Special-shaped lithium ion battery

Abstract

The utility model discloses a special-shaped lithium ion battery, including oval core, electrolyte and oval shell, the core includes positive sheet, negative sheet and the diaphragm of setting between positive sheet and negative sheet, positive sheet the diaphragm and negative sheet are sequentially laminated and are coiled to form the core, the core with electrolyte are sealed together in the inside of shell, the oval core includes first end and second end of opposite setting, the first end is connected with positive tab, and the second end is connected with negative tab, the positive tab extends outward from the first end and passes out the shell, and the negative tab extends outward from the second end and passes out the shell, the utility model discloses through reasonable structure design, can improve the space utilization of battery in electronic product, and adapts the electronic product of diversification and unique modeling, makes electronic product structure more compact and light.

Description

Technical Field

[0001] This utility model belongs to the field of secondary battery technology, and in particular relates to an irregularly shaped lithium-ion battery. Background Technology

[0002] As people's living standards improve, consumer electronics are increasingly favored by young people, who demand not only good functionality but also stylish designs. Consequently, consumer electronics have become increasingly diverse, featuring novel styles and unique designs. Lithium-ion batteries, as a crucial component of consumer electronics, also require continuous innovation and iteration.

[0003] Currently, the main shapes of lithium-ion batteries sold on the market are prismatic and cylindrical. Prismatic lithium-ion batteries have larger cells and lower energy density, but offer higher space utilization in electronic products. Cylindrical lithium-ion batteries, on the other hand, have smaller cells and higher energy density, but offer lower space utilization in electronic products. Therefore, both prismatic and cylindrical lithium-ion batteries have some drawbacks in use. With the increasing diversification of electronic products, the shortcomings of prismatic and cylindrical lithium-ion batteries are becoming increasingly prominent, failing to effectively meet the structural requirements of diverse and uniquely shaped electronic products.

[0004] In particular, for modern electronic products with curved designs, traditional square or cylindrical batteries often result in wasted space or are unable to effectively fit the internal space of the product. While square batteries have high space utilization, their sharp edges limit their ability to fit into curved product cavities; and while cylindrical batteries have high energy density, they leave a lot of unused "dead corner" space in rectangular spaces, reducing overall space utilization efficiency. Furthermore, as consumer electronics become thinner and more personalized, the shape, size, and performance of batteries need to be more flexible to adapt to the needs of different products.

[0005] In view of this, it is indeed necessary to provide an irregularly shaped lithium-ion battery that can effectively solve the above problems. Utility Model Content

[0006] The purpose of this utility model is to provide an irregularly shaped lithium-ion battery that addresses the shortcomings of existing technologies. Through a reasonable structural design, it can improve the space utilization of the battery in electronic products, adapt to diverse and uniquely shaped electronic products, and make the electronic products more compact and lightweight.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] An irregularly shaped lithium-ion battery includes an elliptical core, an electrolyte, and an elliptical outer shell. The core includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The positive electrode, the separator, and the negative electrode are sequentially stacked and wound to form the core. The core and the electrolyte are sealed together inside the outer shell.

[0009] The elliptical core includes a first end and a second end disposed opposite to each other. The first end is connected to a positive electrode tab, and the second end is connected to a negative electrode tab. The positive electrode tab extends outward from the first end and passes through the outer shell, and the negative electrode tab extends outward from the second end and passes through the outer shell.

[0010] Preferably, the major axis w1, minor axis w2 and length l of the lithium-ion battery satisfy the relationship: length (l) > major axis (w1) + minor axis (w2).

[0011] Preferably, the lithium-ion battery has a major axis w1 of 30-38 mm, a minor axis w2 of 20-28 mm, and a length l of 75-85 mm.

[0012] Preferably, the lithium-ion battery has a major axis w1 of 33 mm, a minor axis w2 of 26 mm, and a length l of 79 mm.

[0013] Preferably, the capacity of the lithium-ion battery is 10000~13000mAh.

[0014] Preferably, the outer shell is made of aluminum-plastic film, which has two semi-elliptical grooves. The two semi-elliptical grooves are folded together and heat-sealed to form a closed elliptical cylinder, and the core is sealed inside the elliptical cylinder.

