CN116864931A - Battery cell, battery pack and vehicle - Google Patents
Battery cell, battery pack and vehicle Download PDFInfo
- Publication number
- CN116864931A CN116864931A CN202210313581.9A CN202210313581A CN116864931A CN 116864931 A CN116864931 A CN 116864931A CN 202210313581 A CN202210313581 A CN 202210313581A CN 116864931 A CN116864931 A CN 116864931A
- Authority
- CN
- China
- Prior art keywords
- battery
- battery cell
- post
- positive
- posts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 210000004027 cell Anatomy 0.000 claims description 122
- 210000005056 cell body Anatomy 0.000 claims description 6
- 238000000034 method Methods 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 6
- 238000009826 distribution Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 9
- 238000004088 simulation Methods 0.000 description 9
- 238000010276 construction Methods 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 5
- 238000007789 sealing Methods 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 238000007726 management method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006872 improvement Effects 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
- 238000012545 processing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- 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
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/543—Terminals
- H01M50/547—Terminals characterised by the disposition of the terminals on the cells
- H01M50/55—Terminals characterised by the disposition of the terminals on the cells on the same side of the cell
-
- 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
- H01M50/10—Primary casings; Jackets or wrappings
- H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
-
- 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
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/543—Terminals
- H01M50/547—Terminals characterised by the disposition of the terminals on the cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Connection Of Batteries Or Terminals (AREA)
Abstract
The invention relates to the technical field of batteries, in particular to a battery cell, a battery pack and a vehicle, wherein the battery cell comprises a battery cell main body, the battery cell main body is provided with a plurality of side parts, the side parts comprise a first side part and a second side part which are oppositely arranged, the first side part is provided with a first pole, the second side part is provided with a second pole, and the polarities of the first pole and the second pole are opposite; wherein the length ratio between the longest side and the shortest side of the plurality of sides is not less than 3; the first side part and the second side part are provided with not less than three polar posts in total, and the first side part is provided with a plurality of polar posts with different polarities. With this configuration, it is possible to obtain a uniform current density during the process of charging the battery cells.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a battery monomer, a battery pack and a vehicle.
Background
Unlike the conventional fuel-oil vehicle, the main power source of the new energy vehicle (taking an electric vehicle as an example) is a power battery, specifically, the power battery is mainly carried on the electric vehicle (such as a chassis carried on the electric vehicle) in a battery pack mode, and the driving motor configured by the electric vehicle converts the electric energy carried by the power battery into mechanical energy and then provides driving power for the electric vehicle. The attribute related to the power source capability is one of the core competitiveness of the electric automobile, or the attribute related to the power source capability is one of the core attributes of the electric automobile which need to be improved. Considering from the perspective of users (car owners), the method is characterized in that higher requirements are put on the endurance mileage (which essentially belongs to the attribute of the power battery) of the electric car, the charging speed of the power battery, the power performance attribute and the like. Considering from the product aspect of the power battery, the energy density, the quick charge capability, the cycle life, the direct current internal resistance and other properties of the power battery are required to be higher.
Currently, the form of a battery pack mounted on a vehicle mainly includes two types: one form of conventional construction, such as generally: the battery pack comprises a plurality of battery modules, and each battery module further comprises a plurality of battery cells. Another is a blade battery based architecture, such as typically: the power battery comprises a plurality of blade batteries, wherein the blade batteries are equivalent to battery cells, and the blade batteries can skip the middle structure of the battery module in the process of forming the battery pack to directly form the battery pack in a grouping way due to structural innovation of the blade batteries. Compared with the traditional structural form, the blade battery has the advantages of improving the volume utilization rate due to the structural advantage, and being hopeful to be filled with more battery monomers in the same space, so that the energy density of the battery pack can be improved.
Since the tab side corresponding to the tab is generally a side with a smaller area, the overcurrent area of the tab in the blade battery is limited, resulting in a higher tab temperature rise during charge and discharge. In addition, still taking the above-described blade battery (or at least other battery cells having a property in which the length of one of the side portions is significantly long in structure) as an example, the cycle life of the blade battery is significantly affected due to the uneven current density distribution and further increased temperature rise of the blade battery due to the relatively large size of the blade battery in the length direction thereof as compared with the battery cells in the conventional structure.
Accordingly, there is a need in the art for a new solution to the above-mentioned problems.
Disclosure of Invention
Technical problem
The present invention has been made to solve at least some of the above-mentioned problems, or to solve at least some of the above-mentioned problems.
