Electrode sheet, battery cell unit, battery, and electric device

Abstract

An electrode sheet, a battery cell unit, a battery, and an electric device. The electrode sheet comprises a current collector and an active material layer; the current collector comprises a conductive polymer film, and the conductive polymer film is configured to be connected to a polymer material; and the active material layer is provided on at least one surface of the current collector. The electrode sheet has good sealing reliability.

Description

Electrode sheets, cell units, batteries and electrical devices

[0001] This disclosure claims priority to Chinese Patent Application No. 202411203907.8, filed on August 29, 2024, entitled "Electrode, Cell Unit, Battery and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of battery technology, specifically to an electrode, a cell unit, a battery, and an electrical device. Background Technology

[0003] In bipolar batteries, the electrodes are typically made of metal as the current collector. Positive and negative electrode materials are coated on the front and back sides of the current collector, respectively. Then, sealant and physical structural components are used to bond and seal adjacent bipolar electrodes. Common adhesives can achieve bonding and sealing of metal current collectors, but their seal life is short and their reliability is poor in the presence of electrolyte. Therefore, new sealing solutions are needed. Summary of the Invention

[0004] The purpose of this disclosure is to provide an electrode, a cell unit, a battery, and an electrical device that solves the problem of poor sealing reliability of electrodes using metal current collectors.

[0005] To achieve the objectives of this disclosure, the following technical solutions are provided:

[0006] In a first aspect, this disclosure provides an electrode sheet, comprising:

[0007] A current collector, the current collector comprising a conductive polymer film, the current collector being used to connect with a polymer material;

[0008] An active material layer is disposed on at least one surface of the current collector.

[0009] In one embodiment, the conductive polymer film includes a first surface and a second surface disposed opposite to each other, and the active material layer further includes a first active material layer and a second active material layer, wherein the first active material layer is disposed on the first surface and the second active material layer is disposed on the second surface, and the first active material layer and the second active material layer have opposite polarities.

[0010] In one embodiment, the current collector further includes a metal film disposed between the conductive polymer film and the active material layer.

[0011] In one embodiment, the conductive polymer film includes at least one current collector layer.

[0012] In one embodiment, the current collector layer includes a matrix and a conductive material filled inside the matrix, wherein the matrix includes any one of polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyimide, polyphenylene sulfide, and polytetrafluoroethylene.

[0013] In one embodiment, the conductive material includes any one of carbon materials, metallic materials, and conductive polymer materials.

[0014] In one embodiment, the conductive material accounts for a mass ratio of 'a' to the conductive polymer film, satisfying the condition: 1% ≤ a ≤ 50%.

[0015] In one embodiment, the thickness of the conductive polymer film is d1, which satisfies: 10μm≤d1≤25μm.

[0016] In one embodiment, the orthogonal projection of the active material layer onto the current collector is located within the conductive polymer film;

[0017] Furthermore, the four peripheral edges of the conductive polymer film extend beyond the corresponding edges of the active material layer.

[0018] In a second aspect, this disclosure provides a battery cell unit, including a first insulating seal and an electrode, wherein the electrode includes an electrode as described in any embodiment of the first aspect, the first insulating seal is a polymer material, and two adjacent electrodes are connected to the first insulating seal through the conductive polymer film.

[0019] In one embodiment, the battery cell further includes a first outer electrode and a second outer electrode. The first outer electrode, the electrode, and the second outer electrode are stacked in a first direction. The electrode includes a conductive polymer film. The conductive polymer film includes a first surface and a second surface opposite to each other in the first direction. A first active material layer is disposed on the first surface, and a second active material layer is disposed on the second surface.

[0020] The first external electrode includes a first external current collector and a third active material layer. The third active material layer is disposed on the end face of the first external current collector facing the second surface, and the third active material layer has a different polarity from the second active material layer.

[0021] The second outer electrode includes a second outer current collector and a fourth active material layer. The fourth active material layer is disposed on the end face of the second outer current collector facing the first surface, and the fourth active material layer and the first active material layer have opposite polarities.

[0022] In one embodiment, the battery cell unit includes a plurality of electrode sheets, which are stacked in a first direction. A first outer electrode sheet is disposed at one end of the plurality of electrode sheets in the first direction, and a second outer electrode sheet is disposed at the other end of the plurality of electrode sheets in the first direction.

[0023] In one embodiment, the battery cell further includes a plurality of second insulating seals, wherein the second insulating seal is disposed between the first external current collector and the current collector, and the second insulating seal is disposed between the second external current collector and the current collector, wherein the second insulating seal is made of polymer material.

[0024] In one embodiment, the first insulating seal and the second insulating seal are made of the same material as the substrate of the current collector layer, and the first insulating seal and the second insulating seal are the same in shape and size.

[0025] In one embodiment, the dimensions of the first insulating seal and the second insulating seal in the second direction are L1, satisfying: 8μm≤L1≤60μm, and the second direction is perpendicular to the first direction.

[0026] In one embodiment, the first insulating seal and the second insulating seal extend beyond the current collector by a length L2 in the second direction, satisfying: 1μm≤L2≤10μm.

[0027] In one embodiment, the width of the heat-pressed seal between the first insulating seal and the second insulating seal in the second direction is L3, which satisfies: 5μm≤L3≤20μm.

[0028] In one embodiment, the dimensions of the first insulating seal and the second insulating seal in the first direction are d2, satisfying: 60μm≤d2≤200μm.

