Laminated battery structure capable of quickly positioning short-circuit position of battery cell

Abstract

The utility model discloses a laminated battery structure capable of quickly positioning a short circuit position of a battery cell, which comprises a plurality of laminated battery cell units, each battery cell unit comprises a positive plate, a negative plate and an insulating positioning plate which are sequentially laminated, and the positive plates, the negative plates and the insulating positioning plates are isolated by diaphragms. And the insulating positioning sheet is arranged in the battery cell unit in a removable penetrating manner. The laminated battery structure capable of quickly positioning the short-circuit position of the battery cell has the characteristics of quick positioning of the short-circuit position, high repair efficiency and accurate analysis of short-circuit reasons.

Description

Technical Field

[0001] The utility model relates to the technical field of secondary battery packaging structures, in particular to a laminated battery structure for quickly locating a short-circuit position of a battery cell. Background Art

[0002] In recent years, as the lamination process has gradually matured, the advantages of laminated batteries have become more prominent. Compared with other process batteries, the advantages of laminated batteries are mainly reflected in: high size flexibility, the size of each pole piece can be designed according to the battery size, so that the battery can be made into any size; strong stability, stable internal structure, high safety, stable expansion force, small internal resistance, resulting in longer cycle life; high energy density. The internal space of the battery is fully utilized, and the volume capacity is higher.

[0003] The key process of the stacking process is the control of "stacking". The "Z"-shaped stacking is to first cut the positive and negative electrode raw materials into rectangular electrode pieces of the same size, and then stack them on the diaphragm respectively. The diaphragm "Z"-shaped runs through the two electrodes to separate the two poles. Since the stacking process has a large short-circuit risk, a short-circuit detection process is required after the battery cell is formed.

[0004] If after the battery cell is assembled as a whole, it is found during short circuit testing that a short circuit is caused by contact between the internal positive and negative electrodes, not only will manual retesting of the short circuit be required to reduce production efficiency, but the battery cell may also be scrapped, the electrodes will be wasted, and production costs will increase.

[0005] At the same time, since there may be many factors that affect the short circuit of the battery cell, it is extremely difficult to repair it. Specifically, the causes of the short circuit of the battery cell may include the following situations:

[0006] For example, short circuit caused by burr problem. It is inevitable that the pole piece will fall off or have burrs during the cutting process. When stacking, some of these foreign objects will be rolled into the battery cell, mixed between the positive and negative electrodes and the diaphragm, piercing the diaphragm and causing a short circuit inside the battery cell.

[0007] For example, short circuits caused by dust problems, during the battery stacking process, dust in the air or metal powder on the pole pieces and diaphragms can cause micro short circuits inside the battery. Micro short circuits caused by impurities can cause irreversible reactions, which is the main reason for excessive self-discharge of batteries during use.

[0008] For example, a short circuit is caused by direct contact between the positive and negative electrodes. During the lamination process, the diaphragm should completely wrap the positive and negative electrodes, and the size of the negative electrode should be slightly larger than the positive electrode. In some cases, there is a problem with the diaphragm's deviation correction process, causing the diaphragm to be unable to completely wrap the positive and negative electrodes, and the diaphragm shifts to one end, causing the positive and negative electrodes to directly contact, forming a short circuit.

[0009] For example, in the case of a short circuit caused by a diaphragm rupture, the diaphragm's mechanical strength is insufficient. Under the condition of forced external force, the diaphragm may be torn, causing the positive and negative electrodes to come into contact, resulting in a short circuit in the battery cell.

[0010] Since the causes of short circuits are complex, detection equipment can only qualitatively determine whether a short circuit exists in the battery but cannot accurately determine the location of the short circuit. As a result, the battery cannot be repaired, causing the battery cell to be scrapped, increasing production costs and reducing production efficiency. Utility Model Content

[0011] The utility model aims to provide a laminated battery structure for quickly locating the short-circuit position of a battery cell, which has the characteristics of fast short-circuit position positioning, high repair efficiency and accurate short-circuit cause analysis.

