CN116315444A - Z-shaped laminated battery diaphragm, battery core and battery - Google Patents
Z-shaped laminated battery diaphragm, battery core and battery Download PDFInfo
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- CN116315444A CN116315444A CN202310354728.3A CN202310354728A CN116315444A CN 116315444 A CN116315444 A CN 116315444A CN 202310354728 A CN202310354728 A CN 202310354728A CN 116315444 A CN116315444 A CN 116315444A
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Images
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0583—Construction or manufacture of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention relates to the technical field of lithium ion batteries, and discloses a Z-shaped laminated battery diaphragm, an electric core and a battery. The disclosed Z-shaped laminated battery diaphragm is provided with a plurality of bending positions which are perpendicular to the length extension path of the battery diaphragm, and a high diffusion coefficient film layer which is parallel to the length direction of each bending position is arranged corresponding to each bending position; the high diffusion coefficient film layer is made of raw materials including high diffusion coefficient materials, and the diffusion coefficient of the high diffusion coefficient materials is more than or equal to 10 ‑11 cm 2 And/s. A disclosed cell comprising: the battery separator described above. The disclosed battery comprises the battery cell. The battery diaphragm provided by the invention has longer cycle life after being manufactured into a battery.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a Z-shaped laminated battery diaphragm, an electric core and a battery.
Background
In the circulation process of the laminated structure lithium ion battery, the electrolyte is too much and unevenly distributed, so that the electrolyte cannot be rapidly inserted into a negative electrode due to larger polarization at the charging terminal, and the enriched lithium ions are accumulated in an overlapping area to cause edge expansion and gradually separate out lithium; at present, a method for reducing the electrolyte amount is adopted to delay the occurrence of lithium precipitation expansion, but the later circulation is affected.
In view of this, the present application is specifically proposed.
Disclosure of Invention
The present invention aims to provide a zigzag laminated battery separator, a cell and a battery, which aim to cover at least one of the problems mentioned in the background art.
The invention is realized in the following way:
in a first aspect, the invention provides a zigzag laminated battery separator, the battery separator has a plurality of bending positions perpendicular to a length extension path thereof, and a high diffusion coefficient film layer parallel to the length direction of each bending position is arranged corresponding to each bending position; the high diffusion coefficient film layer is made of raw materials including high diffusion coefficient materials, and the diffusion coefficient of the high diffusion coefficient materials is more than or equal to 10 -11 cm 2 /s。
In an alternative embodiment, the battery separator comprises a continuous separator body having a plurality of body folds perpendicular to its length extension path, the back or inner side of each body fold being correspondingly covered with a high diffusion coefficient film.
In an alternative embodiment, the battery separator comprises a plurality of intermittent separator bodies, wherein adjacent separator bodies are connected by a high diffusion coefficient film layer, and the high diffusion coefficient film layer enables the intermittent separator bodies to be connected to form a complete battery separator.
In an alternative embodiment, the separator body is a base film or a composite separator.
In an alternative embodiment, the high diffusion coefficient material is selected from at least one of amorphous carbon, natural graphite, and carbonized synthetic graphite.
In an alternative embodiment, each high diffusion coefficient film layer has a width of 1.0 to 3.0mm.
In an alternative embodiment, the high diffusion coefficient film layer is made of a high diffusion coefficient coating comprising, in parts by weight:
35-80 parts of high diffusion coefficient material, 20-65 parts of binder and 3-10 parts of dispersing agent;
preferably, the binder is selected from at least one of polytetrafluoroethylene, styrene-butadiene rubber, polypropylene, polyethylene or EVA.
Preferably, the high diffusion coefficient coating further comprises 45-65 parts of solvent, wherein the solvent is at least one selected from NMP and deionized water;
preferably, the dispersing agent is selected from at least one of sodium methylene cellulose and polyvinylpyrrolidone.
