Electrode plate, electrochemical apparatus, battery module, battery pack, and device
This application relates to an electrode plate, an electrochemical apparatus, a battery module, a battery pack, and a device. The electrode plate includes a current collector and an electrode active material layer disposed on at least one surface of the current collector. 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; and a conductive primer layer containing a conductive material and a binder is disposed between the current collector and the electrode active material layer, the binder in the conductive primer layer containing an acrylic based/acrylate based water-dispersible binder. The electrode plate of this application has good quality, and the electrochemical apparatus containing the electrode plate has a high energy density and a good electrical performance and long-term reliability.
1 . An electrode plate, comprising a current collector and two electrode active material layers respectively disposed on two opposite surfaces of the current collector, wherein
the current collector comprises a support layer and two conductive layers respectively disposed on two opposite surfaces of the support layer, and a single-sided thickness D 2 of each one of the two conductive layers satisfies: 30 nm≤D 2 ≤3 μm;
the support layer is insulating and comprises an insulating polymer material or an insulating polymer composite material;
each one of the two conductive layers is a metal conductive layer comprising a material selected from aluminum, nickel, titanium, silver, nickel-copper alloy, aluminum-zirconium alloy, and any combination thereof; and
two conductive primer layers respectively disposed between the current collector and each one of the two electrode active material layers, the two conductive primer layers containing a conductive material and a binder, the binder containing an acrylic based or acrylate based water-dispersible binder,
the current collector further comprises:
an upper protective layer and a lower protective layer respectively disposed on two opposite surfaces of each one of the two conductive layers, wherein each of the upper protective layers is disposed between a respective one of the conductive layers and a respective one of the conductive primer layers, each of the lower protective layers is disposed between a respective one of the conductive layers and the support layer,
wherein, for each one of the two conductive layers, each one of the upper protective layer and the lower protective layer respectively disposed on the two opposite surfaces of said conductive layer is a metal oxide layer comprising one or more of aluminum oxide, cobalt oxide, chromium oxide, and nickel oxide,
wherein a thickness D 3 of each of the upper protective layers or each of the lower protective layers satisfies: D 3 ≤ 1/10 D 2 and 1 nm≤D 3 ≤200 nm,
wherein, for each one of the two conductive layers, a thickness of the upper protective layer disposed on one of the two opposite surfaces of said conductive layer D 3 is denoted as D 3 ′, a thickness of the lower protective layer disposed on the other one of the two opposite surfaces of said conductive layer D 3 is denoted as D 3 ″, D 3 ′ and D 3 ″ satisfy: ½ D 3 ′≤D 3 ″≤⅘ D 3 ′.
2 . The electrode plate according to claim 1 , wherein
the insulating polymer material is one selected from at least one of polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, polyphenylene diamide, acrylonitrile-butadiene-styrene copolymer, polybutylene terephthalate, polyparaphenylene terephthalamide, polypropylene, polyoxymethylene, epoxy resin, phenol-formaldehyde resin, polytetrafluoroethylene, polyphenylene sulfide, polyvinylidene fluoride, silicone rubber, polycarbonate, cellulose and its derivatives, starch and its derivatives, protein and its derivatives, polyvinyl alcohol and its cross-linked products, and polyethylene glycol and its cross-linked products; and
the insulating polymer composite material is one selected from a composite material formed of an insulating polymer material and an inorganic material, wherein the inorganic material is at least one of a ceramic material, a glass material, and a ceramic composite material.
3 . The electrode plate according to claim 1 , wherein a thickness D 1 of the support layer satisfies: 1 μm≤D 1 ≤30 μm; or
the room temperature Young's modulus of the support layer satisfies: 20 GPa≥E≥4 GPa; or there are cracks in the two conductive layers.
4 . The electrode plate according to claim 3 , wherein the thickness D 1 of the support layer satisfies: 1 μm≤D 1 ≤15 μm.
5 . The electrode plate according to claim 1 , wherein the single-sided thickness D 2 of each one of the two conductive layers satisfies: 300 nm≤D 2 ≤2 μm.
6 . The electrode plate according to claim 5 , wherein the single-sided thickness D 2 of each one of the two conductive layers satisfies: 500 nm≤D 2 ≤1.5 μm.
7 . The electrode plate according to claim 1 , wherein, for each one of the two conductive layers, the thickness D 3 of the upper protective layer and the lower protective layer respectively disposed on the two opposite surfaces of said conductive layer satisfies: 10 nm≤D 3 ≤50 nm.
8 . The electrode plate according to claim 1 , wherein, for each one of the conductive primer layers, based on the total weight of said conductive primer layer, the conductive material by weight is 10% to 99%, or the binder by weight is 1% to 90%.
9 . The electrode plate according to claim 1 , wherein the acrylic based/acrylate based water-dispersible binder is one selected from at least one of polyacrylic acid, polyacrylate, sodium polyacrylate, lithium polyacrylate, polyacrylic acid-polyacrylonitrile copolymer, and polyacrylate-polyacrylonitrile copolymer; or
the conductive material is at least one of a conductive carbon material and a metal material, wherein the conductive carbon material is one selected from at least one of: zero-dimensional conductive carbon, preferably acetylene black and/or conductive carbon black; one-dimensional conductive carbon, preferably carbon nanotube; two-dimensional conductive carbon, preferably conductive graphite and/or graphene; and three-dimensional conductive carbon, preferably reduced graphene oxide; and the metal material is one selected from at least one of aluminum powder, iron powder and silver powder; or
the conductive material preferably contains the one-dimensional conductive carbon material and/or the two-dimensional conductive carbon material, preferably the one-dimensional conductive carbon material and/or the two-dimensional conductive carbon material is 1 wt % to 50 wt % of the conductive material, and more preferably, the conductive material contains the one-dimensional conductive carbon material and the zero-dimensional conductive carbon material, or contains the two-dimensional conductive carbon material and the zero-dimensional conductive carbon material, or contains the one-dimensional conductive carbon material, the two-dimensional conductive carbon material and the zero-dimensional conductive carbon material.