Technical proposal
In view of this, a first aspect of the present invention provides a battery cell comprising: the battery cell comprises a battery cell body, wherein the battery cell body is provided with a plurality of side parts, the side parts comprise a first side part and a second side part which are oppositely arranged, the first side part is provided with a first pole, the second side is provided with a second pole, and the polarities of the first pole and the second pole are opposite; wherein the length ratio between the longest side and the shortest side of the plurality of sides is not less than 3; the first side part and the second side part are provided with not less than three polar posts in total, and the first side part is provided with a plurality of polar posts with different polarities.
With this configuration, it is possible to obtain a uniform current density during the process of charging the battery cells.
For the above battery cell, in one possible embodiment, the second side portion is provided with a positive electrode post and a negative electrode post, and the number of the positive electrode posts and the negative electrode posts provided on the first side portion or the second side portion is the same.
By this construction, a specific arrangement of the pole on both sides is given.
Specifically, the positive electrode and the negative electrode are provided in pairs in terms of polarity, and include an even number in terms of number.
In one possible embodiment, the number of positive electrode posts and negative electrode posts provided on the first side portion or the second side portion is greater than 1.
By this construction a specific arrangement of the pole on the different sides is given. Illustratively, 3 positive posts and 3 negative posts are disposed on each of the first and second sides.
In one possible embodiment, the number of the poles provided on the first side portion and the second side portion is the same for the battery cells.
By this construction, a specific arrangement of the poles on different sides is provided (from a number of level considerations).
For the above battery cell, in one possible embodiment, the number of positive/negative electrode posts provided on the first side portion and the number of negative/positive electrode posts provided on the second side portion correspond.
By this construction, a specific arrangement of the poles on different sides is given (both in terms of number and polarity).
For the above-described battery cells, in one possible embodiment, one or more of the plurality of sides has a length of ≡350mm.
With such a constitution, a specific quantized form of the side part in the battery cell is given.
For the above battery cell, in one possible embodiment, the ratio between the dimension of the first side portion and the second side portion along the first direction and the dimension of the first side portion or the second side portion along the second direction perpendicular to the first direction is equal to or greater than 3.
With such a constitution, a specific proportional relationship of the first side and the second side in the battery cell is given.
For the above battery cell, in one possible embodiment, the positive electrode post of the first side portion coincides with the projection of the negative electrode post on the second side portion along the first direction, and the negative electrode post of the first side portion coincides with the projection of the positive electrode post on the second side portion along the first direction.
By such a constitution, a specific pole distribution mode of the battery cells is given.
For the above battery cell, in one possible embodiment, the projection of the positive electrode post on the first side portion and the projection of the negative electrode post on the second side portion along the first direction do not overlap, and the projection of the negative electrode post on the first side portion and the projection of the positive electrode post on the second side portion along the first direction do not overlap.
By such a constitution, a specific pole distribution mode of the battery cells is given. Illustratively, the positive electrode posts of the first side do not coincide with the projections of all positive and negative electrode posts on the second side in the first direction.
For the above battery cell, in one possible embodiment, the battery cell includes a bare cell including a tab, where the tab is directly connected with a corresponding pole; or the lug is connected with the corresponding pole through the switching structure.
By such a construction, a possible connection between the tab and the post is given.
In one possible embodiment, with respect to the above-mentioned battery cell, at least a portion of the plurality of side portions are orthographic projected in a thickness direction of the battery cell as a plurality of straight lines having an included angle,
with this configuration, a plurality of side portions can be visually distinguished.
It should be noted that, as used herein, the term "visually distinguishable" is to be understood as: the different sides have visually different shapes, colors, materials, markings, etc. Taking the shape as an example, for example, the side part 1 is a plane, the side part 2 is a curved surface, the side parts (1, 2) are both planes, but have included angles and the like. Illustratively, the projection of the contour of the battery cell in the thickness direction is a polygon, and each side of the polygon corresponds to one side of the battery cell.
For the above-mentioned battery cell, in one possible embodiment, a projection of at least a part of the plurality of side portions in a thickness direction of the battery cell is a curve.
With such a configuration, when the plurality of side portions cannot be visually distinguished clearly, the plurality of side portions can be planned so as to be functionally distinguished.
It should be noted that, the "functionally programmed" as referred to herein should be understood as: there is a certain difficulty in visually distinguishing the different sides directly, but they are different sides or the like from the functional aspect of the battery. Such as a continuous plane of sides 1 and 2, but with one part of the plane being side 1 and the other part being side 2, etc. The projection of the contour of the battery cell in the thickness direction comprises a visually indistinguishable arc, and the portion corresponding to the arc is planned as two or more sides of the battery cell by functionally planning.