In a second aspect, the present invention provides a zigzag laminated battery cell, including a zigzag folded battery separator according to any one of the foregoing embodiments, and a plurality of positive electrode sheets and a plurality of negative electrode sheets disposed in cooperation with the zigzag folded battery separator; on the length extension path of the battery diaphragm, the projection of each negative electrode plate on the battery diaphragm exceeds the projection of the positive electrode plate on the battery diaphragm; the high diffusion coefficient film layer is correspondingly coated on the area of the negative electrode plate beyond the positive electrode plate, and is not overlapped with the positive electrode plate, and the diffusion coefficient of the high diffusion coefficient film layer is larger than that of the negative electrode plate.
In an alternative embodiment, the high diffusion coefficient film layer corresponding to the pole piece on the outermost layer is not more than the plane where 1/2 thickness of the pole piece is located in the thickness direction of the battery cell;
preferably, the interval between the centers of two adjacent high diffusion coefficient film layers is equal to the width of the negative plate.
In a third aspect, the present invention provides a zig-zag laminated battery comprising a cell according to the previous embodiments.
The invention has the following beneficial effects:
the application provides a battery diaphragm, an electric core and a battery. Through setting up high diffusion coefficient rete in diaphragm kink (corresponding to the negative pole piece region of battery), its diffusion coefficient is higher than most negative pole material, and when negative pole material was the diffusion coefficient and is less than the material of high diffusion coefficient rete, under normal liquid injection volume, electrolyte was redistributed, and the preferential absorption subassembly embedding to the dynamics better of state priority of standing of enriched lithium ion can slow down edge expansion, promotes cycle number.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a battery separator according to an embodiment of the present disclosure after being developed;
fig. 2 is a schematic diagram of the cell structure of the battery provided in embodiment 1;
fig. 3 is a schematic diagram of the cell structure of the battery provided in embodiment 2;
fig. 4 is a schematic diagram of the cell structure of the battery provided in embodiment 3;
fig. 5 is a schematic diagram of the cell structure of the battery provided in embodiment 4;
fig. 6 is a schematic diagram of the cell structure of the battery provided in example 5;
fig. 7 is a schematic structural view of the cell portion provided in the present application after being unfolded.
Icon: 100-cell; 110-a battery separator; 111-a diaphragm body; 112-a high diffusion coefficient film layer; 120-negative plate; 130-positive plate.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The zigzag laminated battery and the separator thereof provided in the embodiments of the present application are described in detail below.
As shown in fig. 1, the zigzag laminated battery diaphragm 110 provided in the embodiment of the present application has a plurality of bending positions perpendicular to the length extension path of the battery diaphragm 110, and a high diffusion coefficient film layer 112 parallel to the length direction of each bending position is provided corresponding to each bending position; the diffusion coefficient of the high diffusion coefficient material made of the raw materials including the high diffusion coefficient material is more than or equal to 10 by the high diffusion coefficient film 112 -11 cm 2 /s。
The zigzag lamination battery diaphragm 110 that this application provided sets up high diffusion coefficient rete 112 in diaphragm kink (corresponding to the negative pole piece 120 region of battery), and its diffusion coefficient is higher than most negative pole material, and when negative pole material was the diffusion coefficient material that is less than high diffusion coefficient rete 112, under normal annotating the liquid measure, electrolyte was redistributed, and the preferential absorption subassembly embedding to dynamics better of state of standing of enriched lithium ion can slow down edge expansion, promotes cycle number.
Specifically, the structure of the battery separator 110 may be of the following two types:
1. as shown in fig. 2, the battery separator 110 includes a plurality of intermittent separator bodies 111, and adjacent separator bodies 111 are connected by a high diffusion coefficient film layer 112, wherein the high diffusion coefficient film layer 112 connects the plurality of intermittent separator bodies 111 to form a complete battery separator 110.
2. The battery separator 110 includes a continuous separator body 111, and the continuous separator body 111 has a plurality of body bends perpendicular to the length extension path thereof, and the back or inner side of each body bend is correspondingly covered with a high diffusion coefficient film layer 112.
There are 3 specific configurations for such a structural battery separator 110.