[0015] Preferably, the positive electrode tab is bent inward along one end plane of the outer shell to form a first bent section, and a first protective paper is disposed between the first bent section and one end plane of the outer shell; the negative electrode tab is bent inward along the other end plane of the outer shell to form a second bent section, and a second protective paper is disposed between the second bent section and the other end plane of the outer shell.

[0016] Preferably, one surface of the first protective paper and the second protective paper are respectively coated with an adhesive layer, wherein the adhesive layer is one of acrylic adhesive, silicone adhesive, vinyl ester adhesive, nitrile rubber adhesive or neoprene rubber adhesive.

[0017] Preferably, the outer surface of the outer shell is tightly fitted with a heat-shrink film, and the heat-shrink film is pressed tightly against the peripheral edges of the first protective paper and the second protective paper respectively.

[0018] Preferably, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector. The positive electrode sheet is provided with a liquid guiding channel penetrating the positive active material layer along the Y direction, and the surface of the liquid guiding channel is covered with insulating adhesive paper. The positive electrode tab is disposed in the middle or at the end of the positive electrode sheet.

[0019] Preferably, the width of the liquid guiding channel along the X direction is 3~15mm.

[0020] Preferably, the thickness of the positive current collector (h1), the thickness of the positive active material layer (h2), and the thickness of the insulating tape (h3) satisfy the following relationship: thickness of positive current collector (h1) + thickness of positive active material layer (h2) > thickness of positive current collector (h1) + thickness of insulating tape (h3).

[0021] Preferably, the sum of the thickness of the positive current collector and the thickness of the positive active material layer is 80~150μm, and the sum of the thickness of the positive current collector and the thickness of the insulating adhesive paper is 30~40μm.

[0022] Preferably, there are multiple liquid guiding channels, which are evenly distributed along the X direction of the positive electrode sheet, and the surface of each liquid guiding channel is covered with the insulating adhesive paper.

[0023] Preferably, the heat resistance temperature of the insulating adhesive paper is ≥130℃, and the substrate of the insulating adhesive paper is one of PET, PP, PEEK, PI, PTFE, PA or PPS.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] 1) The irregularly shaped lithium-ion battery provided by this utility model adopts an elliptical structure design, breaking through the limitations of traditional square and cylindrical batteries. The elliptical shape combines the space utilization of square batteries with the energy density advantages of cylindrical batteries. The ratio of the major and minor axes of the elliptical shell can be flexibly adjusted according to the internal space of electronic products, allowing the battery to better adapt to the space of electronic products of various shapes, especially those with curved designs. Compared with traditional cylindrical batteries, elliptical batteries can provide a larger electrode area in the same volume, thereby improving the energy density of the battery; compared with traditional square batteries, the elliptical battery's cornerless design gives it better flexibility in space utilization. This innovative geometric design allows electronic products to be more compact and lightweight, providing product designers with greater design freedom.

[0026] 2) This invention features a Y-direction penetrating liquid-conducting channel on the positive electrode sheet, covered with insulating paper, significantly improving the wetting performance of the electrolyte inside the battery. In traditional lithium-ion batteries, under high-density winding, the electrolyte struggles to penetrate evenly into the electrode, affecting ion transport efficiency. This invention's innovative liquid-conducting channel design provides a rapid penetration pathway for the electrolyte, ensuring its uniform distribution within the electrode material and effectively improving the battery's charge-discharge performance and cycle life. Simultaneously, the insulating paper covering the liquid-conducting channel ensures insulation between the positive and negative electrodes, preventing short circuits and enhancing battery safety. This structural design not only solves the electrolyte wetting problem but also indirectly improves the battery's energy density and power density by increasing electrolyte utilization. Attached Figure Description

[0027] Figure 1 This is one of the structural schematic diagrams of an irregularly shaped lithium-ion battery according to an embodiment of the present invention;

[0028] Figure 2 This is an exploded view of the structure of an irregularly shaped lithium-ion battery according to an embodiment of the present invention;

[0029] Figure 3 This is a second schematic diagram of the structure of an irregularly shaped lithium-ion battery according to an embodiment of the present invention;

[0030] Figure 4 This is the third schematic diagram of the structure of an irregularly shaped lithium-ion battery according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of the heat-shrinkable film for an irregularly shaped lithium-ion battery according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the positive electrode sheet of an irregularly shaped lithium-ion battery according to an embodiment of the present invention.

