Battery cell and battery

Abstract

The utility model relates to the technical field of batteries, and provides a battery cell and a battery. The battery cell provided by the utility model comprises a shell, a pole group arranged in the shell, electrolyte filled in the shell, and a liquid storage part arranged between the pole group and the shell, the liquid storage component comprises an adsorption layer arranged on the shell and a separation layer arranged between the adsorption layer and the shell, the separation layer is used for preventing the electrolyte from making contact with the shell, part of the electrolyte is adsorbed and stored in the adsorption layer, and when the adsorption layer is extruded by the expanded pole group, the electrolyte can be released to infiltrate the pole group. The battery cell disclosed by the utility model can prevent the electrolyte from being contacted with the inner wall of the shell, reduce the bad risks of self-discharge and liquid leakage, improve the problem of insufficient infiltration of the central position caused by non-uniform distribution of the electrolyte at the top, the middle part and the bottom of the pole group, improve the cycle performance of the battery cell, reduce the risk of cycle diving, and improve the product quality.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, especially a battery core, and the utility model also relates to a battery provided with the battery core. BACKGROUND

[0002] According to different packaging modes of lithium batteries, the battery core manufacturing mainstream model is divided into three kinds of square shell battery core, soft package battery core and cylindrical battery core, and early cylindrical battery core mainly has 18650, 21700 and the like, and is applied to the electric tool and electric vehicle fields. With the development of 4680 large cylindrical battery core by Tesla, compared with the previous 18650, 21700 and the like, the 4680 battery core energy density is increased by 5 times, the output power is increased by 6 times, and the cost of the battery core per kilowatt hour is reduced by 16%. Therefore, based on the advantages of energy density increase and structural part cost reduction, the market share of 4680 large cylindrical battery core in the power battery core field is gradually increased.

[0003] At present, the large cylindrical battery core is made into a large cylindrical battery core by winding the pole group into a circular pole group with a winding needle, the existing large cylindrical battery mainly improves the energy storage performance by increasing the size, specifically, from the cylindrical 18650 model to the 21700 model, and now to the large cylindrical 46800 model, the increase of the size reduces the number of vehicle battery cores and increases the battery pack capacity under the condition of constant unit volume, thereby improving the endurance of the vehicle, on the other hand, the reduction of the number of battery cores can greatly reduce the cost of the structure. In addition, the existing lithium battery is mainly made into a group by winding or laminating, due to the defects of laminating, such as easy to bring in foreign matters, high replacement cost and low production efficiency, the cylindrical battery core or the special-shaped battery core often adopts the winding mode for production due to the problems of low replacement cost and low production efficiency.

[0004] However, the current large cylindrical battery core is mostly made of a steel shell with a surface nickel plating design, the battery core design space is compact (assembly ratio 98%), and the remaining space in the shell is very small, so the amount of electrolyte injected into the battery core is low, due to gravity and other factors, the distribution of the free electrolyte in the shell is uneven, the electrolyte consumption in the top, middle and bottom of the winding core during the battery core circulation is uneven, which leads to uneven charge and discharge reaction, and there is a risk of cycle diving in the middle and late stages, and there is a risk that the cycle performance does not meet the customer's requirements, and there is also a problem of electrolyte corrosion of the steel shell during the charge and discharge process of the battery core, which is not conducive to the improvement of product quality and experience. UTILITY MODEL CONTENTS

[0005] Therefore, the utility model aims at providing a battery core which is beneficial to improving product quality.

[0006] To achieve the above-mentioned purpose, the technical scheme of the utility model is as follows:

[0007] An electric core comprises a shell, a pole group arranged in the shell, an electrolyte filled in the shell, and a liquid storage component arranged between the pole group and the shell;

[0008] The liquid storage component comprises an adsorption layer arranged on the shell, and a partition layer arranged between the adsorption layer and the shell, the partition layer is used for preventing the electrolyte from contacting the shell, the adsorption layer adsorbs and stores part of the electrolyte, and the adsorption layer can release the electrolyte to soak the pole group when the pole group is expanded and pressed.

[0009] Further, the adsorption layer comprises a foam layer arranged on the shell, or the adsorption layer is made of polyurethane material.

[0010] Further, the porosity of the foam layer is between 30% and 70%, and / or the pore diameter of each pore in the foam layer is between 50 and 200 nm.

[0011] Further, the thickness dimension t1 of the adsorption layer is between 50 and 300 microns, and / or the thickness dimension t2 of the partition layer is between 3 and 10 microns.

[0012] Further, the partition layer comprises a film layer arranged between the adsorption layer and the shell.