[0012] The utility model can be realized by the following technical solutions:

[0013] The utility model discloses a laminated battery structure for quickly locating a short-circuit position of a battery cell, comprising a plurality of laminated battery cell units, wherein the battery cell units comprise a positive electrode sheet, a negative electrode sheet, and an insulating positioning sheet which are laminated in sequence, wherein the positive electrode sheet, the negative electrode sheet, and the insulating positioning sheet are isolated by a diaphragm, and the insulating positioning sheet is detachably interlaced and arranged inside the battery cell unit.

[0014] The laminated structure of the utility model adds insulating spacers on the basis of the existing laminated structure. The insulating spacers can separate each layer of the laminated unit in the form of an integral unit. The lamination sequence is as follows: negative electrode sheet + diaphragm + positive electrode sheet + diaphragm + insulating spacers + negative electrode sheet + diaphragm + positive electrode sheet + diaphragm + insulating spacers... In this way, a complete battery cell unit is formed in each layer. After all the battery cells are stacked to form a battery, the short circuit detection method can be used to quickly and accurately confirm whether the battery is short-circuited and the location of the short circuit. If the battery is not short-circuited, the insulating spacers can be pulled out. If a short circuit occurs, the battery cells can be retested in layers to accurately identify the specific short-circuited battery cells.

[0015] Furthermore, the insulating spacer is a PET film, a PVC film or a PI film. The selected insulating spacers all have certain mechanical strength and can be recycled and reused.

[0016] Furthermore, the insulating spacer is a color film, and the insulating spacers of adjacent stacking units have different colors. By using the colored insulating spacers, intuitive extraction is achieved, and the insulating spacers are prevented from being retained inside the stacking structure after the short circuit test is passed.

[0017] Furthermore, the size of the diaphragm is larger than the negative electrode sheet, the size of the negative electrode sheet is larger than the insulating spacer, and the size of the insulating spacer is larger than the positive electrode sheet, which not only ensures the NP ratio between the electrode sheets to ensure the safety of the battery, but also facilitates the removal of the insulating spacer.

[0018] Furthermore, the laminated battery is a sodium ion battery or a lithium ion battery, which meets the testing requirements of different types of batteries.

[0019] Furthermore, the sodium ion battery is a polyanion sodium ion battery, a layered oxide sodium ion battery or a Prussian blue material sodium ion battery, and different types of sodium ion batteries can adopt this structure.

[0020] Furthermore, the diaphragm is a PE film, a PP film or a PP / PE film, and there is no obvious requirement for the type of diaphragm, which meets the use requirements of the existing design.

[0021] Furthermore, the positive electrode sheet and the negative electrode sheet are manufactured by coating with a transfer coating process or an extrusion coating process, and the existing process and electrode sheet structure can be directly adopted, and there is no special requirement for the electrode sheet process.

[0022] Furthermore, after the battery passes the short-circuit test, the insulating positioning sheet is removed, and an aluminum-plastic film or steel shell packaging shell is used to form the battery, and positive and negative pole ears are arranged on the outside of the packaging shell.

[0023] Furthermore, the number of stacked battery cell units is two or more, so that multiple battery cell units can be quickly positioned in the event of a short circuit.

[0024] The utility model discloses a laminated battery structure for quickly locating the short-circuit position of a battery cell, which has the following beneficial effects:

[0025] First, the short circuit position can be located quickly. In the laminated structure of the utility model, the battery can be divided into N battery cells. The process of battery short circuit detection is also the process of short circuit detection of each layer of battery cells. When a short circuit is found, the short circuit position can be quickly determined.

[0026] Second, the repair efficiency is high. The addition of insulating locating pieces can quickly confirm the short-circuit position and confirm the short-circuit of the battery cell. Through manual single-layer retest, the specific number of layers where the short circuit occurs can be accurately confirmed, thereby improving the efficiency of retest and search.

[0027] Third, the cause of short circuit is accurately analyzed. Although there are many factors that cause short circuit in battery cells, by relying on the N single-layer battery cell units divided by insulating positioning sheets, after confirming the specific number of layers where the short circuit occurs, the cause of the short circuit can be accurately analyzed by directly hitting the short-circuit layer. If the short circuit is caused by factors other than defective electrodes, it can effectively reduce the loss of electrodes and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Attached Figure 1 This is a schematic structural diagram of a laminated battery structure for quickly locating a short-circuit position of a battery cell according to the utility model;

[0029] The markings in the accompanying drawings include: 1. negative electrode sheet; 2. separator; 3. positive electrode sheet; 4. insulating positioning sheet. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with embodiments.

