WO2021203715A1 - 一种电芯 - Google Patents

一种电芯 Download PDF

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Publication number
WO2021203715A1
WO2021203715A1 PCT/CN2020/131694 CN2020131694W WO2021203715A1 WO 2021203715 A1 WO2021203715 A1 WO 2021203715A1 CN 2020131694 W CN2020131694 W CN 2020131694W WO 2021203715 A1 WO2021203715 A1 WO 2021203715A1
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WIPO (PCT)
Prior art keywords
battery cell
hole
electrode
cell according
axial
Prior art date
Application number
PCT/CN2020/131694
Other languages
English (en)
French (fr)
Inventor
李伟
王念举
押媛媛
贾学恒
刘刚
Original Assignee
天津力神电池股份有限公司
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Application filed by 天津力神电池股份有限公司 filed Critical 天津力神电池股份有限公司
Priority to EP20930381.7A priority Critical patent/EP4071879A4/en
Publication of WO2021203715A1 publication Critical patent/WO2021203715A1/zh
Priority to US17/727,796 priority patent/US20220247020A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/154—Lid or cover comprising an axial bore for receiving a central current collector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H01M10/0427—Button cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0468—Compression means for stacks of electrodes and separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/14—Primary casings; Jackets or wrappings for protecting against damage caused by external factors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/184—Sealing members characterised by their shape or structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/60—Arrangements or processes for filling or topping-up with liquids; Arrangements or processes for draining liquids from casings
    • H01M50/609—Arrangements or processes for filling with liquid, e.g. electrolytes
    • H01M50/627—Filling ports
    • H01M50/636—Closing or sealing filling ports, e.g. using lids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/60—Arrangements or processes for filling or topping-up with liquids; Arrangements or processes for draining liquids from casings
    • H01M50/668—Means for preventing spilling of liquid or electrolyte, e.g. when the battery is tilted or turned over
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to the technical field of structural design of secondary batteries, and specifically provides a battery.
  • Lithium-ion batteries are green and environmentally friendly, with long cycle life, good rate performance, safety and reliability, and are widely used in various energy storage products, consumer electronics products and power battery products.
  • Lithium-ion batteries can be divided into soft-packed lithium-ion batteries, square aluminum-shell batteries and steel-shell cylindrical batteries according to the manufacturing process.
  • the steel shell cylindrical battery cell is widely used in power automobile batteries because of the high degree of standardization of the process and the relatively low cost.
  • customers have increasingly higher requirements for the energy density and appearance of batteries.
  • the common cylindrical batteries on the market need to occupy part of the space of the batteries to implement the polarity separation of the batteries.
  • the positive and negative electrodes of the battery are the bottom shell and the cover of the battery respectively.
  • the separation of the positive and negative polarities is achieved by sealing on the cover side of the shell with an insulating rubber ring.
  • the above structure occupies about 4-6mm length of the cell, which is equivalent to 5.7%-10% of space waste; the above structure will drastically reduce the energy density when the height of the cell is reduced.
  • the button cell transfers the cell polarity separation function to the radial direction.
  • the positive and negative poles of this type of cell are still connected to the bottom shell and the shell cover respectively.
  • the bottom shell and the shell cover are coaxially buckled together, and the middle is filled.
  • the insulation layer realizes the polarity separation, and the polarity separation structure is on the outermost circle of the cell (refer to patent: ZL201080007121.9). This structure needs to occupy about 0.6mm of the outer circle of the circular cross-section. For the cell with a diameter of 8-20mm, This is equivalent to a waste of 6% to 15% of space.
  • the pole composition of the cylindrical battery core has two processes: winding and lamination. Practice has proved that the energy density of the winding structure is the best. When the cylindrical pole group is formed by winding, it will inevitably be left due to the placement of the winding needle. The diameter of the center hole caused by the winding is generally greater than 1 mm. This winding center hole wastes battery cell space on the one hand, and on the other hand, the existence of the hole may also cause the structure of the pole group to collapse during use, so most cylindrical batteries will place a pin in the center hole of the pole group. Stable structure, however, this process adds additional process complexity.
  • the purpose of this application is to provide a battery cell.
  • a battery cell provided by the present invention includes:
  • An electrode group including a central hole, which includes at least one positive electrode and one negative electrode, and a separator separating the positive and negative electrodes.
  • the positive electrode, the negative electrode and the separator are formed in a spiral winding manner around a central hole, the central hole
  • the diameter is greater than 0 and smaller than the diameter of the battery cell;
  • a set of pin assemblies with polarity separation function is included, which includes a pin assembly housing with an axial through hole, and the pin assembly housing is partially or fully inserted into the electrode set
  • the central hole also includes an insulating material for separating the polarity of the cell and at least one electrode lead-out conductor.
  • the insulating material is provided in the axial through hole of the pin assembly housing, and the electrode lead-out conductor passes through The insulating substance, the positive electrode and/or the negative electrode are conductively connected to the electrode lead-out conductor, so as to realize the polarity separation of the battery core;
  • a set of cell shells, the cell shell and the pin assembly are hermetically connected to form a ring-shaped sealed cavity capable of accommodating the electrode set.
  • the longitudinal section of the housing of the pin assembly is It includes a circular tube with an axial through hole and a disc-shaped flange formed outwardly at the top of the circular tube.
  • the longitudinal section of the battery shell is U-shaped.
  • the longitudinal section of the housing of the pin assembly is The shape includes a round tube with an axial through hole and a round cup formed outwardly at the top of the round tube.
  • the cell shell is in the shape of a disc, and its longitudinal section is in the shape of a "one".
  • the longitudinal section of the housing of the pin assembly is Shape, which is a round tube with an axial through hole.
  • the longitudinal section of the battery shell is shape.
  • the insulating substance is partially or completely disposed in the axial through hole of the pin assembly housing.
  • the longitudinal section of the insulating material is The shape includes a cylindrical portion inserted into the axial through hole and an annular portion formed by expanding the bottom end of the cylindrical portion and completely covering the lower end surface of the axial through hole wall.
  • it also includes at least one liquid injection hole for injecting electrolyte into the cell.
  • liquid injection hole is provided on the polarity separation component and/or on the cell shell.
  • liquid injection hole is provided on the insulating substance of the polarity separation component.
  • liquid injection hole is sealed by a sealing member to prevent the electrolyte from leaking from the liquid injection hole.
  • sealing element adopts one of the following structures:
  • the sealing element adopts an end cap structure, which includes an end and an embedded part arranged at the lower end of the end block, the end is covered on the axial through hole, and the embedded part is inserted into the shaft Into the through hole;
  • the sealing element is at least one steel ball, the steel ball is inserted into the axial through hole, and the steel ball is in interference fit with the axial through hole.
