CN217361857U - Battery cell structure and lithium ion battery - Google Patents
Battery cell structure and lithium ion battery Download PDFInfo
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- CN217361857U CN217361857U CN202221065559.9U CN202221065559U CN217361857U CN 217361857 U CN217361857 U CN 217361857U CN 202221065559 U CN202221065559 U CN 202221065559U CN 217361857 U CN217361857 U CN 217361857U
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Abstract
The utility model discloses an electric core structure and a lithium ion battery, which relates to the technical field of batteries, wherein the electric core structure comprises a negative plate, a first positive plate and a second positive plate which are alternately superposed in sequence, and diaphragms are arranged among the negative plate, the first positive plate and the second positive plate; the first positive plate comprises a composite base foil and a first positive active material layer, the first positive active material layer is arranged on the surface of the composite base foil, the composite base foil comprises a ductility insulating layer and a conducting layer, and the conducting layer is arranged on the upper surface and the lower surface of the ductility insulating layer. The application can prevent the lithium ion battery from short circuit caused by contact of the second positive plate and the negative plate active material in the needling process, avoid causing thermal runaway, improve the safety performance of the lithium ion battery, and improve the energy density of the lithium ion battery.
Description
Technical Field
The utility model relates to a battery technology field, concretely relates to electricity core structure and lithium ion battery.
Background
The lithium ion battery has the characteristics of high energy density, high power density, good cycle performance, no memory effect, environmental friendliness and the like, and is widely applied to power supplies of various mobile devices. With the large-scale application of the lithium ion battery, the safety problem of the battery is increasingly prominent, and when the lithium ion battery encounters the abnormal conditions of collision, extrusion, needling and the like, the short circuit occurs inside the battery, and a large amount of heat is accumulated to cause thermal runaway, so that accidents such as fire, explosion and the like are caused. At present, a common mode for causing a battery short circuit is often used for easily triggering a contact between a positive plate and a negative active material to cause an internal short circuit phenomenon in the process when the safety of a needling experiment is detected on a lithium ion battery, so that thermal runaway is caused, and the safety performance of the lithium ion battery is greatly reduced.
SUMMERY OF THE UTILITY MODEL
1. Technical problem to be solved by the utility model
To current lithium ion battery, in the acupuncture experimentation, the easy short circuit phenomenon in leading to the battery because of triggering between positive plate and the negative pole active material, and then causes the thermal runaway, influences lithium ion battery's security performance's technical problem, the utility model provides an electricity core structure and lithium ion battery, it not only can prevent that lithium ion battery from contacting and the short circuit at acupuncture in-process positive plate and negative pole piece active material, avoids causing the thermal runaway, improves lithium ion battery's security performance, and can improve lithium ion battery's energy density.
2. Technical scheme
In order to solve the above problem, the utility model provides a technical scheme does:
a cell structure comprises a negative plate, a first positive plate and a second positive plate which are alternately stacked in sequence, wherein diaphragms are arranged among the negative plate, the first positive plate and the second positive plate; the first positive plate comprises a composite base foil and a first positive active material layer, the first positive active material layer is arranged on the surface of the composite base foil, the composite base foil comprises a ductility insulating layer and a conducting layer, and the conducting layer is arranged on the upper surface and the lower surface of the ductility insulating layer.
In the application, the cell structure is formed by alternately and sequentially overlapping the negative pole plate, the first positive pole plate and the second positive pole plate, when the felting needle is pricked, since the first positive electrode sheet includes the composite base foil including the ductile insulating layer and the conductive layer, and the first positive electrode active material layer, the extensible insulating layer has good insulating property and good extensibility, so that the extensible insulating layer is easy to extend along the direction of the puncture needle, so that the puncture needle and the second positive pole piece are separated by the extending insulating layer, thereby preventing the puncture needle from contacting with the second positive pole piece, in the process, because the inside of the whole battery core has no temperature rise and no voltage drop, the short circuit caused by contact of the felting needle between the first positive plate or the second positive plate and the negative plate (negative active material) is isolated, and the thermal runaway is avoided, so that the safety performance of the battery core structure and the safety performance of the lithium ion battery are greatly improved. Simultaneously, because ductility insulating layer's upper and lower surface all is equipped with the conducting layer for the compound base foil of this application compares in traditional foil, has higher energy density and security performance. Therefore, the cell structure can prevent the lithium ion battery from short circuit caused by contact of the second positive plate and the negative plate active material in the needling process, avoid thermal runaway, improve the safety performance of the lithium ion battery, and improve the energy density of the lithium ion battery.