One of which is that a plurality of high diffusion coefficient film layers 112 are arranged on the same side of the membrane body 111, after being folded in a zigzag shape, the membrane body presents a state that the former is positioned at the back of the bending part and the latter is positioned at the inner side of the bending part, as shown in fig. 3 and 4, fig. 3 shows that the high diffusion coefficient film layers 112 positioned at the back of the bending part correspond to the edge of the end of the negative electrode, and the high diffusion coefficient film layers 112 positioned at the inner side of the bending part correspond to the edge of the end of the positive electrode; fig. 4 shows that the high diffusion coefficient film 112 on the back of the bending portion corresponds to the edge of the positive electrode end, and the high diffusion coefficient film 112 on the inner side of the bending portion corresponds to the edge of the negative electrode end.
One of them is that a plurality of high diffusion coefficient film layers 112 are arranged on one side of the membrane body 111 according to the former one, and the latter one is arranged on the other side of the membrane body 111, and after being folded in a zigzag manner, all the high diffusion coefficient film layers 112 are shown to be positioned on the inner side of the bending position, as shown in fig. 5, or all the high diffusion coefficient film layers 112 are shown to be positioned on the back of the bending position, as shown in fig. 6.
After the second type of membrane (i.e., the membrane with the continuous membrane body 111) is applied to the zigzag laminated battery, the overlapping edge gap can be effectively filled due to the thicker position of the high diffusion coefficient membrane layer 112, and the redundant electrolyte in the edge gap can be absorbed, and meanwhile, the edge interface contact can be improved; after charging is finished, lithium ions in the electrolyte are enriched under dynamic driving due to polarization and are automatically diffused to the coating, so that edge thickening and edge lithium precipitation are effectively reduced, lithium precipitation is further reduced, and long circulation is improved.
Further, the high diffusion coefficient film layer 112 is made of a high diffusion coefficient paint, which comprises, by weight:
35-80 parts of high diffusion coefficient material, 20-65 parts of binder and 3-10 parts of dispersing agent. The high-diffusion-coefficient film 112 formed by the coating with the composition ratio has better combination property with the membrane body 111, and the problem that the high-diffusion-coefficient film 112 falls off after long-time circulation of the battery does not occur.
Preferably, the binder is selected from at least one of polytetrafluoroethylene, styrene-butadiene rubber, polypropylene, polyethylene or EVA. The adhesive has better adhesion.
Preferably, the high diffusion coefficient coating further comprises 45-65 parts of a solvent, wherein the solvent is at least one selected from NMP and deionized water.
Preferably, the dispersing agent is at least one selected from the group consisting of sodium methylene cellulose and polyvinylpyrrolidone.
The high diffusion coefficient film layer 112 is formed by: the high diffusion coefficient coating is coated on the forming part, and a film layer is formed after the solvent is volatilized, wherein the above solvent with the parts ensures that the coating has better fluidity and viscosity, and the high diffusion coefficient film layer 112 with better physical properties can be prepared.
The zigzag diaphragm shown in fig. 2 may be prepared by, for example, arranging the diaphragm bodies 111 in a mold at intervals in advance, then pouring a coating into the interval holes, and air-drying to obtain the diaphragm; the zigzag diaphragm shown in fig. 3-6 can be prepared, for example, by spreading the diaphragm in advance, setting a mold at a position where the high diffusion coefficient film layer 112 is required to be attached, and then pouring a coating into the mold; alternatively, the coating is brushed at the position where the high diffusion coefficient film layer 112 is required to be attached, and the battery separator 110 provided in the embodiment of the present application is obtained after the coating is dried.
As shown in fig. 2 to 7, the zigzag laminated battery cell 100 provided in the embodiment of the present application includes a zigzag folded battery separator 110 provided in the embodiment of the present application, and a plurality of positive electrode sheets 130 and a plurality of negative electrode sheets 120 that are disposed in cooperation with the zigzag folded battery separator 110; the projection of each negative electrode sheet 120 on the battery separator 110 exceeds the projection of the positive electrode sheet 130 on the battery separator 110 on the length extension path of the battery separator 110; the high diffusion coefficient film 112 is correspondingly coated on the area of the negative electrode plate 120 beyond the positive electrode plate 130, and is not overlapped with the positive electrode plate 130. The high diffusion coefficient film 112 has a diffusion coefficient greater than that of the negative electrode sheet 120.
