A battery structure

Abstract

The application discloses a battery structure and belongs to the technical field of battery preparation. The battery structure is composed of an electrolytic tank, a positive electrode leading-out area and a negative electrode leading-out area, and the three are relatively sealed and independent. One end of the negative electrode leading-out area and one end of the positive electrode leading-out area are connected with the outer wall of the electrolytic tank respectively, and one side of the positive electrode leading-out area is parallel to the negative electrode leading-out area. The application mainly provides a completely compatible connection mode for different electrode support materials and tab, so that it is possible to use low-cost, lightweight polymer materials, carbon-based materials and composite materials as electrode support materials. The liquid, quasi-liquid and gel-state conductive materials used in the application realize flexible connection of the electrode and the electrode support material, which is beneficial to reducing the ohmic impedance of the battery, improving the reliability of the connection, simplifying the battery production process, shortening the battery preparation process, reducing the battery cost and simultaneously providing a new way for battery lightweight.

Description

Technical Field

[0001] This invention relates to a battery structure and belongs to the field of battery manufacturing technology. Background Technology

[0002] As the global energy crisis worsens, new energy technologies are increasingly gaining attention, leading to a surge in demand for batteries from new energy vehicles and clean energy power generation and storage. Currently, lithium-ion batteries dominate the market. This has both spurred their rapid development and, due to supply shortages, driven up production costs. Despite several optimizations, copper and aluminum foil current collectors in lithium-ion batteries still account for over 10% of the total battery weight and over 8% of the total cost.

[0003] Scholars are exploring both lighter and more economical current collectors and new battery systems, such as sodium-ion, potassium-ion, magnesium-ion, zinc-ion, and aluminum-ion batteries. Against this backdrop, various current collectors have emerged, such as sandwich-structure current collectors with metal plating on both sides of a polymer film, carbon cloth current collectors, and composite current collectors of polymer and carbon-based materials. Despite the advantages of these new current collectors, the difficulty of connecting them to the electrode tabs remains a persistent problem.

[0004] On October 19, 2018, CN108682788A disclosed a flexible lithium battery electrode. Both patents weld metal tabs to both sides of the composite current collector tab part, so that the metal tabs can be used as tabs of the composite current collector. The current in the cell can be delivered through the conversion of the metal tabs.

[0005] CN110936010A, published on March 31, 2020, discloses a method for welding composite current collector tabs in lithium batteries. First, two metal tabs are used to clamp the tabs of the composite current collector tab, namely the tab of the electrode A, and perform a pre-welding to form the electrode B. Then, the electrode B and the electrode A are stacked alternately from bottom to top and pre-welded a second time. Finally, the multilayer metal tabs are finally welded to the corresponding positive or negative electrode tabs of the lithium battery.

[0006] Publication No. CN115548415A disclosed on February 2, 2023, a method for combining a soft-pack cylindrical battery based on a full tab, which is: using laser welding to connect the negative electrode tab to the negative electrode current collector, the negative end face of the full tab core to the negative electrode tab, and the positive current collector to the positive end face of the full tab core, but it is not applicable to the connection of non-metallic current collectors.

[0007] Kazuma Shiraishi et al. (doi.org / 10.2320 / matertrans.M2013424) proposed a method for connecting aluminum and carbon fiber cloth, which requires first nickel plating the carbon fiber cloth, then welding it using a melting method, and finally reinforcing the connection area with ABS resin. This method for connecting metal and non-metal materials is complex and incompatible with current battery manufacturing processes.

[0008] To address the above issues, a battery structure is proposed that can solve the connection problems of various current collectors (metal, non-metal, and composite metal and non-metal current collectors) without changing the electrode structure or increasing the cost of equipment upgrades, thus possessing universal applicability. Summary of the Invention

[0009] The technical problem to be solved by this invention is to provide a battery structure that aims to solve the connection problem between the novel current collector (or electrode support material) and the electrode tab, while simplifying the battery manufacturing process, shortening the battery manufacturing process, reducing the battery production cost, and improving the battery energy density, which has the significance of guiding actual production.

