Folding battery cell structure and battery

Abstract

The utility model relates to the technical field of batteries, and provides a folding battery cell structure and a battery, and the folding battery cell structure comprises a composite pole piece structure which continuously folds and extends along the width direction of the battery, the composite pole piece structure comprises a positive electrode dressing structure, and a first negative electrode dressing structure and a second negative electrode dressing structure which are respectively positioned on two sides of the positive electrode dressing structure along the thickness direction of the composite pole piece structure; the positive electrode dressing structure, the first negative electrode dressing structure and the second negative electrode dressing structure all uninterruptedly extend from one end of the composite pole piece structure to the other end of the composite pole piece structure along the length direction of the composite pole piece structure; according to the folding battery cell structure, the condition that the whole battery cell is greatly expanded in the thickness direction due to high expansion of the negative electrode in the circulating process when composite materials such as silicon carbon or silicon oxygen are used is avoided, and particularly, expansion of the silicon-containing negative electrode is effectively inhibited; and the energy density of the battery is greatly improved due to the adoption of a silicon material while the expansion of the battery core is inhibited.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a foldable battery cell structure and a battery. Background Art

[0002] Existing lithium and sodium ion batteries usually use conventional winding and lamination methods to prepare the core. Among them, winding is a production process. After cutting the pole piece, diaphragm, terminal strip, etc. into a magnetic pole core, it is rolled into a product of matching size. Lamination is the process of alternating the pole piece and the diaphragm together to finally complete the production process of the multi-layer laminated pole core. After assembly, the expansion surface of the core corresponds to the plane with the largest area of ​​the battery. The expansion generated during the conventional graphite cycle is not obvious. However, if composite materials such as silicon-carbon or silicon-oxygen are used, the high expansion of the negative electrode during the cycle will cause a large expansion in the thickness direction of the entire battery cell.

[0003] In addition, the utility model patent with application number 201510298240.9 discloses a laminated lithium-ion battery, which includes a lithium-ion battery core, which includes a positive electrode sheet, a belt-type negative electrode sheet and a separator, wherein the belt-type negative electrode sheet is a continuous, uncut belt-type structure, and the belt-type negative electrode sheet is wrapped by two layers of separators to form a coating, and the two layers of separators are recorded as the first separator and the second separator from top to bottom; the coating is continuously folded to form a Z-shape, and the positive electrode sheet is arranged at each bend of the Z-shaped coating, that is, in the vertical direction, it is in the order of: first separator, belt-type negative electrode sheet, second separator, positive electrode sheet, second separator, belt-type negative electrode sheet, first separator, positive electrode sheet, and then continue the order of first separator, belt-type negative electrode sheet, second separator, etc. This laminated lithium-ion battery uses a single positive electrode sheet cut into multiple sheets and then grasped for lamination. The size limit of the grasping equipment is not suitable for small-sized battery cell structures. Utility Model Content

[0004] The main purpose of the utility model is to provide a foldable battery cell structure, aiming to solve the technical problem that the battery cell in the prior art expands greatly in the thickness direction and is not suitable for small-sized battery cell structures.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a foldable battery cell structure, which includes:

[0006] A composite electrode sheet structure that is continuously folded and extended along the width direction of the battery, the composite electrode sheet structure comprising a positive electrode dressing structure and a first negative electrode dressing structure and a second negative electrode dressing structure that are respectively located on both sides of the positive electrode dressing structure along the thickness direction of the composite electrode sheet structure, the positive electrode dressing structure, the first negative electrode dressing structure and the second negative electrode dressing structure each extend uninterruptedly from one end of the composite electrode sheet structure to the other end of the composite electrode sheet structure along the length direction of the composite electrode sheet structure.

[0007] Further, the composite pole piece structure includes a first diaphragm and a second diaphragm;

[0008] The first separator is disposed between the first negative electrode dressing structure and the positive electrode dressing structure;

[0009] The second separator is disposed between the second negative electrode dressing structure and the positive electrode dressing structure.

[0010] Furthermore, the first diaphragm extends uninterruptedly from one end of the composite pole piece structure to the other end of the composite pole piece structure along the length direction of the composite pole piece structure, and / or the second diaphragm extends uninterruptedly from one end of the composite pole piece structure to the other end of the composite pole piece structure along the length direction of the composite pole piece structure.

[0011] Furthermore, the folded battery cell structure includes a first outer foil layer and a second outer foil layer, the first outer foil layer is connected to the side of the first negative electrode dressing structure away from the positive electrode dressing structure, and the second outer foil layer is connected to the side of the second negative electrode dressing structure away from the positive electrode dressing structure.

[0012] Furthermore, the first outer foil layer and the second outer foil layer are two parts of a whole foil.