A second aspect of the invention provides a battery pack comprising a battery cell as described in any one of the preceding claims.
It will be appreciated that the battery pack has all the technical effects of any of the foregoing battery cells, and will not be described in detail herein.
A third aspect of the invention provides a vehicle provided with a battery cell according to any one of the preceding claims; or the vehicle is provided with the aforementioned battery pack.
It will be appreciated that, similar to the aforementioned battery pack, the vehicle has all the technical effects of the battery cells described in any of the foregoing, and will not be described in detail herein.
The battery cell is characterized by comprising a battery cell body, wherein the battery cell body is provided with a plurality of side parts, the side parts comprise a first side part and a second side part which are oppositely arranged, the first side part is provided with a first pole, the second side part is provided with a second pole, and the polarities of the first pole and the second pole are opposite;
wherein the length ratio between the longest side and the shortest side of the plurality of sides is not less than 3;
wherein the first side part and the second side part are provided with not less than three polar posts in total, and
the first side part is provided with a plurality of polar posts with different polarities.
The battery cell according to item 1, wherein the second side portion is provided with a positive electrode post and a negative electrode post, and
the number of the positive electrode posts and the number of the negative electrode posts arranged on the first side part or the second side part are the same.
The battery cell according to claim 2, wherein the number of the positive electrode posts and the negative electrode posts provided on the first side portion or the second side portion is greater than 1.
The battery cell according to claim 2, wherein the number of the poles provided on the first side portion and the second side portion is the same.
The battery cell according to claim 2, wherein the number of positive/negative electrode posts provided on the first side portion corresponds to the number of negative/positive electrode posts provided on the second side portion.
Proposal 6. The battery cell according to proposal 1, wherein the length of one or more of the plurality of side parts is not less than 350mm.
The battery cell according to any one of claims 1 to 6, wherein a ratio between a dimension between the first side portion and the second side portion in a first direction and a dimension of the first side portion or the second side portion in a second direction perpendicular to the first direction is not less than 3.
The battery cell according to claim 7, wherein the positive electrode post of the first side portion coincides with the projection of the negative electrode post on the second side portion in the first direction, and the negative electrode post of the first side portion coincides with the projection of the positive electrode post on the second side portion in the first direction.
The battery cell according to claim 7, wherein the positive electrode post of the first side portion and the negative electrode post of the second side portion are not overlapped in the projection of the first direction, and the negative electrode post of the first side portion and the positive electrode post of the second side portion are not overlapped in the projection of the first direction.
The battery cell according to item 1, wherein the battery cell comprises a bare cell comprising a tab,
the electrode lugs are directly connected with the electrode posts corresponding to the electrode lugs; or alternatively
The electrode lugs are connected with the electrode posts corresponding to the electrode lugs through the switching structure.
The battery cell according to claim 1, wherein at least a part of the plurality of side portions are orthographic projected in a thickness direction of the battery cell as a plurality of straight lines having an included angle.
The battery cell according to claim 1, wherein at least a part of the plurality of side portions is curved in a projection in a thickness direction of the battery cell.
A battery pack, characterized in that the battery pack comprises the battery cell of any one of the proposals 1 to 12.
A vehicle, characterized in that the vehicle is provided with the battery cell of any one of the proposals 1 to 12; or alternatively
The vehicle is provided with the battery pack of proposal 13.
Drawings
The battery cell of the present invention will be described below with reference to the accompanying drawings, mainly in conjunction with a blade battery. In the accompanying drawings:
FIG. 1 shows a schematic diagram of the structure of a bare cell inside a blade battery according to an embodiment of the invention;
fig. 2 and 3 are respectively illustrating structural views of a blade battery (battery cell) by two embodiments of the present invention, and fig. 4 and 5 are respectively illustrating a first side view and a second side view of the embodiment shown in fig. 2;
fig. 6 is a schematic diagram showing the current density distribution in a blade battery of the prior art, and fig. 7 is a schematic diagram showing the current density distribution in a blade battery according to an embodiment of the present invention;
fig. 8 is a schematic diagram showing simulation results of current density distribution of a blade battery of the prior art, and fig. 9 is a schematic diagram showing simulation results of current density distribution of a blade battery of an embodiment of the present invention;
fig. 10 shows a schematic structure of a battery cell according to a second embodiment of the present invention, fig. 11 shows a schematic structure of a battery cell according to a third embodiment of the present invention, fig. 12 shows a schematic structure of a battery cell according to a fourth embodiment of the present invention, and fig. 13 shows a schematic structure of a battery cell according to a fifth embodiment of the present invention; and
fig. 14 shows a schematic structural view of a battery cell according to a sixth embodiment of the present invention.
