CN216213793U - Battery cell, battery and power consumption device - Google Patents
Battery cell, battery and power consumption device Download PDFInfo
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- CN216213793U CN216213793U CN202122363005.9U CN202122363005U CN216213793U CN 216213793 U CN216213793 U CN 216213793U CN 202122363005 U CN202122363005 U CN 202122363005U CN 216213793 U CN216213793 U CN 216213793U
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- electrode assembly
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- pole piece
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- electrolyte
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- 239000003792 electrolyte Substances 0.000 claims abstract description 56
- 230000035699 permeability Effects 0.000 claims abstract description 17
- 238000004804 winding Methods 0.000 claims description 23
- 238000005056 compaction Methods 0.000 claims description 22
- 239000000178 monomer Substances 0.000 abstract description 10
- 238000009841 combustion method Methods 0.000 abstract 1
- 230000002349 favourable effect Effects 0.000 abstract 1
- 239000011148 porous material Substances 0.000 description 17
- 125000006850 spacer group Chemical group 0.000 description 11
- 238000002955 isolation Methods 0.000 description 10
- 239000013543 active substance Substances 0.000 description 9
- 230000006866 deterioration Effects 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- 238000000429 assembly Methods 0.000 description 7
- 230000000712 assembly Effects 0.000 description 7
- 229910001416 lithium ion Inorganic materials 0.000 description 7
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 6
- 239000011149 active material Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 239000007773 negative electrode material Substances 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
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- 239000007774 positive electrode material Substances 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 235000015842 Hesperis Nutrition 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 235000012633 Iberis amara Nutrition 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
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- 230000017525 heat dissipation Effects 0.000 description 1
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- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- VVNXEADCOVSAER-UHFFFAOYSA-N lithium sodium Chemical compound [Li].[Na] VVNXEADCOVSAER-UHFFFAOYSA-N 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- WJZHMLNIAZSFDO-UHFFFAOYSA-N manganese zinc Chemical compound [Mn].[Zn] WJZHMLNIAZSFDO-UHFFFAOYSA-N 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
-
- 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
- H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
- H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
- H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
- H01M50/209—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for prismatic or rectangular cells
-
- 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
-
- 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
- H01M50/491—Porosity
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
-
- 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
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Secondary Cells (AREA)
Abstract
The application discloses battery monomer, this battery monomer includes first electrode subassembly and the second electrode subassembly of piling up along vertical direction, wherein, first electrode subassembly includes first separator, the second electrode subassembly includes the second separator, the air permeability of second separator is greater than the air permeability of first separator, make the second electrode subassembly can reserve more electrolyte when contacting with electrolyte, this part electrolyte is favorable to the conduction to scatter the local heat that produces on the second electrode subassembly, avoid the second electrode subassembly to take place local dry combustion method or last high temperature and use, thereby prolong the holistic life of second electrode subassembly and battery monomer.
Description
Technical Field
The application relates to the field of batteries, in particular to a single battery, a battery and an electric device of the battery.
Background
Batteries are widely used in electronic devices such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, and the like. The battery can include cadmium nickel battery, nickel hydrogen battery, lithium ion battery, secondary alkaline zinc manganese battery, etc.
In the development of battery technology, the service life of a battery is related to convenience, and when the service life of the battery is short, the battery is easy to frequently replace in the use process of the battery, so that inconvenience in the use process is caused, and the economic benefit is influenced.
Disclosure of Invention
The application provides a battery monomer, battery and power consumption device, its life that can prolong the battery.
In a first aspect, the present application provides a battery cell comprising:
a first electrode assembly and a second electrode assembly stacked in a vertical direction, the first electrode assembly being disposed below the second electrode assembly,
the first electrode assembly includes a first separator, and the second electrode assembly includes a second separator having a gas permeability greater than a gas permeability of the first separator.
The contact area of the second electrode assembly stacked above with the electrolyte is small compared to the first electrode assembly stacked below, and the temperature rise capability of the second electrode assembly is higher than that of the first electrode assembly under the heat conduction effect of the electrolyte, so that the second electrode assembly is easily operated continuously at a high temperature state, and the service life is shortened. By adopting the scheme, the capacity of the second isolating piece for storing the electrolyte is improved, the probability of continuous high-temperature work of the second electrode assembly can be reduced, the service life of the whole battery is prolonged, and the convenience of the battery in the use process is improved.
