CN116995188A - Pole piece and battery cell - Google Patents
Pole piece and battery cell Download PDFInfo
- Publication number
- CN116995188A CN116995188A CN202311240505.0A CN202311240505A CN116995188A CN 116995188 A CN116995188 A CN 116995188A CN 202311240505 A CN202311240505 A CN 202311240505A CN 116995188 A CN116995188 A CN 116995188A
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- Prior art keywords
- pole piece
- tab
- hole
- area
- length direction
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- 239000011248 coating agent Substances 0.000 claims abstract description 19
- 238000000576 coating method Methods 0.000 claims abstract description 19
- 230000007423 decrease Effects 0.000 claims description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 abstract description 39
- 229910052744 lithium Inorganic materials 0.000 abstract description 39
- 238000004080 punching Methods 0.000 abstract description 32
- 238000001556 precipitation Methods 0.000 abstract description 19
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 abstract description 10
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 10
- 238000005342 ion exchange Methods 0.000 abstract description 7
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 230000009467 reduction Effects 0.000 abstract description 5
- 239000013543 active substance Substances 0.000 abstract description 3
- 210000004027 cell Anatomy 0.000 description 27
- 239000003792 electrolyte Substances 0.000 description 10
- 238000005452 bending Methods 0.000 description 7
- 238000002474 experimental method Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 230000004580 weight loss Effects 0.000 description 6
- 238000000926 separation method Methods 0.000 description 5
- 230000004308 accommodation Effects 0.000 description 4
- 230000002035 prolonged effect Effects 0.000 description 4
- 239000011149 active material Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 239000006182 cathode active material Substances 0.000 description 1
- 230000022131 cell cycle Effects 0.000 description 1
- 210000001787 dendrite Anatomy 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000002344 surface layer 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
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Connection Of Batteries Or Terminals (AREA)
Abstract
The invention discloses a pole piece and an electric core, and belongs to the technical field of lithium ion batteries. The pole piece comprises a current collector, a pole lug and a coating. Wherein, the tab is connected to the current collector. The coating is coated on the current collector, the coating comprises a first area, the first area corresponds to the lug, the first area is provided with a plurality of first containing holes, the plurality of first containing holes are distributed along the length direction, the two sides of the lug are along the length direction, and the sum of the volumes of the first containing holes in the unit area is gradually reduced. Wherein the mass loss of the pole piece is less than 1%. If the pole piece is an anode pole piece, the plurality of first containing holes can increase the area for lithium ion exchange. If the pole piece is a cathode pole piece, the first accommodating holes can reduce the volume of active substances participating in the reaction. In addition, by controlling the punching of the first area only and the gradual reduction of the punching volume along the length direction from the two sides of the tab, the influence on the battery energy density is greatly reduced while the lithium precipitation is not easy to occur near the tab.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a pole piece and an electric core.
Background
In the related art, the lithium is separated from the battery cell, which is a common problem in the use process of the lithium battery, and lithium dendrites formed by separating lithium ions not only can increase the thickness of the battery cell, but also can cause the phenomenon that a diaphragm is punctured to cause short circuit in the battery cell. In the prior art, the pole piece coating is uniformly perforated, but the energy density of the battery is obviously reduced by the mode, and the requirement of the battery cannot be met.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides the pole piece, which can reduce the lithium separation risk when being applied to the battery core, and does not obviously reduce the energy density of the battery.
The invention also provides an electric core with the pole piece.
The invention also provides another battery cell with the pole piece.
According to an embodiment of the first aspect of the invention, a pole piece comprises:
a current collector having a set length direction;
the electrode lug is connected with the current collector;
the coating is coated on the current collector, the coating comprises a first area, the first area corresponds to the electrode lug, a plurality of first containing holes are formed in the first area, the first containing holes are distributed along the length direction, the two sides of the electrode lug face the length direction, and the sum of the volumes of the first containing holes in the unit area is gradually reduced.