List of reference numerals:
1. a bare cell; 11. left short side; 111. a first positive tab; 112. a first negative electrode tab; 12. A right short side; 121. a second positive tab; 122. a second negative electrode tab; 2. a blade battery; 211. a first positive electrode post; 212. a first negative electrode post; 213. an explosion-proof valve; 221. a second positive electrode post; 222. a second negative electrode post; 223. sealing nails (liquid injection holes); 224. two-dimensional codes.
Detailed Description
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention. For example, although the present embodiment is described in connection with a blade battery, it is not intended to limit the scope of the invention, and one skilled in the art may modify the blade battery into other shapes or modify the lamination structure corresponding to the blade battery into a wound structure without departing from the principles of the present invention.
It should be noted that, in the description of the present invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the apparatus or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The singular forms "a", "an" and "the" include plural referents.
Furthermore, it should be noted that, in the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.
Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, it will be appreciated by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, charge, discharge principles, etc. of the battery pack, which are well known to those skilled in the art, have not been described in detail in order to highlight the gist of the present invention.
Referring to fig. 1 to 5, fig. 1 illustrates a schematic structure of a bare cell inside a blade battery according to one embodiment of the present invention, fig. 2 and 3 illustrate schematic structures of blade batteries (battery cells) according to two embodiments of the present invention, respectively, and fig. 4 and 5 illustrate a first side view and a second side view of the embodiment of fig. 2, respectively. As shown in fig. 1 to 5, the blade battery 2 as a battery cell has a substantially rectangular structure (actually, a rectangular parallelepiped with a small thickness), and the length ratio between the long side and the short side of the rectangular structure is 3 or more, and the long side thereof is 350mm or more in size, for example. The rectangular structure is provided with positive pole post and negative pole post on its two short sides of length direction. The internal structure of the blade battery 2 at least comprises a bare cell 1 and electrolyte filled in the bare cell, wherein the bare cell mainly comprises a positive plate, a negative plate and a diaphragm, the positive plate and the negative plate are respectively provided with the positive lug and the negative lug, and the positive lug and the negative lug are respectively connected with a positive pole post and a negative pole post corresponding to the positive lug and the negative lug. Illustratively, the left short side 11 of the bare cell is provided with a first positive tab 111 and a first negative tab 112 from top to bottom, and the right short side 12 of the bare cell is provided with a second positive tab 121 and a second negative tab 122 from bottom to top. Wherein the first positive tab 111 and the second negative tab 122 are substantially collinear in the horizontal direction, and the first negative tab 112 and the second positive tab 121 are substantially collinear in the horizontal direction. Namely: two short sides of the bare cell are respectively provided with a positive electrode lug and a negative electrode lug. The positions of the positive electrode tab on one short side and the negative electrode tab on the other short side correspond to each other as viewed in the long side direction of the rectangular structure.
The left short side of the battery cell 2 is provided with a first positive electrode post 211 and a first negative electrode post 212 at positions corresponding to the first positive electrode tab 111 and the second negative electrode tab 122, and the right short side of the blade battery 2 is provided with a second positive electrode post 221 and a second negative electrode post 222 at positions corresponding to the first negative electrode tab 112 and the second positive electrode tab 121, that is: the positions and the polarities of the electrode lugs and the electrode posts are in one-to-one correspondence. The tab may be connected to the pole corresponding to the polarity and the position through a switching structure (for example, the switching structure is usually a switching sheet, and the switching sheet may include but is not limited to a copper sheet, an aluminum sheet, or a sheet structure made of other conductive materials) (for example, a connection manner includes but is not limited to ultrasonic welding, laser welding, and riveting), or may be directly connected to the pole corresponding to the polarity and the position (for example, a connection manner includes but is not limited to ultrasonic welding, laser welding, and riveting).
In one possible embodiment, an explosion-proof valve 213 is disposed between the first positive electrode column 211 and the first negative electrode column 212, and the main function of the explosion-proof valve is: when the gas pressure in the blade battery is greater than the preset pressure level, the gas in the blade battery can be timely discharged by opening the explosion-proof valve, so that the safety of the battery pack assembled by the blade battery is ensured.
