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US 2023/0155165 A1Published application
Lithium ion secondary battery
AssigneeNEC Corporation
InventorsKazuhiko INOUE, Noboru YOSHIDA, Kenichi SHIMURA
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Abstract
The lithium ion secondary battery is a secondary battery in which a positive electrode 30 and a negative electrode 40 are stacked alternatively via a separator 25, wherein the separator 25 is a single layer and is not melted or softened at least 200° C., a thermal shrinkage ratio of the separator being 3% or below, wherein an insulating layer 70 is formed on a surface of the positive electrode 30, the surface facing to the separator 25.
Claims14
A lithium ion secondary battery, comprising:
- a positive electrode having a current collector, a positive electrode active material layer, and a porous insulating layer,
- a negative electrode, and
- a separator,
- wherein the positive electrode and the negative electrode are stacked alternately via the separator,
- wherein the separator is a single layer and is not melted or softened at least 200° C., a thermal shrinkage ratio of the separator being 3% or below,
- wherein the porous insulating layer contains inorganic particles and a binder, and is formed on an entire of a surface of the positive electrode, the surface facing to the separator,
- wherein the positive electrode is obtained by applying a porous insulating layer composition containing the inorganic particles and the binder directly onto the surface of the positive electrode, and the porous insulating layer composition is not applied on a surface of the separator,
- wherein the porous insulating layer has a uniform thickness of the entire porous insulating layer that includes pores, and a thickness of the porous insulating layer is 1 μm or more and less than 10 μm,
- wherein the inorganic particles are aluminum oxide,
- wherein the binder is polyvinylidene fluoride (PVdF), and
- wherein the positive electrode active material layer includes a lithium nickel composite oxide as a positive electrode active material, and the lithium nickel composite oxide is represented by formula (A),
- LiyNi(1-x)MxO2 (A),
- wherein, in formula (A), 0<x<0.5, 0<y≤1.2, and M is at least one element selected from the group consisting of Co, Al, Mn, Fe, Ti and B.
10 more elements
A method for manufacturing a lithium ion secondary battery, the method comprising:
- preparing a positive electrode, which has a current collector, a positive electrode active material layer and a porous insulating layer, a negative electrode, and a separator,
- producing a stacked assembly by arranging the positive and negative electrodes to face each other with the separator interposed therebetween,
- placing the stacked assembly into an outer package, and injecting an electrolyte solution so that the positive and negative electrodes can be impregnated with the electrolyte solution, and
- sealing an opening of the outer package is,
- wherein the separator is a single layer and is not melted or softened at least 200° C., a thermal shrinkage ratio of the separator being 3% or below,
- wherein the porous insulating layer contains inorganic particles and a binder, and is formed on an entire of a surface of the positive electrode, the surface facing to the separator,
- wherein the positive electrode is obtained by applying a porous insulating layer composition containing the inorganic particles and the binder directly onto the surface of the positive electrode, and the porous insulating layer composition is not applied on a surface of the separator,
- wherein the porous insulating layer has a uniform thickness of the entire porous insulating layer that includes pores, and a thickness of the porous insulating layer is 1 μm or more and less than 10 μm,
- wherein the inorganic particles are aluminum oxide,
- wherein the binder is polyvinylidene fluoride (PVdF), and
- wherein the positive electrode active material layer includes a lithium nickel composite oxide as a positive electrode active material, and the lithium nickel composite oxide is represented by formula (A),
- LiyNi(1-x)MxO2 (A),
- wherein, in formula (A), 0<x<0.5, 0<y≤1.2, and M is at least one element selected from the group consisting of Co, Al, Mn, Fe, Ti and B.
10 more elements
Dependencies are inferred from the claim text.