The structure of the zigzag lamination battery cell 100 is the same as that of the existing zigzag lamination battery cell 100, and the difference is only that: the battery separator 110 has a different structure, and the end of the negative electrode plate 120 is correspondingly coated with a high diffusion coefficient film 112.
The zigzag lamination battery cell 100 includes the zigzag lamination battery diaphragm 110 provided in the embodiment of the present application, so that lithium is less separated and the cycle performance is good.
Preferably, the high diffusion coefficient film 112 corresponding to the outermost pole piece is not beyond the plane where 1/2 of the thickness of the pole piece is located in the thickness direction of the cell 100. The purpose of this arrangement is to ensure that the edges of the coating do not extend beyond the surface of the cell 100, avoiding an unnecessary increase in the thickness of the cell 100.
Preferably, the interval L between the centers of two adjacent high diffusion coefficient film layers 112 is equal in width to the negative electrode sheet 120. Thus, after the negative electrode plate 120 and the battery diaphragm 110 are assembled, no gap exists between the bending parts of the negative electrode plate 120 and the diaphragm.
The zigzag lamination battery provided by the embodiment of the application comprises the battery cell 100 provided by the embodiment of the application. Therefore, the lithium precipitation is less, and the cycle performance is good.
The features and capabilities of the present invention are described in further detail below in connection with the examples.
Example 1
As shown in fig. 2, the structure of the diaphragm of the zigzag lamination battery cell 100 provided in this embodiment is: the battery membrane 110 includes a plurality of intermittent membrane bodies 111, and adjacent membrane bodies 111 are connected by a high diffusion coefficient membrane layer 112, wherein the high diffusion coefficient membrane layer 112 connects the plurality of intermittent membrane bodies 111 to form a complete battery membrane 110.
The high diffusion coefficient film 112 has a width of 3mm and a thickness of 16 μm, and the paint for forming the high diffusion coefficient film 112 comprises the following components:
42 parts of amorphous carbon, 5 parts of a binder (PMMA), 3 parts of a dispersing agent (sodium methylene cellulose) and 50 parts of a solvent (NMP).
The negative electrode sheet 120 is a sheet of artificial graphite coated on copper foil, the positive electrode sheet 130 is a sheet of lithium iron phosphate coated on aluminum foil, and the membrane body 111 is a 16 μm membrane made of PP material, which has the same thickness as the high diffusion coefficient membrane layer 112.
The cell 100 was assembled as a 5Ah model Z-type laminated battery.
Example 2
As shown in fig. 3, in the zigzag laminated battery cell 100 provided in this embodiment, the battery separator 110 includes a continuous separator body 111, the continuous separator body 111 has a plurality of body bends perpendicular to the length extension path thereof, and the back or inner side of each body bend is correspondingly covered with a high diffusion coefficient film 112.
The plurality of high diffusion coefficient film layers 112 are disposed on the same side of the membrane body 111, and after being folded in a zigzag shape, the former is located at the back of the bending position, and the latter is located at the inner side of the bending position. Fig. 3 shows that the high diffusion coefficient film 112 on the back side of the bend corresponds to the edge of the negative electrode end, and the high diffusion coefficient film 112 on the inner side of the bend corresponds to the edge of the positive electrode end.
The high diffusion coefficient film 112 has a width of 3mm and a thickness of 40 μm, and the paint for forming the high diffusion coefficient film 112 comprises the following components:
48 parts of natural graphite, 5 parts of a binder (styrene-butadiene rubber), 2 parts of a dispersing agent (polyvinylpyrrolidone) and 55 parts of a solvent (deionized water).
The negative electrode sheet 120 is a sheet coated with artificial graphite on a copper foil, the positive electrode sheet 130 is a sheet coated with lithium iron phosphate on an aluminum foil, and the membrane body 111 is a 20 μm membrane made of PE.
The cell 100 was assembled as a 25Ah model Z-type laminated battery.
Example 3
This embodiment is substantially the same as embodiment 2 as shown in fig. 4, except that: the high diffusion coefficient film 112 located on the back of the bend corresponds to the edge of the positive electrode end, and the high diffusion coefficient film 112 located on the inner side of the bend corresponds to the edge of the negative electrode end.