In one possible embodiment, a sealing pin 223 and a two-dimensional code 224 are provided between the second positive electrode post 221 and the second negative electrode post 222. The blade battery is provided with a liquid injection hole at a position corresponding to the sealing nail, namely the sealing nail is arranged in the liquid injection hole. Electrolyte can be filled into the blade battery assembled into the battery pack through the electrolyte filling hole, and the electrolyte filling hole can be sealed through the sealing nail after the electrolyte filling is completed. The two-dimensional code is mainly used for identifying the identity information of the corresponding battery pack.
It is understood that a person skilled in the art may determine a specific entry included in the identity information expressed by the two-dimensional code according to actual requirements. At this time, the two-dimensional code is just a specific example of the identification information, and a person skilled in the art may change the two-dimensional code according to the actual situation, for example, other manners such as a bar code may be adopted. Still take the two-dimensional code as an example, the person skilled in the art can also flexibly adjust the setting position of the two-dimensional code on the battery pack according to the actual situation, such as adjusting to the position on the same side as the explosion-proof valve or any other reasonable position.
Unlike fig. 2, 4 and 5, in the embodiment shown in fig. 3, the left positive electrode post is not coaxial with the right negative electrode post (nor is the left positive electrode post coaxial with the right positive electrode post), and the left negative electrode post is not coaxial with the right positive electrode post (nor is the right negative electrode post coaxial with the right positive electrode post).
Still taking a blade battery as an example, for a conventional blade battery, the overcurrent area of the positive electrode tab corresponding to the positive electrode post is assumed to be S1, the overcurrent area of the negative electrode tab corresponding to the negative electrode post is assumed to be S2, and the overcurrent values of the positive electrode tab and the negative electrode tab are assumed to be I/S1 and I/S2, respectively. After the structure of the present invention is used, assuming that the current passing areas of the positive electrode tab and the negative electrode tab are 1/2 of the above-mentioned S1 and S2, respectively, the current at this time is I/2 due to the current dividing action of the bipolar column, and the analysis and calculation show that the current passing values of the positive electrode tab and the negative electrode tab at this time are I/S1 and I/S2, respectively. Therefore, the overcurrent capacity of the lugs of the two structural modes is consistent, and the temperature rise in the same time is consistent. However, since the internal resistance of the blade battery is not a simple series-parallel relationship, and is also affected by factors such as diffusion resistance, electrochemical resistance, etc., the current distribution in different areas of the bare cell is uneven. Since the present invention adopts a structure including four poles (a pair of positive/negative poles is provided for each short side), the current density is more uniformly distributed throughout the battery.
Referring to fig. 6, fig. 6 is a schematic diagram showing the current density distribution in a blade battery of the prior art. For convenience of explanation, it is assumed in the present embodiment that the battery pack includes only one battery cell, i.e., one battery cell constitutes the battery pack. As shown in fig. 6, for the battery cell of the conventional structure (one positive electrode post and one negative electrode post are provided at each of the two short sides), the internal resistance of the battery cell increases due to the longer electron transfer path and the larger ohmic resistance of the electrode sheet during charging thereof, and thus the current density in the right end region in fig. 6 becomes larger, which causes the temperature rise of the electrode tab near the right side region (a end) to be higher.
Referring to fig. 7, fig. 7 shows a schematic diagram of the current density distribution in a blade battery by an embodiment of the present invention. As shown in fig. 7, after the structure of the present invention is used, the current density is uniformly distributed due to the shunt effect of the bipolar posts, so that the current passing area of each tab is 1/2 of that of the conventional structure in the case that the total current passing area of the tabs is uniform, and the temperature rise problem of the tabs and the corresponding posts can be improved.
Referring to fig. 8 and 9, fig. 8 is a schematic diagram showing the results of simulation of the current density distribution of the blade battery of the prior art, and fig. 9 is a schematic diagram showing the results of simulation of the current density distribution of the blade battery of an embodiment of the present invention. For a blade battery having the properties of "14 mm by 600mm by 112mm in size, 122Ah in cell capacity, NCM in positive electrode, and graphite in negative electrode", 1C (122 Ah) charging was performed in the 10% soc-80% soc interval, and the current density of the anode sheet of the blade battery having the aforementioned properties was simulated by electrochemical simulation. As shown in FIG. 8, the anode ear root current density of the conventional structure is maximized>22A/m 2 ) The current density of the electrode tab area is kept at 8A/m 2 The following is given. As shown in FIG. 9, in the case of using the present invention, the anode ear root current density was still maximum, but the difference from the rest was kept at 2A/m 2 Within and all smaller than 8A/m 2 The uniformity of the current density is improved by more than 7 times (the current density of the two are extremely poor compared).
