WO2024073892A1 - Collecteur de courant composite, électrode, batterie secondaire et dispositif électrique - Google Patents

Collecteur de courant composite, électrode, batterie secondaire et dispositif électrique Download PDF

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Publication number
WO2024073892A1
WO2024073892A1 PCT/CN2022/123873 CN2022123873W WO2024073892A1 WO 2024073892 A1 WO2024073892 A1 WO 2024073892A1 CN 2022123873 W CN2022123873 W CN 2022123873W WO 2024073892 A1 WO2024073892 A1 WO 2024073892A1
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Prior art keywords
conductive
current collector
base layer
composite current
layer
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PCT/CN2022/123873
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English (en)
Chinese (zh)
Inventor
伍平生
王岳利
雷克武
尚鲲鹏
薛颜同
Original Assignee
宁德时代新能源科技股份有限公司
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Priority to PCT/CN2022/123873 priority Critical patent/WO2024073892A1/fr
Publication of WO2024073892A1 publication Critical patent/WO2024073892A1/fr

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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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of batteries, and in particular to a composite current collector, an electrode, a secondary device and an electrical device.
  • the existing composite current collector has a large resistance, which makes the internal resistance of the battery cell containing the composite current collector large, resulting in heat generation during battery charging and discharging, which can easily cause safety problems.
  • the method of increasing the number of tabs is generally adopted, but this reduces the space for accommodating active materials in the battery cell, thereby reducing the energy density of the battery cell.
  • the present application provides a composite current collector, an electrode, a secondary battery and an electrical device, which can solve the technical problem of low energy density of battery cells.
  • the present application provides a composite current collector.
  • the composite current collector of the present application comprises a support layer, the support layer comprises a base layer and a conductor component, the base layer has two opposite surfaces in the thickness direction, the conductor component is arranged in the base layer and/or on the side wall of the base layer adjacent to the surface; and a conductive layer, the conductive layer is stacked on at least one of the surfaces of the base layer, and the conductive layer is electrically connected to the conductor component.
  • the composite current collector of the embodiment of the present application effectively reduces the resistance of the support layer by adding a conductive component to the support layer, which can effectively reduce the number of pole ears of the battery cell containing the composite current collector of the present application, thereby increasing the content of active materials contained in the battery cell, thereby effectively improving the energy density of the battery cell.
  • the conductive component is electrically connected to the conductive layer, thereby effectively reducing the resistance of the composite current collector of the present application, so that the overheating phenomenon of the battery cell containing the composite current collector of the present application during the charging and discharging process is alleviated.
  • the conductor component includes at least one of a conductive connector and a conductive network structure; wherein the conductive network structure is formed by the distribution of conductive additives in the base layer.
  • the conductor component includes the conductive network structure, and the mass of the conductive additive accounts for 10% to 80% of the total mass of the conductive additive and the base layer.
  • the conductor component includes the conductive network structure, and the resistivity of the support layer is greater than 0 and ⁇ 20 ⁇ 10 -8 ⁇ m.
  • the conductive property and mechanical property of the support layer 1 can be improved, such as making the resistivity of the support layer greater than 0 and ⁇ 20 ⁇ 10 -8 ⁇ m.
  • the conductor component includes the conductive network structure, and the conductive additive includes at least one of conductive particles, conductive sheets, and conductive fibers.
  • the material of the conductive particles and the conductive sheets independently includes at least one of a metal element, an alloy, and a conductive composite structure material; and the conductive fibers include at least one of metal fibers and carbon fibers.
  • the conductive composite structural material includes at least one of nickel-coated graphite, nickel-coated carbon fiber, and nickel-coated carbon black.
  • the particle size of the conductive particles is greater than 0 and ⁇ 6 ⁇ m.
  • the length or width of the conductive sheet is greater than 0 and ⁇ 6 ⁇ m.
  • the diameter of the conductive fiber is greater than 0 and ⁇ 6 ⁇ m, and the length of the conductive fiber is greater than 0 and ⁇ 20 mm.
  • the conductive particles and conductive sheets of the above-mentioned particle sizes and types can form a more abundant and uniform conductive network structure in the base layer, and can improve the conductive stability and mechanical properties of the support layer.
  • the conductive layer is stacked on both surfaces of the substrate layer.
  • the conductive layer is stacked on both surfaces of the substrate layer that are opposite to each other, and the support layer can play a conductive connection role between the two conductive layers, thereby improving the overall conductivity of the composite current collector of the present application.
  • the edge of at least one of the conductive layers extends along the side wall of the base layer and is electrically connected to another conductive layer.