[0033] In the diagram: 1. Core; 11. Positive electrode tab; 12. Negative electrode tab; 2. Outer shell; 3. First protective paper; 4. Second protective paper; 5. Heat shrink film; 10. Positive current collector; 20. Positive active material layer; 30. Liquid guiding channel; 40. Insulating adhesive tape. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] In the description of this application, unless otherwise expressly specified and limited, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more; unless otherwise specified or explained, the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In current technologies, consumer electronics are evolving towards diversification and irregular shapes, highlighting the inherent limitations of traditional prismatic and cylindrical lithium-ion batteries. While prismatic batteries offer higher space utilization, they suffer from lower energy density; cylindrical batteries, while possessing higher energy density, struggle to effectively fill the internal space of irregularly shaped devices. When applied to electronic products with irregular internal structures, neither battery form factor can simultaneously meet the demands for high energy density and high space adaptability, resulting in unused redundant space within the device or forced sacrifice of battery capacity.

[0037] To address the aforementioned issues, researchers discovered that matching the battery form factor with the internal structure of the device was the key to breakthrough. Analysis of the impact of tab layout on irregularly shaped packaging revealed that a centralized tab arrangement easily induces localized stress, while a distributed layout optimizes mechanical stability. Further research into the core 1 morphology revealed that the elliptical structure, while maintaining the reliability of the winding process, can adapt to different spatial shapes through differentiated design of the long and short axes. This led to a technical approach that combines the synergistic design of the elliptical core 1 and the outer casing 2 with tabs positioned at both ends.

[0038] Therefore, referring to Figures 1-2 This utility model provides an irregularly shaped lithium-ion battery, including an elliptical core 1, an electrolyte, and an elliptical shell 2; the elliptical core 1 includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the separator and the negative electrode sheet are sequentially stacked and wound to form the elliptical core 1, and the elliptical core 1 and the electrolyte are sealed together inside the elliptical shell 2.

[0039] The elliptical core 1 includes a first end and a second end that are arranged opposite to each other. The first end is connected to a positive electrode tab 11, and the second end is connected to a negative electrode tab 12. The roots of both the positive electrode tab 11 and the negative electrode tab 12 are covered with tab adhesive. The positive electrode tab 11 extends outward from the first end and passes through the elliptical outer shell 2, and the negative electrode tab 12 extends outward from the second end and passes through the elliptical outer shell 2.

[0040] Among them, the elliptical core 1 refers to a winding structure with an elliptical cross-section. Specifically, this can be achieved by adjusting the winding tension or the shape of the winding needle, so that the positive electrode, separator, and negative electrode are stacked to naturally form an elliptical cross-section. This shape maintains the stability of the winding structure while adapting to irregularly shaped spaces through the differentiated design of the long and short axes. The elliptical outer shell 2 refers to a packaging structure that matches the shape of the core 1. Specifically, it can be formed by folding an aluminum-plastic film to create a closed cavity.

[0041] The placement of the positive electrode tab 11 and the negative electrode tab 12 at opposite ends means that the two tabs are respectively located at both ends along the long axis of the core 1. Specifically, this can be achieved by welding the tabs to the ends of the positive and negative electrode sheets and then extending them outwards. This layout avoids localized stress caused by concentrated tab arrangement, and at the same time, the perpendicular extension of the tabs to the end face of the outer shell 2 reduces the risk of bending.

[0042] Specifically, the positive electrode, separator, and negative electrode are stacked and wound to form an elliptical core 1. During the winding process, tension control ensures tight adhesion between the layers, forming a stable elliptical cross-sectional structure. The elliptical outer shell 2 is pre-formed into a cavity that matches the core 1. During encapsulation, the long axis of the core 1 is aligned with the long axis of the outer shell 2, eliminating gaps caused by shape mismatch in traditional irregular-shaped encapsulation. The positive electrode tab 11 and the negative electrode tab 12 are led out from both ends of the core 1, with the tabs extending perpendicular to the end face of the outer shell 2. A protective structure prevents direct contact with the encapsulation material when they exit the outer shell 2. The tab layout at both ends of the core 1 ensures more uniform current distribution and disperses the expansion stress of the winding structure during charging and discharging.

