Cylindrical lithium battery core rod

Abstract

The utility model provides a cylindrical lithium battery core rod which comprises a first core rod body and a second core rod body, one end part of the first core rod body is provided with a connecting part which protrudes outwards, one end part of the second core rod body is provided with a connecting port, and the connecting part is connected with the connecting port, so that the first core rod body and the second core rod body are tightly connected into a whole; the other end of the first core rod body and the other end of the second core rod body are both closed ends, each closed end is provided with at least one liquid injection opening, and a curing agent is injected into the first core rod body and the second core rod body through the liquid injection openings. Two parts are machined in the length direction, combined use is achieved, deformation is not prone to occurring, and machining is convenient. Two cavities capable of being filled with reactants are formed in the middle of the core rod and are sealed by adopting a low-melting-point material, and the reactants react with electrolyte to consume electrolyte and quickly cure, so that the impedance of the battery is increased, and the thermal runaway process of the battery is prevented or delayed.

Description

Technical Field

[0001] The utility model relates to the field of lithium batteries, in particular to a cylindrical lithium battery core rod. Background Art

[0002] In the existing lithium battery field, large cylindrical lithium batteries are wound with positive plates, negative plates, and separators, and a core hole is left after the needle is removed. During the life cycle, pole piece expansion, internal high temperature, abnormal gas production, etc. can cause the core hole to collapse, leading to internal short circuits and safety risks. Adding a core rod at the core hole position can prevent the above problems from occurring, provide structural support for the battery cell, and increase stability.

[0003] Common core rods include stainless steel or aluminum alloy hollow tubes and plastic tubes with polygonal inner holes. The former is usually inserted after the winding core is formed, and the latter can replace the winding needle for winding and finally remain inside the winding core. The plastic tube is made of one or more of PC, PP, PE, PVC, etc., and glass fiber is added to improve strength. The center hole is a polygon or other special shape such as a triangle, quadrilateral, pentagon, hexagon, etc.

[0004] However, the structure of the above mandrel still has the following problems:

[0005] 1. The metal tube is inserted after the core is formed, which can easily scratch the isolation film and is difficult to fix. It is rarely used in the industry.

[0006] 2. The melting point of plastic pipe material is high, generally greater than 150°C, which is close to the thermal runaway temperature threshold. It cannot provide protection when the internal temperature is high or there is an abnormal short circuit.

[0007] 3. The plastic tube is formed by injection molding or stretching. When the battery height is high, the core rod is easy to deform and it is inconvenient to process.

[0008] In view of this, the inventor of the present application designed a cylindrical lithium battery core rod in order to overcome the above technical problems. Utility Model Content

[0009] The technical problem to be solved by the utility model is to provide a cylindrical lithium battery core rod in order to overcome the defects in the prior art that the metal core rod easily scratches the isolation membrane and is difficult to fix, and the plastic core rod has a high melting point, is prone to abnormal short circuit, and is easy to deform.

[0010] The utility model solves the above technical problems through the following technical solutions:

[0011] A cylindrical lithium battery core rod, characterized in that the cylindrical lithium battery core rod comprises a first core rod body and a second core rod body, one end of the first core rod body is provided with a connecting portion protruding outward, one end of the second core rod body is provided with a connecting port, the connecting portion is connected to the connecting port, so that the first core rod body and the second core rod body are tightly connected as a whole;

[0012] The other end of the first core rod body and the other end of the second core rod body are both closed ends, and each of the closed ends is respectively provided with at least one liquid injection port, and the first core rod body and the second core rod body are injected with reactants through the liquid injection port.

[0013] According to one embodiment of the utility model, a first cavity is provided in the first core rod body, a second cavity is provided in the second core rod body, the first cavity and the second cavity are connected to each other, and the liquid injection port is connected to the corresponding first cavity and the second cavity.

[0014] According to an embodiment of the present invention, the first core rod body is cylindrical, and the connecting portion includes a plurality of snap fasteners extending outwardly along one end of the first core rod body, and the snap fasteners are arranged in a ring shape at intervals from each other.

[0015] According to an embodiment of the utility model, the second core rod body is cylindrical, the shape of the connecting port matches the connecting portion, and the snap-fit ​​component is snapped into the connecting port.

[0016] According to an embodiment of the present invention, the diameters of the first mandrel body and the second mandrel body are 4 mm to 10 mm.

[0017] According to an embodiment of the present invention, the first core rod body and the second core rod body are made of polycarbonate, polypropylene, polyethylene, or polyvinyl chloride.

[0018] According to an embodiment of the present utility model, at least one notch is provided on the tube wall of the other end of the first core rod body and the other end of the second core rod body for winding the battery core.