  • the battery cell is a lithium ion battery cell, which further includes at least one lithium-inserted electrode.
  • the electrodes and the diaphragm are in the form of flat strips.
  • the electrode group adopts one of the following sequence sequences:
  • the pin assembly and the battery shell are made of materials with waterproof characteristics.
  • the material with waterproof properties is a metal material or a non-metal material.
  • the metal material is stainless steel, aluminum or aluminum alloy.
  • non-metallic material is ceramic or plastic.
  • the positive electrode and/or the negative electrode are conductively connected to the electrode lead-out conductor, and adopt one of the following structures:
  • the first type the lower end of the electrode lead-out conductor is welded to one end of the transition conductor, and the other end of the transition conductor is welded to the positive electrode and/or the negative electrode;
  • the second type the lower end of the electrode lead-out conductor is welded to the positive electrode and/or the negative electrode. Further, the material of the insulating material is polypropylene.
  • cross-sectional shape of the battery core is circular or elliptical.
  • the core difference between the battery cell obtained according to the present invention and the traditional battery cell is that the polarity separation function of the battery cell is realized in the central hole of the electrode group.
  • the insulating material used to separate the polarity of the cell is placed in the central hole of the electrode group, at least one electrode lead conductor is placed in the central hole of the electrode group, one end of the electrode lead conductor is electrically connected to the positive electrode and/or the negative electrode, and the other One end leaks out as a positive electrode and/or a negative electrode to lead out a pole.
  • the positive electrode is led out from the center hole of the electrode group through the above structure, the negative electrode is conductively connected to the metal shell, and the insulating material is filled in the center hole to achieve cell polarity separation, and the formed cell positive pole is the center hole
  • the lead out conductor, the negative pole is a metal shell.
  • the negative electrode is led out from the center hole of the electrode group through the above structure, the positive electrode is connected to the metal shell, and the insulating material is filled in the center hole to insulate the conductor from the center hole from the metal shell to achieve cell polarity separation.
  • the positive pole of the battery cell is a metal shell, and the negative pole is a conductor drawn from the center hole.
  • the positive electrode and the negative electrode are led out from the center hole of the electrode group through two conductors through the above structure, and the insulating material is filled in the center hole of the electrode group to insulate the two conductors to achieve the polarity separation of the battery cores.
  • the positive and negative electrodes are the above-mentioned conductors connected to the positive and negative electrodes, respectively.
  • the materials of the pin assembly and the battery shell have waterproof characteristics.
  • the battery core obtained according to the present invention can form a ring-shaped cavity through the battery shell and the pin assembly in a sealed connection, and the electrode group can be contained in it to form a stable electrochemical working environment. When assembling, it can be connected by plastic sealing and welding.
  • At least one injection hole is reserved in the cell shell and the pin assembly shell, and the electrolyte is injected into the cell through the injection hole, and a sealing member is provided at the injection hole.
  • the sealing member seals the electrolyte in the cell, and the liquid injection hole is arranged in the center hole of the electrode group, which can further save cell space, improve the utilization rate of cell space, and obtain higher energy density.
  • Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention.
  • Figure 2 is a schematic structural diagram of Embodiment 2 of the present invention.
  • Figure 3 is a schematic structural diagram of Embodiment 3 of the present invention.
  • FIG. 4 is a schematic diagram of the connection structure between the battery core housing and the pin assembly housing in Embodiment 1 of the present invention
  • FIG. 5 is a schematic diagram of the connection structure between the battery core housing and the pin assembly housing in Embodiment 2 of the present invention.
  • FIG. 6 is a schematic diagram of the connection structure between the battery core housing and the pin assembly housing in Embodiment 3 of the present invention.
  • FIG. 7 is a schematic diagram of the second implementation structure of the sealing element in the embodiment of the present invention.
  • Figure 8 is a schematic structural diagram of Embodiment 5 of the present invention.
  • FIG. 9 is a schematic structural diagram of Embodiment 6 of the present invention.
  • FIG. 10 is a schematic structural diagram of Embodiment 7 of the present invention.
  • FIG. 11 is a schematic diagram of an implementation structure of a cross-section of a battery core according to the present invention.
  • the battery core of this embodiment includes:
  • An electrode group 200 including a central hole, which includes at least one positive electrode 201 and one negative electrode 202, and a separator 203 separating the positive and negative electrodes.
  • the positive electrode 201, the negative electrode 202, and the separator 203 are spirally wound around a central hole
  • the diameter of the central hole is greater than 0 and smaller than the diameter of the battery core;
  • a set of pin assembly with polarity separation function is included, which includes a pin assembly housing 101 with an axial through hole, and the pin assembly housing 101 is partially inserted into the electrode set
  • the central hole also includes an insulating material 102 for separating the polarity of the cell, a positive electrode lead-out conductor 103 and a negative electrode lead-out conductor 104, the insulating material 102 is arranged in the axial through hole of the pin assembly housing 101 ,
  • the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 pass through the insulating material 102, and the positive electrode 201 and the negative electrode 202 are respectively conductively connected to the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 to realize the cell electrode.
  • a set of cell housings 300, the cell housings 300 and the pin assembly are hermetically connected to form a ring-shaped sealed cavity capable of accommodating the electrode set.
  • the lower ends of the positive electrode lead conductor 103 and the negative electrode lead conductor 104 are welded to one end of the positive electrode transition conductor 204 and the negative electrode transition conductor 205, and the other ends of the positive electrode transition conductor 204 and the negative electrode transition conductor 205 are respectively connected to the The positive electrode 201 and the negative electrode 202 are welded and connected;
  • the insulating substance 102 is partially disposed in the axial through hole of the pin assembly housing.
  • the longitudinal section of the insulating material 102 is The shape includes a cylindrical portion inserted into the axial through hole and an annular portion formed by expanding the bottom end of the cylindrical portion and completely covering the lower end surface of the axial through hole wall. With this structure, it is avoided that the lower end surface of the axial through hole wall contacts the positive electrode lead conductor 103 and the negative electrode lead conductor 104 to cause a short circuit.
  • all the insulating materials can also be arranged in the axial through holes, leaving only the columnar portion, and this transformation also belongs to the scope of protection of the present application. It should be noted that the positions of the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 can be replaced.
  • a layer of insulating tape 300-a is laid on the inner surface of the bottom end of the cell housing 300 to prevent short-circuits between the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 and the cell housing 300, and also to prevent the positive electrode A short circuit occurs between the transition conductor 204, the negative electrode transition conductor 205, and the cell housing 300.
  • the longitudinal section of the pin assembly housing 101 is It includes a circular tube with an axial through hole and a disc-shaped flange formed at the top of the circular tube.