[0029] In one embodiment, the battery cell further includes a plurality of separators, wherein the separator is disposed between the first active material layer and the fourth active material layer, and between the second active material layer and the third active material layer, and the end of the separator in the second direction is connected to the second insulating seal.

[0030] Thirdly, this disclosure provides a battery including at least one cell unit as described in any embodiment of the second aspect.

[0031] In one embodiment, the battery includes a casing, and the cell unit is housed within the casing. The cell unit includes an electrode, a first outer electrode, and a second outer electrode. The first outer electrode, the electrode, and the second outer electrode are stacked in a first direction. The electrode includes a first surface and a second surface opposite to each other in the first direction. A first active material layer is disposed on the first surface, and a second active material layer is disposed on the second surface. The first direction is perpendicular to the first surface.

[0032] The first external electrode includes a first external current collector and a third active material layer. The third active material layer is disposed on the end face of the first external current collector facing the second surface, and the third active material layer has a different polarity from the second active material layer.

[0033] The second outer electrode includes a second outer current collector and a fourth active material layer. The fourth active material layer is disposed on the end face of the second outer current collector facing the first surface. The fourth active material layer and the first active material layer have opposite polarities.

[0034] The housing includes a first surface and a second surface opposite to each other in the first direction, the first surface being electrically connected to the first outer electrode and the second surface being electrically connected to the second outer electrode.

[0035] Fourthly, this disclosure provides an electrical device, including an electrical appliance and a battery cell unit as described in any embodiment of the second aspect or a battery as described in any embodiment of the third aspect, wherein the battery or the battery cell unit supplies power to the electrical appliance.

[0036] The electrode provided in this disclosure includes a current collector, which comprises a conductive polymer film. An active material layer is disposed on the current collector. The current collector, which includes a conductive polymer film, can meet the current conduction requirements in electrode applications. Secondly, when sealing the electrodes of a bipolar battery, the sealant and / or sealing element are mostly made of polymer materials. The conductive polymer film of this disclosure can be connected to the polymer material (i.e., to the sealant) to achieve sealing between the electrodes. Because homogeneous materials (same or similar substances, in this disclosure, referring to both being organic substances) have stronger bonding, the sealing reliability is higher. Furthermore, there is no need for passivation or other anti-corrosion treatment on the surface of the current collector, and it avoids the sealing failure and leakage problems caused by oxidation corrosion and electrolyte corrosion that exist in the use of metal current collectors. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a cross-sectional view of an electrode sheet according to an embodiment;

[0039] Figure 2 is a cross-sectional view of a battery cell unit according to an embodiment;

[0040] Figure 3 is a cross-sectional view of a battery cell unit according to another embodiment.

[0041] Explanation of reference numerals in the attached drawings: 100-cell unit, 10-electrode, 11-current collector, 111-first surface, 112-second surface, 12-first active material layer, 13-second active material layer, 20-first outer electrode, 21-first outer current collector, 22-third active material layer, 30-second outer electrode, 31-second outer current collector, 32-fourth active material layer, 41-first insulating seal, 42-second insulating seal, 50-receiving space, 60-diaphragm, X-first direction, Y-second direction. Detailed Implementation

[0042] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0043] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.

[0044] Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the specification of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used in this disclosure includes any and all combinations of one or more of the associated listed items.

[0045] The following detailed description of some embodiments of this disclosure is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0046] Referring to Figure 1, this disclosure provides an electrode 10, which includes a current collector 11 and an active material layer; the current collector 11 includes a conductive polymer film and is used to connect with the polymer material. The active material layer is disposed on at least one surface of the current collector 11.

[0047] Optionally, the conductive polymer film includes a first surface 111 and a second surface 112 disposed opposite to each other in a first direction X. The first direction X is perpendicular to the first surface 111, and the second direction Y is perpendicular to the first direction X.

[0048] Optionally, the active material layer includes a first active material layer 12 and a second active material layer 13. The first active material layer 12 is disposed on the first surface 111, and the second active material layer 13 is disposed on the second surface 112. The first active material layer 12 and the second active material layer 13 have opposite polarities. The presence of the first active material layer 12 and the second active material layer 13 with opposite polarities on both sides of the current collector 11 makes the electrode 10 a bipolar electrode. Bipolar electrodes can improve charge and discharge efficiency, simplify the battery structure, and improve the internal space utilization and energy density of the battery.

[0049] Optionally, the current collector 11 may have an active material layer on only the first surface 111 or the second surface 112. The polarity of the active material layer on the current collector 11 is different from the polarity of its counterpart active material layer.

[0050] Optionally, the current collector 11 has good conductivity in both the first direction X and the second direction Y. The current collector 11 with multi-directional conductivity has a shorter electron transport path, which can effectively reduce the internal resistance of the battery and give full play to the advantages of the electrode 10.

[0051] Optionally, the first active material layer 12 is a positive electrode active material layer and the second active material layer 13 is a negative electrode active material layer; or, the first active material layer 12 is a negative electrode active material layer and the second active material layer 13 is a positive electrode active material layer.

[0052] Specifically, when the first active material layer 12 is a positive electrode active material layer, the first active material layer 12 includes components such as positive electrode material, conductive agent, and binder. This disclosure does not specifically limit these materials, and appropriate materials can be selected according to actual application requirements. The positive electrode material can be a phosphate positive electrode active material or a ternary positive electrode active material. In specific embodiments, it includes one or more of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide phosphate, lithium fluorinated vanadium phosphate, lithium titanate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide. The conductive agent includes one or more of graphite, carbon black, acetylene black, graphene, carbon fiber, C60 (carbon 60), and carbon nanotubes, without limitation. The type of binder includes one or more of polyvinylidene chloride, soluble polytetrafluoroethylene, styrene-butadiene rubber, hydroxypropyl methylcellulose, methylcellulose, carboxymethyl cellulose, polyvinyl alcohol, acrylonitrile copolymer, sodium alginate, chitosan, and chitosan derivatives, without limitation.