[0013] Furthermore, the positive electrode dressing structure includes a first positive electrode dressing layer and a second positive electrode dressing layer, a separator foil layer is arranged between the first positive electrode dressing layer and the second positive electrode dressing layer, the first positive electrode dressing layer extends uninterruptedly from one end of the composite pole sheet structure to the other end of the composite pole sheet structure along the length direction of the composite pole sheet structure, and the second positive electrode dressing layer extends uninterruptedly from one end of the composite pole sheet structure to the other end of the composite pole sheet structure along the length direction of the composite pole sheet structure.

[0014] Furthermore, the composite pole piece structure is continuously folded and extended along the width direction of the battery to form a sawtooth structure.

[0015] Furthermore, the folding angle of the sawtooth structure is an arc angle or an angle formed by two straight lines.

[0016] Furthermore, the folded battery cell structure includes a rigid shell, and the composite pole piece structure is accommodated in the rigid shell.

[0017] In addition, the utility model also provides a battery, which includes the above-mentioned folded battery cell structure.

[0018] The beneficial effects of the foldable battery cell structure provided by the present application are:

[0019] Since the composite electrode structure used in the folding battery cell structure provided by the embodiment of the utility model is continuously folded and extended along the width direction of the battery, compared with the problem of larger expansion in the thickness direction of the traditional battery cell, it is equivalent to adjusting the expansion surface of the battery cell to the width direction of the battery, avoiding the situation that the high expansion of the negative electrode during the cycle process when using composite materials such as silicon-carbon or silicon-oxygen will cause a larger expansion in the thickness direction of the entire battery cell, especially effectively suppressing the expansion of the silicon-containing negative electrode. While suppressing the expansion of the battery cell, the energy density of the battery is greatly improved because silicon materials can be used. In addition, the positive electrode dressing structure, the first negative electrode dressing structure, and the second negative electrode dressing structure each extend continuously from one end of the composite electrode sheet structure to the other end of the composite electrode sheet structure along the length direction of the composite electrode sheet structure, which is equivalent to the positive electrode dressing structure, the first negative electrode dressing structure, and the second negative electrode dressing structure are all integral structures extending along the length direction of the composite electrode sheet structure. No independent small-sized cutting sheet structure is used to form the composite electrode sheet structure, which is conducive to the grasping of components such as suction cups or robotic arms required for battery cell production, and is particularly suitable for the production of small-sized battery cell structures, such as aluminum shell batteries for mobile phones.

[0020] In a further solution, the folded battery cell structure includes a rigid shell, and the composite pole piece structure is accommodated in the rigid shell, which can be made of a hard aluminum shell or a steel shell or other similar materials to effectively inhibit the expansion of the battery cell in the width direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A simplified schematic diagram of a folded battery cell structure provided by one embodiment of the present application, wherein the composite pole piece structure has been folded and extended;

[0023] Figure 2 A schematic structural diagram of a folded battery cell structure provided in one embodiment of the present application, wherein the composite pole piece structure is not folded and extended.

[0024] The reference numerals in the above drawings are as follows:

[0025] 1- Rigid housing;

[0026] 2-fold;

[0027] 100-composite pole piece structure;

[0028] 101- positive electrode dressing structure;

[0029] 102-a first positive electrode dressing layer;

[0030] 103- a second positive electrode dressing layer;

[0031] 104-a first negative electrode dressing structure;

[0032] 105- a second negative electrode dressing structure;

[0033] 106- first diaphragm;

[0034] 107-Second diaphragm. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0037] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, 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 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 therefore should not be understood as a limitation on the present application.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In order to illustrate the technical solution described in this application, a detailed description is given below in conjunction with specific drawings and embodiments.

[0040] See also Figure 1 and Figure 2 The present utility model provides a foldable battery cell structure, which includes:

[0041] A composite pole sheet structure 100 is continuously folded and extended along the width direction d of the battery, and the composite pole sheet structure 100 includes a positive electrode dressing structure 101 and a first negative electrode dressing structure 104 and a second negative electrode dressing structure 105 respectively located on both sides of the positive electrode dressing structure 101 along the thickness direction t of the composite pole sheet structure 100, and the positive electrode dressing structure 101, the first negative electrode dressing structure 104 and the second negative electrode dressing structure 105 each extend continuously from one end of the composite pole sheet structure 100 to the other end of the composite pole sheet structure 100 along the length direction of the composite pole sheet structure 100.