[0010] The technical problem to be solved by this invention is achieved by the following technical solution:

[0011] A battery structure comprising an electrolytic cell, a positive electrode lead-out region, and a negative electrode lead-out region, wherein the three are relatively sealed and independent, one end of the negative electrode lead-out region and one end of the positive electrode lead-out region are respectively connected to the outer wall of the electrolytic cell, and one side of the positive electrode lead-out region is parallel to the negative electrode lead-out region.

[0012] The positive electrode lead-out area is the area where the positive electrode and the tab are connected, including a positive electrode lead-out groove, a positive electrode fixing component, a positive electrode tab lead-out groove and a positive electrode tab fixing component, and a conductive filling material. The positive electrode fixing component fixes the positive electrode and is pressed into the positive electrode lead-out groove, and the positive electrode tab fixing component fixes the positive electrode tab and is pressed into the positive electrode tab lead-out groove.

[0013] The negative electrode lead-out area is the area where the negative electrode connects to the electrode tab, including the negative electrode lead-out groove, the negative electrode fixing component, the negative electrode tab lead-out groove and the negative electrode tab fixing component, and the conductive filling material. The negative electrode fixing component fixes the negative electrode and presses it into the negative electrode lead-out groove, and the negative electrode tab fixing component fixes the negative electrode tab and presses it into the negative electrode tab lead-out groove.

[0014] The conductive filler material is filled in the positive electrode lead-out area and the negative electrode lead-out area respectively, and is used to connect the positive electrode and the positive electrode tab or to connect the negative electrode and the negative electrode tab respectively; the electrolytic cell is filled with electrolyte.

[0015] Preferably, the conductive filler material is in liquid, quasi-liquid, or gel state, and is used for connecting positive electrodes to positive electrodes or negative electrodes to negative electrodes.

[0016] Preferably, the conductive filler material is mercury;

[0017] Liquid alloys with elements such as gallium, bismuth, cadmium, tin, lead, dysprosium, and indium as the main components;

[0018] Or liquid or quasi-liquid materials filled with metallic conductive agents, non-metallic conductive agents, and mixed metallic or non-metallic materials;

[0019] Or conductive gel materials filled with metallic conductive agents, non-metallic conductive agents, and mixed metallic or non-metallic materials;

[0020] It may be a conductive polymer material filled with polypyrrole, polyphenylene sulfide, polyphthalocyanine compounds, polyaniline, polythiophene, or a mixture of metal conductive agents, non-metal conductive agents, or metal or non-metal materials.

[0021] The method for manufacturing the positive electrode of the battery includes the following steps:

[0022] S1. Conductive materials, binders, and conductive additives are mixed in a solvent at a mass ratio of 7-8:1-2:1 to form a slurry.

[0023] S2. Apply the slurry to the support material, dry it, and cut it into a 2cm×2cm+1cm×0.3cm convex electrode sheet, or use 3D printing to print the slurry into a 2cm×2cm+1cm×0.3cm convex electrode sheet.

[0024] Preferably, one end of the positive electrode lead-out region is connected to the negative electrode lead-out region.

[0025] Preferably, one end of the positive electrode lead-out region is close to the negative electrode lead-out region.

[0026] Preferably, the positive electrode lead-out groove, negative electrode lead-out groove, positive electrode tab lead-out groove, and negative electrode tab lead-out groove are all provided with a sealing structure.

[0027] Preferably, the electrode is an electrode in the form of a coating made by fully mixing and coating materials such as support material, active material, conductive additive, binder, modifier, and solvent, or a self-supporting electrode or a 3D printed electrode.

[0028] Preferably, the supporting material on the electrode is a single material or a mixture of two or more materials, including a metal or alloy conductive current collector, a non-metal conductive current collector, a semiconductor material, a non-conductive polymer material, a gel material, or a ceramic material.

[0029] Preferably, the non-metallic conductive current collector is a single material or a mixture of two or more materials such as graphite, graphene, carbon nanotube carbon-based materials, conductive polymer materials, gel materials, ceramic materials, metals and alloys.

[0030] Preferably, the conductive material is one of lithium iron phosphate, lithium manganese oxide, graphite or zinc powder, the conductive additive is carbon black, the binder is polyvinylidene fluoride or sodium carboxymethyl cellulose, the support material is nylon matte finish, conductive carbon cloth, copper foil, and the solvent is N-methylpyrrolidone or water.

[0031] Preferably, the metal conductive agent is silver or copper metal nanoparticles, nanowires, or two-dimensional sheet-like nanomaterials.