The pole piece provided by the embodiment of the invention has at least the following beneficial effects: the first region corresponds to the tab setting position, and is provided with a plurality of first accommodation holes, by the both sides of tab along length direction, the volume of first accommodation hole in the unit region reduces gradually, if the pole piece is the positive pole piece, then a plurality of first accommodation holes can increase the area that supplies lithium ion exchange, makes the regional difficult lithium that separates of tab nearby, if the pole piece is the negative pole piece, then a plurality of first accommodation holes can reduce the volume of the active material that participates in the reaction, makes the regional difficult lithium that separates that takes place near the tab. In addition, by controlling the punching of the first area only and the gradual reduction of the punching volume along the length direction from the two sides of the tab, the influence on the energy density of the battery can be greatly reduced while the lithium is not easy to be separated near the tab when the pole piece is applied to the battery.
According to some embodiments of the invention, the apertures of the first accommodating holes are equal, and the depths of the first accommodating holes gradually decrease from two sides of the tab to the length direction.
According to some embodiments of the invention, the length of the first region is L, the thickness of the coating is H, the depth H of the first accommodating hole is 0< H, the distance between the first accommodating hole and the tab is d,0< d < L, and the relation between the depth H of the first accommodating hole and the distance between the hole and the tab is satisfied: h= (1-d/L) 0.9H.
According to some embodiments of the invention, the depth of each first accommodating hole is equal, and the aperture of each first accommodating hole gradually decreases from two sides of the tab to the length direction.
According to some embodiments of the present invention, the first region has a length L and a width W, the first accommodating hole has a distance d from the tab of 0< d < L, the first accommodating hole has a radius R, and the first accommodating hole having the largest radius has a diameter R1, where 0.005W < R1 < 0.02W; the following relation is satisfied between the radius R of the first accommodating hole and the distance d between the first accommodating hole and the tab: r= (1-d/L) R1.
According to some embodiments of the invention, the number of the first accommodating holes per unit area gradually decreases from two sides of the tab to the length direction.
According to some embodiments of the invention, the mass loss of the pole piece is less than 1%.
According to some embodiments of the invention, the first region is provided with a plurality of hole groups, the hole groups comprise a plurality of first accommodating holes which are arranged at intervals along the width direction, the hole groups are arranged at intervals along the length direction, and the hole depths and the radii of the first accommodating holes in the same hole group are equal.
According to some embodiments of the invention, the coating further comprises a second region, the second region corresponding to the bending region of the cell, the second region being provided with a plurality of second receiving holes, the plurality of second receiving holes being uniformly distributed in the second region.
According to a second aspect of the present invention, an electrical core includes a diaphragm, a first pole piece and a second pole piece, where the diaphragm is disposed between the first pole piece and the second pole piece, and at least one of the first pole piece and the second pole piece is a pole piece provided in the first aspect of the present invention.
The battery cell provided by the embodiment of the invention has at least the following beneficial effects: at least one of the first pole piece and the second pole piece is the pole piece provided by the embodiment of the first aspect, so that the battery cell at least has all advantages of the pole piece, the first area corresponds to the arrangement position of the pole lug, the first area is provided with a plurality of first accommodating holes, the volumes of the first accommodating holes in the unit area are gradually reduced along the length direction from two sides of the pole lug, and if the pole piece is an anode pole piece, the plurality of first accommodating holes can increase the area for lithium ion exchange, so that lithium precipitation is not easy to occur in the area near the pole lug; if the pole piece is a cathode pole piece, the first containing holes can reduce the volume of active substances participating in the reaction, so that lithium is not easy to be separated in the area near the tab. In addition, by controlling the punching of the first area only and the gradual reduction of the punching volume along the length direction from the two sides of the tab, the influence on the battery energy density is greatly reduced while the lithium precipitation is not easy to occur near the tab.
According to a third aspect of the present invention, an electrical core includes a plurality of first pole pieces, a plurality of second pole pieces, and a plurality of diaphragms, wherein the plurality of first pole pieces and the plurality of second pole pieces are sequentially stacked, the diaphragms are disposed between adjacent first pole pieces and second pole pieces, and a part of the plurality of first pole pieces and the plurality of second pole pieces are the pole pieces provided in the first aspect of the present invention.