[0043] The irregularly shaped lithium-ion battery of this invention adopts an elliptical structure design, which has the following significant advantages compared with traditional square and cylindrical batteries:

[0044] The elliptical structure combines the space utilization of square batteries with the energy density of cylindrical batteries. The elliptical shape, lacking sharp edges, better adapts to the curved internal spaces of electronic products, reducing potential "dead corners" in rectangular spaces. Furthermore, by adjusting the ratio of the major and minor axes to fit spaces with different curvatures, space utilization is improved. Simultaneously, the elliptical battery retains the simple structure and low manufacturing cost of cylindrical batteries, achieving a high energy density. Therefore, this invention achieves a high degree of adaptation between the battery shape and the internal spaces of irregularly shaped devices, maintaining high energy density while improving space utilization.

[0045] In one embodiment of this invention, the major axis w1, minor axis w2, and length l of the lithium-ion battery satisfy the relationship: length (l) > major axis (w1) + minor axis (w2). This dimensional ratio design gives the battery an ideal aspect ratio, ensuring sufficient electrode area while facilitating flexible arrangement in electronic products.

[0046] Among them, the major axis w1 refers to the dimension of the elliptical cross-section in the longest direction, which can be achieved by adjusting the mold forming parameters. The selection of this parameter directly affects the space occupied by the battery in the assembly direction. The minor axis w2 refers to the dimension of the elliptical cross-section in the shortest direction, which can be achieved by controlling the stacking thickness of the core 1. The setting of this parameter determines the spatial adaptability of the battery in the vertical assembly direction. The length l refers to the extension dimension of the battery along the winding direction, which can be achieved by adjusting the number of winding turns. The configuration of this parameter determines the distribution of the effective volume inside the battery.

[0047] Specifically, by constraining the geometric relationship l > w1 + w2, the battery achieves a longitudinally elongated structure while maintaining the space utilization advantages of an elliptical cross-section. This structure, when adapting to irregularly shaped spaces within electronic products, fully utilizes the longitudinal dimension to expand the effective volume, while avoiding spatial interference problems caused by excessive lateral dimensions. In the winding process, this proportional relationship ensures the uniformity of electrode stacking and maintains the electrolyte wetting efficiency within the elongated structure, thereby achieving increased energy density within a limited space.

[0048] Compared to existing technologies, traditional square batteries suffer from limited space utilization due to their right-angled structure, while cylindrical batteries are difficult to adapt to irregularly shaped spaces due to their fixed diameter. This solution overcomes the dimensional constraints of traditional shapes through a synergistic design of an elliptical cross-section and longitudinal extension. It retains the surface adaptability advantages of cylindrical batteries while possessing the directional assembly characteristics of square batteries. No existing technology has been found to achieve a balance between spatial adaptation and energy density through specific geometric proportions.

[0049] Through the above technical solution, this application solves the problem of balancing space utilization and energy density in irregularly shaped electronic products using traditional batteries. The battery's slender structure can fit into the asymmetrical space inside the device, while increasing energy storage capacity by longitudinally expanding the effective volume, thus achieving a balance between shape adaptability and performance indicators while ensuring electrolyte wetting efficiency.

[0050] In a preferred embodiment of this invention, the lithium-ion battery has a major axis w1 of 30-38 mm, a minor axis w2 of 20-28 mm, and a length l of 75-85 mm. This size range was determined through extensive experimentation and optimization, effectively balancing the requirements of battery energy density and battery volume, and meeting the space constraints and energy demands of most modern consumer electronics products. More preferably, the lithium-ion battery has a major axis w1 of 33 mm, a minor axis w2 of 26 mm, and a length l of 79 mm; these specific values ​​demonstrate the best performance balance in practical applications.

