Battery cell and battery

Abstract

The utility model provides a battery cell and a battery. The battery cell comprises a first pole piece and a second pole piece, the diaphragm comprises a first part and a second part, the first part and the second part are attached to the two sides of the first pole piece respectively, and the same sides of the first part and the second part are connected with each other; the second pole piece is attached to the first part, and the second part, the first pole piece, the first part and the second pole piece are stacked in the thickness direction of the first pole piece. According to the battery cell, the diaphragm can be prevented from being turned over when the battery cell falls off, so that the battery cell is prevented from being short-circuited and fired.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, in particular to an electric core and a battery. Background Art

[0002] In the prior art, the anti-drop performance of a battery is one of the key factors that must be considered in the battery design process, which determines whether the battery can maintain its original functions and structural integrity after an accidental drop. A battery with excellent anti-drop performance can reduce the damage risk caused by accidental drops and ensure the safe and stable operation of the device. To improve the anti-drop performance of the battery, we need to optimize in multiple aspects, and the structural design is the key. The outer shell of the battery should have sufficient strength and rigidity to resist the impact force generated during the drop. At the same time, the layout and fixing method of the internal components also need to be reasonably designed to reduce the damage to the battery caused by vibration and impact during the drop. Among them, the anti-drop performance of the soft-pack battery is poor, and it is easy to cause phenomena such as short circuit and fire during the drop, especially the short circuit and fire phenomenon caused by the folding of the separator, thus posing a safety hazard. Therefore, a new electric core and battery are needed to have better anti-drop performance. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an electric core that can prevent the separator from folding during a drop, thereby effectively avoiding short circuit and fire of the electric core.

[0004] The utility model also provides a battery including the above-mentioned electric core.

[0005] The electric core according to the first aspect embodiment of the utility model includes: a first pole piece; a separator including a first part and a second part, the first part and the second part are respectively attached to both sides of the first pole piece, and the same sides of the first part and the second part are connected to each other; a second pole piece attached to the first part, and the second part, the first pole piece, the first part and the second pole piece are stacked along the thickness direction of the first pole piece.

[0006] The electric core according to the first aspect embodiment of the utility model has at least the following beneficial effects: by fixedly connecting the separator attached to both sides of the first pole piece on one side in the width direction of the first pole piece, the positioning of the separator relative to the first pole piece can be made more firm, so that when the electric core drops, the separator is less likely to fold after being impacted by the electrolyte, and it can better avoid the direct contact between the first pole piece and the second pole piece caused by the folding of the separator, thereby effectively avoiding the phenomenon of short circuit and fire of the electric core.

[0007] According to some embodiments of the present utility model, the first pole piece includes a first side and a second side, the first side and the second side are spaced apart along the width direction of the first pole piece, the position where the first part and the second part are connected abuts against or is close to the first side, and the separator extends beyond the second side in the width direction of the first pole piece.

[0008] According to some embodiments of the present utility model, the length by which the separator extends beyond the second side does not exceed 3 mm and is not less than 1 mm.

[0009] According to some embodiments of the present utility model, both ends of the separator extend beyond both ends of the first pole piece in the length direction of the first pole piece.

[0010] According to some embodiments of the present utility model, the length by which the separator extends beyond both ends of the first pole piece in the length direction does not exceed 3 mm and is not less than 1 mm.

[0011] According to some embodiments of the present utility model, the other side of the first part and the other side of the second part are connected to each other.

[0012] According to some embodiments of the present utility model, the battery cell further includes a tab, a through hole is provided in the first part, and the tab passes through the through hole and is connected to the first pole piece.

[0013] According to some embodiments of the present utility model, the first pole piece is an anode piece.

[0014] According to some embodiments of the present utility model, the first part and the second part are of an integral structure.

[0015] The battery according to the embodiments of the second aspect of the present utility model includes the battery cell according to any one of the above embodiments.

[0016] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a battery cell in some embodiments of the present utility model;

[0018] Figure 2 It is a side view of a battery cell in some embodiments of the present utility model;

[0019] Figure 3 It is a top view of a battery cell in some embodiments of the present utility model.

[0020] Reference Numerals in the Drawings:

[0021] The first electrode - 1; the separator - 2; the first part - 21; the second part - 22; the second electrode - 3. Detailed implementation mode

[0022] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0023] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as up and down, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying 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 construed as a limitation to the present utility model.