In a specific embodiment, for a blade cell having the properties of "28.6 mm thick by 600mm long by 112mm high, 292Ah capacity, NCM positive electrode, graphite negative electrode, copper/aluminum foil thickness of 6/12 μm each, and 80/81 tab layers of positive/negative electrodes, the tab size of a conventional blade cell was 70mm wide by 25mm high, and the tab size of the blade cell of the present invention was 35mm wide by 25mm high. Under the condition of 2.2C (642.4 Ah) fast charge in the 10-80% SOC interval, thermal simulation is carried out on the pole and the pole lug of a conventional blade battery and a bare cell adopting the blade battery, and the simulation results are shown in table 1.
Simulation results show that in the bare cell of the blade battery, the temperature rise of the positive electrode lug is reduced by 24.3 ℃, the temperature rise of the negative electrode lug is reduced by 48.3 ℃, the average temperature rise of the bare cell is reduced by 5.4 ℃, and meanwhile, the temperature rises of the positive electrode column and the negative electrode column corresponding to the positive electrode lug and the negative electrode lug are respectively reduced by 32.1 ℃ and 53.4 ℃.
TABLE 1 results of temperature rise simulation of cells
| Bare cell | Positive tab | Negative electrode ear | Positive pole | Negative pole post | |
| Conventional structure | 72.9 | 108.7 | 140.3 | 117.1 | 145.8 |
| The invention is that | 67.5 | 84.4 | 92.0 | 85.0 | 92.4 |
| Improvement of temperature rise | 5.4 | 24.3 | 48.3 | 32.1 | 53.4 |
Remarks: for ease of illustration, the model based on the above table is simplified to the following scenario: only the post, the top cover and the bare cell are considered to generate heat through overcurrent, and the external heat dissipation condition is air.
It can be seen that in the blade battery, as the positive pole and the negative pole are respectively arranged at two sides of the blade battery, the uniformity of the current density of the blade battery in different areas is ensured through the shunt effect, the temperature rise of the electrode lugs is reduced, and the bare cell of the example can realize 2.2C fast charge (10-80% SOC, 19 min). In addition, the reduction of the temperature of the bare cell is also beneficial to prolonging the service life of the battery pack. Meanwhile, since the current density is uniform, other performances of the bare cell are obviously improved, such as: charging capability, power performance, etc.
In a specific example, a blade cell with the properties of "600 mm long by 100mm wide by 18mm thick, 150Ah capacity, lithium iron phosphate for positive electrode, graphite for negative electrode, 12 μm aluminum foil for positive electrode current collector/2 μm primer, 8 μm copper foil for negative electrode current collector/2 μm primer, 18 μm PP material for separator between positive and negative electrodes" was used. The conventional structure is such that a positive electrode post and a negative electrode post are respectively protruded along both sides of the lengthwise direction of the blade battery. The structure of the invention is that a pair of poles (a positive pole and a negative pole) respectively extend out along two sides of the length direction of the battery pack. Test data for the relevant performance of the blade cells formed based thereon are compared as shown in table 2 below.
Table 2 test data for cell performance
| Test item | Conventional structure | The invention is that |
| 10% -80% SOC maximum continuous charging rate (C) | 1.5(28min) | 2.5 (16.8 min full) |
| 1C/1C cycle at 25℃to 80% SOH (cycles) | 3500 | 4300 |
| DCR@25℃50％SOC10s2C(mΩ) | 0.34 | 0.27 |
| 25 ℃ 1C/1C cycle 5 times of cell average temperature (DEG C) | 33 | 28 |
In addition, the structure of the invention can reduce the number of the voltage acquisition elements for the battery pack formed by the blade batteries, thereby reducing the processing difficulty of the battery pack.
Specifically, in the process of assembling the blade batteries into a battery Pack (Pack), the serial and parallel connection of the bare cells are achieved by connecting the corresponding positive and negative poles of different bare cells by using connectors, and meanwhile, the battery management system (Battery Management System, BMS) needs to monitor the voltage of each blade battery (the voltage of the bare cell), so that a voltage collecting element (usually an FPC or a PCB) needs to be mounted on the blade battery, and the voltage collecting element needs to be connected to the positive and negative poles of the blade battery at the same time during voltage collection.