[0013] Further, the film layer is made of polypropylene material.

[0014] Further, the partition layer and the adsorption layer are connected through an adhesive layer, and / or the partition layer and the shell are connected through the adhesive layer.

[0015] Further, the cross section of the shell and / or the cross section of the pole group is a regular N-polygon, wherein the value of N is an integer not less than 2.

[0016] Further, the pole group is provided with a support for supporting the pole group, and the support is arranged in line with the central axis of the pole group, and / or the value of N is 6, 8 or 12.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The electric core disclosed by the utility model, through the setting of the partition layer, can prevent the contact of the electrolyte and the inner wall of the shell, especially avoid the corrosion of the electrolyte to the shell in the charging and discharging process, so as to reduce the self-discharge and the risk of liquid leakage, at the same time, the setting of the adsorption layer can also increase with the charging and discharging cycle, and when the pole group continuously expands and the inner pressure of the shell continuously increases, the adsorption layer is extruded and releases the electrolyte into the pole group, thereby improving the cycle performance of the electric core, reducing the risk of cycle diving, and improving the product quality.

[0019] In addition, the adsorption layer adopts a foam layer, which can have good adsorption performance. The adsorption layer is made of polyurethane material, which can have good elasticity and corrosion resistance. The porosity of the foam layer is between 30% and 70%, the pore diameter of each hole in the foam layer is between 50 and 200 nm, and the thickness size t1 of the adsorption layer is between 50 and 300 microns, which can ensure that it has good adsorption capacity and liquid storage capacity. The thickness size t2 of the partition layer is between 3 and 10 microns, which can ensure the blocking effect of the lithium ion channel between the electrolyte and the shell, and avoid the corrosion of the shell by the electrolyte.

[0020] In addition, the partition layer adopts a film layer, and the film layer is made of polypropylene material, which can have the characteristics of good density, good chemical corrosion resistance and good heat resistance, so that the electrolyte is not easy to penetrate the film layer, and the lithium ion channel between the electrolyte and the shell is better blocked, thereby avoiding corrosion inside the shell. The partition layer and the adsorption layer are connected through the adhesive layer, which is beneficial to the arrangement and installation of the partition layer and the adsorption layer in the shell, and improves the blocking effect of the lithium ion channel between the electrolyte and the shell.

[0021] In addition, the cross section of the shell and the cross section of the pole group are regular N-polygon, wherein N is an integer not less than 2, that is, the cross section of the shell and the cross section of the pole group are regular polygon, compared with the large cylindrical assembly mode, the space waste between the electric cores can be reduced, the seamless assembly between the electric cores can be realized, the space in the battery pack can be perfectly utilized, and the battery pack assembly rate is improved. The setting of the supporting piece can support the pole group and prevent the collapse of the internal space of the electric core.

[0022] Another purpose of the utility model is to provide a battery, wherein the battery is provided with the electric core as described above.

[0023] The battery disclosed by the utility model and the electric core described above have the same beneficial effects as the prior art, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which form a part of this patent, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0025] Figure 1 The overall structure schematic diagram of the battery cell is shown in the embodiment of the present application;

[0026] Figure 2 The structure schematic diagram when the liquid storage component and the shell are assembled is shown in the embodiment of the present application;

[0027] Figure 3 The structure schematic diagram when the battery cells are grouped is shown in the embodiment of the present application;

[0028] Legend of reference signs:

[0029] 1, shell; 2, support body; 3, adsorption layer; 4, partition layer; 5, adhesive layer. DETAILED DESCRIPTION

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0031] In the following description, specific details are set forth in order to provide a thorough understanding of embodiments of the application. However, persons having ordinary skill in the art will readily recognize that embodiments of the application can be practiced without these specific details. In other instances, well-known structures, devices, circuits, and processes have not been described in detail so as not to unnecessarily obscure aspects of the application.

[0032] In the description of the present application, it should be noted that if the terms indicating the orientation or position relationship such as "upper", "lower", "inner", "outer" and the like appear, they are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the device or element indicated to have a specific orientation, to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, if the terms "first", "second" and the like appear, they are also only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0033] Moreover, in the description of the utility model, unless otherwise expressly limited, the terms "mounting", "connection", "connecting" and "connector" should be understood broadly. For example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood in combination with the specific circumstances.

[0034] The utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0035] Embodiment one

[0036] The utility model relates to a kind of battery, which is beneficial to solve the problem of poor cycle performance of traditional large cylindrical battery, and there is self-discharge and leakage risk.

