Lightweight battery structure

Abstract

The utility model discloses a lightweight battery structure, which comprises a battery roll core and a polymer conductive film layer, the battery roll core comprises a negative plate, a diaphragm layer and a positive plate, and the negative plate, the diaphragm layer and the positive plate are sequentially stacked; the polymer conductive film layer is wrapped on the outermost surface of the battery roll core and comprises a polymer film and a conductive piece, and the conductive piece is embedded on the polymer film. Therefore, as the polymer film material in the polymer conductive film layer is light, the overall quality and the manufacturing cost of the battery can be reduced, meanwhile, the conductive part is arranged on the polymer film, and the polymer film has a conductive effect through the conductive part, so that the traditional structural mode that a battery roll core is wrapped by a metal foil can be replaced, and the battery can be used for manufacturing the battery. Therefore, the overall weight of the battery can be reduced, and the lightweight design of the battery is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production, in particular to a lightweight battery structure. Background Art

[0002] The rapid development of electric vehicles, portable electronic devices, mobile power supplies, and energy storage systems has led to increasingly higher demands on battery mass energy density and cost-effectiveness. Lightweight design can further improve battery mass energy density and reduce manufacturing costs. Taking lithium-ion batteries as an example, the specific capacity requirements for positive and negative electrode active materials are increasing, the amount of binder and conductive agent added to the positive and negative electrodes is decreasing, the thickness of the separator is becoming thinner, and the electrolyte concentration is moving towards ultra-high. The current collectors for the positive and negative electrodes have become increasingly thinner, gradually evolving from pure aluminum foil and copper foil to composite current collectors such as copper-plated or aluminum-plated plastic surfaces. Battery casing materials are beginning to consider using high-strength plastics or composite materials to replace traditional metal casings. Battery structural designs are becoming increasingly compact, with the use of auxiliary materials minimized through structural design methods such as frameless or simplified packaging.

[0003] Currently, cylindrical batteries or elliptical batteries are one of the common types of batteries, and their lightweight design has begun to attract widespread attention. In some cylindrical batteries or elliptical batteries, taking the alkaline nickel-zinc cylindrical AA battery as an example, the positive electrode sheet, the separator layer, and the negative electrode sheet are wound to form a core, which is placed in the battery shell to form a battery cell. Among them, after the positive electrode sheet is welded with a metal nickel sheet, the nickel sheet tab is directly welded to the top of the positive electrode to form the positive electrode of the cylindrical battery. Since the outermost circle of the core is the negative electrode sheet, it is necessary to wrap a layer of conductive metal foil on the outermost surface of the core as the negative electrode tab. The metal foil can directly contact the cup bottom and cup body of the cylindrical steel shell to form the negative electrode of the battery. Usually, the metal foil wrapped on the outermost surface of the core is relatively heavy, which is not conducive to improving the mass energy density of the battery and reducing the manufacturing cost, and it is impossible to achieve a lightweight design of the battery. Utility Model Content

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a lightweight battery structure, thereby increasing the mass energy density of the battery and reducing the manufacturing cost of the battery.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] A lightweight battery structure comprises: a battery core and a polymer conductive film layer, wherein the battery core comprises a negative electrode sheet, a separator layer and a positive electrode sheet, wherein the negative electrode sheet, the separator layer and the positive electrode sheet are stacked in sequence; the polymer conductive film layer is connected to the negative electrode sheet, and the polymer conductive film layer is wrapped around the outermost surface of the battery core, wherein the polymer conductive film layer comprises a polymer film and a conductive part, and the conductive part is embedded in the polymer film.

[0007] In one embodiment, the conductive member is a conductive thread or a conductive tape, and the conductive thread or the conductive tape is embedded in the polymer film by weaving.

[0008] In one embodiment, the diameter of the conductive filament is 2-20 μm.

[0009] In one embodiment, the thickness of the conductive tape is 5-20 μm, and the width of the conductive tape is 0.5-5 mm.

[0010] In one embodiment, the conductive member is a metal conductive member.

[0011] In one embodiment, the thickness of the polymer conductive film layer is 5-25 μm.

[0012] In one embodiment, the conductive element accounts for 10%-50% of the polymer conductive film layer.

[0013] In one embodiment, the polymer membrane is a hydrophobic polymer membrane.

[0014] In one embodiment, a battery shell is further included, wherein a receiving cavity is formed on the battery shell, and the polymer conductive film layer and the battery coil core are disposed in the receiving cavity.

[0015] In one embodiment, the cross-section of the battery roll core is a circular structure.

[0016] Compared with the prior art, the present invention has at least the following advantages:

[0017] 1. The lightweight battery structure of the utility model uses a polymer conductive film layer instead of the traditional metal foil to wrap the battery core, thereby reducing the overall weight of the battery, realizing a lightweight design of the battery, and helping to improve the mass energy density of the battery.

[0018] 2. The lightweight battery structure of the present invention can reduce the use of metal conductive materials by embedding conductive parts on the polymer film, thereby reducing the manufacturing cost of the battery.