The battery cell provided by the embodiment of the invention has at least the following beneficial effects: the first pole piece and the second pole piece are the pole pieces provided by the embodiment of the first aspect, so that the battery cell has at least all advantages of the pole pieces, the first area corresponds to the pole lug setting position, the first area is provided with a plurality of first containing holes, the volumes of the first containing holes in the unit area are gradually reduced along the length direction from two sides of the pole lug, if the pole piece is an anode pole piece, the first containing holes can increase the area for lithium ion exchange, lithium is not easy to be separated out in the area near the pole lug, and if the pole piece is a cathode pole piece, the first containing holes can reduce the volumes of active substances participating in the reaction, so that lithium is not easy to be separated out in the area near the pole lug. In addition, by controlling the punching of the first area only and the gradual reduction of the punching volume along the length direction from the two sides of the tab, the influence on the battery energy density is greatly reduced while the lithium precipitation is not easy to occur near the tab.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The invention is further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic illustration of a pole piece according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view of a first embodiment pole piece of the present invention;
FIG. 3 is a cross-sectional view of a second embodiment pole piece of the present invention;
fig. 4 is a schematic view of a third embodiment pole piece of the present invention.
Reference numerals:
current collector 100, tab 200, coating 300, aperture set 310, first receiving aperture 311, second receiving aperture 320, first region 330, second region 340.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.
In the description of the present invention, the meaning of a number is one or more, the meaning of a number is two or more, and greater than, less than, exceeding, etc. are understood to exclude the present number, and the meaning of a number is understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.
In the description of the present invention, the descriptions of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Referring to fig. 1 to 4, an embodiment of the first aspect of the present invention provides a pole piece including a current collector 100, a tab 200, and a coating 300. Wherein, the current collector 100 has a set length direction. Tab 200 is connected to current collector 100. The coating 300 is coated on the current collector 100, the coating 300 includes a first region 330, the first region 330 is wound around the tab 200, the first region 330 is provided with a plurality of first accommodating holes 311, the plurality of first accommodating holes 311 are distributed along the length direction, the two sides of the tab 200 face the length direction, and the sum of the volumes of the first accommodating holes 311 in the unit region is gradually reduced.
The first area 330 corresponds to the position where the tab 200 is arranged, the first area 330 is provided with a plurality of first accommodating holes 311, the two sides of the tab 200 are along the length direction, the volume of the first accommodating holes 311 in the unit area is gradually reduced, if the pole piece is an anode pole piece, the plurality of first accommodating holes 311 can increase the area of the first area 330 for lithium ion exchange, namely, the bottom wall and the side wall of the first accommodating holes 311 can be used for lithium ion exchange, and the area near the tab 200 is not easy to be separated. If the electrode sheet is a cathode sheet, the first receiving holes 311 can reduce the volume of the cathode active material participating in the reaction, so that lithium is not likely to be separated in the vicinity of the tab 200. In addition, by controlling the punching of the first region 330 only and the gradual reduction of the punching volume in the longitudinal direction from both sides of the tab 200, it is possible to reduce the influence on the battery energy density to a large extent while preventing the occurrence of lithium precipitation in the vicinity of the tab 200 when the electrode sheet is applied to a battery.
Lithium analysis experiments were performed on the embodiment and the control group, and the experimental results are shown in the following table 1:
table 1: lithium separation experiment result I
The experimental group 1 is a solution adopted in the present embodiment, whereas the control group 1 is a solution with the same total punching volume as the experimental group 1 but the same volume of the first accommodating hole 311, and the control group 2 is a solution with the same volume of the single first accommodating hole 311 and the similar weight loss as the experimental group 1. From the above table, it can be seen that the punching mode in which the sum of the volumes of the first receiving holes 311 in the unit area is sequentially reduced is consistent with the punching mode in which the punching volume is unchanged, so as to improve the lithium precipitation effect of the corresponding area of the tab 200, reduce the weight loss and reduce the influence on the energy density of the battery. And when the mass loss is similar, compared with the method of the control group 2 with unchanged punching volume, the punching mode of the embodiment improves the lithium precipitation of the battery cell obviously.