Optionally, the conductive layer is a metal conductive layer.
Optionally, the thickness of the conductive layer is 0.5-1.5 μm.
Optionally, the ductile insulating layer has a thickness of 2-15 μm.
Optionally, the ductile insulating layer is an insulating film.
Optionally, the negative electrode plate includes a copper foil and a negative active material layer, and the negative active material layer is disposed on the surface of the copper foil.
Optionally, the second positive plate includes an aluminum foil and a second positive active material layer, and the second positive active material layer is disposed on the surface of the aluminum foil.
Optionally, the lithium battery further comprises a positive tab and a negative tab, the positive tab is connected with the positive plate, and the negative tab is connected with the negative plate.
Optionally, the number of the pole pieces of the first positive pole piece and the second positive pole piece is N, the number of the negative pole pieces is 2N +1, the number of the diaphragms is 4N, and N is a positive integer.
Meanwhile, the application also provides a lithium ion battery which comprises the battery cell structure.
3. Advantageous effects
Adopt the technical scheme provided by the utility model, compare with prior art, have following beneficial effect:
(1) the electric core structure provided by the embodiment of the application has a simple structure, when the puncture needle is punctured, since the first positive electrode sheet includes the composite base foil including the ductile insulating layer and the conductive layer, and the first positive electrode active material layer, the extensible insulating layer has good insulating property and good extensibility, so that the extensible insulating layer is easy to extend along the direction of the puncture needle, so that the puncture needle and the second positive pole piece are separated by the extending insulating layer, thereby preventing the puncture needle from contacting with the second positive pole piece, in the process, because the inside of the whole battery core has no temperature rise and no voltage drop, the short circuit caused by contact of the felting needle between the first positive plate or the second positive plate and the negative plate (negative active material) is isolated, and the thermal runaway is avoided, so that the safety performance of the battery core structure and the safety performance of the lithium ion battery are greatly improved. Simultaneously, because ductility insulating layer's upper and lower surface all is equipped with the conducting layer for the compound base foil of this application compares in traditional foil, has higher energy density and security performance. Therefore, the cell structure can prevent the lithium ion battery from short circuit caused by contact of the positive plate and the negative plate active material in the needling process, avoid thermal runaway, improve the safety performance of the lithium ion battery, and improve the energy density of the lithium ion battery.
(2) According to the cell structure provided by the embodiment of the application, the thickness of the conducting layer is 0.5-1.5 microns, so that the influence on the cell structure and the thickness of the lithium ion battery is small, and the energy density of the cell structure and the energy density of the lithium ion battery are ensured.
(3) The electric core structure that this application embodiment provided and, through setting up the thickness of ductility insulating layer is 2-15 mu m for thickness to first positive plate and electric core structure influences lessly, and can ensure the planarization of battery, hardness homogeneity, guarantees that the ductility insulating layer can be better separates felting needle and positive plate, prevents positive plate and negative pole piece (negative pole active material) contact short circuit, avoids causing thermal runaway.
(4) The embodiment of the application provides an electricity core structure, through setting up the ductility insulating layer is insulating film, not only easily preparation, low in production cost, and insulating characteristic is good, and extensibility can be good.
(5) Compared with the traditional lithium ion battery, the lithium ion battery provided by the embodiment of the application can effectively avoid short circuit caused by contact of the positive plate and the negative plate (negative active material) during the pricking pin experiment, avoids thermal runaway, and has high safety performance and energy density.
Drawings
Fig. 1 is a schematic structural diagram of an electrical core structure provided in an embodiment of the present invention.