  • the conductive layer By controlling the conductive layer to extend along the side wall of the base layer, the relatively stacked conductive layers are electrically connected, which further reduces the overall resistance of the composite current collector of the embodiment of the present application and increases the strength of the stacking combination of the conductive layer and the base layer.
  • the conductor component further includes the conductive connector, and the conductive connector is disposed on the side wall of the base layer and is electrically connected to the two conductive layers at the same time; and/or the conductive connector is embedded in the base layer along the thickness direction of the base layer.
  • the conductive layer is stacked on both surfaces of the base layer, and the conductor member is the conductive connector, which is disposed on the side wall of the base layer and electrically connected to the two conductive layers at the same time; or further, the conductive connector is embedded in the base layer along the thickness direction of the base layer.
  • the resistivity between the two conductive layers is greater than 0 and ⁇ 15 ⁇ 10 ⁇ 8 ⁇ m.
  • the conductive connector includes at least one of the following structures: sheet, strip, mesh, column, sphere, tube, cone.
  • the conductive connectors of these shapes can not only realize the electrical connection of two relatively arranged conductive layers, but also play the role of reinforcing ribs to enhance the mechanical strength of the support.
  • the thickness of the matrix layer is 2-20 ⁇ m.
  • the overall thickness range of the composite current collector of the embodiment of the present application can be adjusted to adjust the mechanical properties of the composite current collector of the embodiment of the present application and reduce the volume of the composite current collector.
  • the tensile strength at break of the matrix layer is ⁇ 100Mpa; the elongation at break of the matrix layer is ⁇ 3%.
  • the tensile strength at break and the elongation at break within this range can effectively improve the overall mechanical properties of the composite current collector of the embodiment of the present application.
  • the material of the base layer includes at least one of silicone rubber, polyolefin, maleic anhydride grafted polyolefin, polyester plastic, and composite resin. Using these polymer substances as the material of the base layer gives the base layer good mechanical properties.
  • the present application provides an electrode, comprising a current collector and an active layer, wherein the current collector is a composite current collector of the present application.
  • the electrode of the present application embodiment has high capacity density and low internal resistance, and has excellent cycle performance.
  • the present application provides a secondary battery, including an electrode, wherein the electrode is an electrode of an embodiment of the present application.
  • the secondary battery of the embodiment of the present application has high energy density, low internal resistance, and improved cycle performance.
  • the present application provides an electric device, the electric device comprising the secondary battery of the present application, the secondary battery being used to provide electric energy.
  • the power supply system contained in the electric device of the present application has stable power supply, long power supply time and high safety.
  • FIG1 is a schematic diagram of a cross-sectional structure of a conventional composite current collector along the length direction;
  • FIG2 is a schematic diagram of a cross-sectional structure of a composite current collector along its length direction in some embodiments of the present application;
  • FIG3 is a schematic diagram of a cross-sectional structure along the length direction of the composite current collector when the conductor component contained in the composite current collector shown in FIG2 is a conductive network structure component;
  • FIG4 is a schematic diagram of a cross-sectional structure along the width direction of the composite current collector shown in FIG3 , in which an edge of a conductive layer included in the composite current collector extends along the side wall of the base layer and is electrically connected to another conductive layer;
  • FIG5 is a schematic diagram of a cross-sectional structure along the length direction of the composite current collector when the conductor component contained in the composite current collector shown in FIG2 is a conductive connector;
  • FIG6 is a schematic diagram of a cross-sectional structure of a composite current collector along its length direction in some other embodiments of the present application.
  • FIG. 7 is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application.
  • a base layer 111, a surface of the base layer 11, 112, another surface 112 of the base layer 11, 113, a side wall of the base layer 11;
  • Conductor components 121.
  • Conductive network structural components 122.
  • Conductive connecting components 122.
  • the term "and/or" is only a description of the association relationship of associated objects, indicating that three relationships may exist.
  • a and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone.
  • the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.
  • multiple refers to more than two (including two).
  • multiple groups refers to more than two groups (including two groups), and “multiple pieces” refers to more than two pieces (including two pieces).
  • Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.
  • the inventors have noticed that the energy density of battery cells containing composite current collectors is relatively low during their charge and discharge cycles.
  • the inventors have further studied and found that the low energy density of such battery cells during their charge and discharge cycles is largely related to the composite current collectors contained in their electrodes.
  • Figure 1 the structure of this type of composite current collector is shown in Figure 1, which includes a support layer 01 and a conductive layer 02 bonded to the opposite surface of the support layer 01, and the support layer 01 is an insulating layer.
  • the conductive layer 02 contained therein has conductive properties, since the support layer 01 is insulating and the relatively arranged conductive layers 02 are separated from each other and not electrically connected, the overall block resistance of the existing composite current collector is large. After being made into a finished battery cell, the internal resistance of the finished battery cell is often large, which causes the battery cell to easily overheat during the charging and discharging process.
