CN210429959U

CN210429959U - Long-life lithium ion battery

Info

Publication number: CN210429959U
Application number: CN201921759637.3U
Authority: CN
Inventors: 周素霞; 王晓明; 刘勇标; 杨浩田
Original assignee: Jiangsu Zhuogao New Material Technology Co Ltd
Current assignee: Jiangsu Zhuogao New Material Technology Co Ltd
Priority date: 2019-10-19
Filing date: 2019-10-19
Publication date: 2020-04-28
Anticipated expiration: 2029-10-19

Abstract

The utility model discloses a long-life lithium ion battery, include and stack the electric core that the coiling formed in proper order by positive plate, diaphragm and negative plate, the surface coating of one side at least of diaphragm has ceramic coating, the both sides surface of positive plate has all coated the anodal material coating, the surface coating of the anodal material coating of positive plate one side or both sides has conductive ceramic layer, conductive ceramic layer's surface coating has first polymer glue film, the both sides surface of negative plate has all coated the negative pole graphite layer, the surface coating on the negative pole graphite layer of negative plate one side or both sides has second polymer glue film. Through coating conductive ceramic layer on the positive pole piece, increase lithium ion transfer ability, make lithium ion transfer distribution more even, increased the anodal active material in the lithium cell and the anodal electric conductivity between active material and the anodal mass flow body of positive pole, increased anodal lithium storage space, reduce lithium cell internal resistance simultaneously, improve the cycle life of lithium cell.

Description

Long-life lithium ion battery

Technical Field

The utility model relates to a lithium battery diaphragm technical field, concretely relates to high life lithium ion battery.

Background

Lithium ion batteries have been widely used in consumer electronics, electric tools, electric vehicles, and other industries, and have the advantages of high operating voltage, high energy density, long cycle life, high power, environmental friendliness, and the like. As lithium ion batteries become more widely used, they are challenged by higher energy density and higher safety performance. The diaphragm is one of the important raw materials of the lithium ion battery, and indexes such as thickness, heat resistance, mechanical strength and porosity of the diaphragm have important influence on energy density, safety performance, internal resistance, functions and the like of the battery.

The traditional PE diaphragm and the PP diaphragm are high in heat shrinkage rate and weak in affinity with electrolyte, the reserved size of the diaphragm is large in battery design, the volume energy density is small, once thermal runaway occurs, the temperature of the battery can rise rapidly, and the safety performance of the lithium ion battery faces challenges. At present, a ceramic layer is coated on the surface of a polyolefin diaphragm to increase the thermal stability of the diaphragm, and because the bonding force between the ceramic coating and a pole piece is weak, in order to improve the bonding force between the diaphragm and the pole piece, a polymer adhesive layer needs to be coated on the surface of the ceramic coating or the surface of a base film, wherein the polymer is PVDF or PMMA or a copolymer thereof, but the polymer adhesive layer causes the ventilation loss of the diaphragm and is not beneficial to the lithium ion conduction; when the polymer is coated on the diaphragm, the coating process requirement is high due to the thin thickness of the diaphragm, the coating process is complex and difficult to control, and when the diaphragm coated by the polymer adhesive layer and the pole piece are wound into a battery cell, phenomena such as dislocation of the pole ear, poor Hi-pot and the like are easy to occur; and because the ceramic does not contribute to the conductivity of the positive and negative current collectors of the battery, and the ceramic diaphragm is not beneficial to the lithium ion desorption in the heavy-current discharge process of the lithium battery, the internal resistance of the battery is high, lithium dendrite is easy to form, and the cycle life of the lithium battery is shortened.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the disappearance that prior art exists, provide a long-life lithium ion battery, its coating process that can simplify the polymer glue film improves pole piece and diaphragm's adhesion force, avoids electric core coiling in-process appearance utmost point ear dislocation, Hi-pot phenomenon such as bad, reduces the lithium cell internal resistance simultaneously, improves electric conductive property, improves the circulation life of lithium cell.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a long-life lithium ion battery, includes and stacks the electric core that the coiling formed in proper order by positive plate, diaphragm and negative plate, the surface coating of at least one side of diaphragm has ceramic coating, the both sides surface of positive plate has all coated the anodal material coating, the surface coating of the anodal material coating of positive plate one side or both sides has conductive ceramic layer, conductive ceramic layer's surface coating has first polymer glue film, the both sides surface of negative plate has all coated the negative pole graphite layer, the surface coating of the negative pole graphite layer of negative plate one side or both sides has second polymer glue film.

As a preferred scheme, the positive plate is an aluminum foil, the positive material coating is one of a lithium nickelate coating, a lithium cobaltate coating, a lithium manganate coating, a lithium iron phosphate coating or a ternary material coating, and the ternary material coating is a nickel cobalt manganese coating.

As a preferred scheme, the conductive ceramic layer is a lithium lanthanum zirconium oxide coating, a lithium titanium aluminum phosphate coating or an aluminum lithium germanium phosphorus coating, and the coating thickness of the conductive ceramic layer is 3-6 μm.

Preferably, the negative electrode sheet is a copper foil.

As a preferable scheme, the first polymer adhesive layer is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the first polymer adhesive layer is 2 to 20 μm.

As a preferable scheme, the second polymer adhesive layer is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the second polymer adhesive layer is 2 to 20 μm.

Preferably, one side of the separator is coated with a ceramic coating, and the ceramic coating is coated on the side of the separator facing the positive plate.

As a preferable mode, the separator is a polyolefin-based film.

Compared with the prior art, the utility model has obvious advantages and beneficial effects, specifically speaking, 1, through coating the polymer glue film to positive plate or negative plate, simplified the coating technology, the coating is more even, makes the cohesive force between pole piece and the diaphragm better, has also avoided phenomenon such as utmost point ear dislocation, Hi-pot harmfulness that appear in the electric core coiling process, has also reduced the ventilative loss of diaphragm simultaneously, is more favorable to the lithium ion conduction, improves lithium ion battery's cyclicity ability and security performance; 2. by coating the conductive ceramic layer on the positive plate, the specific surface area of the conductive ceramic is large, the conductivity is high, the lithium ion transfer capacity is improved, the ionic conductivity is improved, the lithium ion transfer distribution is more uniform, the lithium ion loss caused by the formation of lithium dendrites is reduced, the interface stability between an electrolyte and the positive plate can be improved, the internal resistance of the lithium battery is reduced, and the cycle service life of the lithium battery is prolonged.

To more clearly illustrate the structural features and technical means of the present invention and the specific objects and functions achieved thereby, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments:

drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

the attached drawings indicate the following:

10. a positive plate; 11. coating of a positive electrode material; 12. a conductive ceramic layer; 13. a first polymer glue layer; 20. a diaphragm; 21. a ceramic coating; 30. a negative plate; 31. a negative graphite layer; 32. a second polymer glue layer.

Detailed Description

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the indicated position or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

As shown in fig. 1, a long-life lithium ion battery includes a battery core formed by sequentially stacking and winding a positive plate 10, a separator 20 and a negative plate 30, wherein a ceramic coating 21 is coated on a surface of one side of the separator 20 facing the positive plate 10, a positive material coating 11 is coated on surfaces of two sides of the positive plate 10, a conductive ceramic layer 12 is coated on a surface of the positive material coating 11 of one side of the positive plate 10 facing the separator 20, a first polymer adhesive layer 13 is coated on a surface of the conductive ceramic layer 12, a negative graphite layer 31 is coated on a surface of the negative plate 30, and a second polymer adhesive layer 32 is coated on a surface of the negative graphite layer 31 of one side of the negative plate 30 facing the separator 20.

In the present invention, the diaphragm 20 is a polyolefin base film. The positive plate 10 is an aluminum foil, the positive material coating 11 is one of a lithium nickelate coating, a lithium cobaltate coating, a lithium manganate coating, a lithium iron phosphate coating or a ternary material coating, and the ternary material coating is a nickel-cobalt-manganese coating. The conductive ceramic layer 12 is a lithium lanthanum zirconium oxide coating, a lithium titanium aluminum phosphate coating or an aluminum lithium germanium phosphorus coating, and the coating thickness of the conductive ceramic layer 12 is 3-6 mu m. The first polymer adhesive layer 13 is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the first polymer adhesive layer 13 is 2-20 mu m. The negative plate 30 is a copper foil, the second polymer adhesive layer 32 is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the second polymer adhesive layer 32 is 2-20 μm.