Fig. 2 is a cross-sectional view of a first positive plate in the electric core structure provided by the embodiment of the utility model.
Fig. 3 is a cross-sectional view of a composite base foil in a cell structure according to an embodiment of the present invention.
Fig. 4 is a cross-sectional view of a second positive plate in a cell structure provided by an embodiment of the present invention.
Fig. 5 is a cross-sectional view of a negative plate in a cell structure according to an embodiment of the present invention.
Detailed Description
For a further understanding of the present invention, reference will be made to the following detailed description taken in conjunction with the accompanying drawings and examples.
The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and are not limiting of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings. The utility model discloses in words such as first, second, be for the description the utility model discloses a technical scheme is convenient and set up, and does not have specific limiting action, is general finger, right the technical scheme of the utility model does not constitute limiting action. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to 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. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art. The technical solutions in the same embodiment and between the technical solutions in different embodiments can be arranged and combined to form a new technical solution without contradiction or conflict, which is all within the scope of the present invention.
Example 1
With reference to fig. 1 to 5, this embodiment provides an electrical core structure, including a negative plate 1, a first positive plate 2, and a second positive plate 3, which are alternately stacked in sequence, where diaphragms 4 are disposed between the negative plate 1, the first positive plate 2, and the second positive plate 3; wherein, first positive plate 2 includes composite base foil 5 and first positive active material layer 6, first positive active material layer 6 locates composite base foil 5 is on the surface, composite base foil 5 includes ductility insulating layer 7 and conducting layer 8, conducting layer 8 locates ductility insulating layer 7's upper and lower surface.
In the application, through the cell structure formed by sequentially and alternately superposing the negative plate 1, the first positive plate 2 and the second positive plate 3, when the puncture needle is punctured, because the first positive plate 2 comprises the composite base foil 5 and the first positive active material layer 6, the composite base foil 5 comprises the ductile insulating layer 7 and the conductive layer 8, and the ductile insulating layer 7 has good insulating property and good extensibility, the ductile insulating layer 7 can easily extend along the direction of the puncture needle, so that the puncture needle and the second positive plate 3 are separated by the ductile insulating layer 7, and can not be contacted with the second positive plate, and in the process, because no temperature rise and no voltage drop exist in the whole cell, the short circuit caused by the puncture needle contact between the first positive plate 2 or the second positive plate 3 and the negative plate 1 (negative active material) can be isolated, and the thermal runaway can be avoided, thereby very big promotion electric core structure's security performance and lithium ion battery's security performance. Simultaneously, because ductility insulating layer 7's upper and lower surface all is equipped with conducting layer 8 for the compound base foil 5 of this application compares in traditional foil, has higher energy density and security performance. Therefore, the cell structure can prevent the lithium ion battery from short circuit caused by contact of the positive plate and the negative plate active material in the needling process, avoid thermal runaway, improve the safety performance of the lithium ion battery, and improve the energy density of the lithium ion battery.
In practical application, the first positive electrode active material layer consists of 97.4 wt% of positive electrode materialThe material, 1.3% conductive agent material and 1.3% binder. In practical application, the preparation method of the first positive electrode plate 2 is as follows: dissolving a positive electrode material, a conductive agent and a binder in the proportion of 97.4%, 1.3% and 1.3% in N-methylpyrrolidone (NMP) to obtain slurry; and coating the slurry on the surface of the composite base foil, and baking, rolling, slitting and punching to obtain the first positive plate 2. In practical application, the positive electrode material may be any one or more of lithium cobaltate, lithium manganate, lithium iron phosphate, and ternary material (polymer of nickel cobalt manganese). For example, the ternary material may be LiNi 8 Co 1 Mn 1 O 2 (abbreviated as NCM811), the conductive agent is a mixture of carbon nanotubes and carbon black, and the binder material is a polyvinylidene fluoride (PVDF) binder, such as PVDF 9700.
Example 2
Compared with the technical scheme of embodiment 1, the cell structure of this embodiment may be improved as follows: the conductive layer 8 is a metal conductive layer.