In some embodiments, the porosity of the second separator is greater than the porosity of the first separator.
The porosity is the ratio of the pore area on the separator of unit area, and by adopting the scheme, the porosity of the second separator is larger than that of the first separator, so that the second separator can have larger pore area for storing part of the electrolyte, and the electrolyte storage capacity of the second separator can be effectively improved.
In some embodiments, the first electrode assembly and the second electrode assembly are both wound electrode assemblies, and the length of the second separator is greater than the length of the first separator in the winding direction.
When the porosity is constant, the larger the area of the separator, the larger the number of pores and the total area. By adopting the scheme, the total area of the pores on the second isolating piece is larger than that of the pores on the first isolating piece, so that the electrolyte storage capacity of the second isolating piece is higher than that of the first isolating piece.
In some embodiments, the number of windings of the second spacer is greater than the number of windings of the first spacer in the winding direction.
By adopting the above-described scheme, when the first electrode assembly and the second electrode assembly are the same in size, the total length of the second separator may be greater than the total length of the first separator, and the capacity of the second separator to store the electrolyte may be made higher than the capacity of the first separator to store the electrolyte. In addition, in the multi-layer structure formed by winding the separators, the gaps between the layers can absorb and store a certain amount of electrolyte by using a capillary effect, so that the number of winding turns of the second separator is greater than that of the first separator, and a plurality of the gaps can be formed in the second electrode assembly to store the electrolyte.
In some embodiments, the first electrode assembly further comprises a first pole piece, the second electrode assembly further comprises a second pole piece, the first pole piece and the second pole piece are of the same polarity, and the compaction density of the first pole piece is greater than the compaction density of the second pole piece.
In the pole piece of excessive pressure, the extrusion degree between the material granule is too big for the compaction density of pole piece is great and the porosity is less, also can reduce the absorption capacity to the electrolyte. By adopting the scheme, the compaction density of the first pole piece is greater than that of the second pole piece, so that the porosity of the second pole piece is greater than that of the first pole piece, and the absorption capacity of the second pole piece to electrolyte is improved.
In some embodiments, the first and second pole pieces are both positive pole pieces, and the first pole piece has a compacted density of 3.2-3.5g/cm 3 The second pole piece has a compacted density of 3.0-3.25g/cm 3 (ii) a Or,
the first pole piece and the second pole piece are only negative pole pieces, and the compaction density of the first pole piece is 1.55-1.7g/cm 3 The compacted density of the second pole piece is 1.4-1.55g/cm 3 。
In a certain range, the higher the compaction density of the pole piece is, the higher the capacity of the battery is, but when the pole piece is overpressured by 2, the lithium ion intercalation difficulty is easily caused, thereby causing the problems of capacity reduction, cycle deterioration and internal resistance increase of the battery. Consequently, through adopting above-mentioned scheme, can set for the compaction density of pole piece in comparatively suitable within range, avoid influencing the capacity of battery, simultaneously, adjust the compaction density of first pole piece and second pole piece, still keep on the basis in reasonable scope between them for the compaction density of first pole piece is greater than the compaction density of second pole piece, thereby makes the ability that the second pole piece absorbed electrolyte higher.
In some embodiments, the first electrode assembly further comprises a first recess, the second electrode assembly further comprises a second recess, the first recess and the second recess each for storing at least a portion of the electrolyte, the second recess having a volume greater than a volume of the first recess.
The electrode assembly is provided with grooves, for example, an active material layer on the positive or negative electrode tab is provided with a groove structure, which may serve to allow a portion of the electrolyte to remain in the grooves by using the adsorption capacity of the liquid when contacting the electrolyte. By adopting the scheme, the first groove on the first electrode assembly and the second groove on the second electrode assembly can absorb and store certain electrolyte, so that the migration speed of lithium ions can be increased, and the performance of electric cycle can be improved; and the groove structure on the second electrode assembly can be made to have stronger capacity of adsorbing and storing electrolyte, and can adsorb and store more electrolyte.
In a second aspect, an embodiment of the present application provides a battery, including: a battery cell as in any embodiment of the first aspect.