  • the longitudinal section of the cell housing 300 is U-shaped, and the cell The housing 300 and the pin assembly housing 101 are an integral structure, or may be a spliced structure.
  • the liquid injection hole 400 is provided on the insulating material 102 of the polar separation assembly, and the liquid injection hole is sealed by a sealing member 400-a to prevent the electrolyte from leaking from the liquid injection hole 400.
  • the seal adopts an end cap structure, which includes an end portion and an embedded portion provided at the lower end of the end block, the end portion is covered on the axial through hole, and the embedded portion is inserted into the axial through hole. In the hole, both the embedded part and the end part can achieve double sealing of the liquid injection hole 400.
  • the difference between the battery core of this embodiment and the first embodiment is that the structure of the battery core housing 300 and the pin assembly housing 101 are different, and the remaining structures are the same as those of the first embodiment.
  • This embodiment includes an electrode group 200 including a central hole, which includes at least one positive electrode 201 and one negative electrode 202, and a separator 203 separating the positive and negative electrodes.
  • the positive electrode 201, the negative electrode 202, and the separator 203 surround a central hole. It is formed in a spiral winding manner, and the diameter of the central hole is greater than 0 and smaller than the diameter of the battery core;
  • a set of pin assembly with polarity separation function is included, which includes a pin assembly housing 101 with an axial through hole, and the pin assembly housing 101 is partially inserted into the electrode set
  • the central hole also includes an insulating material 102 for separating the polarity of the cell, a positive electrode lead-out conductor 103, and a negative electrode lead-out conductor 104.
  • the insulating material 102 is arranged in the axial through hole of the pin assembly housing 101 ,
  • the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 pass through the insulating material 102, and the positive electrode 201 and the negative electrode 202 are respectively conductively connected to the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 to realize the cell electrode.
  • Sexual separation
  • a set of cell housings 300, the cell housings 300 and the pin assembly are hermetically connected to form a ring-shaped sealed cavity capable of accommodating the electrode set.
  • the lower ends of the positive electrode lead conductor 103 and the negative electrode lead conductor 104 are welded to one end of the positive electrode transition conductor 204 and the negative electrode transition conductor 205, and the other ends of the positive electrode transition conductor 204 and the negative electrode transition conductor 205 are respectively connected to the The positive electrode 201 and the negative electrode 202 are welded and connected;
  • the insulating substance 102 is partially disposed in the axial through hole of the pin assembly housing.
  • the longitudinal section of the insulating material 102 is The shape includes a cylindrical portion inserted into the axial through hole and an annular portion formed by expanding the bottom end of the cylindrical portion and completely covering the lower end surface of the axial through hole wall. With this structure, it is avoided that the lower end surface of the axial through hole wall contacts the positive electrode lead conductor 103 and the negative electrode lead conductor 104 to cause a short circuit.
  • a layer of insulating tape 300-a is laid on the inner surface of the bottom end of the cell housing 300 to prevent short-circuits between the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 and the cell housing 300, and also to prevent the positive electrode A short circuit occurs between the transition conductor 204, the negative electrode transition conductor 205, and the cell housing 300.
  • the longitudinal section of the pin assembly housing 101 is The shape includes a circular tube with an axial through hole and a circular cup formed outwardly at the top of the circular tube.
  • the cell shell is in the shape of a disc, and its longitudinal section is in the shape of a "one".
  • the battery core housing 300 and the pin assembly housing 101 are an integral structure, or a splicing structure.
  • the liquid injection hole 400 is provided on the insulating material 102 of the polar separation assembly, and the liquid injection hole is sealed by a sealing member 400-a to prevent the electrolyte from leaking from the liquid injection hole 400.
  • the seal adopts an end cap structure, which includes an end portion and an embedded portion provided at the lower end of the end block, the end portion is covered on the axial through hole, and the embedded portion is inserted into the axial through hole. In the hole, both the embedded part and the end part can achieve double sealing of the liquid injection hole 400.
  • the difference between the battery core of this embodiment and the first and second embodiments is that the structure of the battery core housing 300 and the pin assembly housing 101 are different, and the remaining structures are the same as those of the first and second embodiments. .
  • This embodiment includes an electrode group 200 including a central hole, which includes at least one positive electrode 201 and one negative electrode 202, and a separator 203 separating the positive and negative electrodes.
  • the positive electrode 201, the negative electrode 202, and the separator 203 surround a central hole. It is formed in a spiral winding manner, and the diameter of the central hole is greater than 0 and smaller than the diameter of the battery core;
  • a set of pin assembly with polarity separation function is included, which includes a pin assembly housing 101 with an axial through hole, and the pin assembly housing 101 is partially inserted into the electrode set
  • the central hole also includes an insulating material 102 for separating the polarity of the cell, a positive electrode lead-out conductor 103, and a negative electrode lead-out conductor 104.
  • the insulating material 102 is arranged in the axial through hole of the pin assembly housing 101 ,
  • the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 pass through the insulating material 102, and the positive electrode 201 and the negative electrode 202 are electrically connected to the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104, respectively, so as to realize the cell electrode.
  • Sexual separation
  • a set of cell housings 300, the cell housings 300 and the pin assembly are hermetically connected to form a ring-shaped sealed cavity capable of accommodating the electrode set.
  • the lower ends of the positive electrode lead conductor 103 and the negative electrode lead conductor 104 are welded to one end of the positive electrode transition conductor 204 and the negative electrode transition conductor 205, and the other ends of the positive electrode transition conductor 204 and the negative electrode transition conductor 205 are respectively connected to the The positive electrode 201 and the negative electrode 202 are welded and connected;
  • the insulating substance 102 is partially disposed in the axial through hole of the pin assembly housing.
  • the longitudinal section of the insulating material 102 is The shape includes a cylindrical portion inserted into the axial through hole and an annular portion formed by expanding the bottom end of the cylindrical portion and completely covering the lower end surface of the axial through hole wall. With this structure, it is avoided that the lower end surface of the axial through hole wall contacts the positive electrode lead conductor 103 and the negative electrode lead conductor 104 to cause a short circuit.
  • the positions of the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 can be replaced. It should be noted that a layer of insulating tape 300-a is laid on the inner surface of the bottom end of the cell housing 300 to prevent short-circuits between the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 and the cell housing 300, and also to prevent the positive electrode A short circuit occurs between the transition conductor 204, the negative electrode transition conductor 205, and the cell housing 300.
  • the longitudinal section of the pin assembly housing 101 is Shape, which is a round tube with an axial through hole.
  • the longitudinal section of the cell housing 300 is shape.
  • the pin assembly housing 101 is an integrally formed structure, or may be a spliced and formed structure.
  • the battery cell housing 300 has a splicing structure.