[0019] 3. The lightweight battery structure of the present invention uses a polymer conductive film layer to wrap the outermost surface of the battery coil core, and makes the polymer conductive film layer contact the negative electrode sheet to form a negative electrode ear, thereby avoiding direct contact between the negative electrode sheet and the battery casing, and further avoiding the occurrence of electrochemical side reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments.

[0021] Figure 1 This is a schematic structural diagram of a lightweight battery structure in one embodiment of the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of the battery coil core and polymer conductive film layer of the lightweight battery structure;

[0023] Figure 3 for Figure 1 Schematic diagram of the structure in which the polymer conductive film layer of the lightweight battery structure is woven with conductive wire and polymer wire.

[0024] Figure 4 for Figure 1 Schematic diagram of the structure in which the polymer conductive film layer of the lightweight battery structure is woven with conductive tape and polymer film tape. DETAILED DESCRIPTION

[0025] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0026] See also Figure 1 、 Figure 2 and Figure 3 As shown, a lightweight battery structure includes: a battery core 100 and a polymer conductive film layer 200, the battery core 100 includes a negative electrode sheet 110, a separator layer 120 and a positive electrode sheet 130, and the negative electrode sheet 110, the separator layer 120 and the positive electrode sheet 130 are stacked in sequence; the polymer conductive film layer is connected to the negative electrode sheet, and the polymer conductive film layer 200 is wrapped on the outermost surface of the battery core 100, the polymer conductive film layer 200 includes a polymer film and a conductive part, and the conductive part is embedded in the polymer film.

[0027] It should be noted that in some cylindrical or elliptical batteries, after the positive and negative electrodes are wound into a battery core 100, a layer of metal foil needs to be wrapped around the outermost surface of the battery core 100. However, due to the heavy weight of metal foil, it is not conducive to the lightweight design of the battery. Therefore, in the present invention, by wrapping the battery core 100 with a polymer conductive film layer 200, the weight and manufacturing cost of the battery are reduced, and the mass energy density of the battery is further improved. Specifically, because the polymer film in the polymer conductive film layer 200 is relatively light, the overall weight of the battery can be reduced. At the same time, by providing a conductive member on the polymer film, the polymer film is made conductive by the conductive member. In this way, the traditional structure of wrapping the battery core 100 with metal foil can be replaced, thereby reducing the overall weight of the battery, achieving a lightweight design of the battery, and improving the mass energy density of the battery. At the same time, by embedding the conductive member on the polymer film, the present invention can reduce the amount of metal conductive material used, thereby reducing the manufacturing cost of the battery.

[0028] Furthermore, cylindrical alkaline nickel-zinc (NiZn) AA batteries are currently primarily used in small electronic devices such as digital cameras, flashlights, electric toys, and wireless mice, placing higher design requirements on lightweighting. The polymer conductive film layer of the present invention is not only lighter but also thinner than traditional metal foils. For example, the total thickness of the polymer conductive film layer is 5-25 μm, making it more suitable for alkaline NiZn batteries, making them lighter and thus improving their mass energy density.

[0029] It should also be noted that when the polymer conductive film layer 200 wraps the battery core 100, one side of the polymer conductive film layer 200 is first connected to the diaphragm layer 120 and the negative electrode sheet 110 on the winding tail end of the battery core 100, and then surrounds and wraps the battery core 100, that is, the polymer conductive film layer is in contact with the negative electrode sheet to form a negative electrode ear, thereby preventing the negative electrode sheet from directly contacting the battery casing, and further avoiding the occurrence of electrochemical side reactions; at the same time, by wrapping the battery core 100 with the conductive polymer conductive film layer 200, not only can physical protection be provided for the battery core 100, preventing the battery from expanding, deforming or being damaged during charging and discharging, but also the conductivity of the battery can be improved, the internal resistance of the battery can be reduced, thereby realizing a lightweight design of the battery, improving the mass energy density of the battery and reducing the manufacturing cost of the battery.

[0030] In one embodiment, the conductive element is a conductive thread 220a or a conductive tape 220b, which is inlaid on the polymer film by weaving. That is, by weaving, the conductive element is interwoven on the polymer film, so that the polymer film forms a polymer conductive film layer 200 with conductive function. For example, the polymer material can be made into a thread-like or tape-like structure, and similarly, the conductive material can be made into a thread-like or tape-like structure, that is, the conductive element forms the conductive thread 220a or the conductive tape 220b. For details, please refer to Figure 3 As shown, when the conductive wire 220a structure is used, the diameter of the conductive wire 220a is preferably 2-20 μm, for example, 10 μm, and the conductive wire 220a and the polymer wire 210a are interwoven together by weaving. For example, a vertical and horizontal up-down weaving structure is used to interweave the conductive wire 220a and the polymer wire 210a. Figure 4 As shown, when the conductive tape 220b structure is adopted, the thickness of the conductive tape 220b is preferably 5-20μm, for example 10μm, and the width of the conductive tape 220b is preferably 0.5-5mm, for example 1mm. Similarly, the conductive tape 220b and the polymer film tape 210b are interwoven by weaving to form a polymer conductive film layer 200 with conductive function. For example, a vertical and horizontal up-down weaving structure is adopted to interweave the conductive tape 220b and the polymer film tape 210b together; preferably, in the polymer conductive film layer formed by weaving, the proportion of conductive parts in the polymer conductive film layer is 10%-50%, that is, the proportion of conductive wire 220a or conductive tape 220b in the polymer conductive film layer can be 10%-50%, which can not only reduce the use of metal conductive materials and reduce costs, but also reduce the overall weight of the battery, thereby improving the mass energy density of the battery.