In a third aspect, an embodiment of the present application provides an electric device, which includes the battery of the second aspect, and the battery is used for providing electric energy.
Drawings
Features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;
fig. 2 is an exploded schematic view of a battery provided in accordance with some embodiments of the present application;
fig. 3 is an exploded schematic view of a battery cell provided in some embodiments of the present application;
FIG. 4 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 3;
FIG. 5 is a schematic structural view of a first electrode assembly and a second electrode assembly provided in accordance with some embodiments of the present application;
FIG. 6 is a schematic view of the structures of a first electrode assembly and a second electrode assembly according to further embodiments of the present application;
fig. 7 is an expanded view of a first pole piece and a second pole piece provided in some embodiments of the present application.
In the drawings, the drawings are not necessarily to scale.
Reference numerals
1-a vehicle;
10-battery, 20-controller, 30-motor;
11-box body, 111-first box body part, 112-second box body part, 113-containing space;
100-cell, 110-case, 120-end cap, 130-first electrode assembly, 131-first separator, 132-first pole piece, 133-first groove, 140-second electrode assembly, 141-second separator, 142-second pole piece, 143-second groove;
L 1 length of first spacer, L 2 -a length of the second spacer;
N 1 number of windings of first spacer, N 2 -the number of windings of the second spacer;
x-vertical direction.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof in the description and claims of this application and the description of the figures above, are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.
Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
In the description of the present application, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "attached" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally 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 application can be understood by those of ordinary skill in the art as appropriate.
The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this application generally indicates that the former and latter related objects are in an "or" relationship.
In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.
The appearances of "a plurality" in this application are intended to mean more than two (including two).
In this application, the battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, and the embodiment of the present application is not limited thereto. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the cylindrical battery monomer, the square battery monomer and the soft package battery monomer are also not limited in the embodiment of the application.
Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.
The battery cell comprises a shell, an end cover, an electrode assembly and electrolyte, wherein the end cover and the shell are sealed to form a containing space, and the electrode assembly and the electrolyte are placed in the containing space. The electrode assembly includes a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive current collector and a positive active substance layer, and the positive active substance layer is coated on the surface of the positive current collector; the positive electrode current collector comprises a positive electrode current collecting portion and a positive electrode convex portion protruding out of the positive electrode current collecting portion, the positive electrode current collecting portion is coated with a positive electrode active substance layer, at least part of the positive electrode convex portion is not coated with the positive electrode active substance layer, and the positive electrode convex portion serves as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer, and the negative pole active substance layer is coated on the surface of the negative pole current collector; the negative current collector comprises a negative current collecting part and a negative convex part protruding out of the negative current collecting part, the negative current collecting part is coated with a negative active material layer, at least part of the negative convex part is not coated with the negative active material layer, and the negative convex part is used as a negative electrode tab. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the spacer may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.
A plurality of electrode assemblies may be arranged in the same battery cell, and the electrode assemblies are placed in a sealed space formed by the shell and the end cover together for sealing after positive and negative electrode pairing. The cycle performance and the service life of the whole battery cell are related to multiple indexes of each electrode assembly in the shell in the using process. The applicant has found that the battery cells can be arranged in the box body in various ways, wherein when one battery cell is used, a plurality of electrode assemblies in the shell body can be in an up-down stacking state, and the cycle performance index and the service life of the battery cell are generally far lower than the preset targets during the use of the battery cell. Through further experiments and battery dismantling by the applicant, it was found that a plurality of electrode assemblies in such a battery cell exhibited different life states, and the rate of life deterioration of the electrode assembly stacked on top was much greater than that of the electrode assembly stacked on bottom. Therefore, as time goes by, the state of the different electrode assemblies is increasingly different, and the cycle performance and the overall life of the battery cell are rapidly reduced.
Further research by the applicant has found that the above situation is caused by the fact that the contact area of the electrode assembly stacked above with the electrolyte is too small, so that heat generated during the chemical reaction of the electrode assembly is difficult to conduct to other places through the electrolyte, the rate of heat generation is greater than the rate of heat dissipation, the temperature of the electrode assembly is continuously increased, and the temperature increase leads to the increase of the water loss rate of the electrode assembly, and further increases the temperature. When the temperature of the electrode assembly is excessively high, the chemical balance inside the electrode assembly is broken, side reactions are caused, and the performance of chemical materials is also degraded, thereby shortening the cycle life of the electrode assembly and the battery cell as a whole.