  • the liquid injection hole 400 is provided on the insulating material 102 of the polar separation assembly, and the liquid injection hole is sealed by a sealing member 400-a to prevent the electrolyte from leaking from the liquid injection hole 400.
  • the seal adopts an end cap structure, which includes an end portion and an embedded portion provided at the lower end of the end block, the end portion is covered on the axial through hole, and the embedded portion is inserted into the axial through hole. In the hole, both the embedded part and the end part can achieve double sealing of the liquid injection hole 400.
  • this embodiment can provide another type of seal 400-a of the liquid injection hole 400 on the basis of Embodiment 1, Embodiment 2, and Embodiment 3.
  • the seal 400-a It is a steel ball, and there can be multiple steel balls. A plurality of steel balls are sequentially inserted into the axial through hole, the steel ball is inserted into the axial through hole, and the steel ball communicates with the axial direction.
  • the hole has an interference fit to achieve sealing.
  • this embodiment can be improved based on the above-mentioned Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4 respectively.
  • the positive electrode lead-out conductor 103 (currently, it can also be replaced by the negative electrode lead-out conductor 104) is drawn from the insulating material, and the corresponding negative electrode 202 is welded and connected to the cell housing 300.
  • the insulating tape 300-a is only arranged on the side of the positive electrode lead-out conductor 103 to prevent a short circuit between the positive electrode lead-out conductor 103 and the cell housing 300, and also to prevent the positive electrode transition conductor 204 and the cell housing 300 from being short-circuited. A short circuit occurred.
  • Embodiment 1 The remaining structures of this embodiment are correspondingly combined with the structures of Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4.
  • this embodiment can be improved based on the above-mentioned Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5 respectively.
  • the liquid injection hole 400 is provided on the cell housing 300.
  • the liquid injection hole 400 can also be opened in other positions of the cell housing 300 according to the conventional knowledge mastered by those skilled in the art.
  • Embodiment 1 The remaining structures of this embodiment are correspondingly combined with the structures of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5.
  • this embodiment can be improved based on the above-mentioned Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, Embodiment 5, and Embodiment 6, respectively.
  • the positive electrode transition conductor 204 and the negative electrode transition conductor 205 are omitted, and the lower ends of the positive electrode lead conductor 103 and the negative electrode lead conductor 104 are directly welded to the positive electrode 201 and the negative electrode 202 respectively.
  • Embodiment 1 The remaining structures of this embodiment are correspondingly combined with the structures of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, Embodiment 5, and Embodiment 6.
  • the cross-sectional shape of the battery cell of the present invention can be a circle or an ellipse and other shapes that can be made according to the conventional knowledge mastered by those skilled in the art.
  • the solution of the present invention is preferably applicable to cylindrical lithium ion batteries.
  • the electrode group 200 selected for the cell of the present invention is consistent with the traditional cylindrical cell, that is, at least one positive electrode 201, at least one negative electrode 202, and a diaphragm 203 separating the positive and negative electrodes are coaxially spirally wound into electrodes.
  • the positive electrode 201 is usually composed of a foil-shaped (or mesh-shaped) metal current collector and a positive electrode active material coated on the surface.
  • the foil material is particularly preferably aluminum (or aluminum alloy), and the positive electrode active material can be lithium cobaltate/phosphoric acid.
  • the negative electrode 202 is usually composed of a foil-shaped (or mesh-shaped) metal current collector and a negative electrode active material coated on the surface.
  • the foil material is particularly preferably copper (or copper alloy), and the negative electrode active material can be carbon material/titanic acid One or several mixtures of lithium/lithium.
  • the diaphragm 203 is preferably a plastic film, particularly a polyolefin film, such as a polyethylene film. Of course, the diaphragm 203 can also be a multilayer structure, such as ceramic/polyethylene/ceramic.
  • the above-mentioned positive electrode/negative electrode/diaphragm is usually made into a flat strip shape, which is wound into the electrode group 200 in a spiral form in a fixed sequence.
  • the usual winding sequence can be one of the following two structures: positive electrode/diaphragm/negative electrode/diaphragm, negative electrode/diaphragm/positive electrode/diaphragm. Regardless of the method of winding, after the winding is completed and the winding needle is pulled out, a central hole will be formed in the center of the electrode assembly. The diameter of the central hole is approximately equal to the diameter of the winding needle, usually greater than 1mm.
  • the dimensions of the cell housing 300, the electrode group 200, the center hole, and the pin assembly 100 are all set according to the conventional knowledge mastered by those skilled in the art, and will not be described in detail.
  • the present invention can adopt the following processing technology, taking the structure in embodiment 1 as an example:
  • Polypropylene plastic is injected into the pin assembly housing 101 by template injection to form the insulating material 102, and finally the positive electrode lead-out conductor 103 and the negative electrode lead-out conductor 104 in the hole are completely wrapped, and a through hole is formed in the insulating material 102.
  • the liquid injection hole, the insulating material 102 is tightly combined with the inner wall of the metal pin assembly housing 101.
  • the electrolyte is injected into the cell through the injection hole of the pin assembly 100, and then the injection hole is sealed.
  • the battery cell that realizes the above operation is then subjected to general procedures such as traditional composition selection to finally form a rechargeable lithium ion cylindrical battery cell.