  • the current method is to increase the number of tabs contained in the finished battery cells to reduce the internal resistance of the finished battery cells. Although this can reduce the internal resistance of the finished battery cells to a certain extent, it also directly leads to an increase in the space required for folding the tabs during assembly of the finished battery cells, thereby reducing the space for accommodating active substances in the battery cells, thereby reducing the energy density of the finished battery cells.
  • reducing the overall resistance of the composite current collector is one of the effective means to effectively solve the energy density of the finished battery cell. If the overall resistance of the composite current collector can be effectively reduced, the internal resistance of the battery cell can be effectively reduced, thereby effectively reducing the number of tabs contained in the battery cell, thereby effectively increasing the space for the battery cell to accommodate active materials, and thus improving the energy density of the battery cell. In this way, the energy density of the battery cell can be improved.
  • the inventors have designed a composite current collector after in-depth research, by modifying the conductivity of the support layer contained in the composite current collector, that is, adding a conductor component in the base layer of the support layer and/or on the side wall of the base layer, and making the conductor component electrically connected to the conductive layer contained in the composite current collector.
  • the support layer contains a conductor component
  • the support layer is conductive and its resistance is significantly reduced.
  • the conductor component is electrically connected to the conductive layer contained in the composite current collector, thereby significantly reducing the overall resistance of the composite current collector.
  • the composite current collector provided in the embodiment of the present application can be used in a battery cell, which can be used in an electrical device using the battery cell as a power source or various energy storage systems using a battery as an energy storage element.
  • the electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like.
  • the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, and the like
  • the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.
  • the embodiment of the present application provides a composite current collector, the structure of the composite current collector of the embodiment of the present application is shown in Figures 2 to 6, and includes a support layer 1 and a conductive layer 2.
  • the support layer 1 includes a base layer 11 and a conductor component 12, and the base layer 11 has two opposite surfaces 111 and a surface 112 in the thickness direction, and the conductor component 12 is arranged in the base layer 11 or on the side wall 112 of the base layer 11 adjacent to the surface 111 or simultaneously arranged in the base layer 11 and on the side wall 112.
  • the conductive layer 2 is stacked on at least one of the surfaces 111 and 112 of the base layer 11 of the support layer 1, and the conductive layer 2 is electrically connected to the conductor 12.
  • the support layer 1 constitutes the support of the composite current collector of the embodiment of the present application, and serves as a bearing layer structure of the conductive layer 2 , and is used to laminate and combine the conductive layer 2 with the support layer 1 .
  • the base layer 11 serves as the main structure of the support layer 1 and also gives the support layer 1 a morphological structure. At the same time, the base layer 11 also serves as a carrier of the conductor component 12, so that the conductor component 12 is attached to the base layer 11, thereby improving the conductivity of the base layer 11.
  • the conductor component 12 is arranged in dependence on the base layer 11, and serves as a conductive modification component of the support layer 1, thereby reducing the resistance of the support layer 1. At the same time, the conductor component 12 connects the conductive layer 2, thereby improving the overall conductivity of the composite current collector of the embodiment of the present application and reducing its resistance.
  • the conductive layer 2 is stacked with at least one of the surface 111 and the surface 112 of the support layer 1 to serve as the conductive surface of the composite current collector in the embodiment of the present application, and is used for the arrangement of the electrode active layer.
  • the composite current collector of the embodiment of the present application effectively reduces the resistance of the support layer 1 by adding a conductive component 12 to the support layer 1 contained therein.
  • the conductive component 12 is electrically connected to the conductive layer 2, which effectively reduces the resistance of the composite current collector, thereby effectively reducing the internal resistance of the battery cell containing the composite current collector of the embodiment of the present application and reducing the number of poles of the battery cell, increasing the content of active materials contained in the battery cell, and thus improving the energy density of the battery cell. Therefore, based on the composite current collector of the embodiment of the present application, the energy density of the battery cell is improved, and the overheating phenomenon occurring during the charging and discharging process is alleviated.
  • the conductive component 12 Based on the role of the conductive component 12 contained in the support layer 1, as described above, it mainly plays the role of improving the conductivity of the support layer 1 and reducing its resistance. According to the specific type of the conductive component 12, the conductive component 12 can be arranged with the base layer 11 and electrically connected with the conductive layer 2 in at least the following manner.
  • the conductor component 12 includes at least one of a conductive network structure 121 and a conductive connection 122.
  • the conductive network structure 121 refers to a conductive additive distributed in the base layer 11.