[0032] Preferably, silver nanoparticles or silver nanomaterials are dispersed in the slurry to form a conductive silver paste, and the mass fraction of silver nanoparticles or silver nanomaterials in the mixture of silver nanoparticles or silver nanomaterials and slurry is 70-90%.

[0033] Preferably, the electrode tab is made of a single metal or alloy material and a non-metallic conductive material.

[0034] Preferably, the battery in the battery structure is a soft-pack battery, a hard-shell battery, or a 3D-printed battery structure, and the battery shell material is a single metal, a polymer material, a carbon-based material, a ceramic material, or a composite material of two or more.

[0035] It should be noted that electrolytic cell B is the main area of ​​the battery that houses the positive electrode, negative electrode, electrolyte, electrolyte solution, separator, and other structures.

[0036] Preferably, the positive electrode and the positive electrode fixing component, and the electrode tab and the electrode tab fixing component are all connected by fusion welding, pressure welding, riveting, adhesive bonding, threaded connection and other physical and chemical connection methods.

[0037] Preferably, the battery in the battery structure is a monovalent metal and ion battery or a multivalent metal and ion battery.

[0038] Furthermore, monovalent metals include Li, Na, and Ka; multivalent metals include Mg, Zn, and Al.

[0039] The beneficial effects of this invention are: this invention mainly provides a fully compatible connection method for different electrode support materials and electrodes, making it possible to use low-cost, lightweight polymer materials, carbon-based materials and their composite materials as electrode support materials;

[0040] The conductive materials used in this invention, including liquid, quasi-liquid, and gel states, enable flexible connection between electrodes and electrode support materials. This helps reduce the ohmic impedance of the battery, improve the reliability of the connection, simplify the battery manufacturing process, shorten the battery preparation process, reduce battery costs, and also provides a new approach to battery lightweighting. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the present invention;

[0042] Figure 2 The diagram shows the cycle performance of the batteries in Examples 1-4 of this invention.

[0043] In the diagram: negative electrode lead-out area A; electrolytic cell B; positive electrode lead-out area C; positive electrode lead-out groove 1, negative electrode lead-out groove 2, positive electrode tab lead-out groove 3, negative electrode tab lead-out groove 4, positive electrode fixing component 5, negative electrode fixing component 6, positive electrode tab fixing component 7, negative electrode tab fixing component 8. Detailed Implementation

[0044] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this invention, the invention will be further described below in conjunction with specific illustrations and embodiments.

[0045] like Figure 1-2 As shown, a battery structure is provided, which consists of an electrolytic cell B, a positive electrode lead-out region C, and a negative electrode lead-out region A. The three are relatively sealed and independent. One side of the negative electrode lead-out region A and one side of the positive electrode lead-out region C are respectively connected to the outer wall of the electrolytic cell B. One side of the positive electrode lead-out region is parallel to the negative electrode lead-out region.

[0046] The positive electrode lead-out area B is the area where the positive electrode and the tab are connected. It includes the positive electrode lead-out groove 1, the positive electrode fixing component 5, the positive electrode tab lead-out groove 3, the positive electrode tab fixing component 7, and the conductive filling material. The positive electrode fixing component 5 fixes the positive electrode and is pressed into the positive electrode lead-out groove 3, and the positive electrode tab fixing component 7 fixes the positive electrode tab and is pressed into the positive electrode tab lead-out groove 3.

[0047] The negative electrode lead-out area A is the area where the negative electrode and the electrode tab are connected, including the negative electrode lead-out groove 2, the negative electrode fixing component 6, the negative electrode tab lead-out groove 4, the negative electrode tab fixing component 8, and the conductive filling material. The negative electrode fixing component 6 fixes the negative electrode and is pressed into the negative electrode lead-out groove 2, and the negative electrode tab fixing component 8 fixes the negative electrode tab and is pressed into the negative electrode tab lead-out groove 4.

[0048] The conductive filler material is filled into the positive electrode lead-out area A and the negative electrode lead-out area C respectively; the electrolytic cell B is filled with electrolyte.

[0049] One end of the positive electrode lead-out region A is connected to the negative electrode lead-out region C.

[0050] In another embodiment, one end of the positive electrode lead-out region A is close to the negative electrode lead-out region C.