[0053] When the second active material layer 13 is a negative electrode active material layer, the second active material layer 13 includes components such as a negative electrode material, a conductive agent, and a binder. The negative electrode material can be graphite-based, silicon-based, or lithium titanate-based, specifically artificial graphite, natural graphite, graphene, etc. The conductive agent and binder can be the same as those in the first active material layer 12.

[0054] Optionally, the current collector 11 can be a single-layer structure.

[0055] The electrode 10 disclosed herein uses a conductive polymer film as a current collector 11 and an active material layer is provided on the current collector 11. Using a conductive polymer film as the current collector 11 can meet the current conduction requirements in the application of the electrode 10. Moreover, both the conductive polymer film and the adhesive are organic materials during the sealing process, resulting in stronger bonding between homogeneous materials. This makes it easier to achieve bonding and sealing with polymer seals. Furthermore, there is no need to perform anti-corrosion treatments such as passivation on the surface of the conductive polymer film, and it avoids sealing failure and leakage problems caused by oxidation corrosion and electrolyte corrosion that exist in the use of metal current collectors. The sealing reliability of this electrode 10 is higher.

[0056] In one embodiment, the current collector 11 further includes a metal film disposed between the conductive polymer film and the active material layer.

[0057] Optionally, when the current collector 11 is provided with a metal film, the active material layer is disposed on the surface of the metal film facing away from the conductive polymer film.

[0058] Optionally, a metal film is disposed on at least one surface of the conductive polymer film in the first direction X.

[0059] The metal film can be aluminum film, copper film, silver film, etc., without restriction.

[0060] Optionally, the size of the metal film is smaller than that of the conductive polymer film, and the portion of the conductive polymer film extending beyond the metal film is used for connection with the polymer material.

[0061] Setting a metal film between the conductive polymer film and the active material layer is beneficial to enhancing the conductivity of the current collector 11 and meeting the current conduction requirements of the electrode 10.

[0062] In one embodiment, the current collector 11 includes at least one current collection layer.

[0063] Optionally, multiple current collectors are stacked in the first direction X, and the materials of the multiple current collectors can be the same or different. Optionally, the current collectors located near the first active material layer 12 or the second active material layer 13 have better conductivity. The current collector located in the central region in the first direction X can have stronger structural strength, which is beneficial to improving the mechanical strength and stability of the current collector 11. Optionally, the current collectors near the first active material layer 12 or the second active material layer 13 can be metal layers or conductive polymer layers; the materials of the current collectors near the first active material layer 12 or the second active material layer 13 can be the same or different, without limitation.

[0064] Specifically, when the current collector is a metal layer and the active material layer is a negative electrode active material layer, the metal layer on the side closer to the negative electrode active material layer is a copper layer; when the current collector is a metal layer and the active material layer is a positive electrode active material layer, the metal layer on the side closer to the positive electrode active material layer is an aluminum layer.

[0065] The multi-layered current collector structure allows for flexibility and customization based on specific needs. By adjusting the materials and thicknesses of different layers, efficient current collection and conduction can be achieved, increasing the energy density and power density of the electrode 10. Simultaneously, the multi-layered current collector also enhances the mechanical strength and stability of the electrode 10, reducing the risk of short circuits and overheating, and improving battery safety.

[0066] In one embodiment, the current collector layer includes a matrix and a conductive material filled inside the matrix. The matrix includes any one of polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyimide, polyphenylene sulfide, and polytetrafluoroethylene. The matrix can also be polyacetylene, polyaniline, polypyrrole, polythiophene, etc., without limitation.

[0067] Optionally, there may be multiple current collector substrates, with gaps formed between them, and conductive material filling the gaps. Alternatively, bonding and reactions may occur between the conductive material and the current collector substrate.

[0068] Specifically, a polymer matrix material is used to fill a polymer matrix material to form a polymer conductive component.

[0069] Conductive materials can be carbon materials, metallic materials, and conductive polymer materials.

[0070] Carbon materials include at least one of carbon black, carbon nanotubes, and graphene.

[0071] Metallic materials include at least one of gold, silver, platinum, palladium, nickel, titanium, copper, and aluminum.

[0072] Conductive polymeric materials include at least one of polyaniline, polypyrrole, polythiophene, and polyacetylene.

[0073] Preferably, the conductive material is a metallic material, which has good conductivity, is easy to process and disperse, and can also suppress lithium plating.

[0074] The metallic material can be either metal particles or metal wires. In some embodiments of this application, the size of the metal particles is 20 nm to 2000 nm. Controlling the size of the metal particles within this range facilitates their dispersion in the polymer matrix and effectively reduces undesirable phenomena such as agglomeration, thereby improving the uniformity of the polymer as a flux layer. It should be noted that when the metallic material is metal particles, the above-mentioned size refers to the particle size (D50); when the metallic material is metal wires, the axial or radial dimension of the metal wires is in the range of 20 nm to 2000 nm. Furthermore, the size of the metal wires is 80 nm to 1000 nm. Nanowires with sizes within this range have better bonding with the polymer matrix and can form a more stable polymer matrix. Specifically, the dimensions of the metallic materials can be, for example, 2nm, 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, or 100nm. In the embodiments of this application, scanning electron microscopy can be used to characterize the dimensions of the nanomaterials.