In addition, because the current is required to flow through the tab 200 and be output outwards, the current density of the battery cell in the area near the tab 200 is high in the use process, side reactions are high, the electrolyte consumption speed in the area near the tab 200 is high, and the lithium is separated from the purple spots due to the lack of the electrolyte in the later cycle of the battery. The plurality of first accommodating holes 311 can accommodate more electrolyte in the process of filling the battery cell, so that the electrolyte can better infiltrate the battery cell through the plurality of first accommodating holes 311, and thus the battery cell can be provided with enough electrolyte in a later cycle. For example, the volume of electrolyte that can be contained in the area near the conventional cell tab 200 is V1, the surface layer is depleted to make V1 almost 0 in the later period of the conventional cell cycle, and the inside of the cell may be purple spot due to insufficient electrolyte. When the surface of the pole piece is perforated, the volume of the single first accommodating hole 311 is V2, and n first accommodating holes 311 are provided, so that the total volume capable of accommodating the electrolyte is v1+nv2. And after the V1 is exhausted, V2 can also provide electrolyte to support the consumption required by the later circulation of the battery cell, so that the time of purple spots caused by insufficient electrolyte can be prolonged.
Referring to fig. 2, in some embodiments, the apertures of the first accommodating holes 311 are equal, and the hole depths of the first accommodating holes 311 are gradually reduced from two sides of the tab 200 to the length direction, so that the sum of the volumes of the first accommodating holes 311 in the unit area is gradually reduced from two sides of the tab 200, the sum of the volumes of the first accommodating holes 311 in the area far from the tab 200 along the length direction is smaller while lithium precipitation is less likely to occur in the area near the tab 200, and the influence on the battery energy density can be reduced. Further, the length of the first region 330 is L, the thickness of the coating 300 is H, the depth H of the first accommodating hole 311 is 0< H, the distance between the first accommodating hole 311 and the tab 200 is d,0< d < L, and the depth H of the first accommodating hole 311 and the distance d between the hole and the tab 200 satisfy the relationship: h= (1-d/L) 0.9H.
Lithium analysis experiments were performed on the embodiment and the control group, and the experimental results are shown in the following table 2:
table 2: lithium separation experiment result II
The experimental group 2 is a solution adopted in the present embodiment, the control group 4 is a solution with the maximum perforation depth being the same as that of the experimental group 2 but with the perforation depth unchanged, and the control group 5 is a solution with the perforation depth unchanged and the weight loss being similar to that of the experimental group 2. From the above table, it can be seen that the punching mode in which the punching depth is sequentially reduced is consistent with the punching mode in which the punching depth is unchanged in terms of improving the lithium precipitation effect of the corresponding region of the tab 200, and the weight loss can be reduced, so that the influence on the battery energy density can be reduced. When the quality loss is the same, compared with the method of the control group 2 with unchanged punching depth, the punching mode of the embodiment improves the lithium precipitation of the battery cell obviously.
Referring to fig. 3, in some embodiments, the depths of the first accommodating holes 311 are equal, and the diameters of the first accommodating holes 311 gradually decrease from both sides of the tab 200 in the longitudinal direction, so that the sum of the volumes of the first accommodating holes 311 in the unit area gradually decreases from both sides of the tab 200, and the sum of the volumes of the plurality of first accommodating holes 311 in the area far from the tab 200 in the longitudinal direction is small while lithium precipitation is less likely to occur in the area near the tab 200, so that the influence on the battery energy density can be reduced. Further, the length of the first region 330 is L, the width is W, the distance between the first accommodating hole 311 and the tab 200 is d,0< d < L, the radius of the first accommodating hole 311 is R, and the radius of the first accommodating hole 311 with the largest radius is R1, wherein 0.005W < R1 < 0.02W; the following relationship is satisfied between the radius R of the first accommodating hole 311 and the distance d between the first accommodating hole 311 and the tab 200: r= (1-d/L) R1. The first hole 311 with the largest radius is one or more first holes 311 closest to the tab 200 as compared with the other first holes 311, and the factors determining the aperture of the largest first hole 311 are many, such as the thickness of the coating 300, the type of active material, the design power of the battery cell, etc., and the aperture of the largest first hole 311 is determined, and then the apertures of the other first holes 311 are determined.