[0042] Since the composite pole piece structure 100 used in the folding battery cell structure provided in the embodiment of the utility model is continuously folded and extended along the width direction d of the battery, it is equivalent to adjusting the battery cell expansion surface to the battery width direction d to solve the problem of larger expansion in the thickness direction t compared with the traditional battery cell, thereby avoiding the situation in which the high expansion of the negative electrode during the cycle process when using composite materials such as silicon-carbon or silicon-oxygen will cause a larger expansion in the thickness direction t of the entire battery cell, especially effectively suppressing the expansion of the silicon-containing negative electrode. While suppressing the expansion of the battery cell, the energy density of the battery can be greatly improved due to the use of silicon material.

[0043] In addition, the positive electrode dressing structure 101, the first negative electrode dressing structure 104 and the second negative electrode dressing structure 105 each extend uninterruptedly from one end of the composite electrode sheet structure 100 to the other end of the composite electrode sheet structure 100 along the length direction of the composite electrode sheet structure 100, which is equivalent to the positive electrode dressing structure 101, the first negative electrode dressing structure 104 and the second negative electrode dressing structure 105 are all integral structures extending along the length direction of the composite electrode sheet structure 100, and no independent small-sized cutting sheet structure is used to form the composite electrode sheet structure 100, which is conducive to the grasping of components such as suction cups or robotic arms required for the production of battery cells, and is particularly suitable for the production of small-sized battery cell structures, such as aluminum shell batteries for mobile phones.

[0044] According to an embodiment of the present invention, the composite pole piece structure 100 is continuously folded and extended along the width direction d of the battery to form a sawtooth structure, or it can be understood that the composite pole piece structure 100 is continuously extended along the width direction d of the battery along a continuously extending Z-shaped structure.

[0045] According to a specific embodiment of the present invention, the corner 2 of the sawtooth structure is an arc angle or an angle formed by two straight lines, which also means that the corner of the sawtooth structure referred to herein is not necessarily a strict straight line angle.

[0046] According to a preferred embodiment of the present invention, the thickness of the composite pole piece structure 100 is uniform. Taking the composite pole piece structure 100 continuously folding and extending along the width direction d of the battery to form a sawtooth structure as an example, the uniform thickness of the composite pole piece structure 100 means that the sharp corners of the sawtooth structure on the same side of the thickness direction t are flush, so that the shape of the continuously folded and extended composite pole piece structure 100 is regular. However, the present invention is not limited to the solution in this embodiment.

[0047] See also Figure 1 According to a preferred embodiment of the utility model, the folded battery cell structure includes a rigid shell 1, and the composite pole piece structure 100 is accommodated in the rigid shell 1. Specifically, a hard aluminum shell or a steel shell or other similar materials can be used to effectively inhibit the expansion of the battery cell in the width direction d.

[0048] In order to more clearly show the details of the folded battery cell structure of the embodiment of the utility model, the detailed structure of the composite electrode structure 100 is mainly referred to Figure 2 The composite pole piece structure 100 before folding is illustrated.

[0049] See also Figure 2 According to one embodiment of the present invention, the composite electrode structure 100 includes a first diaphragm 106 and a second diaphragm 107; wherein the first diaphragm 106 is arranged between the first negative electrode dressing structure 104 and the positive electrode dressing structure 101; and the second diaphragm 107 is arranged between the second negative electrode dressing structure 105 and the positive electrode dressing structure 101.

[0050] See also Figure 2 According to a preferred embodiment of the utility model, the first diaphragm 106 extends uninterruptedly from one end of the composite pole piece structure 100 to the other end of the composite pole piece structure 100 along the length direction of the composite pole piece structure 100, and / or the second diaphragm 107 extends uninterruptedly from one end of the composite pole piece structure 100 to the other end of the composite pole piece structure 100 along the length direction of the composite pole piece structure 100.

[0051] In this embodiment, it is preferred that the first diaphragm 106 and the second diaphragm 107 each extend uninterruptedly from one end of the composite pole piece structure 100 to the other end of the composite pole piece structure 100 along the length direction of the composite pole piece structure 100 .

[0052] See also Figure 2 According to one embodiment of the utility model, the folded battery cell structure includes a first outer foil layer 108 and a second outer foil layer 109, the first outer foil layer 108 is connected to the side of the first negative electrode dressing structure 104 away from the positive electrode dressing structure 101, and the second outer foil layer 109 is connected to the side of the second negative electrode dressing structure 105 away from the positive electrode dressing structure 101.

[0053] In this embodiment, the first outer foil layer 108 and the second outer foil layer 109 are preferably made of copper foil or a similar replaceable material.

[0054] According to an embodiment of the present invention, the first outer foil layer 108 and the second outer foil layer 109 are two parts of a whole foil, that is, the first outer foil layer 108 and the second outer foil layer 109 are an integral structure.

[0055] However, as another embodiment, the first outer foil layer 108 and the second outer foil layer 109 may also be two sheets of foil connected to each other.