[0075] In one embodiment, the mass ratio of conductive material to conductive polymer film in the current collector layer is 'a', satisfying the condition: 1% ≤ a ≤ 50%. Specifically, the mass ratio of conductive material can be 1%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. Preferably, the mass ratio of conductive material added to the conductive polymer film is 10%-40%. Within this range, the mass ratio of conductive material satisfies the current-carrying function of the current collector 11, and due to the good thermal conductivity of metal particles, the heat distribution in the current collector layer and the bonding area is uniform, thereby enhancing the sealing effect of the battery during high-temperature use.

[0076] When a < 1%, the conductive material has a poor effect on improving the conductivity of the conductive polymer film. When a > 50%, the conductive material is prone to agglomeration in the conductive polymer film, resulting in uneven heat distribution in the conductive polymer film. When 1% ≤ a ≤ 50%, the conductive particles are evenly distributed in the conductive polymer film and can effectively improve the conductivity of the conductive polymer film.

[0077] In one embodiment, when a conductive polymer is used as the substrate of the current collector layer, the conductivity of the substrate is ≥10 S / m. Conductivity within this range can further increase the rate performance and cycle stability of the battery. In this embodiment, a conductivity meter can be used to test the conductivity of the current collector 11.

[0078] This disclosure adds conductive particles to the matrix to enable the current collector 11 to meet the current conduction requirements of the electrode 10, thereby improving the conductivity of the current collector 11.

[0079] In one embodiment, the thickness of the conductive polymer film is d1, satisfying: 10μm≤d1≤25μm. Optionally, d1 can be 10μm, 15μm, 20μm, 25μm, etc.

[0080] When d1 < 10 μm, the conductive polymer film of current collector 11 is too thin, which will lead to a decrease in the electronic conductivity and mechanical strength of current collector 11, making it prone to deformation or damage during use. When d1 > 25 μm, the conductive polymer film of current collector 11 is too thick, which will increase the internal resistance of the battery, limit the charging and discharging speed of the battery, and also increase the size and weight of the battery, affecting the flexibility and portability of the battery. When 10 μm ≤ d1 ≤ 25 μm, the conductive polymer film of current collector 11 can simultaneously ensure electronic conductivity and internal resistance of the battery, thereby improving the cycle performance of the battery.

[0081] Referring to Figure 1, in one embodiment, the orthographic projection of the active material layer on the current collector 11 is located within the conductive polymer film; and the four peripheral edges of the conductive polymer film extend beyond the corresponding edges of the active material layer.

[0082] Optionally, the orthographic projection of the first active material layer 12 on the first surface 111 is located within the first surface 111; the orthographic projection of the second active material layer 13 on the second surface 112 is located within the second surface 112; and the four peripheral edges of the conductive polymer film extend beyond the corresponding edges of the first active material layer 12 and the second active material layer 13.

[0083] Optionally, the projected shape of the first active material layer 12 and / or the second active material layer 13 can be any of a circle, a rectangle, etc., without limitation.

[0084] The fact that the periphery of the conductive polymer film extends beyond the corresponding edge of the active material layer helps to improve the current collection efficiency, and allows for the conduction and dispersion of abnormal current and heat generated inside the electrode 10, thereby increasing the safety and stability of the electrode 10. It also facilitates the assembly and connection of the electrode 10, such as by setting a first insulating seal 41 at the periphery of the conductive polymer film to connect with the other electrodes.

[0085] Referring to Figure 2, this disclosure provides a battery cell unit 100, including a first insulating seal 41 and an electrode 10 as described in any of the preceding embodiments. The first insulating seal 41 is made of a polymer material, and two adjacent electrode 10s are connected to the first insulating seal 41 through a conductive polymer film.

[0086] The battery cell unit 100 using the electrode 10 of this disclosure has better charging power and output power, and the electrode 10 using a conductive polymer film as the current collector 11 has a better sealing effect with the first insulating sealant 41 of polymer material.

[0087] Referring to Figure 2, in one embodiment, the battery cell 100 further includes a first outer electrode 20 and a second outer electrode 30. The first outer electrode 20, the electrode 10, and the second outer electrode 30 are stacked in a first direction X, which is perpendicular to the first surface 111. The first outer electrode 20 includes a first outer current collector 21 and a third active material layer 22. The third active material layer 22 is disposed on the end face of the first outer current collector 21 facing the second surface 112 of the electrode 10. The third active material layer 22 has a different polarity than the second active material layer 13. The second outer electrode 30 includes a second outer current collector 31 and a fourth active material layer 32. The fourth active material layer 32 is disposed on the end face of the second outer current collector 31 facing the first surface 111 of the electrode 10. The fourth active material layer 32 has a different polarity than the first active material layer 12.

[0088] Optionally, the third active material layer 22 has the same polarity as the first active material layer 12 and has similar composition.

[0089] Optionally, the fourth active material layer 32 has the same polarity as the second active material layer 13 and has similar composition.

[0090] Optionally, the first external current collector 21 and / or the second external current collector 31 may be a conductive polymer film or a metal foil, without limitation. Preferably, the first external current collector 21, the second external current collector 31, and the current collector 11 all include a conductive polymer film.

[0091] The current collectors of all electrodes in the battery cell unit 100 disclosed herein are made of conductive polymer film. The conductive polymer film has good conductivity in both the first direction X and the second direction Y, resulting in a shorter electron transport path and effectively reducing the internal resistance of the battery.