Lithium analysis experiments were performed on the embodiment and the control group, and the experimental results are shown in the following table 3:
table 3: lithium separation experiment result III
The experimental group 3 is a solution adopted in the present embodiment, the control group 6 is a solution with the same punching depth as the experimental group 3 but with a constant punching radius, and the control group 7 is a solution with a constant punching depth and a weight loss similar to the experimental group 4. As can be seen from the above, when the mass loss is the same, the punching method of the present embodiment improves the lithium precipitation of the battery cell obviously compared with the method with the same punching depth but the same punching radius, and has better improvement effect on the lithium precipitation near the tab 200 compared with the scheme with the same punching radius and the similar mass loss.
Referring to fig. 4, in some embodiments, the aperture and the hole depth of each first accommodating hole 311 are equal, and the number of the first accommodating holes 311 in a unit area is gradually reduced from two sides of the tab 200 to the length direction, so that the sum of the volumes of the first accommodating holes 311 in a unit area is gradually reduced from two sides of the tab 200 to the length direction, and the sum of the volumes of the plurality of first accommodating holes 311 in the area far from the tab 200 along the length direction is smaller while lithium precipitation is not easy to occur in the area near the tab 200, so that the influence on the battery energy density can be reduced.
It can be understood that, in the above embodiments, the size of the first accommodating hole 311 in the unit area can be influenced by changing the aperture and depth of the first accommodating hole 311 and the number of the first accommodating holes 311 in the unit area 330, so that a plurality of parameters can be changed according to actual needs when the punching operation is performed, and only the sum of the volumes of the first accommodating holes 311 in the unit area is gradually reduced along the length direction from two sides of the tab 200.
In some embodiments, the mass loss of pole piece 200 is less than 1%. By controlling the depth of perforation, the radius of perforation and the density of perforation, the mass loss of the pole piece 200 is less than 1%, thereby reducing the influence on the battery energy density to a great extent. Referring to the table of the three lithium separation experiments, the mass loss of the experimental groups is less than 1%, and the requirements on the mass loss of the pole piece 200 can be met.
Referring to fig. 4, in some embodiments, the first area 330 is provided with a plurality of hole groups 310, the hole groups 310 include a plurality of first accommodating holes 311 that are arranged at intervals along the width direction, the plurality of hole groups 310 are arranged at intervals along the length direction, and the hole depths and the radii of the first accommodating holes 311 in the same hole group 310 are equal, so that the volumes of the first accommodating holes 311 in the plurality of hole groups 310 are sequentially reduced from two sides of the tab 200 to the length direction.
Referring to fig. 1, in some embodiments, the coating 300 further includes a second region 340, where the second region 340 corresponds to a bending region of the battery cell, and the second region 340 is provided with a plurality of second receiving holes 320, and the plurality of second receiving holes 320 are uniformly distributed in the second region 340. Specifically, the battery cell is provided with an extension area and two bending areas, and the extension area is connected with the two bending areas along the width direction. Since the bending region is also easy to generate lithium precipitation, the time of generating lithium precipitation in the bending region can be prolonged by providing a plurality of second accommodating holes 320 in the bending region, and the principle is the same as that of providing a plurality of first accommodating holes 311 in the first region 330, which is not described herein. Wherein, the larger the battery cell multiplying power is, the denser the punching is or the larger the aperture of the second accommodating hole 320 is, and the greater the punching depth is. It is understood that the first receiving hole 311 and the second receiving hole 320 may be formed by laser drilling.