In practical application, the metal conducting layer is made of any one of aluminum, copper, nickel, titanium, silver, nickel-copper alloy and aluminum-zirconium alloy; specifically, if the metal conductive layer is made of aluminum, the aluminum material is low in price, and the surface of the aluminum is provided with an oxide layer, the potential of the positive electrode is high, and the conductive layer with the oxide layer cannot be oxidized, so that the energy density of the battery can be ensured.
Example 3
Compared with the technical scheme of embodiment 1, the cell structure of this embodiment may be improved as follows: the thickness of the conducting layer 8 is 0.5-1.5 μm, the arrangement has small influence on the thickness of the cell structure and the lithium ion battery, and the energy density of the cell structure and the lithium ion battery is ensured. In practice, the thickness of the conductive layer 8 is 1 μm.
Example 4
Compared with any one of the technical solutions in embodiments 1 to 3, the cell structure in this embodiment may be improved as follows: the thickness of the ductility insulating layer 7 is 2-15 μm, so that the thickness influence on the first positive plate and the battery cell structure is small, the flatness and the hardness uniformity of the battery can be ensured, the ductility insulating layer can better separate the felting needle from the positive plate, the positive plate and the negative plate (negative active material) are prevented from being in contact short circuit, and the thermal runaway is avoided. In practice, the ductile insulating layer 7 has a thickness of 8 μm.
Example 5
Compared with the technical scheme of embodiment 4, the cell structure of this embodiment may be improved as follows: the extensible insulating layer 7 is an insulating film, is easy to manufacture, low in production cost, good in insulating property and good in extensibility.
In practical application, the material of the insulating film is one or more of polyamide, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polybutylene terephthalate, epoxy resin, polyformaldehyde, phenolic resin, polypropylene, polytetrafluoroethylene, silicon rubber, polyvinylidene fluoride, cellulose and derivatives thereof, starch and derivatives thereof, protein and derivatives thereof, polyvinyl alcohol and cross-linked products thereof, and polyethylene glycol and cross-linked products thereof. The insulating film prepared by the material has insulativity and good ductility.
In practical application, the composite base foil 5 is prepared by depositing conductive layers on the upper and lower surfaces of the insulating film, wherein the conductive layers are metal aluminum layers. The deposition method can be evaporation, thermal evaporation or magnetron sputtering. For example, the composite base foil 5 is formed by depositing metal aluminum layers on the upper and lower surfaces of the insulating film layer by vacuum evaporation. Specifically, the insulating film layer is placed in a vacuum plating chamber, a high-purity aluminum ingot in a metal evaporation chamber is melted and evaporated at the high temperature of 1500 ℃, the evaporated metal passes through a cooling system in the vacuum plating chamber, and then an aluminum layer is deposited on the surface of the insulating film layer.
Example 6
With reference to fig. 5, compared with the technical solution of embodiment 1, the cell structure of this embodiment may be improved as follows: the negative plate 1 comprises a copper foil 9 and a negative active material layer 10, and the negative active material layer 10 is arranged on the surface of the copper foil 9.
In practical use, the negative electrode active material layer 10,the cathode material consists of 94.4 percent of cathode material, 1.1 percent of conductive agent material and 1.8 percent of binder according to weight percentage. Wherein the cathode material is 12% SiO 2 And 88% graphite, the conductive agent material is C65 mixed with CNT, and the binder is SBR mixed with AG.
In practical application, 94.4% of negative electrode material, 1.0% of C65 conductive agent, 0.1% of CNT conductive agent, 1.5% of SBR and 3% of AG binder are dispersed and dissolved in water to obtain slurry, and then the slurry is coated on the surface of the copper foil 9, and the negative electrode sheet 1 is prepared through the processes of baking, rolling, slitting, punching and the like.
Example 7
With reference to fig. 4, compared with the technical solution of embodiment 1, the cell structure of this embodiment may be improved as follows: the second positive plate 3 comprises an aluminum foil 11 and a second positive active material layer 12, and the second positive active material layer 12 is arranged on the surface of the aluminum foil 11.