[0031] Furthermore, after the weaving operation is completed, the polymer conductive film layer can be subjected to a hot pressing operation, so that the overall thickness of the polymer conductive film layer can be made more uniform, thereby improving the conductive performance, further reducing the internal resistance of the battery and local heat accumulation, etc.; preferably, after the hot pressing operation, the thickness of the polymer conductive film layer can be made 5-25μm, so that the polymer conductive film layer can be made more suitable for alkaline nickel-zinc batteries, thereby making the alkaline nickel-zinc batteries smaller in size and lighter in weight, thereby improving the energy density of the alkaline nickel-zinc batteries.

[0032] Among them, preferably, the conductive member is a metal conductive member, for example, the metal conductive member can be copper, zinc, tin, copper-tin alloy, tin-zinc alloy or tin-bismuth-indium alloy, etc., wherein, for lithium-ion batteries, the material of the general conductive member can be copper, and for alkaline nickel-zinc batteries, the material of the conductive member can be copper, zinc, tin, copper-tin alloy, tin-zinc alloy or tin-bismuth-indium alloy, etc. In one embodiment, the polymer film is a hydrophobic polymer film. Hydrophobicity means that the surface of the polymer film has hydrophobicity, making it difficult for water droplets to adhere to the film to prevent moisture penetration. By adopting a polymer film with hydrophobicity, it is possible to prevent the electrolyte from penetrating into the polymer film. In this way, it is possible to avoid the problem that the battery roll core 100 cannot be fully wetted due to the reduction of the electrolyte. For example, the polymer film is a hydrophobic polymer material such as polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, etc. It should also be noted that when selecting polymer membrane materials, matching selections can also be made based on the composition and properties of different battery electrolytes. For example, for lithium-ion batteries, polymer membranes that are resistant to organic solvents are required, while for nickel-zinc batteries or nickel-metal hydride batteries, polymer membranes that are resistant to alkalis are required.

[0033] In one embodiment, the lightweight battery structure further includes a battery housing 300 having a housing cavity. The polymer conductive film layer 200 and the battery core 100 are disposed within the housing cavity, with the battery housing 300 protecting the battery core 100. The battery housing 300 is a steel shell, with the polymer conductive film layer 200 positioned between the battery core 100 and the battery housing 300. For example, if the battery is cylindrical, the cross-section of the battery housing 300 is circular, and accordingly, the cross-section of the battery core 100 is also circular.

[0034] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A lightweight battery structure, characterized in that: include: A battery roll core, the battery roll core comprising a negative electrode sheet, a separator layer, and a positive electrode sheet, wherein the negative electrode sheet, the separator layer, and the positive electrode sheet are stacked in sequence; and A polymer conductive film layer, the polymer conductive film layer is connected to the negative electrode sheet, and the polymer conductive film layer is wrapped on the outermost surface of the battery roll core, the polymer conductive film layer includes a polymer film and a conductive part, and the conductive part is embedded in the polymer film.

2. The lightweight battery structure according to claim 1, characterized in that: The conductive element is a conductive thread or a conductive tape, and the conductive thread or the conductive tape is embedded in the polymer film by weaving.

3. The lightweight battery structure according to claim 2, characterized in that: The diameter of the conductive filament is 2-20 μm.

4. The lightweight battery structure according to claim 2, characterized in that: The thickness of the conductive tape is 5-20 μm, and the width of the conductive tape is 0.5-5 mm.

5. The lightweight battery structure according to any one of claims 1 to 4, characterized in that: The conductive member is a metal conductive member.

6. The lightweight battery structure according to any one of claims 1 to 4, characterized in that: The thickness of the polymer conductive film layer is 5-25 μm.

7. The lightweight battery structure according to any one of claims 1 to 4, characterized in that: The conductive element accounts for 10%-50% of the polymer conductive film layer.

8. The lightweight battery structure according to any one of claims 1 to 4, characterized in that: The polymer membrane is a hydrophobic polymer membrane.

9. The lightweight battery structure according to any one of claims 1 to 4, characterized in that: The battery case further comprises a battery housing, wherein a receiving cavity is provided on the battery housing, and the polymer conductive film layer and the battery coil core are arranged in the receiving cavity.

10. The lightweight battery structure according to claim 9, characterized in that: The cross section of the battery roll core is a circular structure.

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