An embodiment of the second aspect of the present invention provides an electrical core (not shown in the drawings), where the electrical core is a square electrical core or a cylindrical electrical core, the electrical core includes a diaphragm, a first pole piece and a second pole piece, the diaphragm is disposed between the first pole piece and the second pole piece, at least one of the first pole piece and the second pole piece is a pole piece provided by the embodiment of the first aspect, so that the electrical core has at least all advantages of the pole pieces, where the first pole piece is an anode pole piece and the second pole piece is a cathode pole piece. The first area 330 corresponds to the position where the tab 200 is disposed, the first area 330 is provided with a plurality of first accommodating holes 311, the volumes of the first accommodating holes 311 in the unit area gradually decrease along the length direction from two sides of the tab 200, and if the first pole piece is the pole piece provided by the embodiment of the first aspect, the plurality of first accommodating holes 311 can increase the area for lithium ion exchange, so that lithium precipitation is not easy to occur in the area near the tab 200; if the second pole piece is the pole piece provided by the embodiment of the first aspect, the plurality of first accommodating holes 311 can reduce the volume of the active material participating in the reaction, so that lithium is not easy to be separated in the area near the tab 200. It will be appreciated that both the first and second pole pieces may be pole pieces provided in the embodiments of the first aspect described above. In addition, by controlling the perforation of only the first region 330 and the weight loss of the pole piece to be less than 1%, the influence on the battery energy density is greatly reduced while the lithium precipitation is not easy to occur near the tab 200.
An embodiment of a third aspect of the present invention provides an electrical core (not shown in the drawings), which includes a plurality of first pole pieces, a plurality of second pole pieces, and a plurality of diaphragms, where the plurality of first pole pieces and the plurality of second pole pieces are sequentially stacked, and the diaphragms are disposed between adjacent first pole pieces and second pole pieces, at least a part of the plurality of first pole pieces and the plurality of second pole pieces are the pole pieces provided by the embodiment of the first aspect, so that at least a time for generating lithium precipitation on a part of pole pieces in the electrical core can be prolonged, and a service life of the whole electrical core is prolonged. The battery cell provided by the embodiment is a laminated battery cell, and the laminated battery cell is formed by sequentially stacking a first pole piece and a second pole piece after being coated by a diaphragm.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present invention. Furthermore, embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Claims (11)
1. A pole piece, comprising:
a current collector having a set length direction and a set width direction;
the electrode lug is connected with the current collector;
the coating is coated on the current collector, the coating comprises a first area, the first area corresponds to the electrode lug, a plurality of first containing holes are formed in the first area, the first containing holes are distributed in the length direction, two sides of the electrode lug are in the length direction, and the sum of volumes of the first containing holes in the unit area is gradually reduced.
2. The pole piece of claim 1, wherein the apertures of the first receiving holes are equal, and the depths of the first receiving holes are gradually reduced from both sides of the tab along the length direction.
3. The pole piece of claim 2, wherein the length of the first region is L, the thickness of the coating is H, the depth of the first receiving hole is H,0< H, the distance between the first receiving hole and the tab is d,0< d < L, and the relation between the depth of the first receiving hole H and the distance between the hole and the tab is d: h= (1-d/L) 0.9H.
4. The pole piece of claim 1, wherein the first receiving holes have equal depths, and the apertures of the first receiving holes gradually decrease from both sides of the tab along the length direction.
5. The pole piece of claim 4, wherein the first region has a length L and a width W, the first receiving hole has a distance d from the tab of 0< d < L, the first receiving hole has a radius R, and the first receiving hole having the largest radius has a diameter R1, wherein 0.005W < R1 < 0.02W;
the following relation is satisfied between the radius R of the first accommodating hole and the distance d between the first accommodating hole and the tab: r= (1-d/L) R1.
6. The pole piece of claim 1, wherein the aperture and the depth of each first receiving hole are equal, and the number of the first receiving holes per unit area is gradually reduced from both sides of the tab along the length direction.