In view of this, the present disclosure provides a battery cell, which includes a first electrode assembly and a second electrode assembly, where the first electrode assembly includes a first separator, the second electrode assembly includes a second separator, and a gas permeability of the second separator is greater than a gas permeability of the first separator. The battery cell with the structure can enable different electrode assemblies to have different electrolyte storage capacities, and the electrolyte storage capacity of the lower electrode assembly in the stacking position can be higher than that of the upper electrode assembly, so that the overall cycle life of the battery cell is prolonged.
The battery cell described in the embodiment of the present application is suitable for a battery and an electric device using the battery.
The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above power utilization device.
For convenience of explanation, the following embodiments will be described with an electric device as an example of a vehicle.
Fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application. As shown in fig. 1, a battery 10 is provided inside the vehicle 1, and the battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, and for example, the battery 10 may serve as an operation power source of the vehicle 1.
The vehicle 1 may also include a controller 20 and a motor 30, the controller 20 being configured to control the battery 10 to power the motor 30, for example, for operational power requirements during start-up, navigation, and travel of the vehicle 1.
In some embodiments of the present application, the battery 10 may not only serve as an operating power source of the vehicle 1, but also serve as a driving power source of the vehicle 1, instead of or in part of fuel or natural gas, to provide driving power to the vehicle 1.
Fig. 2 is an exploded view of the battery 10 according to some embodiments of the present disclosure. As shown in fig. 2, the battery 10 includes a case 11 and a battery cell 100, and the battery cell 100 is accommodated in the case 11.
The case 11 is used for accommodating the battery cells 100, and the case 11 may have various structures. In some embodiments, the box body 11 may include a first box body portion 111 and a second box body portion 112, the first box body portion 111 and the second box body portion 112 cover each other, and the first box body portion 111 and the second box body portion 112 together define a receiving space 113 for receiving the battery cells. The second box portion 112 may be a hollow structure with one open end, the first box portion 111 is a plate-shaped structure, and the first box portion 111 covers the open side of the second box portion 112 to form the box body 11 with the accommodating space 113; the first casing portion 111 and the second casing portion 112 may be hollow structures with one side opened, and the opening side of the first casing portion 111 may cover the opening side of the second casing portion 112 to form the casing 11 having the accommodating space 113. Of course, the first and second casing portions 111 and 112 may be various shapes, such as a cylinder, a rectangular parallelepiped, and the like.
In order to improve the sealing property after the first casing portion 111 and the second casing portion 112 are connected, a sealing member, such as a sealant or a gasket, may be provided between the first casing portion 111 and the second casing portion 112.
If the first box portion 111 covers the top of the second box portion 112, the first box portion 111 can also be referred to as an upper box cover, and the second box portion 112 can also be referred to as a lower box body.
In the battery 10, there are a plurality of battery cells 100. The plurality of battery cells 100 may be connected in series, in parallel, or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the plurality of battery cells 100. The plurality of battery monomers 100 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery monomers 100 is accommodated in the box body 11; of course, a plurality of battery cells 100 may be connected in series, in parallel, or in series-parallel to form a battery module (not shown), and a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form a whole and accommodated in the case 11. The plurality of battery cells 100 in the battery module may be electrically connected to each other by a bus member, so as to realize parallel connection, series connection or parallel-series connection of the plurality of battery cells 100 in the battery module.
Referring to fig. 3, fig. 3 is an exploded view of a battery cell 100 according to some embodiments of the present disclosure.
As shown in fig. 3, the present application provides a battery cell 100, the battery cell 100 including a first electrode assembly 130 and a second electrode assembly 140 stacked in a vertical direction X, wherein the first electrode assembly 130 is disposed below the second electrode assembly 140, the first electrode assembly 130 includes a first separator 131, the second electrode assembly 140 includes a second separator 141, and an air permeability of the second separator 141 is greater than an air permeability of the first separator 131.