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Abstract

一种电芯，尤其是一种利用电极组中心孔实施电芯极性分离的圆柱形电芯。包括一个具有中心孔的由正电极（201）、负电极（202）及隔膜（203）卷绕成型的电极组（200），在电极组中心孔内，设置了一组电芯极性分离部件，该部件包含一个插件组件壳体（101）、分离电芯极性的绝缘物质（102）和至少一个电极引出导体（103,104），电极组（200）中的正电极（201）和/或负电极（202）可通过上述导体（103,104）引出，同时该电芯极性分离部件可与电芯外壳（300）密封连接形成环状空腔，将电极组密封在内部形成电化学隔绝工作环境。此种结构设计将电芯极性分离的绝缘材料布置在了卷绕本身存在的不可去除的卷绕中心孔内，节省了原本用于实施极性分离的空间，可提升电芯的能量密度。

Description

一种电芯 技术领域
本发明涉及二次电芯的结构设计技术领域，具体地提供了一种电芯。
背景技术
锂离子电芯绿色环保，循环寿命长、倍率性能及安全可靠性能好，被广泛应用于各储能产品、消费类电子产品以及动力电芯产品。锂离子电芯按照制作工艺可分为软包锂离子电芯，方形铝壳电芯及钢壳圆柱形电芯。其中钢壳圆柱形电芯由于工艺高度标准化，成本相当低廉，被广泛应用于动力汽车电芯。作为高速发展的新能源产业，在激烈的市场竞争下，客户对电芯的能量密度以及外观的要求也越来越高。
目前市场上常见的圆柱形电芯都需要占用部分电芯空间来实施电芯极性分隔。例如，传统18650及21700圆柱形电芯，其电芯的正负极分别是电芯的底壳与壳盖，正负极性的分隔是通过绝缘胶圈在壳盖侧通过滚边工艺密封实现，上述结构占用了电芯约4～6mm长度空间，相当于5.7％～10％空间浪费；上述结构在电芯高度减小时，会急剧降低能量密度，故目前对于高度较小的圆柱形电芯(纽扣电芯)则将电芯极性分隔功能转移到了径向方向，该类电芯的正负极依然分别连接在底壳与壳盖上，底壳与壳盖同轴扣在一起，中间填充绝缘层实现极性分隔，极性分隔结构在电芯最外圈(参考专利：ZL201080007121.9)，这种结构需要占用圆形截面最外圈约0.6mm空间，对于直径8～20mm电芯，相当于6％～15％空间浪费。
目前圆柱形电芯的极组成型有卷绕和叠片两种工艺，实践证明卷绕结构能量密度为最优，当采用卷绕成型圆柱形极组时，不可避免的会遗留因放置卷针而造成的卷绕中心孔，该孔直径一般大于1mm。这个卷绕中心孔一方面浪费电芯空间，另一方面由于孔的存在还可能导致极组在使用过程中结构坍塌，故大多数圆柱形电芯会在极组的中心孔内放置插针以稳定结构，然而，此种工艺额外增加了工艺复杂度。
发明内容
为了解决上述问题，本申请的目的在于提供的一种电芯。
为实现本发明的目的，本发明提供的一种电芯，包括：
一个包含中心孔的电极组，其包括至少一个正电极和一个负电极以及分隔正负电极的隔膜，所述正电极、负电极及隔膜围绕一个中心孔以螺旋卷绕方式成形，所述中心孔直径大于0，小于电芯直径；
在电极组中心孔内，包括一组具有极性分离功能的插针组件，其包括一个带轴向通孔的插针组件壳体，所述插针组件壳体部分或全部插入所述电极组中心孔内、还包括用于分离电芯极性的绝缘物质和至少一个电极引出导体，所述绝缘物质设在所述插针组件壳体的轴向通孔内，所述电极引出导体穿过所述绝缘物质，所述正电极和/或负电极与所述电极引出导体导电连接，以实现电芯极性分离；
一组电芯外壳，所述电芯外壳与所述插针组件密封连接，形成能够容纳所述电极组的环状密闭空腔。
进一步地，所述插针组件壳体的纵截面呈
Figure PCTCN2020131694-appb-000001
型，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆盘形翼缘。
进一步地，所述电芯外壳的纵截面为U形。
进一步地，所述插针组件壳体的纵截面呈
Figure PCTCN2020131694-appb-000002
形，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆杯。
进一步地，所述电芯外壳为圆盘形，其纵截面为“一”字形。
进一步地，所述插针组件壳体的纵截面呈
Figure PCTCN2020131694-appb-000003
形，其为一带有轴向通孔圆管。
进一步地，所述电芯外壳的纵截面为
Figure PCTCN2020131694-appb-000004
形。
进一步地，所述绝缘物质部分或全部设在所述插针组件壳体的轴向通孔内。
进一步地，所述绝缘物质纵截面为
Figure PCTCN2020131694-appb-000005
形，其包括插入所述轴向通孔 内的柱状部以及柱状部底端向外展开形成的、将所述轴向通孔壁下端面完全覆盖的环状部。
进一步地，还包括至少一个用于向所述电芯内注入电解液的注液孔。
进一步地，所述注液孔设置在所述极性分离组件上和/或设置在所述电芯外壳上。
进一步地，所述注液孔设置在所述极性分离组件的绝缘物质上。
进一步地，所述注液孔通过密封件密封，用于防止电解液从所述注液孔泄漏。
进一步地，所述密封件采用如下结构之一：
第一种：所述密封件采用端帽结构，其包括端部以及设置在端块下端的嵌入部，所述端部盖合在所述轴向通孔上，所述嵌入部插入所述轴向通孔内；
第二种：所述密封件为至少一个钢球，所述钢球塞入所述轴向通孔内，且所述钢球与所述轴向通孔过盈配合。
进一步地，所述电芯为锂离子电芯，其还包括至少一个嵌锂电极。
进一步地，电极和隔膜呈扁平条带形式。
进一步地，所述电极组采用如下层序之一：
负电极/隔膜/正电极/隔膜，
正电极/隔膜/负电极/隔膜。
进一步地，所述插针组件与电芯外壳采用具有防水特性的材质。
进一步地，所述具有防水特性的材质为金属材质或非金属材质。
进一步地，所述金属材质为不锈钢、铝或铝合金。
进一步地，所述非金属材质为陶瓷或塑料。
进一步地，所述正电极和/或负电极与所述电极引出导体导电连接，采用如下结构之一：
第一种：所述电极引出导体下端与过渡导体的一端焊接连接，过渡导体的另一端与所述正电极和/或负电极焊接连接；
第二种：所述电极引出导体下端与所述正电极和/或负电极焊接连接。进一步地，所述绝缘物质的材质为聚丙烯材质。
进一步地，所述电芯的截面形状为圆形或椭圆形。
依照本发明所得的电芯，其与传统电芯的核心区别在于，其电芯的极性分离功能在上述的电极组中心孔内实现。用于分离电芯极性的绝缘物质被置于电极组中心孔内，至少一个电极引出导体被置于极组中心孔内，上述电极引出导体一端与正电极和/或负电极导电连接，另一端漏出作为正电极和/或负电极引出极子。
例如，将正电极通过上述结构从电极组中心孔引出，将负电极导电连接在金属外壳上，绝缘物质填充在中心孔内实现电芯极性分离，所构成的电芯正极极子为中心孔引出的导体，负极极子为金属外壳。