  • the conductive connection 122 refers to the conductive network structure 121 and refers to a conductive entity, that is, the conductive network structure 121 is not formed by a conductive additive.
  • These types of conductor components 12 can be effectively arranged on the base layer 11 to improve the conductive performance of the base layer 11, and can effectively achieve electrical connection with the conductive layer 2, thereby reducing the resistance of the support layer 1, that is, can effectively reduce the resistance of the composite current collector of the embodiment of the present application, and can improve the stability of the connection between the conductor component 12 and the base layer 11 and the conductive layer 2, thereby improving the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the conductor component 12 when the conductor component 12 is a conductive network structure 121, as shown in FIG3, the conductive additive constituting the conductive network structure 121 is dispersed in the base layer 11 and forms a conductive network, thereby achieving the effect of improving the conductive performance of the base layer 11.
  • the conductive network structure is electrically connected to the conductive layer 2, that is, the conductive additive 121 dispersed on the surface of the base layer 11 is electrically connected to the surface of the conductive layer 2.
  • the conductive network structure 121 is formed by dispersing the conductive additive, which is also the conductor component 12.
  • the base layer 11 can effectively reduce the resistance of the base layer 11 and give the support layer 1 conductive properties; on the other hand, it can play a mechanical synergistic role with the base layer 11, enhance the strength and stability of the combination of the conductive layer 2 and the base layer 11, improve the mechanical properties and structural stability of the support layer 1, and improve the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the content of the conductive additive in the base layer 11 that forms the conductive network structure 121 in FIG. 3 may be 10% to 80% of the total mass of the conductive additive and the base layer 11, and may be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc., which are typical but non-limiting contents.
  • the conductive additive can form the conductive network structure 121 in the base layer 11, thereby improving the mechanical synergistic effect between the conductive additive and the base layer 11, improving the mechanical properties of the support layer 1, and further improving the processing stability and working stability of the composite current collector in the embodiment of the present application.
  • the conductive additive forms a conductive network structure 121 in the base layer 11 , giving the support layer 1 a resistivity greater than 0 and ⁇ 20 ⁇ 10 ⁇ 8 ⁇ m.
  • the conductive additive forming the conductive network structure 121 in FIG3 may include at least one of conductive particles, conductive sheets, and conductive fibers.
  • the conductive agents of these morphologies can be effectively dispersed in the base layer 11 and form a stable and rich conductive network, thereby improving the conductivity of the support layer 1, reducing its resistance, and playing a mechanical synergistic role with the base layer 11, thereby improving the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the conductive additive when the conductive additive is a conductive particle or a conductive sheet, the particle size of the conductive particle is greater than 0, ⁇ 6 ⁇ m, and further can be ⁇ 2 ⁇ m, and the length or width of the conductive sheet is greater than 0, ⁇ 6 ⁇ m.
  • the materials of the conductive particles and the conductive sheets may include at least one of a metal element, an alloy, and a conductive composite structural material.
  • the conductive composite structural material may include at least one of nickel-coated graphite, nickel-coated carbon fiber, and nickel-coated carbon black.
  • the conductive particles and conductive sheets of these particle sizes and types can have better dispersibility in the base layer 11, and the conductive network contained in the formed conductive network structure 121 is richer and more uniform, which can improve the conductive stability of the support layer 1, and can also improve the mechanical synergistic effect of the conductive additive and the base layer 11.
  • the conductive additive when the conductive additive is a conductive fiber, the diameter of the conductive fiber is greater than 0, ⁇ 6 ⁇ m, and the length of the conductive fiber is greater than 0, ⁇ 20 mm.
  • the conductive fiber may include at least one of metal fiber and carbon fiber. After the conductive fibers of these lengths and types are dispersed in the base layer 11, the probability of contacting each other is higher, the guided network structure formed is richer and more uniform, and the conductive network structure 121 formed is more stable, thereby improving the conductive stability of the support layer 1, and further improving the mechanical synergistic effect between the conductive fibers and the base layer 11.
  • the conductive additives mentioned above can be formed into the conductive network structure 121 as shown in FIG. 3 by forming a mixture of the material of the base layer 11 and components such as the conductive additives, which is then prepared and formed according to the requirements of the film layer, so that the conductive additives are in-situ dispersed in the base layer 11 to form the conductive network structure 121.
  • a conductive layer 2 is stacked on both the surface 111 and the surface 112 of the substrate layer 11, that is, the conductive layer 2 is stacked on both the surface 111 and the surface 112 of the substrate layer 11, as shown in FIG3.