The electrode assembly in the embodiment of the present application may be a winding type electrode assembly or a laminated type electrode assembly, unless otherwise specified, and the present application is not limited thereto. For convenience of explanation, the following description and the accompanying drawings each exemplify a wound electrode assembly.
The first electrode assembly 130 and the second electrode assembly 140 are stacked in the vertical direction X, i.e., the first electrode assembly 130 and the second electrode assembly 140 are placed side by side in the thickness direction X, and since the electrolyte in the case 110 does not generally fill the remaining space in the case 110, more electrolyte is stored in the lower portion of the case 110 by gravity. Thus, it is easy to cause the area of the first electrode assembly 130 stacked therebelow, which is in contact with the electrolyte, to be large, and the first electrode assembly 130 can be continuously in contact with the electrolyte during use, and therefore, heat generated from the first electrode assembly 130 during circulation can be dissipated through the electrolyte without accumulating heat; the second electrode assembly 140 is difficult to contact the electrolyte or to contact the electrolyte over a small area during use, heat is difficult to dissipate, and the second electrode assembly 140 is likely to be in a high temperature state for a long period of time, and thus the problem of deterioration of the life of the second electrode assembly 140 is likely to occur.
The first electrode assembly 130 generally includes two separators therein, and the first separator 131 may be any one of the two separators. The second electrode assembly 140 also typically includes two separators, and the second separator 141 may be any one of the two separators.
The air permeability of the second isolation member 141 is greater than that of the first isolation member 131, and it should be noted here that the air permeability refers to the air permeability of the first isolation member 131 or the second isolation member 141 as a whole, specifically, the time required for the same volume of the same gas to completely pass through the first isolation member 131 and the second isolation member 141 can be tested, and the air permeability of the second isolation member 141 is greater than that of the first isolation member 131, that is, the time for the gas to completely pass through the second isolation member 141 is shorter than that of the gas to completely pass through the first isolation member 131. When the thicknesses of the first and second separators 131 and 141 are fixed, the air permeability of the first or second separator 131 or 141 is related to the total area of pores distributed thereon, and the larger the total area of pores, the more the amount of gas passing through at the same time, the higher the air permeability.
By making the air permeability of the second separator 141 greater than that of the first separator 131, the second electrode assembly 140 can allow more electrolyte to remain on the second separator 141 by virtue of the liquid adsorption capacity when in contact with the electrolyte, so that the capacity of the second electrode assembly 140 to store electrolyte is higher than that of the first electrode assembly 130, and thus, the deterioration of the life of the second electrode assembly 140 can be improved, so that the cycle life of the battery cell 100 as a whole can be extended.
Please refer to fig. 3 and fig. 4, wherein fig. 4 isbase:Sub>A sectional view alongbase:Sub>A-base:Sub>A in fig. 3.
As shown in fig. 3 and 4, the porosity of the second separator 141 is greater than the porosity of the first separator 131.
The porosity is a ratio of the total area of the pores in the first separator 131 or the second separator 141 per unit area, and the porosity is increased by setting a larger number of pores or setting a larger area of a single pore. Therefore, more pores may be provided on the second separator 141 than the first separator 131, and the size of a single pore on the second separator 141 may also be set larger than the size of the first separator 131 so that the porosity of the second separator 141 is larger than the porosity of the first separator 131. By adopting such a structure, the second separator 141 can be made stronger in the ability to store the electrolyte than the first separator 131. When the battery cell 100 shakes or shakes during use, the second separator 141 can retain more electrolyte in the pores by temporarily contacting the electrolyte, so as to improve the deterioration of the life of the second electrode assembly 141.
Referring to fig. 5, fig. 5 is a schematic structural diagram of a first electrode assembly 131 and a second electrode assembly 141 according to some embodiments of the present disclosure.
As shown in fig. 5, the first electrode assembly 131 and the second electrode assembly 141 are each a wound electrode assembly, and the length L of the second separator 141 in the winding direction 1 Is longer than the length L of the first spacer 131 2 。
When the porosity per unit area is constant in the first separator 131 and the second separator 141, the length L of the second separator 141 is increased 2 The total area of the pores of the second separator 141 may be increased such that the length L of the second separator 141 is increased 2 Is larger than the first spacer L 1 The total pore area of the second separator 141 may be larger than the total pore area of the first separator 131, so that the second separator 141 may store more electrolyte in the pores, so as to equalize the temperature rise capability of the whole battery cell 100, delay the life deterioration of the second electrode assembly 141, and finally prolong the service life of the whole battery cell 100.