[0037] Overall structure, as shown in Figure 1 And Figure 2 The battery of the embodiment includes a shell 1, a pole group disposed in the shell 1, an electrolyte filled in the shell 1, and a liquid storage component disposed between the pole group and the shell 1.

[0038] Furthermore, the liquid storage component includes an adsorption layer 3 disposed on the shell 1, and a partition layer 4 disposed between the adsorption layer 3 and the shell 1, the partition layer 4 is used to prevent the electrolyte from contacting the shell 1, and the adsorption layer 3 adsorbs and stores part of the electrolyte, and when the adsorption layer 3 is extruded by the expanding pole group, it can release the electrolyte to soak the pole group.

[0039] At this time, as set forth above, by setting the partition layer 4, the contact between the electrolyte and the inner wall of the shell 1 can be prevented, especially during the charging and discharging process to avoid the electrolyte from corroding the shell 1, thereby reducing the risk of self-discharge and leakage. At the same time, by setting the adsorption layer 3, as the charging and discharging cycle increases, the pole group continuously expands and the internal pressure of the shell 1 continuously increases, the adsorption layer 3 is extruded and releases the electrolyte into the pole group, thereby improving the problem of insufficient soaking at the center position caused by uneven distribution of electrolyte at the top, middle and bottom of the pole group, and improving the cycle performance of the battery and reducing the risk of cycle diving.

[0040] Based on the above overall introduction, in detail, in the embodiment, during specific implementation, the pole group is a winding core pole group, and the shell 1 is a steel shell known to those skilled in the art. At the same time, the liquid storage component is preferably set to completely cover the inner wall of the shell 1, thereby better preventing the electrolyte from corroding the shell 1.

[0041] In this embodiment, as a preferred implementation form, the adsorption layer 3 includes a foam layer arranged on the shell 1 to have good adsorption performance. Specifically, the foam layer can be made of PU (polyurethane) foam, or the adsorption layer 3 can be directly made of polyurethane material, so as to not only have good adsorption performance, but also have good elasticity and corrosion resistance.

[0042] At this time, in order to ensure that the adsorption layer 3 has good adsorption performance, as a preferred implementation form, the porosity of the foam layer is between 30% and 70%, the pore diameter of each pore in the foam layer is between 50 nm and 200 nm, and preferably, the thickness dimension t1 of the adsorption layer 3 is between 50 μm and 300 μm. In specific implementation, the porosity of the foam layer can be specifically 30%, 50% or 70%, the pore diameter of each pore in the foam layer can be specifically 50 nm, 100 nm, 150 nm or 200 nm, and the thickness dimension t1 of the adsorption layer 3 can be specifically 50 μm, 150 μm, 250 μm or 300 μm, so as to ensure that the adsorption layer 3 has good adsorption capacity and liquid storage capacity.

[0043] Similarly, in this embodiment, as a preferred implementation form, the thickness dimension t2 of the partition layer 4 is between 3 μm and 10 μm, so as to ensure the partition effect of the lithium ion channel between the electrolyte and the shell 1, and avoid corrosion of the shell 1 by the electrolyte.

[0044] In addition, as a preferred implementation form, the partition layer 4 of this embodiment includes a film layer arranged between the adsorption layer 3 and the shell 1. The film layer can be preferably made of polypropylene material, so as to have good density, good chemical corrosion resistance and good heat resistance, so that the electrolyte is not easy to penetrate the film layer, and the lithium ion channel between the electrolyte and the shell 1 is better blocked, thereby avoiding corrosion of the inside of the shell 1.

[0045] In addition, in this embodiment, as a preferred implementation form, as shown in Figure 2 , the partition layer 4 and the adsorption layer 3 are connected through the adhesive layer 5, and the partition layer 4 and the shell 1 are connected through the adhesive layer 5. In this way, the arrangement and installation of the partition layer 4 and the adsorption layer 3 in the shell 1 are facilitated, and the partition effect of the lithium ion channel between the electrolyte and the shell 1 is improved.

[0046] In addition, in this embodiment, as a preferred implementation form, as shown in Figure 1 and Figure 3 , the cross section of the shell 1 and the cross section of the pole group are regular N-polygon, where N is an integer not less than 2, that is, the cross section of the shell 1 and the cross section of the pole group are regular polygon. Compared with the large cylindrical assembly mode, some space waste between the battery cells can be reduced, seamless assembly between the battery cells can be facilitated, the space in the battery pack can be perfectly utilized, and the battery pack assembly rate can be improved.