[0051] In one embodiment of this invention, the lithium-ion battery has a capacity of 10,000 to 13,000 mAh. This capacity range is ideal for most high-end portable electronic devices, meeting users' needs for long battery life. Through the innovative design of the elliptical structure and the liquid guiding channel 30, this invention can provide such a high capacity within a limited volume.

[0052] In one embodiment of this invention, the elliptical outer shell 2 is made of aluminum-plastic film. The aluminum-plastic film has two semi-elliptical grooves, which are folded together and heat-sealed to form a closed elliptical cylinder. The core 1 is sealed inside the elliptical cylinder. The aluminum-plastic film outer shell 2 is lightweight, flexible, and has excellent insulation properties, making it more suitable for the application requirements of irregularly shaped batteries compared to traditional metal shells 2. The design of folding and heat-sealing the two semi-elliptical grooves simplifies the manufacturing process, reduces production costs, and ensures good sealing performance.

[0053] The semi-elliptical groove in the aluminum-plastic film refers to a semi-elliptical recessed structure pre-molded onto the surface of the aluminum-plastic film, matching the shape of the core 1. Specifically, this can be achieved using a thermoforming process to create the semi-elliptical groove on the aluminum-plastic film surface. This design allows the two grooves to seamlessly fit together after folding, forming an elliptical cylindrical cavity and ensuring a geometric match between the outer shell 2 and the core 1. The folding and sealing process involves folding the aluminum-plastic film along its centerline to close the two semi-elliptical grooves. This can be achieved using a heat-sealing process to seal the folded edges. This method allows for the closure of the outer shell 2 with a single fold, reducing the number of seams and lowering the risk of electrolyte leakage.

[0054] Specifically, the aluminum-plastic film is pre-processed into a sheet with two symmetrical semi-elliptical grooves. The core 1 is placed in one of the grooves, and then the aluminum-plastic film is folded along the center line to close the two grooves and form an elliptical cylindrical cavity. After folding, the edges are sealed by heat fusion bonding, so that the outer shell 2 forms a completely sealed structure that fully wraps the core 1. Because the groove shape matches the core 1, the internal space utilization of the outer shell 2 is optimized, avoiding the gaps between the traditional square or cylindrical outer shell 2 and the irregularly shaped core 1. At the same time, the folding process requires only a single seam, which reduces the number of seams compared to the multi-piece splicing process, thereby reducing the probability of packaging defects.

[0055] Through the above technical solution, this application solves the problem of difficult molding of irregularly shaped battery casing 2, realizes efficient spatial adaptation between core 1 and casing 2, reduces the number of encapsulation seams, reduces the risk of electrolyte leakage, simplifies the encapsulation process, and improves the structural stability and production yield of irregularly shaped lithium-ion batteries.

[0056] like Figures 3-4As shown, in one embodiment of the present invention, the positive electrode tab 11 is bent inward along one end plane of the elliptical shell 2 to form a first bent section, and a first protective paper 3 is provided between the first bent section and one end plane of the elliptical shell 2; the negative electrode tab 12 is bent inward along the other end plane of the elliptical shell 2 to form a second bent section, and a second protective paper 4 is provided between the second bent section and the other end plane of the elliptical shell 2.

[0057] The bent tab design reduces the overall size of the battery, making it easier to integrate into electronic devices. The protective paper effectively prevents burrs from the tabs from scratching the outer casing 2, while also buffering the contact stress between the tabs and the casing 2, preventing short circuit risks caused by tab damage and improving battery safety.

[0058] In one embodiment of this invention, an adhesive layer is coated on one surface of the first protective paper 3 and the second protective paper 4. The adhesive layer is one of acrylic adhesive, silicone adhesive, vinyl ester adhesive, nitrile rubber adhesive, or neoprene rubber adhesive. The adhesive layer facilitates reliable fixation of the protective paper to the end of the outer casing 2, preventing displacement during use. Different types of adhesives have different temperature adaptability and adhesion strength, and a suitable adhesive type can be selected according to the specific application environment.