  • the conductive layer 2 is stacked on both the surface 111 and the surface 112 of the substrate layer 11, and the support layer 1 not only plays the role of a support for the conductive layer 2, but also plays a conductive connection role between the two layers of the conductive layer 2, thereby improving the overall conductivity of the composite current collector of the embodiment of the present application, and effectively reducing the resistance of the composite current collector of the embodiment of the present application.
  • the conductive layer 2 is a conductive network structure 121 formed by in-situ dispersion of a conductive additive in the substrate layer 11, the conductive layer 2 can be a layer, stacked on any surface of the surface 111 and the surface 112.
  • the edge of at least one conductive layer 2 extends along the side wall 113 of the base layer 11 and is electrically connected to another conductive layer 2. As shown in FIG. 4, the edge of one conductive layer 2 extends an extended end 21 along the side wall 113 of the base layer 11 until it is electrically connected to another conductive layer 2.
  • the conductive layer 2 By controlling the conductive layer 2 to extend along the side wall 113 of the base layer 11, the relatively stacked conductive layers 2 are electrically connected, and the overall resistance of the composite current collector of the present application embodiment is further reduced; and the strength of the stacking combination of the conductive layer 2 and the base layer 11 is also increased, the mechanical properties of the composite current collector of the present application embodiment are improved, and the processing stability and working stability of the composite current collector of the present application embodiment are improved.
  • the support layer 1 also includes a conductive connector 122, which is embedded in the base layer 11 along the thickness direction of the base layer 11. That is, in the exemplary embodiment of the composite current collector shown in FIG5, the conductive network structure 121 and the conductive connector 122 formed by the conductive additive are embedded in the base layer 11 at the same time, and the conductive network structure 121 and the conductive connector 122 together constitute the conductor member 12, then the conductive network structure 121 and the conductive connector 122 are electrically connected to the two conductive layers 2 respectively.
  • the conductive network structure 121 and the conductive connector 122 can play a conductive enhancement role between the conductive network structure 121 and the conductive connector 122, and the conductive performance of the support layer 1 is further increased on the basis of the conductive network structure 121.
  • the conductive connector 122 is embedded and arranged along the thickness direction of the base layer 11, one end thereof is electrically connected to a conductive layer 2, and the other end is electrically connected to another conductive layer 2, thereby effectively enhancing the bonding strength between the conductive layer 2 and the support layer 1, improving the mechanical properties of the composite current collector of the embodiment of the present application, and improving the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the conductive connector 122 contained in the composite current collector shown in FIG. 5 can also be only combined on the surface of the side wall 113 of the base layer 11, and the two ends of the conductive connector 122 are respectively electrically connected to the two conductive layers 2.
  • the conductive connector 122 can be simultaneously arranged on the surface of the side wall 113 of the base layer 11 and embedded in the base layer 11, and the two ends of the conductive connector 122 are respectively electrically connected to the two conductive layers 2.
  • the conductive connector 122 is further provided to achieve the conductive enhancement effect between the electrical network structure 121 and the conductive connector 122, thereby improving the conductivity, processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the conductive connector 122 can also be used as a conductor component 12 alone, that is, when the conductor component 12 is composed of the conductive connector 122. As shown in FIG6, the conductive layer 2 is stacked on the surface 111 and the surface 112 of the base layer 11, and the conductive connector 122 is embedded in the base layer 11 along the thickness direction of the base layer 11. Then the conductive connector 122 is electrically connected to the conductive layer 2, specifically, one end of the conductive connector 122 is electrically connected to one conductive layer 2, and the other end is electrically connected to another conductive layer 2.
  • the two relatively arranged conductive layers 2 can be electrically connected through the conductive connector 122, thereby effectively reducing the resistance between the two conductive layers 2, thereby effectively reducing the resistance of the composite current collector of the embodiment of the present application, and at the same time effectively enhancing the bonding strength between the conductive layer 2 and the support layer 1, improving the mechanical properties of the composite current collector of the embodiment of the present application, and improving the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the conductive connector 122 contained in the composite current collector shown in FIG. 6 can also be only combined on the surface of the side wall 113 of the base layer 11, and the two ends of the conductive connector 122 are respectively electrically connected to the two conductive layers 2.
  • the conductive connector 122 can be simultaneously arranged on the surface of the side wall 113 of the base layer 11 and embedded in the base layer 11, and the two ends of the conductive connector 122 are respectively electrically connected to the two conductive layers 2.
  • the resistance of the composite current collector of the embodiment of the present application can be effectively reduced by the conductive connector 122, and at the same time, the bonding strength between the conductive layer 2 and the support layer 1 is effectively enhanced, the mechanical properties of the composite current collector of the embodiment of the present application are improved, and the processing stability and working stability of the composite current collector of the embodiment of the present application are improved.