例如，将负电极通过上述结构从电极组中心孔引出，将正电极连接在金属外壳上，绝缘物质填充在中心孔内将中心孔所出导体与金属外壳绝缘实现电芯极性分离，所构成的电芯正极极子为金属外壳，负极极子为中心孔引出的导体。
例如，将正电极和负电极均通过上述结构从电极组中心孔通过两个导体引出，绝缘物质填充在电极组中心孔内将上述两个导体绝缘实现电芯极性分离，所构成的电芯正负极子分别为上述与正负电极连接的导体。
为提高密封防水的功能，插针组件与电芯外壳的材质均具有防水特性。
依照本发明所得的电芯，通过电芯外壳与插针组件密封连接，可形成环状空腔，将电极组容纳在其中形成稳定的电化学工作环境。组装时可采用塑封、焊接方式连接。
为实现电解液注入电芯，在电芯外壳与插针组件壳体预留有至少一个注液孔，电解液经所述注液孔注入电芯内，所述注液孔处设有密封件，所述密封件将电解液封堵在电芯内，注液孔设置在电极组中心孔内能够进一步节约电芯空间，提高电芯空间利用率，获得更高的能量密度。
附图说明
图1为本发明实施例1的结构示意图；
图2为本发明实施例2的结构示意图；
图3为本发明实施例3的结构示意图；
图4为本发明实施例1中电芯外壳与插针组件壳体连接结构示意图；
图5为本发明实施例2中电芯外壳与插针组件壳体连接结构示意图；
图6为本发明实施例3中电芯外壳与插针组件壳体连接结构示意图；
图7为本发明实施例中密封件的第二实施结构示意图；
图8为本发明实施例5的结构示意图；
图9为本发明实施例6的结构示意图；
图10为本发明实施例7的结构示意图；
图11为本发明电芯截面的一种实施结构的示意图。
具体实施方式
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。
以下结合附图和具体实施例对本发明作进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
实施例1
如图1所示，本实施例电芯包括：
一个包含中心孔的电极组200，其包括至少一个正电极201和一个负电极202以及分隔正负电极的隔膜203，所述正电极201、负电极202及隔膜203围绕一个中心孔以螺旋卷绕方式成形，所述中心孔直径大于0，小于电芯直径；
在电极组中心孔内，包括一组具有极性分离功能的插针组件，其包括一个带轴向通孔的插针组件壳体101，所述插针组件壳体101部分插入所述电极组中心孔内、还包括用于分离电芯极性的绝缘物质102和正电极引出导体103以及负电极引出导体104，所述绝缘物质102设在所述插针组件壳体101 的轴向通孔内，正电极引出导体103以及负电极引出导体104穿过所述绝缘物质102，所述正电极201和负电极202分别与正电极引出导体103以及负电极引出导体104导电连接，以实现电芯极性分离；
一组电芯外壳300，所述电芯外壳300与所述插针组件密封连接，形成能够容纳所述电极组的环状密闭空腔。
其中，所述正电极引出导体103以及负电极引出导体104下端与正电极过渡导体204、负电极过渡导体205的一端焊接连接，正电极过渡导体204、负电极过渡导体205的另一端分别与所述正电极201和负电极202焊接连接；
其中，所述绝缘物质102部分设在所述插针组件壳体的轴向通孔内。所述绝缘物质102纵截面为
Figure PCTCN2020131694-appb-000006
形，其包括插入所述轴向通孔内的柱状部以及柱状部底端向外展开形成的、将所述轴向通孔壁下端面完全覆盖的环状部。采用此种结构，避免轴向通孔壁下端面与正电极引出导体103以及负电极引出导体104接触发生短路。当然，绝缘物质也可全部设置在轴向通孔内，只保留柱状部，此种变换也属于本申请的保护范围。需要说明的是，正电极引出导体103以及负电极引出导体104的位置可更换。
需要说明的是，电芯外壳300底端内侧面铺设一层绝缘胶带300-a，用于防止正电极引出导体103以及负电极引出导体104与电芯外壳300之间发生短路，同样防止正电极过渡导体204、负电极过渡导体205与电芯外壳300之间发生短路。
如图4所示，所述插针组件壳体101的纵截面呈
Figure PCTCN2020131694-appb-000007
型，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆盘形翼缘，相应地，所述电芯外壳300的纵截面为U形，所述电芯外壳300和插针组件壳体101为一体成型结构，也可为拼接成型结构。
优选地，所述注液孔400设置在所述极性分离组件的绝缘物质102上，所述注液孔通过密封件400-a密封，用于防止电解液从所述注液孔400泄漏。其中，所述密封件采用端帽结构，其包括端部以及设置在端块下端的嵌入部， 所述端部盖合在所述轴向通孔上，所述嵌入部插入所述轴向通孔内，嵌入部和端部均能够实现对注液孔400的双重密封。
实施例2
如图2所示，本实施例的电芯与实施例1的区别在于电芯外壳300和插针组件壳体101的结构不同，其余结构均与实施例1相同。
本实施例包括一个包含中心孔的电极组200，其包括至少一个正电极201和一个负电极202以及分隔正负电极的隔膜203，所述正电极201、负电极202及隔膜203围绕一个中心孔以螺旋卷绕方式成形，所述中心孔直径大于0，小于电芯直径；
在电极组中心孔内，包括一组具有极性分离功能的插针组件，其包括一个带轴向通孔的插针组件壳体101，所述插针组件壳体101部分插入所述电极组中心孔内、还包括用于分离电芯极性的绝缘物质102和正电极引出导体103以及负电极引出导体104，所述绝缘物质102设在所述插针组件壳体101的轴向通孔内，正电极引出导体103以及负电极引出导体104穿过所述绝缘物质102，所述正电极201和负电极202分别与正电极引出导体103以及负电极引出导体104导电连接，以实现电芯极性分离；
一组电芯外壳300，所述电芯外壳300与所述插针组件密封连接，形成能够容纳所述电极组的环状密闭空腔。
其中，所述正电极引出导体103以及负电极引出导体104下端与正电极过渡导体204、负电极过渡导体205的一端焊接连接，正电极过渡导体204、负电极过渡导体205的另一端分别与所述正电极201和负电极202焊接连接；
其中，所述绝缘物质102部分设在所述插针组件壳体的轴向通孔内。所述绝缘物质102纵截面为
Figure PCTCN2020131694-appb-000008
形，其包括插入所述轴向通孔内的柱状部以及柱状部底端向外展开形成的、将所述轴向通孔壁下端面完全覆盖的环状部。采用此种结构，避免轴向通孔壁下端面与正电极引出导体103以及负电极引出导体104接触发生短路。
需要说明的是，正电极引出导体103以及负电极引出导体104的位置可更换。
需要说明的是，电芯外壳300底端内侧面铺设一层绝缘胶带300-a，用于防止正电极引出导体103以及负电极引出导体104与电芯外壳300之间发生短路，同样防止正电极过渡导体204、负电极过渡导体205与电芯外壳300之间发生短路。
如图5所示，插针组件壳体101的纵截面呈
Figure PCTCN2020131694-appb-000009