[0059] In a preferred embodiment, the first protective paper 3 is red barley paper, and the second protective paper 4 is green barley paper. Both red and green barley paper have good insulation and protection properties, and good heat resistance, making them suitable for the application environment of lithium-ion batteries. Furthermore, using protective paper of different colors on the positive electrode tab 11 and the negative electrode tab 12 facilitates the differentiation and identification of the positive and negative electrodes, reducing errors during assembly and use.

[0060] like Figures 3-5 As shown, in one embodiment of this utility model, a heat-shrink film 5 is tightly fitted onto the outer surface of the elliptical outer shell 2, and the heat-shrink film 5 presses tightly against the peripheral edges of the first protective paper 3 and the second protective paper 4. The heat-shrink film 5 further enhances the mechanical strength and sealing performance of the battery, while effectively fixing the protective paper and the bent section of the electrode tab, improving the reliability and stability of the electrode tab lead-out structure.

[0061] like Figure 6 As shown, in one embodiment of the present invention, the positive electrode sheet includes a positive current collector 10 and a positive active material layer 20 disposed on at least one surface of the positive current collector 10. The positive electrode sheet is provided with a liquid guiding channel 30 that penetrates the positive active material layer 20 along the Y direction, and the surface of the liquid guiding channel 30 is covered with insulating adhesive paper 40. The positive electrode tab 11 is disposed in the middle or end of the positive electrode sheet.

[0062] Traditional lithium-ion batteries also have certain limitations in electrolyte wetting. The electrolyte is the medium for ion transport in lithium-ion batteries, and its uniform wetting is crucial to battery performance. However, in traditional battery structures, the electrolyte often fails to uniformly wet the interior of the electrodes, especially in high-density wound batteries, where this problem is more pronounced, affecting charge / discharge performance and cycle life. This invention solves the problem of uneven electrolyte wetting in traditional lithium-ion batteries through the innovative design of the liquid guiding channel 30. The liquid guiding channel 30 provides a rapid penetration path for the electrolyte, ensuring its uniform distribution within the electrode material, effectively improving charge / discharge performance and cycle life. The insulating tape 40 covering the surface of the liquid guiding channel 30 ensures insulation between the positive and negative electrodes, preventing short circuits and improving battery safety.

[0063] The liquid-conducting channel 30 refers to a through-hole structure that penetrates the active material layer along the longitudinal direction (Y direction) of the positive electrode sheet. Specifically, it can be achieved by forming a continuous longitudinal groove on the electrode surface using laser cleaning or gap coating processes. This structure forms a continuous longitudinal electrolyte penetration path after winding. The insulating tape 40 refers to a non-conductive material layer covering the surface of the liquid-conducting channel 30, used to isolate the active material layer from direct contact with the electrolyte. The positive electrode tab 11 being positioned in the middle or at the end refers to selecting the tab welding area according to the distribution of the liquid-conducting channel 30. Specifically, ultrasonic welding can be used to connect the tab to the area of ​​the current collector not covered by the liquid-conducting channel 30.

[0064] Specifically, when the positive electrode sheet forms the core 1 along the winding direction, the longitudinally continuous feature of the liquid guiding channel 30 allows the electrolyte to form a continuous penetration path along the axial direction of the core 1. The electrolyte diffuses longitudinally within the core 1 through the liquid guiding channel 30, transforming the wetting path from traditional disordered penetration to directional penetration. The insulating tape 40 covers the surface of the liquid guiding channel 30, maintaining the channel's open state while preventing internal short circuits caused by exposed current collectors.

[0065] Through the above technical solution, this utility model achieves rapid penetration of electrolyte into the cell along the winding direction, solving the problem of low liquid absorption efficiency caused by discontinuous wetting paths in traditional batteries. The longitudinal through-flow feature of the liquid guiding channel 30 avoids the weakening of the mechanical strength of the electrode sheet due to disordered openings, and the insulation protection measures maintain battery safety performance while improving wetting efficiency.

[0066] In one embodiment of this invention, the width of the liquid guiding channel 30 along the X direction is 3-15 mm. This width range is the optimal range verified through thorough experiments. If the width is less than 3 mm, the liquid guiding channel 30 has limited effect on promoting electrolyte flow and does not adequately improve the electrolyte absorption and retention performance of the cell; if the width exceeds 15 mm, it will weaken the overall structural strength of the electrode, affect the reliability of the winding process, and reduce the content of active materials, leading to a decrease in battery energy density. More preferably, the width of the liquid guiding channel 30 along the X direction is 7 mm.