[0019] According to an embodiment of the present invention, the depth of the notch is 2 mm to 10 mm.

[0020] According to one embodiment of the present invention, the reactant is a low-viscosity liquid, and the low-viscosity liquid includes N,N 4,4-diphenylmethane bismaleimide, bismaleimide oligomer, 1,3-dioxolane, or neopentyl glycol diacrylate.

[0021] According to one embodiment of the utility model, the liquid injection port is sealed with a sealant, and the sealant includes celluloid, ethylene-vinyl acetate copolymer, polycaprolactone, polyolefin elastomer, ethylene-acrylic acid copolymer, terminal isocyanate polyurethane prepolymer or low-density polyethylene.

[0022] The positive and progressive effects of the utility model are:

[0023] The cylindrical lithium battery core rod of the utility model has the following advantages:

[0024] 1. The plastic mandrel replaces the winding needle for winding and finally remains inside the winding core.

[0025] 2. The length direction is divided into two parts for processing, and the combined use is not easy to deform and is convenient for processing.

[0026] 3. Two cavities that can be filled with reactants are set in the middle of the core rod and sealed with low-melting-point materials. When the temperature inside the battery is high and short-circuited abnormally, the sealing material melts, the reactants react with the electrolyte to consume the electrolyte, and solidify quickly, increasing the battery impedance, thereby preventing or delaying the battery thermal runaway process.

[0027] 4. The core rod not only supports the core structure, but also increases the early preventive protection during thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0029] Figure 1 The utility model is a schematic structural diagram of a cylindrical lithium battery core rod.

[0030] Figure 2 It is a structural schematic diagram of the first core rod body in the cylindrical lithium battery core rod of the utility model.

[0031] Figure 3 It is a schematic structural diagram of the second core rod body in the cylindrical lithium battery core rod of the utility model.

[0032] Figure 4 It is a structural schematic diagram of the other end of the first core rod body and the other end of the second core rod body in the cylindrical lithium battery core rod of the utility model.

[0033] Figure 5 This is a front view of a cylindrical lithium battery core rod of the utility model.

[0034] Figure 6 for Figure 5 Sectional view taken along AA.

[0035] [Reference Signs]

[0036] The first mandrel body 10

[0037] The second mandrel body 20

[0038] Connection part 11

[0039] Connection port 21

[0040] Closed end 30

[0041] Liquid injection port 31

[0042] First cavity 12

[0043] Second cavity 22

[0044] Buckle 111

[0045] Gap 40 DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings.

[0047] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.Preferred embodiments of the present invention will now be described in detail, examples of which are shown in the accompanying drawings.Where possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

[0048] In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some terms mentioned in the specification of the present invention may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article.

[0049] Furthermore, it is required that the present invention be understood not only by the actual terms used but also by the meanings contained in each term.

[0050] like Figures 1 to 3 As shown, the utility model discloses a cylindrical lithium battery core rod, which includes a first core rod body 10 and a second core rod body 20. A connecting portion 11 protruding outward is provided at one end of the first core rod body 10, and a connecting port 21 is provided at one end of the second core rod body 20. The connecting portion 11 is connected to the connecting port 21, so that the first core rod body 10 and the second core rod body 20 are tightly connected as a whole.

[0051] Combination Figure 4As shown, the other end of the first core rod body 10 and the other end of the second core rod body are both closed ends 30, and each closed end 30 is respectively provided with at least one injection port 31, through which the reactant is respectively injected into the first core rod body 10 and the second core rod body 20.

[0052] like Figure 5 and Figure 6 As shown, preferably, a first cavity 12 is provided in the first mandrel body 10, and a second cavity 22 is provided in the second mandrel body 20. When the first mandrel body 10 and the second mandrel body 20 are connected to each other as a whole, the first cavity 12 and the second cavity 22 are communicated with each other, and the injection port 31 is communicated with the corresponding first cavity 12 and the second cavity 22.

[0053] Preferably, in this embodiment, the first core rod body 10 is cylindrical, and the connecting portion 11 includes a plurality of buckling members 111 extending outwardly from one end of the first core rod body 10 , and the buckling members 111 are arranged in a ring shape at intervals from each other.

[0054] The second core rod body 20 is cylindrical, the shape of the connecting opening 21 matches the connecting portion 11 , and the fastener 111 is fastened in the connecting opening 21 .

[0055] Further preferably, in this embodiment, the diameters of the first mandrel body 10 and the second mandrel body 20 are preferably 4 mm to 10 mm. The material used for the first mandrel body 10 and the second mandrel body 20 is preferably one or more of polycarbonate (PC), polypropylene (PP), polyethylene (PE) or polyvinyl chloride (PVC), and glass fiber can also be added to improve strength.