[0056] According to a specific embodiment of the utility model, the positive electrode dressing structure 101 includes a first positive electrode dressing layer 102 and a second positive electrode dressing layer 103, and a separator foil layer 110 is arranged between the first positive electrode dressing layer 102 and the second positive electrode dressing layer 103. The first positive electrode dressing layer 102 extends uninterruptedly from one end of the composite pole piece structure 100 to the other end of the composite pole piece structure 100 along the length direction of the composite pole piece structure 100, and the second positive electrode dressing layer 103 extends uninterruptedly from one end of the composite pole piece structure 100 to the other end of the composite pole piece structure 100 along the length direction of the composite pole piece structure 100.

[0057] In this embodiment, the separation foil layer 110 may be made of aluminum foil or a similar replaceable material.

[0058] When making the folding battery cell structure provided by the embodiment of the utility model, two negative electrode sheets (the first negative electrode dressing structure 104 and the second negative electrode dressing structure 105) coated on one side can be used to cover the positive electrode dressing structure 101, separated by a separator (the first separator 106 and the second separator 107) in the middle, to form a composite electrode sheet first, and then fold the electrode sheet in a fan-shaped manner, and after folding, a battery cell (the composite electrode sheet structure 100 that is continuously folded and extended along the width direction d of the battery as referred to herein) is formed, which is then placed in a rigid shell for sealing. First, the prefabrication of the composite electrode sheet simplifies the winding process, and the fan-shaped stacking process forms a winding core, so that the expansion direction of the electrode sheet is opposite to the width direction d of the battery.

[0059] In addition, the utility model also provides a battery, which includes the above-mentioned folding battery cell structure. Therefore, the battery also includes all the advantages of the folding battery cell structure, which will not be repeated here.

[0060] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A foldable battery cell structure, characterized in that: include: A composite electrode sheet structure that is continuously folded and extended along the width direction of the battery, the composite electrode sheet structure comprising a positive electrode dressing structure and a first negative electrode dressing structure and a second negative electrode dressing structure that are respectively located on both sides of the positive electrode dressing structure along the thickness direction of the composite electrode sheet structure, the positive electrode dressing structure, the first negative electrode dressing structure and the second negative electrode dressing structure each extend uninterruptedly from one end of the composite electrode sheet structure to the other end of the composite electrode sheet structure along the length direction of the composite electrode sheet structure.

2. The foldable battery cell structure according to claim 1, characterized in that: The composite pole piece structure comprises a first diaphragm and a second diaphragm; The first separator is disposed between the first negative electrode dressing structure and the positive electrode dressing structure; The second separator is disposed between the second negative electrode dressing structure and the positive electrode dressing structure.

3. The foldable battery cell structure according to claim 2, characterized in that: The first diaphragm extends uninterruptedly from one end of the composite pole piece structure to the other end of the composite pole piece structure along the length direction of the composite pole piece structure, and / or the second diaphragm extends uninterruptedly from one end of the composite pole piece structure to the other end of the composite pole piece structure along the length direction of the composite pole piece structure.

4. The foldable battery cell structure according to claim 1, characterized in that: The folded battery cell structure includes a first outer foil layer and a second outer foil layer, the first outer foil layer is connected to a side of the first negative electrode dressing structure away from the positive electrode dressing structure, and the second outer foil layer is connected to a side of the second negative electrode dressing structure away from the positive electrode dressing structure.

5. The foldable battery cell structure according to claim 4, characterized in that: The first outer foil layer and the second outer foil layer are two parts of a whole foil.

6. The foldable battery cell structure according to claim 1, characterized in that: The positive electrode dressing structure includes a first positive electrode dressing layer and a second positive electrode dressing layer, a separator foil layer is arranged between the first positive electrode dressing layer and the second positive electrode dressing layer, the first positive electrode dressing layer extends uninterruptedly from one end of the composite pole sheet structure to the other end of the composite pole sheet structure along the length direction of the composite pole sheet structure, and the second positive electrode dressing layer extends uninterruptedly from one end of the composite pole sheet structure to the other end of the composite pole sheet structure along the length direction of the composite pole sheet structure.

7. The folded battery cell structure according to any one of claims 1 to 6, characterized in that: The composite pole piece structure is continuously folded and extended along the width direction of the battery to form a sawtooth structure.

8. The foldable battery cell structure according to claim 7, characterized in that: The bending angle of the sawtooth structure is an arc angle or an angle formed by two straight lines.

9. The folded battery cell structure according to any one of claims 1 to 6, characterized in that: The folded battery cell structure comprises a rigid shell, and the composite pole piece structure is accommodated in the rigid shell.

10. A battery comprising the folded battery cell structure according to any one of claims 1 to 9.

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