[0024] In the description of the present utility model, "a plurality of" refers to more than two. If there is a description of the first and the second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0025] In the description of the present utility model, unless otherwise clearly defined, terms such as "arrangement", "installation", and "connection" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0026] The manufacturing process of a soft - package battery is a complex and precise task, involving multiple key links. The following is a detailed description of its manufacturing process:

[0027] 1. Raw material selection and processing: First, high - quality cathode and anode materials, electrolyte, separator and other key raw materials are selected from qualified suppliers. These materials need to undergo strict quality inspection and pre - treatment to ensure compliance with manufacturing requirements, laying a solid foundation for the subsequent manufacturing process.

[0028] 2. Electrode preparation: The cathode and anode materials are respectively mixed with conductive agents and binders, and evenly coated on metal foils through a coating process. Subsequently, through processes such as drying and compaction, electrodes with excellent conductivity and mechanical strength are formed. During the preparation process, the coating thickness, uniformity and material ratio need to be strictly controlled to ensure the electrochemical performance of the battery.

[0029] 3. Separator Processing: As a key component to prevent the short circuit between the positive and negative electrodes of the battery, its processing is equally important. The separator needs to undergo precise cutting, cleaning, drying and other treatments to ensure its excellent ion permeability and barrier properties.

[0030] 4. Cell Assembly: Stack or wind the prepared positive and negative electrode plates and the separator in a predetermined order and manner to form a cell. During the assembly process, it is necessary to ensure the tightness and consistency of the internal structure of the cell to improve the energy density and safety of the battery.

[0031] 5. Electrolyte Injection and Encapsulation: After the cell assembly is completed, inject the electrolyte into the cell through a precise liquid injection system. Subsequently, perform encapsulation treatment on the cell to prevent electrolyte leakage and the intrusion of external substances. The encapsulation process needs to ensure good sealing and will not damage the internal structure of the cell.

[0032] 6. Formation and Grading: The encapsulated cell needs to go through the formation and grading processes. Formation is to make the chemical substances inside the cell fully react through specific charge-discharge cycles and reach a stable state. Grading is to perform grading treatment according to the performance differences of the cells to ensure that the batteries leaving the factory have consistent performance quality.

[0033] 7. Inspection and Quality Control: Finally, conduct comprehensive performance tests and safety tests on the manufactured soft-pack battery. This includes testing the electrical properties such as the capacity, internal resistance, and voltage of the battery, as well as evaluating the safety performance of the battery. Only the batteries that pass all the tests can be recognized as qualified products and put into the market for use.

[0034] During the entire manufacturing process, it is necessary to strictly control the process parameters and environmental conditions to ensure that each operation meets the specification requirements. At the same time, it is also necessary to perform regular maintenance and servicing on the production equipment to ensure its stable and reliable operation. Through strict manufacturing processes and quality control, high-quality and high-performance soft-pack batteries can be produced to meet the market demand.

[0035] And in the stage of inspection and quality control, it is necessary to conduct a drop test on the battery. In the drop test, the separator of the soft-pack battery is very easy to fold over. After the separator folds over, the positive and negative electrode plates of the cell will come into direct contact, resulting in short circuit and fire.

[0036] The drop test of the soft-pack battery is an important part of the battery performance evaluation, aiming to simulate the drop situations that the battery may encounter during actual use to test its safety performance and stability.

[0037] When conducting the anti-drop test, we will set a series of strict parameters, such as drop height, angle, and number of drops, etc., to simulate various impacts that the battery may suffer in the real environment. Through these experiments, we can deeply understand the performance of the soft-pack battery after being subjected to external forces.

[0038] After the experiment, we will carefully check the appearance and structure of the soft-pack battery to observe whether there are obvious damages or deformations. At the same time, we will also detect the electrical performance inside the battery, including key indicators such as voltage and internal resistance, to evaluate the working state of the battery after the drop.

[0039] Due to its unique structural and material advantages, the soft-pack battery may show certain superiority in anti-drop performance. However, since the soft-pack battery is relatively easy to deform when subjected to impacts, after the soft-pack battery is deformed, the separator is easily folded when impacted by the electrolyte, resulting in a short circuit and fire in the battery.