[0092] Referring to Figure 3, in one embodiment, the battery cell unit 100 includes a plurality of electrode sheets 10, which are stacked in a first direction X. A first outer electrode sheet 20 is disposed at one end of the plurality of electrode sheets 10 in the first direction X, and a second outer electrode sheet 30 is disposed at the other end of the plurality of electrode sheets 10 in the first direction X.

[0093] Optionally, the number of electrodes 10 can be 2, 6, 10, 20, etc., without restriction.

[0094] Setting multiple electrodes 10 in the cell unit 100 is beneficial to improving the energy density of the cell unit 100.

[0095] Referring to Figures 2 and 3, in one embodiment, the battery cell unit 100 further includes a plurality of second insulating seals 42. A second insulating seal 42 is disposed between the first external current collector 21 and the conductive polymer film, and a second insulating seal 42 is disposed between the second external current collector 31 and the conductive polymer film. The second insulating seal 42 is made of polymer material.

[0096] Optionally, when there are multiple electrode plates 10, a first insulating seal 41 is provided between two adjacent current collectors 11.

[0097] The first insulating seal 41 and the second insulating seal 42 may be made of at least one of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride or rubber.

[0098] In one embodiment, the first insulating seal 41 and the second insulating seal 42 are made of the same material as the substrate of the current collector 11, and the first insulating seal 41 and the second insulating seal 42 are the same in shape and size.

[0099] Specifically, the material of the connection between the first insulating seal 41 and the second insulating seal 42 and the conductive polymer film is the same as the substrate corresponding to the current collector 11. For example, the current collector 11 is a polyethylene-based conductive component, that is, the substrate of the current collector layer is polyethylene, and the corresponding first insulating seal 41 and second insulating seal 42 are polyethylene.

[0100] The advantage of this design is that the polymer materials of similar structural units have stronger bonding, resulting in better adhesion and sealing between the first insulating seal 41, the second insulating seal 42, and the conductive polymer film.

[0101] The connection between the first insulating seal 41 and the second insulating seal 42 and the conductive polymer film of any current collector 11 can be achieved by thermo-press sealing. The connection between the first insulating seal 41, the second insulating seal 42 and any current collector can be completed without the need for other sealing structures or physical structural components. The sealing structure and sealing process of the battery cell unit 100 disclosed herein are simple, have lower cost, and longer sealing life.

[0102] The first insulating seal 41 or the second insulating seal 42 and the two adjacent electrode plates 10 enclose a sealed receiving space 50, which is suitable for containing an electrolyte. The electrolyte can be a gel electrolyte, a liquid electrolyte, etc., and there are no restrictions.

[0103] The first insulating seal 41 and the second insulating seal 42 are provided to form a receiving space 50 in any two adjacent electrodes in the cell unit 100, which can contain the electrolyte while preventing electrolyte leakage.

[0104] In one embodiment, the dimensions of the first insulating seal 41 and the second insulating seal 42 in the second direction Y are L1, satisfying: 8μm≤L1≤60μm.

[0105] Optionally, L1 can be 8μm, 20μm, 40μm, 50μm, 60μm, etc., without restriction.

[0106] When L1 < 8μm, the dimensions of the first insulating seal 41 and the second insulating seal 42 in the second direction Y are too small, resulting in a small cross-sectional area with the current collector in the second direction Y, leading to poor sealing effect; when L1 > 60μm, the dimensions of the first insulating seal 41 and the second insulating seal 42 in the second direction Y are too large, resulting in low space utilization of the cell unit 100 and the battery; when 8μm ≤ L1 ≤ 60μm, the first insulating seal 41 and the second insulating seal 42 have a small impact on the cell space utilization while ensuring sealing effect.

[0107] In one embodiment, the first insulating seal 41 and the second insulating seal 42 extend beyond the current collector 11 by a length L2 in the second direction Y, satisfying: 1μm≤L2≤10μm.

[0108] Optionally, L2 can be 1μm, 4μm, 6μm, 8μm, 10μm, etc., without restriction.

[0109] When L1 is 8μm, L2 < 8μm.

[0110] When 1μm≤L2≤10μm, setting L2 allows the first insulating seal 41 and the second insulating seal 42 to extend beyond the current collector 11 by a certain length in the second direction Y. This helps ensure good contact and compression between the first insulating seal 41 and the second insulating seal 42 and the current collector 11, providing a reliable sealing effect. At the same time, L2 also allows the first insulating seal 41 and the second insulating seal 42 to adapt to environmental changes, ensuring that they can maintain a seal under any conditions. Furthermore, the portion of the first insulating seal 41 and the second insulating seal 42 extending beyond the current collector 11 can reduce the risk of short circuits between the current collectors 11. When L2<1μm, the adaptability and sealing reliability of the first insulating seal 41 and the second insulating seal 42 decrease. When L2>10μm, the length of the first insulating seal 41 and the second insulating seal 42 extending beyond the current collector 11 in the second direction Y is too long, which will result in waste of the first insulating seal 41 and the second insulating seal 42.

[0111] In one embodiment, the width of the heat-pressed seal of the first insulating seal 41 and the second insulating seal 42 in the second direction Y is L3, which satisfies: 5μm≤L3≤20μm.

[0112] Optionally, L3 can be 5μm, 10μm, 15μm, 20μm, etc., without restriction.

