a pinhole pattern, and a hexagonal lattice (honeycomb) pattern.
18. The battery according to claim 2 , wherein the convexities have different heights from one another.