Since the conventional blade battery has a structure in which the single positive and negative electrode posts are respectively protruded at both short sides, it is difficult to assemble the voltage collecting element that is required to simultaneously connect the positive and negative electrodes during the grouping process. As to cope with this problem, it is generally necessary to additionally design a protrusion structure on top covers of both left and right short sides of the battery pack, respectively, and a connection member connecting the protrusion to the case, a corresponding insulating member, and the like. The addition of the protrusions necessarily occupies the space of the battery pack, and thus, causes a decrease in the energy density of the battery. Concomitantly, additional assembly steps and parts are required in the grouping process, resulting in increased cost of the battery pack.
For the structure of the invention, the poles with different polarities are arranged on the same side, so that the voltage acquisition of the blade battery can be realized by only installing a set of voltage acquisition elements on the same side. Meanwhile, in the production process of the battery pack, all the voltage acquisition elements are on the same side, so that the production difficulty is greatly reduced, and the production efficiency is correspondingly improved. Since the voltage collection can be easily performed and the design of the aforementioned two protrusions related to the voltage collection can be eliminated, the cost of the battery pack can be reduced.
Although the battery cell of the present invention is described in connection with the conventional blade battery in this embodiment, those skilled in the art can change the battery cell to any type and structure of battery cell.
Referring to fig. 10 to 13, fig. 10 shows a schematic structure of a battery cell according to a second embodiment of the present invention, fig. 11 shows a schematic structure of a battery cell according to a third embodiment of the present invention, fig. 12 shows a schematic structure of a battery cell according to a fourth embodiment of the present invention, and fig. 13 shows a schematic structure of a battery cell according to a fifth embodiment of the present invention. Other possible forms of the battery cell of the present invention are described below with reference to fig. 10 to 13.
As shown in fig. 10, the unit cell in this embodiment is substantially square (a shape after projection is performed in the thickness direction of the unit cell), and both the left and right sides of the square are provided with a pair of positive/negative tabs. Taking the upper left positive tab as an example, in this embodiment, the current direction corresponding thereto may be to the negative tab below the same side or to the negative tab on a different side. The structure of this embodiment can be regarded as a structure in which the dimensions of the foregoing blade battery are adjusted. Note that the structures shown in fig. 10 and fig. 11 to 13 mentioned below are only for illustrating the correspondence between the electrodes and the different sides of the battery, and the aspect ratio between the different sides shown in the drawings does not indicate the dimensional relationship between the different sides.
As shown in fig. 11, this embodiment corresponds to the addition of a pair of positive/negative lugs on each side on the basis of fig. 10. Still taking the upper left positive tab as an example, in this embodiment, the current direction corresponding thereto may be to the negative tab below the same side or to the two negative tabs on different sides.
As shown in fig. 12, this embodiment corresponds to the addition of a pair of positive/negative tabs on the third side (upper side) on the basis of fig. 10. The principle of the current direction contained in the current transformer is not described in detail.
As shown in fig. 13, this embodiment corresponds to adding a pair of positive/negative tabs on the opposite side (lower side) of the third side on the basis of fig. 12. The principle of the current direction contained in the current transformer is not described in detail.
In addition, the shape of the cross section of the unit cell as in fig. 10 to 13 may be changed to include, but not limited to, other special shapes such as triangle, L-shape, including arc shape. Taking the L shape as shown in fig. 14 as an example, the positive/negative electrode tab may be arranged on all or a part of six sides thereof, and taking the left side as an example, the positive/negative electrode tab may be arranged in all or a partial region thereof in the vertical direction.
Besides the above-mentioned shapes of the battery cells and the arrangement of the positive/negative electrode tabs on the battery cells having the shapes, the skilled person can determine the materials of the battery cell according to the actual requirements, such as soft package, steel shell, aluminum shell and other materials meeting the requirements.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will fall within the scope of the present invention.
Claims (10)
1. The battery cell is characterized by comprising a battery cell body, wherein the battery cell body is provided with a plurality of side parts, the side parts comprise a first side part and a second side part which are oppositely arranged, the first side part is provided with a first pole, the second side part is provided with a second pole, and the polarities of the first pole and the second pole are opposite;
wherein the length ratio between the longest side and the shortest side of the plurality of sides is not less than 3;
wherein the first side part and the second side part are provided with not less than three polar posts in total, and
the first side part is provided with a plurality of polar posts with different polarities.