It should be noted that, in the present invention, the conductive ceramic layer 12 may also be a mixed coating of lithium lanthanum zirconium oxide, lithium aluminum titanium phosphate or aluminum lithium germanium phosphorus, and the ceramic coating 21 may also be coated on both sides of the diaphragm 20 according to actual needs; the conductive ceramic layer 12 can also be coated on the surfaces of the anode material coatings 11 on the two sides of the anode plate 10; the second polymer glue layer 32 can also be coated on the surfaces of the negative graphite layers 31 on the two sides of the negative plate 30;

to sum up, the utility model discloses a coating polymer glue film has simplified coating process on positive plate 10 or negative plate 30, and the coating is more even for the cohesive force between pole piece and diaphragm 20 is better, has also avoided phenomenons such as utmost point ear dislocation, Hi-pot harmfulness that appear in the electric core coiling process, has also reduced the ventilation loss of diaphragm 20 simultaneously, more is favorable to the lithium ion conduction, improves lithium ion battery's cyclicity ability and security performance; by coating the conductive ceramic layer 12 on the positive plate 10, the specific surface area of the conductive ceramic is large, the conductivity of the conductive ceramic is high, the lithium ion transfer capacity is increased, the ionic conductivity is improved, the lithium ion transfer distribution is more uniform, the lithium ion loss caused by the formation of lithium dendrites is reduced, the interface stability between an electrolyte and a pole piece can be improved, the internal resistance of the lithium battery is reduced, and the cycle service life of the lithium battery is prolonged.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, so any modifications, equivalent replacements, improvements, etc. made to the above embodiments by the technology of the present invention are all within the scope of the technical solution of the present invention.

Claims

1. A long-life lithium ion battery, characterized in that: include and stack the electric core of coiling formation in proper order by positive plate, diaphragm and negative pole piece, the surface coating of one side at least of diaphragm has ceramic coating, the both sides surface of positive plate has all coated the anodal material coating, the surface coating of the anodal material coating of positive plate one side or both sides has conductive ceramic layer, conductive ceramic layer's surface coating has first polymer glue film, the both sides surface of negative pole piece has all coated the negative pole graphite layer, the surface coating of the negative pole graphite layer of negative pole piece one side or both sides has the second polymer glue film.

2. A long-life lithium-ion battery according to claim 1, characterized in that: the positive plate is an aluminum foil, and the positive material coating is one of a lithium nickelate coating, a lithium cobaltate coating, a lithium manganate coating, a lithium iron phosphate coating or a ternary material coating.

3. A long-life lithium-ion battery according to claim 1, characterized in that: the conductive ceramic layer is a lithium lanthanum zirconium oxide coating, a titanium aluminum lithium phosphate coating or an aluminum lithium germanium phosphorus coating, and the coating thickness of the conductive ceramic layer is 3-6 mu m.

4. A long-life lithium-ion battery according to claim 1, characterized in that: the negative plate is a copper foil.

5. A long-life lithium-ion battery according to claim 1, characterized in that: the first polymer adhesive layer is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the first polymer adhesive layer is 2-20 mu m.

6. A long-life lithium-ion battery according to claim 1, characterized in that: the second polymer adhesive layer is one of a PVDF coating, a PMMA coating, a PVDF copolymer coating or a PMMA copolymer coating, and the coating thickness of the second polymer adhesive layer is 2-20 mu m.

7. A long-life lithium-ion battery according to claim 1, characterized in that: and one side of the diaphragm is coated with a ceramic coating, and the ceramic coating is coated on the side, facing the positive plate, of the diaphragm.

8. A long-life lithium-ion battery according to claim 1 or 7, characterized in that: the diaphragm is a polyolefin-based film.