[0113] When L3 < 5 μm, the thermo-pressed sealing width of the first insulating seal 41 and the second insulating seal 42 is too small, resulting in poor sealing effect between the first insulating seal 41 and the second insulating seal 42 and the conductive polymer film; when L3 > 20 μm, the thermo-pressed sealing width of the first insulating seal 41 and the second insulating seal 42 is too large, reducing the volume of electrolyte that can be accommodated in the housing space 50; when 5 μm ≤ L3 ≤ 20 μm, the first insulating seal 41 and the second insulating seal 42 can ensure the sealing effect while also allowing the housing space 50 to accommodate sufficient electrolyte, and the thermo-pressed sealing width is smaller than that of the prior art, which is beneficial to increasing the energy density of the bipolar battery.

[0114] In one embodiment, the dimensions of the first insulating seal 41 and the second insulating seal 42 in the first direction X are d2, satisfying: 60μm≤d2≤200μm.

[0115] Optionally, d2 can be 60μm, 100μm, 140μm, 170μm, 200μm, etc., without restriction.

[0116] When d2 < 60 μm, the receiving space 50 formed by the first insulating seal 41, the second insulating seal 42, and the corresponding electrode 10 is small, which is not conducive to the reception of electrolyte. When d2 > 200 μm, the first insulating seal 41 and the second insulating seal 42 are too thick, making the size of the cell unit 100 in the first direction X too large, which is not conducive to the subsequent use of the cell unit 100. When 60 μm ≤ d2 ≤ 200 μm, the thickness of the first insulating seal 41 and the second insulating seal 42 is appropriate, which can ensure the volume of electrolyte while also making the application scenarios of the cell unit 100 more extensive.

[0117] Referring to Figures 2 and 3, in one embodiment, the battery cell unit 100 further includes a separator 60. The separator 60 is disposed between the first active material layer 12 and the fourth active material layer 32, and between the second active material layer 13 and the third active material layer 22. The end of the separator 60 in the second direction Y is connected to the second insulating seal 42.

[0118] Optionally, when there are multiple electrodes 10, a diaphragm 60 is provided between the first active material layer 12 and the second active material layer 13 of two adjacent electrodes 10.

[0119] The diaphragm 60 is housed within the containment space 50.

[0120] The diaphragm 60 can be any of the following: woven membrane, nonwoven membrane (non-woven fabric), microporous membrane, composite membrane, diaphragm paper, rolled membrane, etc., without limitation. Specifically, it can be polyethylene, polypropylene, polyvinylidene fluoride, etc.

[0121] The diaphragm 60 is suitable for separating the first active material layer 12 and the second active material layer 13 to prevent them from directly contacting each other and causing a short circuit.

[0122] Optionally, when connecting adjacent current collectors 11, 21, or 31, the first insulating sealant 41 and the second insulating sealant 42 can also use sealant to assist in bonding. The residual rate of the sealant after hot-press sealing can be 50%-70%. The residual rate is the proportion of the sealant that fails to completely cure, evaporate, or penetrate to the intended location after hot-press sealing, and remains on the surface of the workpiece or in the gaps. The test method for the residual rate can be the weighing method, the area measurement method, etc.

[0123] Specifically, the residual adhesive rate can be 50%, 55%, 60%, 65%, or 70%. Using sealant to assist the first insulating seal 41 and the second insulating seal 42 helps to improve the sealing performance of the battery cell 100, while also helping to strengthen the connection between the diaphragm 60 and the second insulating seal 42, and reducing the displacement of the diaphragm 60 during use.

[0124] This disclosure provides a battery cell, including at least one battery cell unit 100 as described in any of the preceding embodiments.

[0125] Optionally, the battery cell includes a plurality of battery cell units 100 stacked in the first direction X, and the first external current collector 21 of the first external electrode 20 and the second external current collector 31 of the second external electrode 30 of two adjacent battery cell units 100 are stacked, and the first external current collector 21 and the second external current collector 31 are both conductive polymer films.

[0126] In the battery cell disclosed herein, the electrode 10, the first outer electrode 20, and the second outer electrode 30 all adopt a conductive polymer film. The conductive polymer film has good conductivity in both the first direction X and the second direction Y, resulting in a shorter electron transport path, which can effectively reduce the internal resistance of the battery and fully leverage the advantages of the electrode 10.

[0127] This disclosure provides a battery including at least one cell unit 100 as described in any of the preceding embodiments and / or at least one cell as described in any of the preceding embodiments.

[0128] The battery also includes a casing, and the cell unit 100 and / or the cell are housed within the casing. The casing includes a first surface and a second surface opposite each other in a first direction X, the first surface being electrically connected to a first outer electrode 20, and the second surface being electrically connected to a second outer electrode 30.

[0129] Specifically, the first surface is bonded to the surface of the first external current collector of the first external electrode 20 where no active material layer is provided, thus achieving electrical connection. The second surface is bonded to the surface of the second external current collector of the second external electrode 30 where no active material layer is provided, thus achieving electrical connection.

[0130] Optionally, the battery can be a prismatic battery, a cylindrical battery, or other types such as a prismatic battery, without limitation. Optionally, the casing can be made of a material with high structural strength, specifically metal materials, high-strength plastics, ceramics, etc. Metal materials include aluminum, aluminum alloys, magnesium alloys, iron and iron alloys, etc.

[0131] This configuration facilitates large-area current diversion in the battery, thereby enabling fast charging of the bipolar battery. Optionally, the battery may include multiple cell units 100 stacked in the first direction X, or cells stacked in the first direction X, or a combination of cell units 100 and cells stacked in the first direction X.

[0132] The battery disclosed herein has a simple sealing structure and sealing process, lower cost, and longer sealing life.