In practical use, the first positive electrode active material layer 6 and the second positive electrode active material layer 12 have the same composition.
Example 8
With reference to fig. 1, compared with the technical solution of embodiment 1, the cell structure of this embodiment may be improved as follows: the lithium battery also comprises a positive tab and a negative tab, wherein the positive tab is connected with the first positive plate 2 and the second positive plate 3, and the negative tab is connected with the negative plate 1.
Example 9
Compared with the technical scheme of embodiment 1, the cell structure of this embodiment may be improved as follows: the number of the pole pieces of the first positive pole piece 2 and the second positive pole piece 3 is N, the number of the negative pole pieces 1 is 2N +1, the number of the diaphragms 4 is 4N, and N is a positive integer. Considering that the composite base foil in the first positive plate 2 has good safety performance but poor processability due to the malleable insulating layer, and the conventional metal foil has good processability due to the poor safety performance, the application can improve the safety performance and the processability by aiming at the number of each electrode plate in the cell structure, thereby improving the overall performance of the cell structure.
In practical application, the two outermost pole pieces are the negative pole pieces 1.
As shown in fig. 1, in actual use, the number of the first positive electrode sheet 2 and the second positive electrode sheet 3 is 2, the number of the negative electrode sheets 1 is 5, and the number of the separators 4 is 8.
Example 10
The lithium ion battery of this embodiment, including any one of technical solutions of embodiments 1-9 the electric core structure, lithium ion battery compares traditional lithium ion battery, and this lithium ion battery can effectively avoid positive plate and negative plate (negative pole active material) contact short circuit when the felting needle is experimented, avoids causing thermal runaway, has very high security performance and energy density.
The present invention and its embodiments have been described above schematically, and the description is not limited thereto, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching of the present invention, without departing from the inventive spirit of the present invention, the person skilled in the art should also design the similar structural modes and embodiments without creativity to the technical solution, and all shall fall within the protection scope of the present invention.
Claims (10)
1. A cell structure is characterized by comprising a negative plate, a first positive plate and a second positive plate which are alternately stacked in sequence, wherein diaphragms are arranged among the negative plate, the first positive plate and the second positive plate; the first positive plate comprises a composite base foil and a first positive active material layer, the first positive active material layer is arranged on the surface of the composite base foil, the composite base foil comprises a ductility insulating layer and a conducting layer, and the conducting layer is arranged on the upper surface and the lower surface of the ductility insulating layer.
2. The cell structure of claim 1, wherein the conductive layer is a metal conductive layer.
3. The cell structure of claim 1, wherein the conductive layer has a thickness of 0.5-1.5 μ ι η.
4. The cell structure of any of claims 1-3, wherein the malleable insulating layer has a thickness of 2-15 μm.
5. The cell structure of claim 4, wherein the malleable insulating layer is an insulating film.
6. The cell structure of claim 1, wherein the negative electrode sheet comprises a copper foil and a negative active material layer, and the negative active material layer is disposed on the surface of the copper foil.
7. The cell structure of claim 1, wherein the second positive plate comprises an aluminum foil and a second positive active material layer, and the second positive active material layer is disposed on the surface of the aluminum foil.
8. The cell structure according to claim 1, further comprising a positive tab and a negative tab, wherein the positive tab is connected to the first positive tab and the second positive tab, and the negative tab is connected to the negative tab.
9. The cell structure of claim 1, wherein the number of the first positive plate and the second positive plate is N, the number of the negative plates is 2N +1, the number of the separators is 4N, and N is a positive integer.
10. A lithium ion battery comprising the cell structure of any of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221065559.9U CN217361857U (en) | 2022-05-06 | 2022-05-06 | Battery cell structure and lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221065559.9U CN217361857U (en) | 2022-05-06 | 2022-05-06 | Battery cell structure and lithium ion battery |
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| Publication Number | Publication Date |
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| CN217361857U true CN217361857U (en) | 2022-09-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202221065559.9U Active CN217361857U (en) | 2022-05-06 | 2022-05-06 | Battery cell structure and lithium ion battery |
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| CN (1) | CN217361857U (en) |
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