[0040] In the battery cell, the folding and wrinkling of the separator may bring a series of hazards. These hazards are mainly reflected in the following aspects: 1. Reducing battery performance: The folding and wrinkling of the separator may increase the internal resistance of the battery, which will reduce the charging and discharging efficiency of the battery, and thus affect the overall performance of the battery. 2. Affecting battery life: The wrinkled and folded separator may cause uneven stress distribution during the charging and discharging process of the battery, resulting in local aging or damage of the separator, thereby shortening the cycle life of the battery. 3. Increasing safety risks: The folding and wrinkling of the separator may trigger a short circuit inside the battery. The short circuit will not only cause the battery to heat up, but may even lead to battery combustion or explosion, posing a serious safety threat to users. 4. Affecting battery consistency: During the production process of the battery cell, if there are folds and wrinkles in the separator, it will affect the consistency of the battery cell. This will affect the overall performance of the battery pack and may cause some battery cells to fail prematurely during use.

[0041] Therefore, in order to ensure the safety and performance stability of the battery cell, it is necessary to strictly control the folding and wrinkling problems of the separator during the production process and take corresponding measures for prevention and treatment.

[0042] Refer to Figure 1 、 Figure 2 and Figure 3, for the battery cell in the first embodiment of the present utility model, the separator 2 includes a first part 21 and a second part 22. The first part 21 and the second part 22 are respectively attached to both sides of the first electrode plate 1, and the same sides of the first part 21 and the second part 22 are connected to each other; the second electrode plate 3 is attached to the first part 21, and the second part 22, the first electrode plate 1, the first part 21 and the second electrode plate 3 are stacked along the thickness direction of the first electrode plate 1. When setting the separator 2 on both sides of the first electrode plate 1, in order to completely isolate the first electrode plate 1 and the second electrode plate 3, the areas of the first part 21 and the second part 22 are both larger than the area of the first electrode plate 1, that is, the separator 2 extends out from the periphery of the edge of the first electrode plate 1. By fixedly connecting the extended parts of the separator 2 together, when the separator 2 is impacted by the electrolyte, the movement of the separator 2 is blocked by the first electrode plate 1, so that the separator 2 is less likely to be folded, and the separator 2 can be more firmly attached to the first electrode plate 1 to block the direct contact between the first electrode plate 1 and the second electrode plate 3. After fixedly connecting the extended parts of the separator 2 together to wrap the first electrode plate 1, the second electrode plate 3 is stacked on the separator 2 to form a battery cell.

[0043] When setting the battery cell, pole tabs will be provided on the electrode plates in the battery cell. Taking the first electrode plate 1 as an example, the pole tab will be provided on one side in the width direction of the first electrode plate 1. Then, the connection position of the separator 2 on both sides of the first electrode plate 1 should be set on the other side in the width direction of the first electrode plate 1 to facilitate the connection between the pole tab and the first electrode plate 1.

[0044] According to some embodiments of the present utility model, the separator 2 is folded to form a receiving groove, the first electrode plate 1 is arranged in the receiving groove, the folding position of the separator 2 is located on the first side in the width direction of the first electrode plate 1, and the separator 2 extends beyond the first electrode plate 1 on the second side in the width direction of the first electrode plate 1. Specifically, a relatively wide separator 2 is used, and the separator 2 is folded along the width direction to form a receiving groove. At this time, the receiving groove is composed of two layers of the separator 2. One side of the receiving groove is closed, that is, the position where the separator 2 is folded, and at the closed position, it is equivalent to fixedly connecting between the separators 2 attached to both sides of the first electrode plate 1. The other three sides of the receiving groove are all open.

[0045] During the manufacturing process, various manufacturing methods can be adopted. One method is to first fold the separator 2. After folding the separator 2 to form a receiving groove, the first electrode plate 1 is placed into the receiving groove through the opening of the receiving groove, so that the separator 2 wraps the first electrode plate 1. When folding the separator 2, it is folded along the center line in the width direction of the separator 2, so that the lengths of the separator 2 extending out on the other side of the first electrode plate 1 are the same.

[0046] Another manufacturing method is as follows: Use a relatively wide separator 2. First, attach the separator 2 to one side of the first electrode tab 1, then fold the separator 2 to the other side of the first electrode tab 1 and attach it to the other side of the first electrode tab 1. The separator 2 is divided into a first region and a second region along the center line in the width direction of the separator 2. First, place the first electrode tab 1 into the first region of the separator 2, and then fold it along the center line in the width direction of the separator 2 so that the second region of the separator 2 is attached to the other side of the first electrode tab 1. Further, when attaching the first electrode tab 1 to the first region, set the side edge of the first electrode tab 1 along the center line in the direction opposite to the width of the separator 2, so that less separator 2 can be used and the energy density of the battery cell can be further increased.

[0047] Alternatively, the separator 2 can be directly divided into a first region and a second region along the center line in the width direction. When setting the first electrode tab 1, set one side edge of the first electrode tab 1 along the center line of the separator 2, causing the separator 2 to bend, and then attach the separator 2 to both sides of the first electrode tab 1.

[0048] According to some embodiments of the present utility model, the lengths by which the separator 2 extends beyond both ends of the first electrode tab 1 in the length direction on the second side in the width direction of the first electrode tab 1 are both not more than 3 mm and not less than 1 mm, and the separator 2 extends beyond the first electrode tab 1 at both ends in the length direction of the first electrode tab 1, and the extended length is not more than 3 mm and not less than 1 mm. When the length by which the separator 2 extends beyond the edge of the first electrode tab 1 is too large, it will not only cause waste of the separator 2, but also reduce the energy density of the battery cell because the separator 2 occupies a large amount of space. When the length by which the separator 2 extends beyond the first electrode tab 1 is small, there is also a certain risk of causing a short circuit on the side of the first electrode tab 1 of the battery cell. Therefore, setting the lengths by which the separator 2 extends beyond the first electrode tab 1 on the second side in the width direction of the first electrode tab 1 and the lengths by which the separator 2 extends beyond the first electrode tab 1 at both ends in the length direction of the first electrode tab 1 to be not more than 3 mm and not less than 1 mm can ensure the safety performance of the battery cell and avoid reducing the energy density of the battery cell due to the separator 2 occupying a large amount of space.

[0049] According to some embodiments of the present utility model, on the first side and the second side in the width direction of the first electrode tab 1, the separators 2 attached to both sides of the first electrode tab 1 are fixedly connected. A through hole is provided in the separator 2 located on the second side in the width direction of the first electrode tab 1 to enable the tab to pass through the separator 2 and be connected to the first electrode tab 1. When fixedly connecting the separators 2 on both sides in the width direction of the first electrode tab 1, the positioning of the separator 2 can be made more firm, making it more difficult for the separator 2 to fold, and improving the safety of the battery cell.

[0050] According to some embodiments of the present utility model, a tab is provided on the second side of the first electrode tab 1, and the tab extends to the outside of the separator 2.

[0051] According to some embodiments of the present utility model, the first electrode plate 1 is an anode plate. The anode plate and the cathode plate of a graphite battery are its core components, each having unique characteristics and functions. Anode plate: The anode plate of a graphite battery is usually made of high-quality graphite material. Graphite is known for its excellent electrical conductivity and stable chemical properties, making it perform outstandingly as an anode material in the battery. During the operation of the battery, the anode plate is responsible for providing electrons and exchanging them with ions in the electrolyte through chemical reactions, thereby achieving the conversion of electrical energy. To optimize the performance of the anode plate, its design usually takes into account factors such as the contact area with the electrolyte and the electron transfer efficiency. At the same time, the anode plate also needs to go through a fine processing technology to ensure the stability of its structure and long life.

[0052] Cathode plate: Different from the anode plate, the cathode plate of a graphite battery usually uses a compound material with a specific crystal structure and chemical properties. These materials can effectively adsorb ions during battery charging and release ions during discharging, realizing the storage and release of electrical energy. The design of the cathode plate is also crucial. It must ensure the rapid diffusion of ions in the material and the effective transfer of electrons. To achieve this goal, the structure of the cathode plate is usually designed to be porous to increase the contact area with the electrolyte and optimize the ion transfer path.

[0053] The reason for setting the first electrode plate 1 wrapped by the separator 2 as the anode plate is that in the battery cell, the dimensions of the anode plate in both the length direction and the width direction are larger than those of the cathode plate. After wrapping the anode plate with the separator 2, the anode plate and the cathode plate can be better and more stably isolated, so that the battery has better performance and it is less likely to occur short-circuit phenomena in the battery cell.