[0133] This disclosure provides an electrical device, including an electrical appliance and a battery or a battery cell unit as described in any of the foregoing embodiments, wherein the battery or battery cell unit supplies power to the electrical appliance. The electrical device may be an engine, a lighting system, etc., and is not limited thereto.

[0134] The technical solutions of this disclosure will be described in detail below through specific embodiments.

[0135] Both the examples and comparative examples are lithium-ion bipolar batteries. The battery includes one cell unit, which includes a first outer electrode, an electrode, and a second outer electrode stacked in a first direction. The first active material layer is the positive electrode formula of the lithium-ion battery, and the second active material layer is the negative electrode formula of the lithium-ion battery.

[0136] Example 1

[0137] The number of electrodes is 6. The electrolyte is liquid. The substrate of the conductive polymer film in the current collector, as well as the first and second insulating seals, are all made of PET (polyethylene terephthalate). The conductive material is metallic copper particles with a particle size of 1000 nm and a mass percentage of 50%. d1 = 15 μm, d2 = 100 μm, L1 = 25 μm, L2 = 2 μm, L3 = 6 μm.

[0138] Example 2

[0139] The difference between Example 2 and Example 1 is that the mass percentage of copper particles is 1%.

[0140] Example 3

[0141] The difference between Example 3 and Example 1 is that the mass percentage of copper particles is 10%.

[0142] Example 4

[0143] The difference between Example 4 and Example 1 is that the mass percentage of copper particles is 30%.

[0144] Example 5

[0145] The difference between Example 5 and Example 1 is that the mass percentage of copper particles is 40%.

[0146] Example 6

[0147] The difference between Example 6 and Example 1 is that the main materials of the first insulating seal and the second insulating seal are different from the material of the current collector. The main material of the first insulating seal and the second insulating seal is PI (polyimide), while the main material of the current collector is PET.

[0148] Example 7

[0149] The difference between Example 7 and Example 1 is that the electrolyte is in a gel state, and the liquid content is 30% compared to a liquid electrolyte.

[0150] Example 8

[0151] The difference between Example 8 and Example 1 is that the conductive polymer film in the current collector has a three-layer structure, and the matrix material of each conductive polymer film is PP (polypropylene) / PET / PP, respectively. The material of the first insulating seal and the second insulating seal is PP.

[0152] Comparative Example 1

[0153] The difference between Comparative Example 1 and Example 1 is that the current collector is made of copper-aluminum composite foil, with the copper side close to the negative electrode active material layer and the aluminum side close to the positive electrode active material layer.

[0154] Comparative Example 2

[0155] The difference between Comparative Example 2 and Example 7 is that the current collector is made of copper-aluminum composite foil, with the copper side close to the negative electrode active material layer and the aluminum side close to the positive electrode active material layer.

[0156] Sealing life test:

[0157] The batteries obtained in the examples and comparative examples were placed in an 85°C environment to accelerate the test of their sealing life, and the time when the battery started to leak was detected in days. The test results are shown in Table 1.

[0158] Table 1

[0159] As shown in Table 1, comparing Examples 1 to 8 and Comparative Examples 1 to 2, the sealing life of batteries using conductive polymer films as current collectors is greater than that of batteries using metal composite foils as current collectors.

[0160] Comparing Examples 1 to 5, it can be seen that as the mass percentage of added copper particles increases, the leakage time of the battery at 85°C first increases and then decreases, and the sealing life of the battery first increases and then decreases.

[0161] Comparing Examples 1 and 6, it can be seen that, compared to batteries where the main material of the insulating seal and the current collector are different, batteries where the main material of the insulating seal and the current collector are the same polymer have a better sealing life.

[0162] Comparing Examples 1 and 8, it can be seen that when the current collector uses multiple layers of different substrates, the battery has a longer sealing life.

[0163] Comparing Examples 1 and 7, it can be seen that the battery using a gel electrolyte has a longer sealing life compared to the liquid electrolyte.

[0164] In the description of the embodiments of this disclosure, it should be noted that the orientation or positional relationship of the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and other indicators are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0165] The above-disclosed embodiments are merely preferred embodiments of this disclosure and should not be construed as limiting the scope of this disclosure. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments, and equivalent variations made in accordance with the claims of this disclosure, still fall within the scope of this disclosure.

Claims

1. An electrode (10), characterized in that, include: The current collector (11) includes a conductive polymer film, which can be used to connect with a polymer material; An active material layer is disposed on at least one surface of the current collector (11).

2. The electrode (10) according to claim 1, characterized in that, The conductive polymer film includes a first surface (111) and a second surface (112) facing away from each other. The active material layer also includes a first active material layer (12) and a second active material layer (13). The first active material layer (12) is disposed on the first surface (111), and the second active material layer (13) is disposed on the second surface (112). The first active material layer (12) and the second active material layer (13) have opposite polarities.

3. The electrode (10) according to claim 1, characterized in that, The current collector (11) also includes a metal film disposed between the conductive polymer film and the active material layer.

4. The electrode (10) according to claim 1, characterized in that, The conductive polymer film includes at least one current collector layer.

5. The electrode (10) according to claim 4, characterized in that, The current collector layer includes a matrix and a conductive material filled inside the matrix. The matrix includes any one of polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyimide, polyphenylene sulfide, and polytetrafluoroethylene.

6. The electrode (10) according to claim 5, characterized in that, The conductive material includes any one of carbon materials, metallic materials, and conductive polymer materials.

7. The electrode (10) according to claim 5, characterized in that, The mass ratio of the conductive material to the conductive polymer film is a, satisfying: 1% ≤ a ≤ 50%.