形，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆杯，相应地，所述电芯外壳为圆盘形，其纵截面为“一”字形。其中，所述电芯外壳300和插针组件壳体101为一体成型结构，也可为拼接成型结构。
优选地，所述注液孔400设置在所述极性分离组件的绝缘物质102上，所述注液孔通过密封件400-a密封，用于防止电解液从所述注液孔400泄漏。其中，所述密封件采用端帽结构，其包括端部以及设置在端块下端的嵌入部，所述端部盖合在所述轴向通孔上，所述嵌入部插入所述轴向通孔内，嵌入部和端部均能够实现对注液孔400的双重密封。
实施例3
如图3所示，本实施例的电芯与实施例1、实施例2的区别在于电芯外壳300和插针组件壳体101的结构不同，其余结构均与实施例1、实施例2相同。
本实施例包括一个包含中心孔的电极组200，其包括至少一个正电极201和一个负电极202以及分隔正负电极的隔膜203，所述正电极201、负电极202及隔膜203围绕一个中心孔以螺旋卷绕方式成形，所述中心孔直径大于0，小于电芯直径；
在电极组中心孔内，包括一组具有极性分离功能的插针组件，其包括一个带轴向通孔的插针组件壳体101，所述插针组件壳体101部分插入所述电极组中心孔内、还包括用于分离电芯极性的绝缘物质102和正电极引出导体 103以及负电极引出导体104，所述绝缘物质102设在所述插针组件壳体101的轴向通孔内，正电极引出导体103以及负电极引出导体104穿过所述绝缘物质102，所述正电极201和负电极202分别与正电极引出导体103以及负电极引出导体104导电连接，以实现电芯极性分离；
一组电芯外壳300，所述电芯外壳300与所述插针组件密封连接，形成能够容纳所述电极组的环状密闭空腔。
其中，所述正电极引出导体103以及负电极引出导体104下端与正电极过渡导体204、负电极过渡导体205的一端焊接连接，正电极过渡导体204、负电极过渡导体205的另一端分别与所述正电极201和负电极202焊接连接；
其中，所述绝缘物质102部分设在所述插针组件壳体的轴向通孔内。所述绝缘物质102纵截面为
Figure PCTCN2020131694-appb-000010
形，其包括插入所述轴向通孔内的柱状部以及柱状部底端向外展开形成的、将所述轴向通孔壁下端面完全覆盖的环状部。采用此种结构，避免轴向通孔壁下端面与正电极引出导体103以及负电极引出导体104接触发生短路。
需要说明的是，正电极引出导体103以及负电极引出导体104的位置可更换。需要说明的是，电芯外壳300底端内侧面铺设一层绝缘胶带300-a，用于防止正电极引出导体103以及负电极引出导体104与电芯外壳300之间发生短路，同样防止正电极过渡导体204、负电极过渡导体205与电芯外壳300之间发生短路。
如图6所示，插针组件壳体101的纵截面呈
Figure PCTCN2020131694-appb-000011
形，其为一带有轴向通孔圆管。所述电芯外壳300的纵截面为
Figure PCTCN2020131694-appb-000012
形。其中，插针组件壳体101为一体成型结构，也可为拼接成型结构。此种情况下，电芯外壳300为拼接结构。
优选地，所述注液孔400设置在所述极性分离组件的绝缘物质102上，所述注液孔通过密封件400-a密封，用于防止电解液从所述注液孔400泄漏。其中，所述密封件采用端帽结构，其包括端部以及设置在端块下端的嵌入部，所述端部盖合在所述轴向通孔上，所述嵌入部插入所述轴向通孔内，嵌入部 和端部均能够实现对注液孔400的双重密封。
实施例4
如图7所示，本实施例能够分别在实施例1、实施例2、实施例3的基础上，提供了另外一种注液孔400的密封件400-a，所述密封件400-a为一个钢球，钢球可以为多个，多个钢球依次塞入轴向通孔内，所述钢球塞入所述轴向通孔内，且所述钢球与所述轴向通孔过盈配合，实现密封。
本实施例其余的结构，分别与实施例1、实施例2、实施例3相同。实施例5
如图8所示，本实施例能够分别基于上述实施例1、实施例2、实施例3、实施例4进行改进。本实施例只设置正电极引出导体103(当前，也可更换为负电极引出导体104)从绝缘物质中引出，相对应的负电极202与电芯外壳300焊接连接。
其中，绝缘胶带300-a只设置在正电极引出导体103一侧，用于防止正电极引出导体103与电芯外壳300之间发生短路，同样防止正电极过渡导体204与电芯外壳300之间发生短路。
本实施例其余结构均相应结合实施例1、实施例2、实施例3、实施例4的结构。
实施例6
如图9所示，本实施例能够分别基于上述实施例1、实施例2、实施例3、实施例4、实施例5进行改进。本实施例中，注液孔400设置在所述电芯外壳300上，当然，注液孔400根据本领域技术人员掌握的常规知识，也可开设在电芯外壳300的其它位置上。
本实施例其余结构均相应结合实施例1、实施例2、实施例3、实施例4、实施例5的结构。
实施例7
如图10所示，本实施例能够分别基于上述实施例1、实施例2、实施例 3、实施例4、实施例5、实施例6进行改进。本实施例中，省略了正电极过渡导体204、负电极过渡导体205，采用正电极引出导体103以及负电极引出导体104下端分别与所述正电极201和负电极202直接焊接连接的结构。
本实施例其余结构均相应结合实施例1、实施例2、实施例3、实施例4、实施例5、实施例6的结构。
如图11所示，本发明电芯的横截面形状可为圆形或椭圆形以及其他根据本领域技术人员掌握的常规知识所能做出的形状。
需要说明的是，本发明方案优选适用于圆柱形锂离子电芯。
需要说明的是，本发明电芯选用的电极组200与传统圆柱形电芯一致，即由至少一个正电极201和至少一个负电极202及分隔正负电极的隔膜203同轴螺旋卷绕成电极组200。其正电极201通常由箔状(或网状)金属集流体与涂覆在其面上的正极活性物质组成，箔材特别优选铝(或者铝合金)，正极活性物质可以是钴酸锂/磷酸铁锂/锰酸锂/钛酸锂/NCM三元材料/NCA三元材料中的一种或几种混合物。负电极202通常由箔状(或网状)金属集流体与涂覆在其面上的负极活性物质组成，箔材特别优选铜(或铜合金)，负极活性物质可以是碳素材料/钛酸锂/锂的一种或几种混合物。隔膜203优选一种塑料膜，特别是聚烯烃膜，例如聚乙烯膜。当然，隔膜203也可以是一种多层结构，如陶瓷/聚乙烯/陶瓷。上述正电极/负电极/隔膜通常被制作成扁平的条状，固定序列地以螺旋形式卷绕成电极组200。通常的卷绕顺序可以是以下两种结构中的一种：正电极/隔膜/负电极/隔膜，负电极/隔膜/正电极/隔膜。无论那种方式卷绕，在完成卷绕，拔出卷针后，在电极组中心会形成一个中心孔，该中心孔直径约等于卷针直径，通常大于1mm。
需要说明的是，本发明中，电芯外壳300、电极组200、中心孔以及插针组件100等尺寸，均根据本领域技术人员掌握的常规知识进行设置，不再详述。
本发明可采用如下加工工艺，以实施例1中的结构进行举例：