Referring to fig. 6, fig. 6 is a schematic structural diagram of a first electrode assembly 131 and a second electrode assembly 141 according to another embodiment of the present disclosure.
As shown in fig. 6, the second separator 141 is wound for a number of windings N in the winding direction 1 Greater than the number of winding turns N of the first spacer 131 2 。
The one-turn winding refers to that the separator starts from a certain straight line parallel to the width direction on the separator, extends to another straight line parallel to the width direction on the separator along the winding direction of the electrode assembly, a plane formed by connecting the two straight lines can pass through the center of the electrode assembly, and the separator distributed between the two straight lines is the separator wound by one turn.
In the electrode assembly, an elongated gap may be formed between the separators of adjacent turns, the gap may absorb a certain amount of electrolyte by capillary action and retain the electrolyte, and the larger the size of the gap in the winding direction, the more space is provided for retaining the electrolyte. The number of winding turns N of the second separator 141 1 Greater than the number of winding turns N of the first spacer 131 2 The second separator 141 may form a gap having a larger size in the winding direction, so that the second separator 141 may retain more electrolyte by using the gap to delay the deterioration of the life of the second separator 141, and the life of the second separator 141 may be extended to balance the service life of the entire battery cell 100.
In some embodiments of the present application, optionally, the first electrode assembly 131 further includes a first pole piece 132, the second electrode assembly 141 further includes a second pole piece 142, the first pole piece 132 and the second pole piece 142 have the same polarity, and the compaction density of the first pole piece 132 is greater than the compaction density of the second pole piece 142.
The compacted density of the pole piece is the ratio of the volume of the active substance to the total volume, and is used for representing the degree of filling of the active substance in the volume of the pole piece, and reflects the degree of compaction of the distribution of the active substance. The compaction density of the pole piece can influence the porosity of the pole piece, so that the absorption capacity of the pole piece to the electrolyte is influenced. In the electrode assembly, since the active materials used in the positive electrode sheet and the negative electrode sheet are different, the range of the compaction density requirements for the positive electrode sheet and the negative electrode sheet are also different.
Under the condition that the polarities of the first pole piece 132 and the second pole piece 142 are the same, the compaction density of the first pole piece 132 is made to be larger than that of the second pole piece 142, so that the porosity of the second pole piece 142 is made to be larger than that of the first pole piece 132, and finally the absorption capacity of the second pole piece 142 to the electrolyte is made to be larger than that of the first pole piece 132, so that the service life deterioration of the second pole piece 142 is delayed.
Specifically, in some embodiments of the present application, when the first pole piece 132 and the second pole piece 142 are both positive pole pieces, the compaction density of the first pole piece 132 may be 3.2-3.5g/cm 3 The second pole piece 142 can have a compaction density of 3.0-3.25g/cm 3 Alternatively, when the first and second pole pieces 132, 142 are negative pole pieces, the compaction density of the first pole piece 132 may be 1.55-1.7g/cm 3 The second pole piece 142 may have a compaction density of 1.4 to 1.55g/cm 3 。
Referring to fig. 7, fig. 7 is a schematic expanded view of the first pole piece 132 and the second pole piece 142 according to some embodiments of the present disclosure.
As shown in fig. 7, in some embodiments of the present disclosure, the first electrode assembly 130 further includes a first groove 133, the second electrode assembly 140 further includes a second groove 143, the first groove 133 and the second groove 143 are both for storing at least a portion of the electrolyte, and a volume of the second groove 143 is greater than a volume of the first groove 133.
The first electrode assembly 130 may be provided with a first groove 133, the first groove 133 may be provided on the positive electrode tab or the negative electrode tab of the first electrode assembly 130, and the first groove 133 may be a region of the positive electrode tab or the negative electrode tab coated with an active material and having a smaller thickness than other regions, such that the region is in a form of a recess on the surface of the electrode tab, or may be a current collector exposed without being coated with an active material.