8. The electrode (10) according to claim 1, characterized in that, The thickness of the conductive polymer film is d1, which satisfies the following condition: 10μm≤d1≤25μm.

9. The electrode (10) according to claim 1, characterized in that, The orthogonal projection of the active material layer onto the current collector (11) lies within the conductive polymer film; Furthermore, the four peripheral edges of the conductive polymer film extend beyond the corresponding edges of the active material layer.

10. A battery cell unit (100), characterized in that, It includes a first insulating seal (41) and an electrode (10), wherein the electrode (10) includes the electrode (10) as described in any one of claims 1 to 9, the first insulating seal (41) is a polymer material, and two adjacent electrodes (10) are connected to the first insulating seal (41) through the conductive polymer film.

11. The cell unit (100) according to claim 10, characterized in that, The battery cell unit (100) further includes a first outer electrode (20) and a second outer electrode (30). The first outer electrode (20), the electrode (10) and the second outer electrode (30) are stacked in a first direction (X). The electrode (10) includes a conductive polymer film. The conductive polymer film includes a first surface (111) and a second surface (112) that are opposite to each other in the first direction (X). The first surface (111) is provided with a first active material layer (12), and the second surface (112) is provided with a second active material layer (13). The first external electrode (20) includes a first external current collector (21) and a third active material layer (22). The third active material layer (22) is disposed on the end face of the first external current collector (21) facing the second surface (112). The third active material layer (22) and the second active material layer (13) have opposite polarities. The second outer electrode (30) includes a second outer current collector (31) and a fourth active material layer (32). The fourth active material layer (32) is disposed on the end face of the second outer current collector (31) facing the first surface (111). The fourth active material layer (32) and the first active material layer (12) have opposite polarities.

12. The battery cell unit (100) according to claim 11, characterized in that, The battery cell unit (100) includes a plurality of electrode sheets (10), which are stacked in the first direction (X). The first outer electrode sheet (20) is disposed at one end of the plurality of electrode sheets (10) in the first direction (X), and the second outer electrode sheet (30) is disposed at the other end of the plurality of electrode sheets (10) in the first direction (X).

13. The battery cell unit (100) according to claim 11, characterized in that, The battery cell unit (100) further includes a plurality of second insulating seals (42), and the second insulating seals (42) are disposed between the first external current collector (21) and the conductive polymer film, and the second external current collector (31) and the conductive polymer film are disposed between the second insulating seals (42), and the second insulating seals (42) are made of polymer material.

14. The battery cell unit (100) according to claim 13, characterized in that, The first insulating seal (41) and the second insulating seal (42) are made of the same material as the substrate of the current collection layer, and the first insulating seal (41) and the second insulating seal (42) are the same in shape and size.

15. The battery cell unit (100) according to claim 13, characterized in that, The first insulating seal (41) and the second insulating seal (42) have a dimension of L1 in the second direction (Y) that satisfies: 8μm≤L1≤60μm, and the second direction (Y) is perpendicular to the first direction (X).

16. The battery cell unit (100) according to claim 15, characterized in that, The first insulating seal (41) and the second insulating seal (42) extend beyond the current collector (11) in the second direction (Y) by a length L2, satisfying: 1μm≤L2≤10μm.

17. The battery cell unit (100) according to claim 15, characterized in that, The width of the heat-pressed seal of the first insulating seal (41) and the second insulating seal (42) in the second direction (Y) is L3, which satisfies: 5μm≤L3≤20μm.

18. The battery cell unit (100) according to claim 13, characterized in that, The dimensions of the first insulating seal (41) and the second insulating seal (42) in the first direction (X) are d2, which satisfy: 60μm≤d2≤200μm.

19. The battery cell unit (100) according to claim 13, characterized in that, The battery cell unit (100) further includes a separator (60), which is disposed between the first active material layer (12) and the fourth active material layer (32), and between the second active material layer (13) and the third active material layer (22). The end of the separator (60) in the second direction (Y) is connected to the second insulating seal (42).

20. A battery, characterized in that, It includes at least one cell unit (100) as described in any one of claims 10-19.

21. The battery according to claim 20, characterized in that, The battery includes a casing, and the cell unit (100) is housed in the casing. The cell unit (100) includes an electrode (10), a first outer electrode (20), and a second outer electrode (30). The first outer electrode (20), the electrode (10), and the second outer electrode (30) are stacked in a first direction (X). The electrode (10) includes a first surface (111) and a second surface (112) that are opposite to each other in the first direction (X). The first surface (111) is provided with a first active material layer (12), and the second surface (112) is provided with a second active material layer (13). The first direction (X) is perpendicular to the first surface (111). The first external electrode (20) includes a first external current collector (21) and a third active material layer (22). The third active material layer (22) is disposed on the end face of the first external current collector (21) facing the second surface (112). The third active material layer (22) and the second active material layer (13) have opposite polarities. The second outer electrode (30) includes a second outer current collector (31) and a fourth active material layer (32). The fourth active material layer (32) is disposed on the end face of the second outer current collector (31) facing the first surface (111). The fourth active material layer (32) and the first active material layer (12) have opposite polarities. The housing includes a first surface and a second surface opposite each other in the first direction (X), the first surface being electrically connected to the first outer electrode (20) and the second surface being electrically connected to the second outer electrode (30).

22. An electrical appliance, characterized in that, It includes an electrical device and a cell unit (100) as described in any one of claims 10-19 or a battery as described in claim 20 or 21, wherein the cell unit (100) or the battery supplies power to the electrical device.

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