Example 4
As shown in fig. 5, in the zigzag laminated battery cell 100 provided in this embodiment, the battery separator 110 includes a continuous separator body 111, the continuous separator body 111 has a plurality of body bends perpendicular to the length extension path thereof, and the back or inner side of each body bend is correspondingly covered with a high diffusion coefficient film 112.
The high diffusion coefficient film layers 112 are arranged on one side of the membrane body 111 according to the former mode, the latter mode is arranged on the other side of the membrane body 111, and after Z-shaped folding, all the high diffusion coefficient film layers 112 are positioned on the inner side surfaces of the bending positions.
The high diffusion coefficient film 112 has a width of 2.5mm and a thickness of 50 μm, and the paint for forming the high diffusion coefficient film 112 comprises the following components:
47.5 parts of artificial graphite, 3.5 parts of binder (PMMA), 1 part of dispersing agent (polyvinylpyrrolidone) and 48 parts of solvent (NMP).
The negative electrode plate 120 is a plate coated with artificial graphite on a copper foil, the positive electrode plate 130 is a plate coated with lithium iron phosphate on an aluminum foil, and the membrane body 111 is a 16+2 mu m membrane coated with a single-layer PVDF material on a PP base film.
The cell 100 was assembled as a 25Ah model Z-type laminated battery.
Example 5
As shown in fig. 6, this embodiment is substantially the same as embodiment 5, except that: after the zigzag folding, it is shown that all the high diffusion coefficient film layers 112 are located on the outer side of the bending part.
Comparative example 1
This comparative example provides an existing common 5Ah model zigzag laminate battery. The battery separator 110 is a continuous separator body 111 without a high diffusion coefficient film layer 112.
Comparative example 2
This comparative example is substantially the same as example 2, except that a ceramic (gamma-Al) equivalent to amorphous carbon is selected 2 O 3 ) Alternative to amorphous carbon, gamma-Al in example 2 2 O 3 Is lower than the negative electrode.
Experimental example
The electrochemical properties of examples 1-5 and comparative examples 1-3 were tested.
The test method specifically comprises the following steps: 1. weighing the weight of the battery before liquid injection, the weight of the liquid injection and the weight of the battery after two seals, and calculating the liquid retention amount of the battery; 2. recording the first-time total charge capacity and 0.2C discharge to 2.5V capacity, wherein the ratio of the discharge capacity to the charge capacity is the first coulomb efficiency; 3. after the aging is finished, the battery is discharged to 2.5V at 1C, kept stand for 30min, then charged to 3.65V at constant current and constant voltage at 1C, and subjected to a cycle test at 0.05C. The test results are recorded in table 1.
Table 1 electrochemical performance data for the batteries of each example and comparative example
| Group of | Battery liquid retention amount | Cycle efficiency | First coulombic efficiency |
| Example 1 | 24.0g | 2000 times 91.2% | 88.2％ |
| Example 2 | 102.3g | 2000 times 90.8 percent | 90.8％ |
| Example 3 | 102.0g | 2000 times 90.3% | 90.7％ |
| Example 4 | 102.1g | 2000 times 91.4% | 90.1％ |
| Example 5 | 102.6g | 2000 times 91.0% | 90.2％ |
| Comparative example 1 | 23.5g | 2000 times 89.2% | 89.2％ |
| Comparative example 2 | 101.8g | 2000 times 88.7% | 91.3％ |
From the table, compared with the existing Z-shaped laminated battery corresponding to the common diaphragm, the battery provided by the embodiment of the application has higher liquid retention capacity, and the 2000-cycle efficiency is improved by 1-1.5%, so that the battery prepared by adopting the diaphragm provided by the application can be endowed with higher cycle performance and higher liquid retention performance. Comparing example 2 with comparative example 2, the liquid retention and cycle efficiency of comparative example 2 are significantly worse, demonstrating that the battery separator 110 with the high diffusion coefficient film layer 112 has higher liquid retention and cycle efficiency when the material with high diffusion coefficient is selected.