[0031] like Figure 1 As shown, the utility model discloses a laminated battery structure for quickly locating the short-circuit position of a battery cell, including a plurality of stacked battery cell units, wherein the battery cell unit includes a positive electrode sheet 3, a negative electrode sheet 1, and an insulating positioning sheet 4 stacked in sequence, wherein the positive electrode sheet 3, the negative electrode sheet 1, and the insulating positioning sheet 4 are isolated by a diaphragm 2, and the insulating positioning sheet 4 is detachably interspersed and arranged inside the battery cell unit.

[0032] In the present invention, in order to ensure the convenience of subsequent operations after the short circuit test is passed, the insulating spacer is a PET film, a PVC film or a PI film. For visual operation, the insulating spacer is a color film, and the insulating spacers of adjacent stacking units have different colors.

[0033] In the present invention, in order to ensure the safety of the battery and the operability of removing the insulating spacer, the size of the diaphragm is larger than the negative electrode sheet, the size of the negative electrode sheet is larger than the insulating spacer, and the size of the insulating spacer is larger than the positive electrode sheet.

[0034] The utility model has no special restrictions on the type and material of the battery. Specifically, the laminated battery is a sodium ion battery or a lithium ion battery. Taking the sodium ion battery as an example, the sodium ion battery is a polyanion sodium ion battery, a layered oxide sodium ion battery or a Prussian blue material sodium ion battery. Taking the diaphragm as an example, the diaphragm is a PE film, a PP film or a PP / PE film. Taking the electrode sheet process as an example, the positive electrode sheet and the negative electrode sheet are coated and made by a transfer coating process or an extrusion coating process.

[0035] In the present invention, in order to ensure that the final battery is the same as the existing battery structure and reduce costs, the insulating positioning sheet is removed after the battery passes the short-circuit test, and the housing is formed by an aluminum-plastic film or a steel shell, and positive and negative pole ears are arranged on the outside of the housing. Accordingly, the structure of the present invention can meet the needs of stacking multiple battery cells, such as when the number of stacked battery cells is two or more.

[0036] The above embodiments are only specific embodiments of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and these obvious replacement forms all belong to the protection scope of the present invention.

Claims

1. A laminated battery structure for quickly locating a short-circuit position of a battery cell, comprising a plurality of stacked battery cell units, characterized in that: The battery cell unit comprises a positive electrode sheet, a negative electrode sheet and an insulating spacer which are stacked in sequence. The positive electrode sheet, the negative electrode sheet and the insulating spacer are isolated by a diaphragm. The insulating spacer is detachably inserted and arranged inside the battery cell unit.

2. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 1, characterized in that: The insulating spacer is a PET film, a PVC film or a PI film.

3. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 2, characterized in that: The insulating spacers are color films, and the insulating spacers of adjacent stacked units have different colors.

4. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 3, characterized in that: The size of the diaphragm is larger than that of the negative electrode sheet, the size of the negative electrode sheet is larger than that of the insulating positioning sheet, and the size of the insulating positioning sheet is larger than that of the positive electrode sheet.

5. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 4, characterized in that: The laminated battery is a sodium ion battery or a lithium ion battery.

6. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 5, characterized in that: The sodium ion battery is a polyanion sodium ion battery, a layered oxide sodium ion battery or a Prussian blue material sodium ion battery.

7. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 6, characterized in that: The separator is a PE film, a PP film or a PP / PE film.

8. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 7, characterized in that: The positive electrode sheet and the negative electrode sheet are produced by coating using a transfer coating process or an extrusion coating process.

9. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 8, characterized in that: After the battery passes the short-circuit test, the insulating positioning sheet is removed, and an aluminum-plastic film or steel shell packaging shell is used to form the battery, and a positive electrode ear and a negative electrode ear are arranged outside the packaging shell.

10. The laminated battery structure for quickly locating the short-circuit position of a battery cell according to claim 9, characterized in that: The number of stacked battery cells is two or more.

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