[0067] In one embodiment of this invention, the thickness (h1) of the positive current collector 10, the thickness (h2) of the positive active material layer 20, and the thickness (h3) of the insulating tape 40 satisfy the following relationship: the thickness (h1) of the positive current collector 10 + the thickness (h2) of the positive active material layer 20 > the thickness (h1) of the positive current collector 10 + the thickness (h3) of the insulating tape 40. Given the same thickness of the positive current collector 10, the thickness of the positive active material layer 20 must exceed the thickness of the insulating tape 40. This ensures that an effective electrolyte penetration channel is formed after the positive electrode sheet is wound into the core 1, preventing the core 1 from being too tight and resulting in poor electrolyte wetting performance.

[0068] In a preferred embodiment of this invention, the sum of the thickness of the positive electrode current collector 10 and the thickness of the positive electrode active material layer 20 is 80~150μm, and the sum of the thickness of the positive electrode current collector 10 and the thickness of the insulating adhesive paper 40 is 30~40μm. These numerical ranges were determined through precise calculations and experimental verification, ensuring that the positive electrode sheet has sufficient mechanical strength to resist stress during the winding process, while also ensuring the formation of effective electrolyte penetration channels after winding, and avoiding the problem of reduced battery volumetric energy density due to excessive thickness.

[0069] In one embodiment of this invention, multiple liquid guiding channels 30 are provided, and these channels 30 are uniformly distributed along the X-direction of the positive electrode sheet. Each liquid guiding channel 30 is covered with insulating adhesive paper 40. This uniform distribution of multiple liquid guiding channels 30 overcomes the limitations of traditional single-channel layouts, resulting in a more balanced porosity distribution in different areas of the positive electrode sheet during winding and reducing the risk of localized stress concentration. The uniform distribution of liquid guiding channels 30 along the X-direction ensures that the electrolyte has multiple penetration paths in the lateral dimension of the positive electrode sheet, effectively solving the problem of insufficient wetting that may result from a single-point liquid guiding channel 30.

[0070] In one embodiment of this invention, the heat resistance temperature of the insulating tape 40 is ≥130℃, and the substrate of the insulating tape 40 is one of PET, PP, PEEK, PI, PTFE, PA, or PPS. Lithium-ion batteries may generate heat during charging, discharging, or manufacturing. If the heat resistance of the insulating tape 40 is insufficient, high temperatures can cause the tape to soften, deform, or even decompose, thereby losing effective coverage of the liquid-conducting channel 30 and triggering an internal short circuit. By setting the lower limit of the heat resistance temperature to 130℃, it is possible to ensure that the insulating tape 40 maintains its structural integrity and insulation function within the battery's operating temperature range, improving the battery's safety and long-term stability.

[0071] In a preferred embodiment of this invention, the method for manufacturing the irregularly shaped lithium-ion battery includes the following steps:

[0072] 1) Prepare the positive electrode, negative electrode, and separator: The positive electrode includes a positive current collector 10 and a positive active material layer 20 coated on the surface of the current collector. A liquid guiding channel 30 is formed on the positive electrode, penetrating the positive active material layer 20 along the Y direction. Heat-resistant insulating paper 40 is covered on the surface of the liquid guiding channel 30. A positive electrode tab 11 is welded to the middle of the positive electrode. The negative electrode includes a negative current collector and a negative active material layer coated on the surface of the current collector. A negative electrode tab 12 is welded to the middle of the negative electrode.

[0073] 2) Stacking and winding: The positive electrode, separator and negative electrode are stacked in sequence and wound into an elliptical core 1, so that the liquid guiding channel 30 forms an electrolyte permeation path in the core 1;

[0074] 3) Shell encapsulation: The core 1 is placed into the aluminum-plastic film composed of two semi-elliptical grooves, so that the positive electrode tab 11 and the negative electrode tab 12 extend from both ends of the aluminum-plastic film. Then, the edges of the aluminum-plastic film are heat-sealed to form a sealed elliptical shell 2.