10 . The electrode plate according to claim 1 , wherein, for each one of the two conductive primer layers, a single-sided thickness H of said conductive primer layer is 0.1 μm to 5 μm; or
the acrylic based/acrylate based water-dispersible binder is 50 wt % to 100 wt % of the binder in said conductive primer layer.
11 . The electrode plate according to claim 10 , wherein
a ratio of H to D 2 is 0.5:1 to 5:1.
12 . The electrode plate according to claim 1 , wherein, for each one of the two the electrode active material layers, said electrode active material layer comprises an electrode active material, a binder, and a conductive agent, and an average particle size D50 of said electrode active material is 5 μm to 15 μm.
13 . The electrode plate according to claim 12 , wherein the binder in said electrode active material layer is not less than 1 wt %, based on a total weight of said electrode active material layer.
14 . The electrode plate according to claim 1 , wherein the metal oxide layer is a nickel oxide layer.
15 . An electrochemical apparatus, comprising a positive electrode plate, a negative electrode plate, a separator separating the positive electrode plate from the negative electrode plate, and an electrolyte, wherein the positive electrode plate comprises a positive current collector and a positive electrode active material layer disposed on each one of two opposite surfaces of the positive current collector, and the negative electrode plate comprises a negative current collector and a negative electrode active material layer disposed on each one of the two opposite surfaces of the negative current collector, wherein,
each one of the positive current collector and the negative current collector comprises a support layer and two conductive layers respectively disposed on two opposite surfaces of the support layer, and a thickness D 2 of each of the conductive layers satisfies: 30 nm≤D 2 ≤3 μm;
the support layer of the positive current collector and the support layer of the negative current collector are insulating and comprises an insulating polymer material or an insulating polymer composite material;
the two conductive layers of the positive current collector are each a metal conductive layer comprising a material selected from aluminum, nickel, titanium, silver, nickel-copper alloy, aluminum-zirconium alloy, and any combination thereof, and the two conductive layers of the negative current collector are each a metal conductive layer comprising a material selected from aluminum, copper, nickel, titanium, silver, nickel-copper alloy, aluminum-zirconium alloy, and any combination thereof; and
in the positive electrode plate, two conductive primer layers are respectively disposed between the positive current collector and each one of the positive electrode active material layers,
in the negative electrode plate, two conductive primer layers are respectively disposed between the negative current collector and each one of the two negative electrode active material layers,
each one of the conductive primer layers comprises a conductive material and a binder, the binder containing an acrylic based or acrylate based water-dispersible binder,
each one of the positive current collector and the negative current collector further comprises:
an upper protective layer and a lower protective layer respectively disposed on two opposite surfaces of each one of the two conductive layers, wherein each of the upper protective layers is disposed between a respective one of the conductive layers and a respective one of the conductive primer layers, each of the lower protective layers is disposed between a respective one of the conductive layers and the support layer,
wherein for each one of the two conductive layers of the positive current collector, the upper protective layer and the lower protective layer respectively disposed on the two opposite surfaces of said conductive layer are metal oxide layers comprising one or more of aluminum oxide, cobalt oxide, chromium oxide, and nickel oxide,
wherein, for each one of the two conductive layers of the negative current collector, each one of the upper protective layer and the lower protective layer respectively disposed on the two opposite surfaces of said conductive layer is a metal layer or a metal oxide layer, the metal oxide layer comprises one or more of aluminum oxide, cobalt oxide, chromium oxide, and nickel oxide, the metal layer comprise one or more of nickel, chromium, nickel-based alloy, and copper-based alloy,
wherein a thickness D 3 of each of the upper protective layers or each of the lower protective layers satisfies: D 3 ≤ 1/10 D 2 and 1 nm≤D 3 ≤200 nm,
wherein, for each one of the two conductive layers of each one of the positive current collector and the negative current collector, a thickness D 3 of the upper protective layer disposed on one of the two opposite surfaces of said conductive layer is denoted as D 3 ′, a thickness D 3 of the lower protective layer disposed on the other one of the two opposite surfaces of said conductive layer is denoted as D 3 ″, D 3 ′ and D 3 ″ satisfy: ½ D 3 ′≤D 3 ″≤⅘ D 3 ′.
16 . The electrochemical apparatus according to claim 7 , wherein, for each one of the two conductive layers of the positive current collector, the upper protective layer disposed on one of the two opposite surfaces of said conductive layer is a nickel oxide layer, the lower protective layer disposed on the other one of the two opposite surfaces of said conductive layer is a nickel layer.
17 . The electrochemical apparatus according to claim 16 , wherein, for each one of the two conductive layers of the negative current collector, each one of the upper protective layer and the lower protective layer disposed respectively on the two opposite surfaces of said conductive layer is a nickel layer.
18 . A device, comprising the electrochemical apparatus according to claim 15 , wherein the electrochemical apparatus is used as a power supply for the device.