[0051] Example 1

[0052] The battery structure, constructed using the above-described structure, specifically includes an electrolytic cell B (2.5cm × 2.5cm), a positive electrode lead-out area C (1.25cm × 0.5cm), and a negative electrode lead-out area A.

[0053] (1.25cm × 0.5cm) Battery structure with three relatively sealed independent regions.

[0054] The positive electrode is prepared by thoroughly mixing lithium iron phosphate, PVDF binder, and carbon black (mass ratio of 8:1:1) in the solvent N-methylpyrrolidone to form a slurry. After being coated on a nylon matte support material and thoroughly dried, it is cut into a convex electrode sheet (2cm×2cm+1cm×0.3cm) as the positive electrode and pressed into the positive electrode lead-out groove 1.

[0055] The negative electrode is prepared by thoroughly mixing graphite, PVDF binder, and carbon black (mass ratio of 8:1:1) in the solvent N-methylpyrrolidone to form a slurry. After being coated on a nylon matte support material and thoroughly dried, it is cut into a convex-shaped electrode sheet (2cm×2cm+1cm×0.3cm) as the negative electrode and pressed into the negative electrode lead-out groove 2. The positive and negative electrode tabs are also cut into convex shapes and pressed into the positive electrode lead-out groove 5 and the negative electrode lead-out groove 6, respectively.

[0056] The positive electrode lead-out groove 1, negative electrode lead-out groove 2, positive electrode tab lead-out groove 5 and negative electrode tab lead-out groove 6 are sealed structures that also have a fixing function. The positive electrode lead-out area A and the negative electrode lead-out area C are respectively filled with indium gallium tin liquid alloy.

[0057] Conclusion: The resistances at the positive electrode lead-out slot 1, positive electrode tab lead-out slot 5, negative electrode lead-out slot 2, and electrode tab lead-out slot 6 were measured to be 2.5 ohms and 2.2 ohms, respectively. After adding a separator between the positive and negative electrodes of electrolytic cell B and filling it with electrolyte, the cycle performance of the battery was measured as follows: Figure 2 As shown.

[0058] Example 2

[0059] This embodiment is basically the same as Embodiment 1, except that:

[0060] The support material is changed from the nylon matte support material in Example 1 to a conductive carbon cloth support material;

[0061] In Example 1, the indium gallium tin liquid alloy filled in the positive electrode lead-out region A and the negative electrode lead-out region C were replaced with conductive silver paste.

[0062] Conclusion: The resistances across positive electrode lead-out slot 1, positive electrode lead-out slot 5, negative electrode lead-out slot 2, and electrode lead-out slot 6 were measured to be 1.9 ohms and 1.6 ohms, respectively. The cycle performance of the battery was measured as follows: Figure 2 As shown.

[0063] Example 3

[0064] This embodiment is basically the same as Embodiment 1, except that:

[0065] In the positive electrode formulation, lithium iron phosphate in Example 1 is replaced with LiMn2O4;

[0066] On the positive electrode, the support material is changed from the nylon matte support material in Example 1 to a conductive carbon cloth support material.

[0067] In the negative electrode formulation, the graphite in Example 1 is replaced with zinc powder;

[0068] On the negative electrode, the support material is changed from the nylon matte support material in Example 1 to copper foil support material;

[0069] In Example 1, the indium gallium tin liquid alloy filled in the positive electrode lead-out region A and the negative electrode lead-out region C were replaced with conductive gel.

[0070] Conclusion: The resistances at the positive electrode lead-out slot 1, positive electrode lead-out slot 5, negative electrode lead-out slot 2, and electrode lead-out slot 6 were measured to be 3.5 ohms and 1.2 ohms, respectively. The cycle performance of the battery was measured as follows: Figure 2 As shown in the image.

[0071] Example 4

[0072] This embodiment is basically the same as Embodiment 1, except that:

[0073] In the positive electrode formulation, the binder PVDF in Example 1 is replaced with sodium carboxymethyl cellulose, while the rest remains unchanged (mass ratio is 7:2:1);

[0074] The process described in Example 1, which involved "thoroughly mixing the contents in the solvent N-methylpyrrolidone to prepare a slurry, coating it onto a nylon matte support material, drying it thoroughly, and then cutting it into a convex-shaped electrode sheet (2cm×2cm+1cm×0.3cm) as the positive electrode," is replaced with: thoroughly mixing the contents in an aqueous solution, printing a convex-shaped integrated electrode (2cm×2cm+1cm×0.3cm) using 3D printing, and then drying it thoroughly as the positive electrode.