  • the support layer contains a conductive connector 122, and the conductive connector 122 is embedded in the base layer, there may be more than two conductive connectors 122, and they are embedded in the base layer at intervals.
  • the resistance between the two conductive layers 2 arranged opposite to each other is reduced, and the uniformity of the resistance between the two conductive layers 2 is improved.
  • the bonding strength between the conductive layer 2 and the support layer 1 can be enhanced, the mechanical properties of the composite current collector of the embodiment of the present application can be improved, and the processing stability and working stability of the composite current collector of the embodiment of the present application can be improved.
  • the plurality of conductive connectors 122 when a plurality of conductive connectors 122 are interspersed and embedded in the base layer 11, the plurality of conductive connectors 122 may be randomly spaced or arranged in an array according to a certain rule. Regardless of the intervals at which they are interspersed and embedded in the base layer 11, improving the uniformity of the resistance between the two conductive layers 2 and reducing the resistance between the two conductive layers 2 are important considerations.
  • the composite current collector of the embodiment of the present application contains two conductive layers 2 arranged opposite to each other, and the conductor member 12 includes a conductive connector 122, that is, when the support layer 1 contains a conductive connector 122, the resistivity between the two conductive layers 2 can be greater than 0, ⁇ 15 ⁇ 10-8 ⁇ m.
  • the resistivity in this range can be achieved by adjusting and controlling the size and distribution density of the conductive connector 122. Therefore, the presence of the conductive connector 122 significantly reduces the resistance between the two conductive layers 2, effectively improves the conductivity of the composite current collector of the embodiment of the present application, and significantly reduces the resistance.
  • the above-mentioned conductive connector 122 may include a structural member with at least one of the following shapes: sheet, strip, mesh, column, sphere, tube, cone.
  • the material of the conductive connector 22 may be a metal member, a conductive filler, such as a sheet, strip, mesh, column, etc.
  • the structural members of these shapes can not only realize the electrical connection of the two relatively arranged conductive layers 2, but also play the role of reinforcing ribs, especially when they penetrate and are embedded in the base layer 11, they can play the role of reinforcing ribs, enhance the mechanical strength of the support body, and also enhance the stacking bonding strength between the two relatively arranged conductive layers 2 and the support layer 1, thereby enhancing the structural stability of the composite current collector of the embodiment of the present application, and improving the processing stability and working stability of the composite current collector of the embodiment of the present application.
  • the thickness d1 of the base layer 11 contained in the support layer 1 in the above embodiments can be set to 2-20 ⁇ m, further can be 3-20 ⁇ m, specifically can be 2 ⁇ m, 5 ⁇ m, 8 ⁇ m, 10 ⁇ m, 12 ⁇ m, 15 ⁇ m, 17 ⁇ m, 20 ⁇ m, etc. Typical but non-limiting thicknesses.
  • the thickness d1 of the base layer 11 is the vertical distance between the surface 111 and the surface 112 thereof.
  • the overall thickness range of the composite current collector of the embodiment of the present application can be adjusted to adjust the mechanical properties of the composite current collector of the embodiment of the present application.
  • the above-mentioned thickness range of the base layer 11 can enhance the mechanical strength of the composite current collector of the embodiment of the present application, improve the mechanical strength of the composite current collector of the embodiment of the present application during processing and use, avoid undesirable phenomena such as breakage, and play a good skeleton role for the conductive component 12 and a good supporting role for the conductive layer 2, thereby improving the mechanical processing stability and working stability of the composite current collector of the embodiment of the present application, extending the service life of the composite current collector of the embodiment of the present application, and can reduce the volume of the composite current collector of the embodiment of the present application, and improve the energy density of the battery cell.
  • the tensile strength at break (TD/MD) of the base layer 11 can be controlled to be ⁇ 100Mpa. In other embodiments, the elongation at break (TD/MD) of the base layer 11 contained in the support layer 1 can be controlled to be ⁇ 3%.
  • the material of the base layer 11 is a polymer resin.
  • the material of the base layer 11 includes at least one of silicone rubber, polyolefin, maleic anhydride grafted polyolefin, polyester plastic, and composite resin.
  • polyolefin can be PET, PP, etc.
  • the use of polymer substances as the material of the base layer 11 gives the base layer 11 good mechanical properties, such as the above-mentioned tensile strength at break (TD/MD) can be controlled to be ⁇ 100Mpa, and the elongation at break (TD/MD) can be controlled to be ⁇ 3%.
  • the tensile strength of the composite current collector of the embodiment of the present application containing the base layer 11 can be increased by at least 30%, and the elongation can be increased by at least 15 times.