7. The pole piece of any of claims 1-6, wherein the mass loss of the pole piece is less than 1%.
8. The pole piece of any of claims 1-6, wherein the first region is provided with a plurality of hole sets, the hole sets including a plurality of first receiving holes arranged at intervals in a width direction, the plurality of hole sets being arranged at intervals in a length direction, the hole depths and radii of the first receiving holes in the same hole set being equal.
9. The pole piece of any of claims 1-6, wherein the coating further comprises a second region, the second region corresponding to the inflection region of the cell, the second region being provided with a plurality of second receiving holes, the plurality of second receiving holes being evenly distributed in the second region.
10. The battery cell is characterized by comprising a diaphragm, a first pole piece and a second pole piece, wherein the diaphragm is arranged between the first pole piece and the second pole piece, and at least one of the first pole piece and the second pole piece is the pole piece of any one of claims 1-9.
11. The battery cell is characterized by comprising a plurality of first pole pieces, a plurality of second pole pieces and a plurality of diaphragms, wherein the first pole pieces and the second pole pieces are sequentially stacked, the diaphragms are arranged between the adjacent first pole pieces and the second pole pieces, and at least one part of the first pole pieces and the second pole pieces is the pole piece of any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311240505.0A CN116995188A (en) | 2023-09-25 | 2023-09-25 | Pole piece and battery cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311240505.0A CN116995188A (en) | 2023-09-25 | 2023-09-25 | Pole piece and battery cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116995188A true CN116995188A (en) | 2023-11-03 |
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Citations (7)
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| JP2012195182A (en) * | 2011-03-17 | 2012-10-11 | Sanyo Electric Co Ltd | Lithium secondary battery electrode and lithium secondary battery including the electrode |
| JP2015082421A (en) * | 2013-10-23 | 2015-04-27 | 日産自動車株式会社 | Electrode, battery, and method and device for manufacturing electrode |
| JP2015095329A (en) * | 2013-11-11 | 2015-05-18 | 日産自動車株式会社 | Lithium ion secondary battery |
| US20170263933A1 (en) * | 2014-09-10 | 2017-09-14 | Mitsubishi Materials Corporation | Positive electrode for lithium-ion secondary cell, and lithium-ion secondary cell |
| CN108311335A (en) * | 2017-12-19 | 2018-07-24 | 深圳市沃特玛电池有限公司 | A kind of paint roller of multi pole ears cell coating machine and the coating method of multi pole ears battery pole piece |
| CN219419085U (en) * | 2023-04-11 | 2023-07-25 | 珠海冠宇电池股份有限公司 | Battery cell |
| CN219626686U (en) * | 2023-03-22 | 2023-09-01 | 珠海冠宇电池股份有限公司 | Negative plate and battery |
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| JP2012195182A (en) * | 2011-03-17 | 2012-10-11 | Sanyo Electric Co Ltd | Lithium secondary battery electrode and lithium secondary battery including the electrode |
| JP2015082421A (en) * | 2013-10-23 | 2015-04-27 | 日産自動車株式会社 | Electrode, battery, and method and device for manufacturing electrode |
| JP2015095329A (en) * | 2013-11-11 | 2015-05-18 | 日産自動車株式会社 | Lithium ion secondary battery |
| US20170263933A1 (en) * | 2014-09-10 | 2017-09-14 | Mitsubishi Materials Corporation | Positive electrode for lithium-ion secondary cell, and lithium-ion secondary cell |
| CN108311335A (en) * | 2017-12-19 | 2018-07-24 | 深圳市沃特玛电池有限公司 | A kind of paint roller of multi pole ears cell coating machine and the coating method of multi pole ears battery pole piece |
| CN219626686U (en) * | 2023-03-22 | 2023-09-01 | 珠海冠宇电池股份有限公司 | Negative plate and battery |
| CN219419085U (en) * | 2023-04-11 | 2023-07-25 | 珠海冠宇电池股份有限公司 | Battery cell |
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Application publication date: 20231103 |