[0056] At least one notch 40 is provided on the tube wall of the other end of the first core rod body 10 and the other end of the second core rod body 20 for winding the battery core. The depth of the notch 40 may preferably be 2 mm to 10 mm.

[0057] In addition, in this embodiment, the reactant may be preferably a low-viscosity liquid, which includes one or more of N,N4,4-diphenylmethane bismaleimide, bismaleimide oligomer, 1,3-dioxolane, or neopentyl glycol diacrylate.

[0058] The first cavity 12 and the second cavity 22 are both configured to be sealed on one side and have an injection port on the other side. After the reactant is injected into the injection port 31, the reactant reacts with the electrolyte to consume the electrolyte, solidifies quickly, increases the battery impedance, and prevents or delays the battery thermal runaway process. The injection port 31 is sealed with a sealant. The sealant may preferably include one or more of celluloid, ethylene-vinyl acetate copolymer (EVA), polycaprolactone (PCL), polyolefin elastomer (POE), ethylene-acrylic acid copolymer (EAA), terminal isocyanate polyurethane prepolymer (PU) or low-density polyethylene (LDPE), and its melting point is 80°C to 130°C.

[0059] The cylindrical lithium battery core rod of the utility model has the following advantages:

[0060] 1. The plastic mandrel replaces the winding needle for winding and finally remains inside the winding core.

[0061] 2. The length direction is divided into two parts for processing, and the combined use is not easy to deform and is convenient for processing.

[0062] 3. Two cavities that can be filled with reactants are set in the middle of the core rod and sealed with low-melting-point materials. When the temperature inside the battery is high and short-circuited abnormally, the sealing material melts, the reactants react with the electrolyte to consume the electrolyte, and solidify quickly, increasing the battery impedance, thereby preventing or delaying the battery thermal runaway process.

[0063] 4. The core rod not only supports the core structure, but also increases the early preventive protection during thermal runaway.

[0064] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary implementation of the present application.

[0065] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0066] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications fall within the protection scope of the present invention.

Claims

1. A cylindrical lithium battery core rod, characterized in that: The cylindrical lithium battery core rod comprises a first core rod body and a second core rod body, one end of the first core rod body is provided with a connecting portion protruding outward, one end of the second core rod body is provided with a connecting port, the connecting portion is connected to the connecting port, so that the first core rod body and the second core rod body are tightly connected as a whole; The other end of the first core rod body and the other end of the second core rod body are both closed ends, and each of the closed ends is respectively provided with at least one liquid injection port, and the first core rod body and the second core rod body are injected with reactants through the liquid injection port.

2. The cylindrical lithium battery core rod according to claim 1, characterized in that: A first cavity is disposed in the first core rod body, a second cavity is disposed in the second core rod body, the first cavity and the second cavity are communicated with each other, and the liquid injection port is communicated with the corresponding first cavity and the second cavity.

3. The cylindrical lithium battery core rod according to claim 1, characterized in that: The first core rod body is cylindrical, and the connecting portion includes a plurality of buckling parts extending outwardly along one end of the first core rod body, and the buckling parts are arranged in a ring shape at intervals from each other.

4. The cylindrical lithium battery core rod according to claim 3, characterized in that: The second core rod body is cylindrical, the shape of the connecting port matches the connecting portion, and the snap-fit ​​component is snap-fitted into the connecting port.

5. The cylindrical lithium battery core rod according to claim 1, characterized in that: The diameters of the first core rod body and the second core rod body are 4 mm to 10 mm.

6. The cylindrical lithium battery core rod according to claim 1, characterized in that: The first core rod body and the second core rod body are made of polycarbonate, polypropylene, polyethylene, and polyvinyl chloride.

7. The cylindrical lithium battery core rod according to claim 1, characterized in that: At least one notch is provided on the tube wall of the other end of the first core rod body and the other end of the second core rod body for winding the battery core.

8. The cylindrical lithium battery core rod according to claim 7, characterized in that: The depth of the notch is 2 mm to 10 mm.

9. The cylindrical lithium battery core rod according to claim 1, characterized in that: The reactant is a low-viscosity liquid, and the low-viscosity liquid includes N,N 4,4-diphenylmethane bismaleimide, bismaleimide oligomer, 1,3-dioxolane, or neopentyl glycol diacrylate.

10. The cylindrical lithium battery core rod according to claim 1, characterized in that: The liquid injection port is sealed with a sealant, and the sealant includes celluloid, ethylene-vinyl acetate copolymer, polycaprolactone, polyolefin elastomer, ethylene-acrylic acid copolymer, terminal isocyanate polyurethane prepolymer or low-density polyethylene.

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