Electrode for lithium ion secondary battery and production method therefor
To provide an electrode for a lithium ion secondary battery capable of enhancing a charge and discharge cycle durability of an electrode that uses a resin current collector. An electrode for a lithium ion secondary battery provided with a resin current collector including a polyolefin resin matrix and a conductive filler A, and an electrode active material layer provided on the resin current collector, in which a crosslinked resin thin-film layer, which contains an Ni filler as a conductive filler B that does not alloy with Li and which has impermeability to the electrolyte solution, is arranged between the resin current collector and a negative electrode active material layer.
1. An electrode for a lithium ion secondary battery comprising:
a resin current collector including a polyolefin resin matrix and a conductive filler A;
a negative electrode active material layer provided on the resin current collector,
a crosslinked resin thin-film layer, which contains an Ni filler as a conductive filler B that does not alloy with Li and which has impermeability to an electrolyte solution, arranged between the resin current collector and the negative electrode active material layer; and
an intermediate layer having an electric conductivity arranged between the resin current collector and the thin-film layer,
wherein a content of the Ni filler is from 50 to 90% by mass relative to 100% by mass of a total amount of the thin-film layer.
2. The electrode for a lithium ion secondary battery according to claim 1 , wherein the thin-film layer contains a crosslinked epoxy resin as the crosslinked resin, and the conductive filler B.
3. The electrode for a lithium ion secondary battery according to claim 1 , wherein the intermediate layer is an epoxy resin layer A containing a carbon-based conductive filler.
4. The electrode for a lithium ion secondary battery according to claim 1 , wherein an epoxy resin layer B containing a carbon-based conductive filler is arranged on a resin current collector surface that is opposite to the surface on which the negative electrode active material layer is formed.
5. A power source obtained by laminating a plurality of single battery layers having the electrode for a lithium ion secondary battery according to claim 1 .
6. A method for producing an electrode for a lithium ion secondary battery comprising:
a step of forming a resin current collector by using a composition for forming a resin current collector which contains a polyolefin resin matrix and a conductive filler A,
a step of forming an intermediate layer by coating a slurry for intermediate layer containing a conductive filler on top of the resin current collector on the side proximate to a negative electrode active material layer followed by drying,
a step of forming a thin-film layer which has conductivity and has impermeability to an electrolyte solution by coating a slurry for thin-film layer containing an Ni filler as a conductive filler B that does not alloy with Li and a crosslinked resin on top of the intermediate layer followed by drying, wherein a content of the Ni filler is from 50 to 90% by mass relative to 100% by mass of a total amount of the thin-film layer, and
a step of forming an electrode active material layer by coating an electrode slurry containing an electrode active material on top of the thin-film layer followed by drying.
7. The method for producing an electrode for a lithium ion secondary battery according to claim 6 , wherein the crosslinked resin is an epoxy resin.
8. The method for producing an electrode for a lithium ion secondary battery according to claim 6 , wherein the step of forming the intermediate layer is to form an epoxy resin layer A as the intermediate layer, and the slurry contains a carbon-based conductive filler and an epoxy resin followed by drying.
9. The method for producing an electrode for a lithium ion secondary battery according to claim 6 , further comprising a step of forming an epoxy resin layer B by coating, on a surface side of the resin current collector that is opposite to the side proximate to the negative electrode active material layer, a slurry containing a carbon-based conductive filler and an epoxy resin followed by drying.