The second electrode assembly 140 may be provided with a second groove 143, the second groove 143 may be provided on the positive electrode tab or the negative electrode tab of the second electrode assembly 140, and the second groove 143 may be a region of the positive electrode tab or the negative electrode tab coated with an active material and having a smaller thickness than other regions, such that the region is in a form of a depression on the surface of the electrode tab, or may be a current collector exposed without being coated with an active material.
When the first electrode assembly 130 or the second electrode assembly 140 contacts the electrolyte, a portion of the electrolyte may remain in the first groove 133 or the second groove 143 by virtue of the adsorption force of the electrolyte. The volume of the second groove 143 is made larger than that of the first groove 133 so that the second groove 143 can store more electrolyte than the first groove 133 when contacting the electrolyte, and thus, part of heat generated by the reaction of the second electrode assembly 140 can be diffused by the electrolyte conduction to lower the use temperature of the second electrode assembly 140 to alleviate the life deterioration of the second electrode assembly 140.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be equivalently replaced, but the modifications or the replacements do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (9)
1. A battery cell, comprising:
a first electrode assembly and a second electrode assembly stacked in a vertical direction, the first electrode assembly being disposed below the second electrode assembly,
the first electrode assembly includes a first separator, the second electrode assembly includes a second separator, and the second separator has a gas permeability greater than a gas permeability of the first separator.
2. The battery cell of claim 1, wherein the porosity of the second separator is greater than the porosity of the first separator.
3. The battery cell according to claim 1, wherein the first electrode assembly and the second electrode assembly are each a wound electrode assembly, and the length of the second separator is greater than the length of the first separator in a winding direction.
4. The battery cell as recited in claim 3, wherein the second separator has a greater number of windings than the first separator in the winding direction.
5. The battery cell of claim 1, wherein the first electrode assembly further comprises a first pole piece, wherein the second electrode assembly further comprises a second pole piece, wherein the first pole piece and the second pole piece are of the same polarity, and wherein the first pole piece has a higher compaction density than the second pole piece.
6. The battery cell of claim 5, wherein the first and second pole pieces are positive pole pieces, and the first pole piece has a compacted density of 3.2-3.5g/cm 3 The compacted density of the second pole piece is 3.0-3.25g/cm 3 (ii) a Or,
the first pole piece and the second pole piece are both negative pole pieces, and the compaction density of the first pole piece is 1.55-1.7g/cm 3 The compacted density of the second pole piece is 1.4-1.55g/cm 3 。
7. The battery cell of claim 1, wherein the first electrode assembly further comprises a first groove, wherein the second electrode assembly further comprises a second groove, wherein the first groove and the second groove are both configured to store at least a portion of the electrolyte, and wherein the volume of the second groove is greater than the volume of the first groove.
8. A battery comprising a cell according to any one of claims 1 to 7.
9. An electric device, characterized in that it comprises a battery according to claim 8 for providing electric energy.
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CN202122363005.9U CN216213793U (en) | 2021-09-28 | 2021-09-28 | Battery cell, battery and power consumption device |
PCT/CN2022/105159 WO2023050972A1 (en) | 2021-09-28 | 2022-07-12 | Battery cell, battery and electric apparatus |
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WO2023050972A1 (en) * | 2021-09-28 | 2023-04-06 | 宁德时代新能源科技股份有限公司 | Battery cell, battery and electric apparatus |
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KR100921347B1 (en) * | 2005-11-08 | 2009-10-14 | 주식회사 엘지화학 | Electrode Assembly Prepared in longitudinal Folding Manner and Electrochemical Cell Employing the Same |
CN201498558U (en) * | 2009-08-25 | 2010-06-02 | 河南环宇集团有限公司 | Flexible package power lithium ion battery with direct-attachment type tabs |
CN209401735U (en) * | 2019-01-28 | 2019-09-17 | 宁德时代新能源科技股份有限公司 | Electrode assembly and secondary cell |
CN110190339A (en) * | 2019-03-01 | 2019-08-30 | 青海时代新能源科技有限公司 | Secondary cell |
CN216213793U (en) * | 2021-09-28 | 2022-04-05 | 宁德时代新能源科技股份有限公司 | Battery cell, battery and power consumption device |
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