Positive electrode plate, electrochemical apparatus, and apparatus
This application relates to the battery field, and specifically, to a positive electrode plate, an electrochemical apparatus, and an apparatus. The positive electrode plate in this application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, where the current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer. A single-sided thickness D 2 of the conductive layer satisfies 30 nm≤D 2 ≤3 μm. A thickness D 1 of the support layer satisfies 1 μm≤D 1 ≤30 μm. The support layer is made of a polymer material or a polymer composite material. The electrode active material layer includes electrode active materials, a binder, and a conductive agent.
1. A positive electrode plate, comprising a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein
the current collector comprises a support layer and a conductive layer disposed on at least one surface of the support layer, a single-sided thickness D 2 of the conductive layer satisfies 30 nm≤D 2 ≤3 μm, a thickness D 1 of the support layer satisfies 1 μm≤D 1 ≤30 μm, and the support layer is made of a polymer material or a polymer composite material; and
the electrode active material layer comprises electrode active materials, a binder, and a conductive agent, and the electrode active materials comprise small particle active materials with an average particle size D50 of 1.0 μm to 7.0 μm and large particle active materials with an average particle size D50 of 7.1 μm to 20.0 μm, wherein D50 is a median particle size in volume distribution;
wherein a conductive primer layer is further disposed between the current collector and the electrode active material layer, the conductive primer layer comprises a conductive material and a binder, wherein the conductive material in the conductive primer layer comprises a conductive carbon material;
wherein a single-sided thickness H of the conductive primer layer is 0.1 μm to 5 μm, and a ratio of H to D 2 is 0.5:1 to 5:1.
2. The positive electrode plate according to claim 1 , wherein a mass ratio of the small particle active materials to the large particle active materials is 1:9 to 9:1.
3. The positive electrode plate according to claim 1 , wherein a binder content of the electrode active material layer is not less than 1 wt %.
4. The positive electrode plate according to claim 1 , wherein a protection layer is further disposed on a surface of the conductive layer of the current collector, the protection layer is disposed on only one surface of the conductive layer of the current collector or disposed on two surfaces of the conductive layer of the current collector; and
a thickness D 3 of the protection layer satisfies D 3 ≤D 2 /10 and 1 nm≤D 3 ≤200 nm.
5. The positive electrode plate according to claim 1 , wherein the conductive layer is a metal conductive layer, and the metal conductive layer is made of at least one of aluminum, nickel, titanium, silver, and aluminum-zirconium alloy.
6. The positive electrode plate according to claim 1 , wherein the thickness D 1 of the support layer satisfies 1 μm≤D 1 ≤15 μm.
7. The positive electrode plate according to claim 1 , the conductive agent is made of at least one of a conductive carbon material and a metal material, wherein the conductive carbon material is selected from at least one of acetylene black, conductive carbon black, carbon nanotube, graphite, graphene, reduced graphene oxide and the metal material is selected from at least one of aluminum powder, iron powder, and silver powder.
8. The positive electrode plate according to claim 1 , wherein the conductive primer layer further comprises an electrode active material.
9. The positive electrode plate according to claim 8 , wherein the binder in the conductive primer layer is the same as or different from the binder in the active material layer.
10. The positive electrode plate according to claim 1 , wherein the small particle active materials and the large particle active materials are different active materials.
11. The positive electrode plate according to claim 1 , wherein
a material of the support layer is selected from the group consisting of an insulation polymer material, an insulation polymer composite material, a conductive polymer material, a conductive polymer composite material, and any combination thereof, wherein,
the insulation polymer material is selected from the group consisting of polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, polydiformylphenylenediamine, acrylonitrile-butadiene-styrene copolymer, polybutylene terephthalate, poly(p-phenylene terephthalamide), ethylene propylene rubber, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyphenyl sulfide, polyvinylidene fluoride, silicone rubber, polycarbonate, cellulose or a derivative thereof, starch or a derivative thereof, protein or a derivative thereof, polyvinyl alcohol or cross-linked product thereof, polyethylene glycol or a cross-linked product thereof, and any combination thereof;
the insulation polymer composite material is a composite material formed of an insulation polymer material and an inorganic material, wherein the inorganic material is selected from the group consisting of a ceramic material, a glass material, a ceramic composite material, and any combination thereof;
the conductive polymer material is selected from the group consisting of a polysulfur nitride polymer material, a doped conjugated polymer material, and a combination thereof;
the conductive polymer composite material is a composite material formed of an insulation polymer material and a conductive material, wherein, the conductive material is selected from the group consisting of a conductive carbon material, a metal material, a composite conductive material, and any combination thereof; the conductive carbon material is selected from the group consisting of carbon black, carbon nanotube, graphite, acetylene black, graphene, reduced graphene oxide, and any combination thereof; the metal material is selected from the group consisting of nickel, iron, copper, aluminum, and any combination thereof; and the composite conductive material is selected from the group consisting of nickel-coated graphite powder, nickel-coated carbon fiber, and a combination thereof.
12. The positive electrode plate according to claim 1 , wherein a room-temperature Young's modulus of the support layer satisfies 20 GPa≥E≥4 GPa.
13. The positive electrode plate according to claim 1 , wherein the single-sided thickness D 2 of the conductive layer satisfies 300 nm≤D 2 ≤2 μm.
14. The positive electrode plate according to claim 1 , wherein the binder is selected from the group consisting of styrene butadiene rubber, oily polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, sodium carboxy methyl cellulose, polystyrene, polyacrylic acid, polytetrafluoroethylene, polyacrylonitrile, polyimide, aqueous PVDF, polyurethane, polyvinyl alcohol, polyacrylate, polyacrylic acid-polyacrylonitrile copolymer, polyacrylate-polyacrylonitrile copolymer, and any combination thereof.
15. The positive electrode plate according to claim 1 , where the binder in the conductive primer layer is selected from the group consisting of styrene butadiene rubber, oily polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, sodium carboxy methyl cellulose, polystyrene, polyacrylic acid, polytetrafluoroethylene, polyacrylonitrile, polyimide, aqueous PVDF, polyurethane, polyvinyl alcohol, polyacrylate, polyacrylic acid-polyacrylonitrile copolymer, polyacrylate-polyacrylonitrile copolymer, and any combination thereof.
16. The positive electrode plate according to claim 1 , wherein the conductive agent in the electrode active material layer comprises at least one of a carbon conductive material and a metal material.
17. The positive electrode plate according to claim 1 , wherein the conductive carbon material of the electrode active material layer and the conductive primer layer is each independently selected from the group consisting of acetylene black, conductive carbon black, carbon nanotube, graphite, graphene, reduced graphene oxide, and any combination thereof.
18. The positive electrode plate according to claim 15 , wherein the metal material is selected from the group consisting of aluminum powder, iron powder, silver powder, and any combination thereof.
19. An electrochemical apparatus, comprising a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, wherein the positive electrode plate is the positive electrode plate according to claim 1 .
20. An apparatus, comprising the electrochemical apparatus according to claim 19 .