  • the material of the base layer 11 may also include an auxiliary agent, such as at least one of a flame retardant, a modifier, etc.
  • the flame retardant may include but is not limited to an inorganic flame retardant
  • the modifier may include but is not limited to dithiol.
  • the base layer 11 may also contain a binder, which can adjust the mechanical properties of the base layer 11 and improve the strength and stability of the conductor member 12 loaded in the base layer 11.
  • the material based on the base layer 11 may contain the following components in parts by weight:
  • the polymer material accounts for 20wt% to 100wt%, the binder accounts for ⁇ 30wt%, and the auxiliary agent accounts for ⁇ 40wt%.
  • the thickness of the conductive layer 2 in the above embodiments can be made thinner.
  • the thickness d2 of the conductive layer 2 in the above embodiments can be 0.1 ⁇ m-5 ⁇ m, 0.3 ⁇ m-5 ⁇ m, and specifically can be 0.1 ⁇ m, 0.5 ⁇ m, 1.0 ⁇ m, 1.5 ⁇ m, 2.0 ⁇ m, 2.5 ⁇ m, 3.0 ⁇ m, 3.5 ⁇ m, 4.0 ⁇ m, 4.5 ⁇ m, 5.0 ⁇ m, etc. Typical but non-limiting thicknesses. In this way, the overall thickness and weight of the composite current collector in the embodiment of the present application can be further reduced, thereby further improving the energy density of the battery cell.
  • the material of the conductive layer 2 can be a common electrode material, such as aluminum, or other electrode materials with good conductivity.
  • the conductive layer 2 can be prepared by electroplating or other methods capable of forming the conductive layer 2.
  • the present invention also provides an electrode.
  • the electrode of the present invention comprises a current collector and an active layer.
  • the current collector is the composite current collector of the above-mentioned embodiment of the application.
  • the active layer is an active layer of electrode material containing electrode material, so the active layer can be an active layer containing positive electrode material or an active layer containing negative electrode material.
  • the electrode of the embodiment of the application is a positive electrode
  • the active layer is an active layer containing negative electrode material
  • the electrode of the embodiment of the application is a negative electrode.
  • the electrode of the embodiment of the present application has low internal resistance, high capacity density, and excellent cycle performance.
  • the embodiment of the present application further provides a secondary battery.
  • the secondary battery of the embodiment of the present application includes an electrode, and the electrode is the electrode of the embodiment of the present application containing the composite current collector of the embodiment of the present application.
  • the electrode of the embodiment of the present application constitutes a battery cell with another electrode and a diaphragm in the secondary battery of the embodiment of the present application. Due to the presence of the electrode of the embodiment of the present application, the internal resistance of the battery cell is low, and a relatively small number of tabs can be set, containing more active substances, thereby giving the battery cell a high energy density and good cycle performance. Therefore, the secondary battery of the embodiment of the present application has low internal resistance, high energy density, and improved cycle performance. Moreover, the working performance during the charging and discharging process is stable, overheating is avoided, and the safety of the secondary battery operation is improved.
  • the secondary battery of the present application may include any one of a battery cell, a battery module, and a battery pack.
  • the battery cell refers to a battery housing and the battery cell encapsulated in the battery housing.
  • a battery module is assembled from the battery cells, that is, it may contain multiple battery cells, and the specific number can be adjusted according to the application and capacity of the battery module.
  • a battery pack is assembled from the battery cells, which means it can contain multiple battery cells, and the specific number can be adjusted according to the application and capacity of the battery pack.
  • the battery cells, battery modules and battery packs all contain the above-mentioned composite current collector, the battery cells, battery modules and battery packs have high energy density, good cycle performance, stable charge and discharge performance and high safety.
  • the battery pack of the embodiment of the present application includes a box body 3 and a plurality of battery cells 4, and the plurality of battery cells 4 form a battery module and are contained in the box body 3.
  • the box body 3 is used to provide a storage space for the plurality of battery cells 4, and the box body 3 can adopt a variety of structures.
  • the box body 3 can include a first part 31 and a second part 32, and the first part 31 and the second part 32 cover each other, and the first part 31 and the second part 32 jointly define a storage space for accommodating the plurality of battery cells 4.
  • the second part 32 can be a hollow structure with one end open, and the first part 31 can be a plate-like structure, and the first part 31 covers the open side of the second part 32, so that the first part 31 and the second part 32 jointly define a storage space; the first part 31 and the second part 32 can also be hollow structures with one side open, and the open side of the first part 31 covers the open side of the second part 32.
  • the box body 3 formed by the first part 31 and the second part 32 can be in a variety of shapes, such as a cylinder, a cuboid, etc.