[0047] In practice, the value of N in the embodiment can be preferably 6, 8 or 12, so that the cross section of the shell 1 and the cross section of the pole group are regular hexagons, regular octagons or regular dodecagons, thereby facilitating seamless assembly between the battery cells and improving the space utilization of the battery pack. Of course, the embodiment is not limited to the cross section shape of the pole group, which can also be set to be, for example, a circle or a rectangle according to the design requirements of the battery cell, but the cross section shape of the pole group is the same as that of the shell 1, which is more conducive to extruding the adsorption layer 3 to release the electrolyte, thereby increasing the cycle performance of the battery cell.

[0048] At the same time, in the embodiment, as a preferred implementation form, the pole group is provided with a support for supporting the pole group, and the support is arranged in line with the center axis of the pole group, which can support the pole group and prevent the internal space of the battery cell from collapsing. The support 2 can be made of a pipe, and the cross section shape is preferably the same as that of the shell 1 and the pole group, which is conducive to the formation of the pole group and the operation of the pole group into the shell.

[0049] In the embodiment, when the cross section of the shell 1 and the cross section of the pole group are regular N-polygons, the application scenarios of the battery cell can be more diversified, the grouping rate of the battery pack can be improved, the remaining space between the battery cells during assembly is smaller, a larger number of battery cells can be accommodated under the condition of the same volume of the battery pack, which has the advantages of changing the packaging shape of the existing large cylindrical battery cell, increasing the space utilization inside the battery cell and the battery pack, improving the grouping utilization rate, effectively improving the endurance of new energy vehicles when applied to vehicles, and solving the problem that the packaging shape of the existing large cylindrical battery cell cannot fully adapt to the requirements of the current vehicle chassis structure and the space layout of parts, resulting in waste of space.

[0050] The battery cell of the embodiment can prevent the contact between the electrolyte and the inner wall of the shell 1 by setting the partition layer 4, especially during the charging and discharging process to avoid corrosion of the shell 1 caused by the electrolyte, thereby reducing the risk of self-discharge and liquid leakage, and at the same time, the adsorption layer 3 can also be continuously increased with the charging and discharging cycle, the pole group continuously expands and the pressure in the shell 1 continuously increases, so that the adsorption layer 3 is extruded and releases the electrolyte into the pole group, improves the problem of insufficient infiltration at the center position caused by uneven distribution of electrolyte at the top, middle and bottom of the pole group, thereby improving the cycle performance of the battery cell and reducing the risk of cycle diving, thereby improving the product quality.

[0051] Embodiment two

[0052] The battery of the embodiment is configured with the battery cell in the first embodiment, and has good cycle performance and is beneficial to the improvement of energy density.

[0053] The battery of the embodiment is configured with the battery cell in the first embodiment, and has good cycle performance and is beneficial to the improvement of energy density.

[0054] The above is only a preferred embodiment of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1.A battery cell, characterized in that: it comprises a shell, a pole group arranged in the shell, an electrolyte filled in the shell, and a liquid storage component arranged between the pole group and the shell; the liquid storage component comprises an adsorption layer arranged on the shell, and a partition layer arranged between the adsorption layer and the shell, the partition layer is used to prevent the electrolyte from contacting the shell, the adsorption layer adsorbs and stores part of the electrolyte, and the adsorption layer can release the electrolyte to soak the pole group when the pole group swells. 2.The battery cell of claim 1, characterized in that: the adsorption layer comprises a foam layer arranged on the shell, or the adsorption layer is made of polyurethane material. 3.The battery cell of claim 2, characterized in that: the porosity of the foam layer is between 30% and 70%; and / or, the pore size of each pore in the foam layer is between 50 nm and 200 nm. 4.The battery cell of claim 1, characterized in that: the thickness dimension t1 of the adsorption layer is between 50 μm and 300 μm; and / or, the thickness dimension t2 of the partition layer is between 3 μm and 10 μm. 5.The battery cell of claim 1, characterized in that: the partition layer comprises a film layer arranged between the adsorption layer and the shell. 6.The battery cell of claim 5, characterized in that: the film layer is made of polypropylene material. 7.The battery cell of claim 1, characterized in that: the partition layer and the adsorption layer are connected through an adhesive layer, and / or the partition layer and the shell are connected through an adhesive layer. 8.The battery cell of claim 1, characterized in that: the cross section of the shell and / or the cross section of the pole group is a regular N-polygon, wherein N is an integer not less than 2. 9.The battery cell of claim 8, characterized in that: the pole group is provided with a support arranged on the pole group to support the pole group, the support is arranged in line with the central axis of the pole group; and / or, N is 6, 8 or 12. 10.A battery, characterized in that: the battery is provided with the battery cell of any one of claims 1 to 9.

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