2. The battery cell of claim 1, wherein the second side is provided with a positive electrode post and a negative electrode post, and
the number of the positive electrode posts and the number of the negative electrode posts arranged on the first side part or the second side part are the same.
3. The battery cell according to claim 2, wherein the number of positive electrode posts and negative electrode posts provided on the first side portion or the second side portion is greater than 1.
4. The battery cell of claim 2, wherein the number of posts disposed on the first side and the second side is the same.
5. The battery cell of claim 2, wherein the number of positive/negative electrode posts disposed on the first side portion and the number of negative/positive electrode posts on the second side portion correspond.
6. The battery cell of claim 1, wherein one or more of the plurality of sides has a length of ≡350mm.
7. The battery cell of any one of claims 1 to 6, wherein a ratio between a dimension between the first side and the second side in a first direction and a dimension of the first side or the second side in a second direction perpendicular to the first direction is ≡3.
8. The battery cell of claim 7, wherein the positive post of the first side portion coincides with a projection of the negative post on the second side portion along the first direction, and wherein the negative post of the first side portion coincides with a projection of the positive post on the second side portion along the first direction.
9. The battery cell of claim 7, wherein the projection of the positive electrode post on the first side and the negative electrode post on the second side along the first direction do not coincide, and wherein the projection of the negative electrode post on the first side and the positive electrode post on the second side along the first direction do not coincide.
10. The battery cell of claim 1, wherein the battery cell comprises a bare cell comprising a tab,
the electrode lugs are directly connected with the electrode posts corresponding to the electrode lugs; or alternatively
The electrode lugs are connected with the electrode posts corresponding to the electrode lugs through the switching structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210313581.9A CN116864931A (en) | 2022-03-28 | 2022-03-28 | Battery cell, battery pack and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210313581.9A CN116864931A (en) | 2022-03-28 | 2022-03-28 | Battery cell, battery pack and vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116864931A true CN116864931A (en) | 2023-10-10 |
Family
ID=88227320
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210313581.9A Pending CN116864931A (en) | 2022-03-28 | 2022-03-28 | Battery cell, battery pack and vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116864931A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117471290A (en) * | 2023-12-25 | 2024-01-30 | 厦门市工科自动化设备有限公司 | Blade battery FPC's check out test set |
-
2022
- 2022-03-28 CN CN202210313581.9A patent/CN116864931A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117471290A (en) * | 2023-12-25 | 2024-01-30 | 厦门市工科自动化设备有限公司 | Blade battery FPC's check out test set |
| CN117471290B (en) * | 2023-12-25 | 2024-04-09 | 厦门市工科自动化设备有限公司 | Blade battery FPC's check out test set |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6510633B2 (en) | Battery pack case with efficient cooling structure | |
| EP2991134B1 (en) | Battery module assembly having refrigerant fluid channel | |
| KR101252944B1 (en) | Battery pack with enhanced radiating ability | |
| EP3136497A1 (en) | Battery module including water cooling structure | |
| EP2991133A1 (en) | Battery module assembly | |
| CN1330038C (en) | Collecting plate and secondary battery with the same | |
| CN101719562A (en) | Electrical core of high-voltage battery | |
| KR20120102343A (en) | Battery pack | |
| CN111769245A (en) | Battery with battery cells connected in series-parallel and battery module | |
| CN116864931A (en) | Battery cell, battery pack and vehicle | |
| KR100316403B1 (en) | Lithium polymer battery for electric vehicle or hybrid electric vehicle | |
| US20100143774A1 (en) | Rechargeable battery and electrode assembly | |
| CN219123419U (en) | Battery cell, battery and electricity utilization device | |
| US20220407190A1 (en) | Battery, device, and method and apparatus for manufacturing battery | |
| CN217444590U (en) | Battery monomer, battery package, vehicle | |
| EP4266464A1 (en) | Battery, electric device, and method and device for preparing battery | |
| KR20120065055A (en) | Battery pack module | |
| KR20060022358A (en) | Secondary battery and electrodes assembly | |
| CN115425368A (en) | Battery module, battery package and consumer | |
| WO2022170492A1 (en) | Battery, power apparatus, and battery manufacturing method and device | |
| CN211929603U (en) | Multi-pole terminal lithium battery | |
| CN114583406A (en) | Battery core, battery core module, power battery pack and vehicle | |
| CN116830376A (en) | Electrode assembly, manufacturing method and device, battery cell, battery and electricity utilization device | |
| CN114512749A (en) | Top cover of lithium ion battery | |
| CN217444461U (en) | Battery monomer, battery package, vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |