Battery roll core, lithium ion battery and electronic atomizer
By using a swelling layer to absorb and precipitate electrolyte in lithium-ion batteries, the contact pressure between the positive electrode, negative electrode, and separator is enhanced, thus solving the problem of insufficient cycle capacity of lithium-ion batteries and achieving high cycle stability of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-03-06
AI Technical Summary
Existing lithium-ion batteries have poor cycle life and cannot meet market demand.
The system employs a swelling layer to absorb free electrolyte and release electrolyte as the electrolyte concentration decreases, ensuring that the electrolyte is at its optimal concentration. The system also increases the contact pressure between the positive electrode, negative electrode, and membrane, thereby improving the interfacial contact tightness.
It improves the cycle stability of lithium-ion batteries and the high cycle stability of battery cores, solving the problem of insufficient cycle capacity of lithium-ion batteries.
Smart Images
Figure CN223977922U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a battery core, a lithium-ion battery, and an electronic atomizer. Background Technology
[0002] With the development of battery technology, people have increasingly higher requirements for batteries. The cycle life of existing lithium-ion batteries is generally within 500 cycles, which cannot meet market demand.
[0003] The poor cycle life of existing lithium-ion batteries has become a pressing technical problem that needs to be solved in the industry. Utility Model Content
[0004] This utility model provides a battery core, a lithium-ion battery, and an electronic atomizer to solve the problem of poor cycle life of lithium-ion batteries.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] This utility model embodiment provides a battery winding core, comprising:
[0007] Positive and negative electrodes;
[0008] A diaphragm is disposed between the positive electrode and the negative electrode; the diaphragm, the positive electrode, and the negative electrode are wound together.
[0009] A swelling layer is disposed on the outermost side of the diaphragm away from the negative electrode. The swelling layer is used to absorb free electrolyte or deposited electrolyte.
[0010] Optionally, the swelling layer includes a substrate and an adhesive layer;
[0011] The substrate serves to swell, and the adhesive layer is used to bond the substrate to the diaphragm.
[0012] Optionally, the substrate material includes oriented polystyrene film or a polymer material formed by the reaction polymerization of diphenylmethane diisocyanate; the adhesive layer material includes acrylic.
[0013] Optionally, the thickness of the swollen layer includes 30μm-50μm;
[0014] The thickness of the swollen layer after swelling is 3 to 5 times the thickness of the swollen layer before swelling.
[0015] Optionally, the width of the swollen layer is less than or equal to the width of the diaphragm;
[0016] The difference between the width of the swollen layer and the width of the diaphragm is within the range of 1 mm ± 1 mm.
[0017] Optionally, the battery core includes at least two separators, with separators provided on both sides of the positive electrode and on both sides of the negative electrode.
[0018] Optionally, the battery core may be circular or square; the separator may be a separator material with a ceramic layer.
[0019] Optionally, the diaphragm includes a base membrane, an adhesive layer, and ceramic; or, the diaphragm includes a base membrane and ceramic.
[0020] Optionally, the base film may be made of polyethylene;
[0021] The adhesive layer is made of polyvinylidene fluoride;
[0022] The positive electrode is lithium cobalt oxide or a ternary material;
[0023] The negative electrode is graphite.
[0024] According to another aspect of the present invention, this embodiment provides a lithium-ion battery, comprising: an electrolyte and a battery core as described in any of the above embodiments.
[0025] According to another aspect of the present invention, this embodiment provides an electronic atomizer, comprising: a battery core as described in any of the first aspects, or a lithium-ion battery as described in the second aspect.
[0026] The battery core provided in this embodiment absorbs the free electrolyte outside the outermost separator through a swelling layer. The increased thickness of the swelling layer increases the pressure exerted by the swelling layer on the positive electrode, negative electrode, and separator, thereby creating a tighter interfacial contact between the positive electrode, negative electrode, and separator. When the electrolyte concentration of the lithium-ion battery decreases, electrolyte precipitates out from the swelling layer to ensure that the electrolyte concentration of the lithium-ion battery remains at the optimal level, thus improving the cycle stability of the battery core and consequently the cycle stability of the lithium-ion battery. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of this utility model and these drawings without creative effort.
[0028] Figure 1 This is a schematic diagram of a battery winding core provided in an embodiment of this utility model;
[0029] Figure 2This is a schematic diagram of another battery winding core provided in an embodiment of the present utility model;
[0030] Figure 3 This is a schematic diagram of another battery winding core provided in an embodiment of the present utility model;
[0031] Figure 4 This is a schematic diagram of another battery winding core provided in an embodiment of the present utility model;
[0032] Figure 5 This is a schematic diagram of another battery winding core provided in an embodiment of the present utility model;
[0033] Figure 6 This is a schematic diagram of the structure of a lithium-ion battery provided in an embodiment of the present invention. Detailed Implementation
[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0035] Based on the above-mentioned technical problems, this embodiment proposes the following solutions:
[0036] Figure 1 This is a schematic diagram of a battery winding core provided in an embodiment of this utility model. See also... Figure 1 This utility model embodiment provides a battery core 100 comprising: a positive electrode 1 and a negative electrode 2; a separator 3 disposed between the positive electrode 1 and the negative electrode 2; the separator 3, the positive electrode 1 and the negative electrode 2 are wound together; and a swelling layer 4 disposed on the outermost side of the separator 3 away from the negative electrode 2, the swelling layer 4 being used to absorb free electrolyte or deposited electrolyte.
[0037] Specifically, a lithium-ion battery is a rechargeable battery. It primarily functions by the movement of lithium ions between the positive electrode (1) and the negative electrode (2). During charging and discharging, Li+ ions repeatedly insert and extract between the two electrodes. When charging, Li+ ions extract from the positive electrode (1), pass through the electrolyte, and insert into the negative electrode (2), resulting in a lithium-rich state at the negative electrode (2). Conversely, when discharging, Li+ ions extract from the negative electrode (2), pass through the electrolyte, and insert into the positive electrode (1), resulting in a lithium-rich state at the positive electrode (1).
[0038] The electrolyte level in a lithium-ion battery refers to the minimum electrolyte level. This minimum level indicates the minimum electrolyte height that must be maintained inside the battery. Maintaining an appropriate electrolyte level is crucial for the normal operation and safety of lithium-ion batteries. The electrolyte conducts lithium ions, ensuring their proper diffusion and movement between the positive and negative electrodes, thus enabling the charging and discharging process. If the electrolyte level falls below the minimum required level, lithium ion movement is restricted, leading to reduced battery capacity, slower charging, or even complete malfunction.
[0039] A separator 3 is disposed between the positive electrode 1 and the negative electrode 2, and a separator 3 is also disposed on the innermost layer. A swelling layer 4 is disposed on the outer side of the outermost separator 3. The swelling layer 4 is disposed between the outermost separator 3 and the outer shell. The swelling layer 4 can absorb the electrolyte that is free outside the outermost separator 3, reducing side reactions. When the electrolyte retention of the battery core 100 decreases, electrolyte is released from the swelling layer 4, thereby increasing the electrolyte concentration of the lithium-ion battery and thus increasing the electrolyte retention of the lithium-ion battery. The electrolyte concentration of the lithium-ion battery is well controlled, effectively improving the electrolyte retention of the lithium-ion battery.
[0040] As the swelling layer 4 absorbs the electrolyte, its thickness increases. The swelling layer 4 expands after absorbing the electrolyte, which can better provide pressure to the center of the battery core 100. This makes the interface contact between the positive electrode 1, the separator 3, the negative electrode 2 and the electrolyte tighter, thereby improving the high cycle stability of the battery core 100 and thus improving the cycle stability of the lithium-ion battery.
[0041] The battery core 100 provided in this embodiment absorbs the free electrolyte outside the outermost separator 3 through the swelling layer 4. The increased thickness of the swelling layer 4 increases the pressure exerted by the swelling layer 4 on the positive electrode 1, negative electrode 2, and separator 3, thereby making the interfacial contact between the positive electrode 1, negative electrode 2, and separator 3 tighter. When the electrolyte concentration of the lithium-ion battery decreases, electrolyte is released from the swelling layer 4 to ensure that the electrolyte of the lithium-ion battery is always at the optimal concentration, thereby improving the cycle stability of the battery core 100 and solving the problem of poor cycle performance of lithium-ion batteries.
[0042] Optional, Figure 2 This is a schematic diagram of another battery winding core provided by an embodiment of this utility model. Based on the above embodiments, combined with... Figure 1 and Figure 2 The swelling layer 4 may include a substrate 41 and an adhesive layer 42; the substrate 41 serves to swell, and the adhesive layer 42 is used to bond the substrate 41 to the diaphragm 3.
[0043] Specifically, this configuration allows the swelling layer 4 to effectively absorb the free electrolyte outside the outermost separator 3 of the battery core 100 through the substrate 41. When the electrolyte level is lower than a preset range, the swelling adhesive paper can release the electrolyte, ensuring that the electrolyte in the lithium-ion battery remains at the optimal concentration. The adhesive layer 42 serves an adhesive function, facilitating a tight bond between the substrate 41 and the separator 3, and ensuring that the substrate 41 uniformly covers the separator 3. For example, the swelling layer 4 can be made of swelling adhesive paper.
[0044] Optionally, based on the above embodiments, further combinations can be made... Figure 1 and Figure 2 The material of the substrate 41 in the above embodiments may include oriented polystyrene film or a polymer material formed by the reaction polymerization of diphenylmethane diisocyanate; the material of the adhesive layer 42 includes acrylic.
[0045] Specifically, the substrate 41 may include OPS (Oriented Polystyrene Films) or TPU. TPU is a polymer material formed by the reaction polymerization of diphenylmethane diisocyanate and other materials, falling between rubber and plastic. For example, the material of the swelling layer 4 may also include a synthetic resin.
[0046] Optional, Figure 3 This is a schematic diagram of another battery winding core provided by an embodiment of this utility model. Based on the above embodiments, combined with... Figure 1 and see Figure 3 The thickness d of the swelling layer 4 may be 30μm-50μm; the thickness of the swelling layer 4 after swelling is 3 to 5 times the thickness of the swelling layer 4 before swelling.
[0047] Specifically, if the thickness d of the swelling layer 4 is too thin, its ability to absorb electrolyte will be insufficient. If the thickness d of the swelling layer 4 is too thick, it will reduce space utilization and lead to a decrease in energy density. By setting the thickness d of the swelling layer 4 to satisfy: 30μm≤d≤50μm, the swelling layer 4 can better adjust the precision of electrolyte retention in the lithium-ion battery. For example, the thickness d of the swelling layer 4 can be set to 45μm.
[0048] The thickness of the swelling layer 4 provided in this embodiment after swelling is 3 to 5 times the thickness of the swelling layer 4 before swelling, which significantly increases the thickness of the swelling layer 4 after swelling. This facilitates the application of pressure towards the center of the battery core 100, thereby making the interface contact between the positive electrode 1, the separator 3, the negative electrode 2 and the electrolyte tighter, and further improving the high cycle stability of the battery core 100.
[0049] Optional, Figure 4This is a schematic diagram of another battery winding core provided by an embodiment of this utility model. Based on the above embodiments, combined with... Figure 1 , Figure 3 and Figure 4 The width w1 of the swollen layer 4 is less than or equal to the width w2 of the diaphragm 3; the difference between the width w1 of the swollen layer 4 and the width w2 of the diaphragm 3 is within the range of 1 mm ± 1 mm.
[0050] Specifically, this design ensures that the width w1 of the swollen layer 4 is slightly smaller than the width w2 of the separator 3. The width w1 of the swollen layer 4 is typically -1 mm of the width w2 of the separator 3, with a tolerance of ≤1 mm. This design ensures that the swollen layer 4 absorbs the electrolyte while maintaining the sealing effect of the battery core 100. Setting the difference between the width of the swollen adhesive paper and the width of the separator 3 to be less than or equal to 2 mm allows the swollen layer 4 to completely cover the outermost separator 3 of the battery core 100, further improving the cycle stability of the battery core 100 and addressing the problem of poor cycle performance in lithium-ion batteries.
[0051] Optionally, based on the above embodiments, see also... Figure 1 The battery core 100 includes at least two layers of separators 3. Separators 3 are provided on both sides of the positive electrode 1 and on both sides of the negative electrode 2.
[0052] Specifically, this design helps prevent short circuits. The separator 3 separates the positive electrode 1 and the negative electrode 2 of the battery, preventing direct contact between them and thus avoiding a short circuit. Through physical isolation, the separator 3 ensures that current can only flow through the external circuit, thereby maintaining the electrochemical reaction of the battery core 100. Furthermore, the separator 3 can control the flow of the electrolyte, ensuring that the electrolyte can only pass through the microporous structure in the separator 3, rather than directly contacting the other electrode. This allows the battery to carry out electrochemical reactions in an orderly manner, thereby ensuring the battery's operational stability and safety.
[0053] Optional, Figure 5 This is a schematic diagram of another battery winding core provided by an embodiment of this utility model. Based on the above embodiments, combined with... Figure 1 and Figure 5 The battery core 100 may be circular or square in shape. The separator 3 comprises a separator material with a ceramic layer.
[0054] Optionally, based on the above embodiments, see also... Figure 5 The diaphragm 3 includes a base membrane, an adhesive layer, and ceramic; or, the diaphragm 3 includes a base membrane and ceramic.
[0055] For example, see [link to previous article] Figure 5 When the battery core 100 is square in shape, the separator 3 includes a base film, an adhesive layer, and ceramic. See also, for an example, [link to example]. Figure 1 When the battery core 100 is circular, the separator 3 includes a base film and ceramic.
[0056] It should be noted that this embodiment exemplifies the case where the battery core 100 is square in shape, and the separator 3 includes a base film, an adhesive layer, and ceramic; when the battery core 100 is circular in shape, the separator 3 includes a base film and ceramic, and no limitation is made here. The separator 3 can also be made of other separator materials with a ceramic layer, and no limitation is made here.
[0057] Specifically, the design and materials of the separator 3 directly affect battery performance. The pore size and distribution of the separator 3 influence the lithium-ion transport rate, thereby affecting the battery's charge / discharge efficiency and power output. By optimizing the design of the separator 3, the battery's reaction rate can be adjusted, improving battery performance and meeting the needs of different application scenarios.
[0058] The separator 3 includes a separator 3 material with a ceramic layer, which ensures battery safety. In the event of battery overheating or internal short circuit, the separator 3 material with the ceramic layer has good thermal stability, preventing the separator 3 from melting or shrinking due to temperature rise, thereby avoiding further damage to the battery and the occurrence of safety accidents, and improving the safety of the battery core 100.
[0059] Optionally, based on the above embodiments, see also... Figure 1 and Figure 5 The base film is made of polyethylene; the adhesive layer is made of polyvinylidene fluoride; the positive electrode 1 is lithium cobalt oxide or a ternary material; and the negative electrode 2 is graphite.
[0060] Optionally, based on the above embodiments, see also... Figure 1 and Figure 5 The accuracy of the liquid retention range of lithium-ion batteries is less than or equal to ±5%. Lithium-ion batteries are configured for cyclic operation, with each charge yielding 70% of the rated capacity and each discharge yielding 70% of the rated capacity.
[0061] Specifically, the liquid retention accuracy of lithium-ion batteries is set to be less than or equal to ±5%. For example, if the required median liquid retention is 1g, the liquid retention range is 1±0.05g. Liquid retention is controlled by adjusting the injection volume and liquid loss through process control.
[0062] By setting up shallow charge and shallow discharge cycles, the risk of side reactions and structural collapse of the lithium-ion battery core 100 during charge and discharge cycles is reduced, thereby improving cycle stability. For example, shallow charge and shallow discharge may include: shallow charge: each charge is stopped at 70% of the rated capacity; shallow discharge: each discharge is stopped at 70% of the rated capacity.
[0063] Figure 6 This is a schematic diagram of the structure of a lithium-ion battery provided in an embodiment of the present invention. Based on the above embodiments, see [link to other embodiments]. Figure 6 The lithium-ion battery 200 provided in this embodiment includes an electrolyte and the battery core 100 proposed in any of the above embodiments, and has the beneficial effects of the battery core 100 proposed in any of the above embodiments, which will not be repeated here.
[0064] This embodiment provides an electronic atomizer. The electronic atomizer provided in this embodiment includes the battery coil proposed in any of the above embodiments, and has the beneficial effects of the battery coil proposed in any of the above embodiments, which will not be elaborated further here. Alternatively, the electronic atomizer provided in this embodiment includes the lithium-ion battery proposed in any of the above embodiments, and has the beneficial effects of the lithium-ion battery proposed in any of the above embodiments, which will not be elaborated further here.
[0065] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.
Claims
1. A battery jelly-roll, characterized by, The battery roll core comprises: a positive electrode and a negative electrode; a separator arranged between the positive electrode and the negative electrode, the separator, the positive electrode and the negative electrode being arranged in a roll shape; a swelling layer arranged on the side of the outermost separator away from the negative electrode, the swelling layer being used to absorb free electrolyte or precipitate the electrolyte.
2. The battery roll core according to claim 1, wherein: the swelling layer comprises a base material and an adhesive layer; the base material plays a swelling role, and the adhesive layer is used to bond the base material with the separator.
3. The battery roll core according to claim 2, wherein: the material of the base material comprises an oriented polystyrene film or a polymer material obtained by reacting and polymerizing diphenylmethane diisocyanate; the material of the adhesive layer comprises acrylic.
4. The battery roll core according to claim 1, wherein: the thickness of the swelling layer comprises 30 μm-50 μm; the thickness of the swelling layer after swelling is 3-5 times the thickness of the swelling layer before swelling.
5. The battery roll core according to claim 1, wherein: the width of the swelling layer is less than or equal to the width of the separator; the difference between the width of the swelling layer and the width of the separator ranges from 1 mm±1 mm.
6. The jelly-roll battery core according to any one of claims 1 to 5, characterized in that, The battery roll core comprises at least two layers of separators, and the positive electrode and the negative electrode are both provided with separators on both sides.
7. The jelly-roll battery core according to claim 6, characterized in that The shape of the battery roll core comprises a circular shape or a square shape; the separator comprises a separator material with a ceramic layer.
8. The battery roll core according to claim 7, wherein: the separator comprises a base film, a glue layer and a ceramic; or the separator comprises a base film and a ceramic; the material of the base film comprises polyethylene; the material of the glue layer comprises polyvinylidene fluoride; the positive electrode is lithium cobaltate or ternary material; the negative electrode is graphite.
9. A lithium-ion battery, characterized by The lithium ion battery comprises: an electrolyte and the battery roll core according to any one of claims 1-8.
10. An electronic atomizer, characterized in that, The lithium ion battery comprises: the battery roll core according to any one of claims 1-8, or the lithium ion battery according to claim 9.