In summary, according to the zigzag lamination battery diaphragm 110 provided by the application, since the high diffusion coefficient film layer 112 is arranged at the bending part of the diaphragm (corresponding to the area of the negative electrode plate 120 of the battery), the diffusion coefficient of the diaphragm is higher than that of most negative electrode materials, when the diffusion coefficient of the negative electrode materials is lower than that of the high diffusion coefficient film layer 112, under the normal liquid injection amount, the electrolyte is redistributed, and the enriched lithium ions are preferentially embedded into the adsorption component with better dynamics in the static state, so that the edge expansion is slowed down, and the cycle times are increased.
The battery cell 100 and the battery provided by the application have higher cycle times due to the battery diaphragm 110.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The Z-shaped laminated battery diaphragm is characterized by comprising a plurality of bending positions which are perpendicular to the length extension path of the battery diaphragm, wherein a high diffusion coefficient film layer parallel to the length direction of each bending position is arranged corresponding to each bending position; the high diffusion coefficient film layer is made of raw materials including high diffusion coefficient materials, and the diffusion coefficient of the high diffusion coefficient materials is more than or equal to 10 -11 cm 2 /s。
2. The battery separator of claim 1, comprising a continuous separator body having a plurality of body folds perpendicular to its length extension path, the back or inner side of each body fold being covered with a respective one of the high diffusion coefficient film layers.
3. The battery separator of claim 1, wherein said battery separator comprises a plurality of intermittent separator bodies, adjacent ones of said separator bodies being connected by a single said high diffusion coefficient film layer, said high diffusion coefficient film layer connecting said plurality of intermittent separator bodies to form a complete battery separator.
4. A battery separator as claimed in claim 2 or claim 3, wherein the separator body is a base film or a composite separator.
5. The battery separator of claim 1, wherein the high diffusion coefficient material is selected from at least one of amorphous carbon, natural graphite, and carbonized synthetic graphite.
6. The battery separator of claim 1, wherein each of the high diffusion coefficient film layers has a width of 1.0 to 3.0mm.
7. The battery separator according to claim 1, wherein the high diffusion coefficient film layer is made of a high diffusion coefficient coating material comprising, in parts by weight:
35-90 parts of high diffusion coefficient material, 3-25 parts of binder and 1-5 parts of dispersing agent;
preferably, the binder is selected from at least one of polytetrafluoroethylene, styrene-butadiene rubber, polypropylene, polyethylene or EVA.
Preferably, the high diffusion coefficient coating further comprises 30-65 parts of solvent, wherein the solvent is at least one selected from NMP and deionized water;
preferably, the dispersing agent is at least one selected from the group consisting of sodium methylene cellulose and polyvinylpyrrolidone.
8. A zigzag laminated battery cell, characterized by comprising the zigzag folded battery diaphragm according to any one of claims 1 to 7, and a plurality of positive electrode sheets and a plurality of negative electrode sheets which are arranged in cooperation with the zigzag folded battery diaphragm; on the length extension path of the battery diaphragm, the projection of each negative electrode plate on the battery diaphragm exceeds the projection of each positive electrode plate on the battery diaphragm; the high diffusion coefficient film layer is correspondingly coated on the area, exceeding the positive plate, of the negative plate, and is not overlapped with the positive plate, and the diffusion coefficient of the high diffusion coefficient film layer is larger than that of the negative plate.
9. The cell of claim 8, wherein the one high diffusion coefficient film layer corresponding to the outermost pole piece is not beyond the plane at 1/2 thickness of the pole piece in the thickness direction of the cell;
preferably, the interval between the centers of two adjacent high diffusion coefficient film layers is equal in width to the negative electrode sheet.
10. A zig-zag laminated battery comprising a cell according to claim 8 or 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310354728.3A CN116315444A (en) | 2023-04-04 | 2023-04-04 | Z-shaped laminated battery diaphragm, battery core and battery |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310354728.3A CN116315444A (en) | 2023-04-04 | 2023-04-04 | Z-shaped laminated battery diaphragm, battery core and battery |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116525766A (en) * | 2023-06-27 | 2023-08-01 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
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2023
- 2023-04-04 CN CN202310354728.3A patent/CN116315444A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116525766A (en) * | 2023-06-27 | 2023-08-01 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
| CN116525766B (en) * | 2023-06-27 | 2023-09-26 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
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