插针组件壳体101内通过模板注塑法注入了聚丙烯塑料，形成绝缘物质102，最终将孔内正电极引出导体103以及负电极引出导体104完全包裹，同时在绝缘物质102形成一个通孔状的注液孔，绝缘物质102与金属插针组件壳体101内壁紧密结合。
将插针组件100的插针组件壳体101插入电极组200的中心孔内，然后将插针组件壳体101内的正电极引出导体103以及负电极引出导体104向外弯折后分别与电极组200的正电极过渡导体204、负电极过渡导体205焊接。上述电极组200与插针组件100完成组装后再整体装入电芯外壳300内，通过激光焊接工艺将插针组件100和电芯外壳300在连接处焊接上，最终形成环状空腔将电极组200容纳在其中。
将电解液通过插针组件100的注液孔注入到电芯内部，然后将注液孔进行密封。实现上述操作的电芯再经过传统化成分选等通用工序最终形成可充放电二次锂离子圆柱电芯。
以上所述仅是本发明的优选实施方式，应当指出的是，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。
以上所述仅是本发明的优选实施方式，应当指出的是，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。

Claims (24)

  1. 一种电芯，其特征在于，包括：
    一个包含中心孔的电极组，其包括至少一个正电极和一个负电极以及分隔正负电极的隔膜，所述正电极、负电极及隔膜围绕一个中心孔以螺旋卷绕方式成形，所述中心孔直径大于0，小于电芯直径；
    在电极组中心孔内，包括一组具有极性分离功能的插针组件，其包括一个带轴向通孔的插针组件壳体，所述插针组件壳体部分或全部插入所述电极组中心孔内、还包括用于分离电芯极性的绝缘物质和至少一个电极引出导体，所述绝缘物质设在所述插针组件壳体的轴向通孔内，所述电极引出导体穿过所述绝缘物质，所述正电极和/或负电极与所述电极引出导体导电连接，以实现电芯极性分离；
    一组电芯外壳，所述电芯外壳与所述插针组件密封连接，形成能够容纳所述电极组的环状密闭空腔。
  2. 根据权利要求1所述的一种电芯，其特征在于，所述插针组件壳体的纵截面呈
    Figure PCTCN2020131694-appb-100001
    型，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆盘形翼缘。
  3. 根据权利要求2所述的一种电芯，其特征在于，所述电芯外壳的纵截面为“U”形。
  4. 根据权利要求1所述的一种电芯，其特征在于，所述插针组件壳体的纵截面呈
    Figure PCTCN2020131694-appb-100002
    形，其包括一带有轴向通孔圆管和在所述圆管顶端向外展开形成的圆杯。
  5. 根据权利要求4所述的一种电芯，其特征在于，所述电芯外壳为圆盘形，其纵截面为“一”字形。
  6. 根据权利要求1所述的一种电芯，其特征在于，所述插针组件壳体的纵截面呈“||”形，其为一带有轴向通孔圆管。
  7. 根据权利要求6所述的一种电芯，其特征在于，所述电芯外壳的纵截面为
    Figure PCTCN2020131694-appb-100003
    形。
  8. 根据权利要求1所述的一种电芯，其特征在于，所述绝缘物质部分或全部设在所述插针组件壳体的轴向通孔内。
  9. 根据权利要求8所述的一种电芯，其特征在于，所述绝缘物质纵截面为
    Figure PCTCN2020131694-appb-100004
    形，其包括插入所述轴向通孔内的柱状部以及柱状部底端向外展开形成的、将所述轴向通孔壁下端面完全覆盖的环状部。
  10. 根据权利要求1所述的一种电芯，其特征在于，还包括至少一个用于向所述电芯内注入电解液的注液孔。
  11. 根据权利要求10所述的一种电芯，其特征在于，所述注液孔设置在所述极性分离组件上和/或设置在所述电芯外壳上。
  12. 根据权利要求11所述的一种电芯，其特征在于，所述注液孔设置在所述极性分离组件的绝缘物质上。
  13. 根据权利要求12所述的一种电芯，其特征在于，所述注液孔通过密封件密封，用于防止电解液从所述注液孔泄漏。
  14. 根据权利要求13所述的一种电芯，其特征在于，所述密封件采用如下结构之一：
    第一种：所述密封件采用端帽结构，其包括端部以及设置在端块下端的嵌入部，所述端部盖合在所述轴向通孔上，所述嵌入部插入所述轴向通孔内；
    第二种：所述密封件为至少一个钢球，所述钢球塞入所述轴向通孔内，且所述钢球与所述轴向通孔过盈配合。
  15. 根据权利要求1所述的一种电芯，其特征在于，所述电芯为锂离子电芯，其还包括至少一个嵌锂电极。
  16. 根据权利要求1所述的一种电芯，其特征在于，电极和隔膜呈扁平条带形式。
  17. 根据权利要求1所述的一种电芯，其特征在于，所述电极组采用如下层序之一:
    负电极/隔膜/正电极/隔膜；
    正电极/隔膜/负电极/隔膜。
  18. 如权利要求1所述的一种电芯，其特征在于，所述插针组件与电芯外壳采用具有防水特性的材质。
  19. 如权利要求18所述的一种电芯，其特征在于，所述具有防水特性的材质为金属材质或非金属材质。
  20. 如权利要求19所述的一种电芯，其特征在于，所述金属材质为不锈钢、铝或铝合金。
  21. 如权利要求19所述的一种电芯，其特征在于，所述非金属材质为陶瓷或塑料。
  22. 如权利要求1所述的一种电芯，其特征在于，所述正电极和/或负电极与所述电极引出导体导电连接，采用如下结构之一：
    第一种：所述电极引出导体下端与过渡导体的一端焊接连接，过渡导体的另一端与所述正电极和/或负电极焊接连接；
    第二种：所述电极引出导体下端与所述正电极和/或负电极焊接连接。
  23. 如权利要求1所述的一种电芯，其特征在于，所述绝缘物质的材质为聚丙烯材质。
  24. 如权利要求1所述的一种电芯，其特征在于，所述电芯的截面形状为圆形或椭圆形。
PCT/CN2020/131694 2020-04-06 2020-11-26 一种电芯 WO2021203715A1 (zh)

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CN111969254B (zh) * 2020-04-06 2024-05-17 天津力神电池股份有限公司 一种电芯
CN112652823A (zh) * 2021-01-18 2021-04-13 江苏德立信电子科技有限公司 一种柱状锂电池及其制备方法
WO2023141979A1 (zh) * 2022-01-28 2023-08-03 宁德时代新能源科技股份有限公司 电池单体、电池、用电设备及电池单体的制造方法和设备

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