[0054] According to some embodiments of the present utility model, the second part 22, the first electrode plate 1, the first part 21 and the second electrode plate 3 are stacked along the thickness direction of the first electrode plate 1 and then wound along the length direction of the first electrode plate 1 to form a wound battery cell. The wound battery cell needs to undergo a glue-wrapping process at the bottom of the bare battery cell. The glue-wrapping process at the bottom of the bare battery cell plays a crucial role in the manufacturing process of lithium-ion batteries, especially having a significant impact on the separator 2. The separator 2 is one of the key components of a lithium-ion battery, mainly functioning to separate the positive and negative electrodes of the battery to prevent them from directly contacting and causing a short circuit, while allowing ions in the electrolyte to pass through to complete the electrochemical reaction.

[0055] In the bottom winding process of the bare battery cell, winding is mainly used to fix and protect the structure of the wound positive and negative electrode sheets and the separator 2. This process ensures the stability and safety of the separator 2 in the battery structure. Specifically, the effects of the winding process on the separator 2 are mainly manifested in the following aspects: Fixing the position: Winding can effectively fix the position of the separator 2, preventing it from shifting or deforming during battery assembly or use. This helps to maintain an appropriate distance between the positive and negative electrodes and prevent the risk of short circuit caused by the movement of the separator 2. Enhancing structural stability: Through winding, the connection between the separator 2 and the positive and negative electrode sheets becomes tighter, enhancing the stability of the entire battery structure. This helps to resist external shocks and vibrations during battery operation and reduce safety problems caused by structural looseness. Generally speaking, the bottom winding process of the bare battery cell mainly reflects in fixing the position and enhancing the structural stability of the separator 2. These effects together improve the safety and reliability of the lithium-ion battery, ensure the normal operation of the battery and extend its service life. And the battery cell in this solution does not need to perform the bottom winding process of the bare battery cell anymore, which not only simplifies the production process to a certain extent but also improves the energy density of the battery cell.

[0056] According to some embodiments of the present invention, the second electrode sheet 3 is located on the side of the first electrode sheet 1 close to the core. Setting the first electrode sheet 1 wrapped with the separator 2 on the outside, then the separator 2 located on the outermost layer of the core can also play a certain protective role, making the safety performance of the battery cell better.

[0057] The battery according to the second aspect embodiment of the present invention includes the battery cell of any one of the above embodiments.

[0058] The embodiments of the present invention have been described in detail above with reference to the drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge scope of those of ordinary skill in the art.

Claims

1. A battery cell, characterized in that: include: First pole piece; A diaphragm, comprising a first portion and a second portion, wherein the first portion and the second portion are respectively attached to two sides of the first pole piece, and the first portion and the second portion are connected to each other on the same side; The second pole piece is attached to the first portion, and the second portion, the first pole piece, the first portion and the second pole piece are stacked along a thickness direction of the first pole piece.

2. The battery cell according to claim 1, characterized in that: The first pole piece includes a first side and a second side, the first side and the second side are arranged along the width direction of the first pole piece, the position where the first part and the second part are connected abuts or is close to the first side, and the diaphragm exceeds the second side in the width direction of the first pole piece.

3. The battery cell according to claim 2, characterized in that: The length of the diaphragm beyond the second side is not more than 3 mm and not less than 1 mm.

4. The battery cell according to claim 3, characterized in that: Both ends of the diaphragm extend beyond both ends of the first pole piece in the length direction of the first pole piece.

5. The battery cell according to claim 4, characterized in that: The length of the diaphragm beyond both ends of the first pole piece in the length direction is no more than 3 mm and no less than 1 mm.

6. The battery cell according to claim 1, characterized in that: The other side of the first portion and the other side of the second portion are connected to each other.

7. The battery cell according to claim 1, characterized in that: The battery cell further includes a pole ear, the first portion is provided with a through hole, and the pole ear passes through the through hole and is connected to the first pole piece.

8. The battery cell according to claim 1, characterized in that: The first pole piece is an anode piece.

9. The battery cell according to claim 1, characterized in that: The first part and the second part are an integrated structure.

10. A battery, characterized in that A battery cell comprising any one of claims 1 to 9.

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