[0075] 4) Electrolyte injection: Electrolyte is injected into the outer casing 2 through the injection port, so that the electrolyte can be evenly penetrated into the core 1 through the liquid guiding channel 30;

[0076] 5) Sealing treatment: Heat-seal the electrolyte inlet to complete the battery sealing;

[0077] 6) Tab treatment: Bend the positive tab 11 and negative tab 12 that protrude from the outer shell 2 respectively, and place protective paper between the bend and the end face of the outer shell 2;

[0078] 7) External packaging: Heat shrink film 5 is applied to the outer surface of the battery and heat-shrinked to ensure that the heat shrink film 5 fits tightly to the battery surface and fixes the tabs and protective paper.

[0079] This novel irregular-shaped lithium-ion battery, through its elliptical structure design, overcomes the shortcomings of traditional lithium-ion batteries in terms of shape adaptability. The elliptical structure allows the battery to better fit into the spaces of various shaped electronic products, especially those with curved designs, thus improving space utilization. This innovative battery design provides electronic product designers with greater design freedom, while also delivering a superior performance and longer battery life experience for consumers.

[0080] It should be noted that the contents not described in detail in this specification are existing technologies known to those skilled in the art, and will not be elaborated here.

[0081] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this utility model are within the protection scope of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. An irregularly shaped lithium-ion battery, characterized in that: The device includes an elliptical core and an elliptical outer shell for encapsulating the core. The core includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator, and the negative electrode sheet are sequentially stacked and wound to form the core. The elliptical core includes a first end and a second end disposed opposite to each other. The first end is connected to a positive electrode tab, and the second end is connected to a negative electrode tab. The positive electrode tab extends outward from the first end and passes through the outer shell, and the negative electrode tab extends outward from the second end and passes through the outer shell.

2. The irregularly shaped lithium-ion battery according to claim 1, characterized in that: The major axis w1, minor axis w2, and length l of the lithium-ion battery satisfy the relationship: l > w1 + w2.

3. The irregularly shaped lithium-ion battery according to claim 2, characterized in that: The lithium-ion battery has a major axis w1 of 30-38 mm, a minor axis w2 of 20-28 mm, and a length l of 75-85 mm.

4. The irregularly shaped lithium-ion battery according to claim 1, characterized in that: The capacity of the lithium-ion battery is 10000~13000mAh.

5. The irregularly shaped lithium-ion battery according to claim 1, characterized in that: The outer shell is made of aluminum-plastic film, which has two semi-elliptical grooves. The two semi-elliptical grooves are folded together and heat-sealed to form a closed elliptical cylinder. The elliptical core is sealed inside the elliptical cylinder.

6. The irregularly shaped lithium-ion battery according to claim 1, characterized in that: The positive electrode tab is bent inward along one end plane of the outer shell to form a first bent section, and a first protective paper is provided between the first bent section and one end plane of the outer shell; The negative electrode tab is bent inward along the plane of the other end of the outer shell to form a second bent section, and a second protective paper is provided between the second bent section and the plane of the other end of the outer shell.

7. The irregularly shaped lithium-ion battery according to claim 6, characterized in that: The outer surface of the housing is tightly fitted with a heat-shrink film, and the heat-shrink film presses tightly against the peripheral edges of the first protective paper and the second protective paper respectively.

8. The irregularly shaped lithium-ion battery according to claim 1, characterized in that: The positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector. The positive electrode sheet is provided with a liquid guiding channel penetrating the positive active material layer along the Y direction, and the surface of the liquid guiding channel is covered with insulating adhesive paper. The positive electrode tab is disposed in the middle or at the end of the positive electrode sheet.

9. The irregularly shaped lithium-ion battery according to claim 8, characterized in that: The width of the liquid guiding channel along the X direction is 3~15mm.

10. The irregularly shaped lithium-ion battery according to claim 8, characterized in that: The liquid guiding channels are provided in multiple ways, and the multiple liquid guiding channels are evenly distributed along the X direction of the positive electrode plate, and the surface of each liquid guiding channel is covered with insulating tape.

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