[0075] In the negative electrode formulation, lithium iron phosphate, conductive additive carbon black, and binder PVDF in Example 1 are replaced with graphite, sodium carboxymethyl cellulose, and carbon black (mass ratio 7:2:1), respectively.

[0076] The process described in Example 1, which involved "thoroughly mixing the materials in the solvent N-methylpyrrolidone to prepare a slurry, coating it onto a nylon matte support material, drying it thoroughly, and then cutting it into a convex-shaped electrode sheet (2cm×2cm+1cm×0.3cm) as the negative electrode," is replaced with: thoroughly mixing the materials in an aqueous solution, printing a convex-shaped integrated electrode (2cm×2cm+1cm×0.3cm) using 3D printing, and then drying it thoroughly to use as the negative electrode.

[0077] The positive electrode lead-out region A and the negative electrode lead-out region C, which were respectively filled with indium gallium tin liquid alloy in Example 1, were replaced with polypyrrole;

[0078] Conclusion: The resistances at the positive electrode lead-out slot 1, positive electrode lead-out slot 5, negative electrode lead-out slot 2, and electrode lead-out slot 6 were measured to be 4.1 ohms and 3.5 ohms, respectively. The cycle performance of the battery was measured as follows: Figure 2 As shown in the image.

[0079] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention, all of which fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A battery structure, characterized in that: The battery structure consists of an electrolytic cell, a positive electrode lead-out area, and a negative electrode lead-out area, which are relatively sealed and independent. One end of the negative electrode lead-out area and one end of the positive electrode lead-out area are respectively connected to the outer wall of the electrolytic cell, and one side of the positive electrode lead-out area is parallel to the negative electrode lead-out area. The positive electrode lead-out area is the area where the positive electrode and the tab are connected, including a positive electrode lead-out groove, a positive electrode fixing component, a positive electrode tab lead-out groove and a positive electrode tab fixing component, and a conductive filling material. The positive electrode fixing component fixes the positive electrode and is pressed into the positive electrode lead-out groove, and the positive electrode tab fixing component fixes the positive electrode tab and is pressed into the positive electrode tab lead-out groove. The negative electrode lead-out area is the area where the negative electrode connects to the electrode tab, including the negative electrode lead-out groove, the negative electrode fixing component, the negative electrode tab lead-out groove and the negative electrode tab fixing component, and the conductive filling material. The negative electrode fixing component fixes the negative electrode and presses it into the negative electrode lead-out groove, and the negative electrode tab fixing component fixes the negative electrode tab and presses it into the negative electrode tab lead-out groove. The conductive filling material is filled in the positive electrode lead-out area and the negative electrode lead-out area respectively, for connecting the positive electrode and the positive electrode tab or connecting the negative electrode and the negative electrode tab respectively; the electrolytic cell is filled with electrolyte; The conductive filler material is in liquid, quasi-liquid, or gel state and is used for connecting positive electrodes to positive electrodes or negative electrodes to negative electrodes.

2. The battery structure according to claim 1, characterized in that: One end of the positive electrode lead-out region is connected to the negative electrode lead-out region.

3. The battery structure according to claim 1, characterized in that: One end of the positive electrode lead-out region is close to the negative electrode lead-out region.

4. The battery structure according to claim 1, characterized in that: The positive electrode lead-out groove, negative electrode lead-out groove, positive electrode tab lead-out groove, and negative electrode tab lead-out groove are all equipped with a sealing structure.

5. A battery structure according to claim 1, characterized in that: The conductive filler material is mercury; Or liquid alloys with gallium, bismuth, cadmium, tin, lead, dysprosium, and indium as the main components; It may be polypyrrole, polyphenylene sulfide, polyphthalocyanine compounds, polyaniline, or polythiophene.

6. A battery structure according to claim 1, characterized in that: The battery casing material is a single metal, a polymer material, a carbon-based material, a ceramic material, or a composite material of two or more types; the battery in the battery structure is a monovalent metal and ion battery or a multivalent metal and ion battery.

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