  • the battery pack there may be multiple battery cells 4, and the multiple battery cells 4 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the multiple battery cells 4 are both connected in series and in parallel.
  • the multiple battery cells 4 may be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 4 is accommodated in the box 3; of course, the battery pack may also be a battery module formed by connecting multiple battery cells 4 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 3.
  • the battery pack may also include other structures, for example, the battery pack may also include a busbar component for realizing electrical connection between the multiple battery cells 4.
  • Each battery cell 4 may be a lithium sulfur battery, a sodium ion battery or a magnesium ion battery, but is not limited thereto.
  • the battery cell 4 may be cylindrical, flat, rectangular or in other shapes.
  • the present application also provides an electric device.
  • the electric device of the present application includes the secondary battery of the above-mentioned embodiment of the present application, and the secondary battery is used to provide electric energy for the electric device.
  • the power supply system contained in the electric device of the present application has stable power supply, long power supply time, and high safety.
  • the electrical device may include any one of an electric vehicle, an electric tool, an electronic device, an electric toy, etc., wherein the electric vehicle may include an electric car.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Cell Electrode Carriers And Collectors (AREA)

Abstract

La présente demande divulgue un collecteur de courant composite, une électrode, une batterie secondaire et un dispositif électrique. Le collecteur de courant composite comprend une couche de support et des couches conductrices ; la couche de support comprend une couche de base et un composant conducteur, la couche de base présente deux surfaces opposées dans la direction de l'épaisseur, et le composant conducteur est disposé dans la couche de base et/ou sur la paroi latérale de la couche de base adjacente aux surfaces ; les couches conductrices sont empilées sur au moins une surface de la couche de base, et les couches conductrices sont électriquement connectées au composant conducteur. Selon le collecteur de courant composite, par fourniture additionnelle du composant conducteur dans la couche de support, la résistance de la couche de support est efficacement réduite, de même que la résistance du collecteur de courant composite, de telle sorte que le phénomène de surchauffe dans le processus de charge et de décharge d'éléments de batterie contenant le collecteur de courant composite de la présente demande peut être atténué ; de plus, le nombre de languettes d'élément de batterie contenant le collecteur de courant composite de la présente demande peut être réduit, ce qui permet d'augmenter la teneur en substances actives contenues dans les éléments de batterie et d'améliorer efficacement la densité d'énergie de la batterie secondaire.
PCT/CN2022/123873 2022-10-08 2022-10-08 Collecteur de courant composite, électrode, batterie secondaire et dispositif électrique WO2024073892A1 (fr)

Priority Applications (1)

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PCT/CN2022/123873 WO2024073892A1 (fr) 2022-10-08 2022-10-08 Collecteur de courant composite, électrode, batterie secondaire et dispositif électrique

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PCT/CN2022/123873 WO2024073892A1 (fr) 2022-10-08 2022-10-08 Collecteur de courant composite, électrode, batterie secondaire et dispositif électrique

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102842735A (zh) * 2011-06-24 2012-12-26 夏普株式会社 非水系二次电池及其制造方法
CN110247056A (zh) * 2018-03-30 2019-09-17 宁德时代新能源科技股份有限公司 一种集流体，其极片和电化学装置
CN110943227A (zh) * 2019-05-31 2020-03-31 宁德时代新能源科技股份有限公司 复合集流体、电极极片及电化学装置
US20210111412A1 (en) * 2019-07-01 2021-04-15 Contemporary Amperex Technology Co., Limited Positive electrode current collector, positive electrode piece, electrochemical device and apparatus
CN112687842A (zh) * 2020-12-25 2021-04-20 合肥国轩高科动力能源有限公司 一种双极性电极及电池
CN214254470U (zh) * 2020-12-18 2021-09-21 比亚迪股份有限公司 一种复合集流体、电池极片、电池和车辆

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102842735A (zh) * 2011-06-24 2012-12-26 夏普株式会社 非水系二次电池及其制造方法
CN110247056A (zh) * 2018-03-30 2019-09-17 宁德时代新能源科技股份有限公司 一种集流体，其极片和电化学装置
CN110943227A (zh) * 2019-05-31 2020-03-31 宁德时代新能源科技股份有限公司 复合集流体、电极极片及电化学装置
US20210111412A1 (en) * 2019-07-01 2021-04-15 Contemporary Amperex Technology Co., Limited Positive electrode current collector, positive electrode piece, electrochemical device and apparatus
CN214254470U (zh) * 2020-12-18 2021-09-21 比亚迪股份有限公司 一种复合集流体、电池极片、电池和车辆
CN112687842A (zh) * 2020-12-25 2021-04-20 合肥国轩高科动力能源有限公司 一种双极性电极及电池

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