Battery unit, flexible battery, battery pack and vehicle

Abstract

The invention discloses a battery unit, a flexible battery, a battery pack and a vehicle, relates to the technical field of batteries, and aims to solve the problems of relatively poor stability and relatively low space utilization rate of battery unit integration. The battery unit comprises a positive electrode diaphragm and a negative electrode diaphragm, the positive electrode diaphragm and the negative electrode diaphragm are located on the same plane and arranged at an interval, and the area of the positive electrode diaphragm is larger than that of the negative electrode diaphragm.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a flexible battery, a battery pack and a vehicle. Background Art

[0002] With the rapid development of battery technology, integrated batteries have great advantages in improving battery energy density, flexibility and optimizing battery performance.

[0003] In the manufacturing field of lithium-ion batteries or sodium-ion batteries, interdigitated membrane electrodes are a common battery structure with a symmetrical geometric structure for the positive and negative electrodes.

[0004] However, under reasonable compaction conditions, the difference in the gram capacity of the positive and negative electrodes will lead to inconsistent coating thickness of the positive and negative electrodes. As a result, the different thicknesses of the positive and negative electrodes will lead to poor integration stability of the battery unit, and because thicker electrodes will occupy a larger space, resulting in low space utilization. Summary of the invention

[0005] The purpose of the present application is to provide a battery cell, a flexible battery, a battery pack and a vehicle, aiming to solve the problems of poor stability and low space utilization of battery cell integration.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] In a first aspect, the present application provides a battery cell, which may include a positive electrode membrane and a negative electrode membrane, wherein the positive electrode membrane and the negative electrode membrane are located in the same plane and are spaced apart, and the area of ​​the positive electrode membrane is greater than that of the negative electrode membrane.

[0008] Since the positive electrode diaphragm and the negative electrode diaphragm are located in the same plane, the volume of the electrode material is equal to the product of the area and thickness of the electrode diaphragm. Normally, the gram capacity of the negative electrode of the battery is greater than the gram capacity of the positive electrode. Therefore, the volume of the positive electrode material is greater than the volume of the negative electrode material. By making the area of ​​the positive electrode diaphragm larger than the area of ​​the negative electrode diaphragm, the thickness of the positive electrode diaphragm can be made the same as the thickness of the negative electrode diaphragm. In this way, when the battery unit is integrated in the thickness direction, the stability is better and no space is wasted, thereby improving space utilization.

[0009] In some embodiments, the positive electrode membrane may be arranged around the negative electrode membrane, so as to avoid wasting space in the plane direction and enable the battery unit to maintain a symmetrical configuration as a whole, thereby making the space arrangement more reasonable and improving space utilization.

[0010] In some embodiments, the battery cell may further include a negative electrode contact point, which is electrically connected to the negative electrode membrane, so that the negative electrode membrane can be easily connected to other battery cells or electrical appliances, thereby realizing the charging and discharging of the battery cell.

[0011] In some embodiments, the positive electrode membrane is arranged around the negative electrode membrane, and a clearance gap is formed on the positive electrode membrane, and the negative electrode contact point is electrically connected to the negative electrode membrane through the clearance gap. In this way, it is convenient to connect the negative electrode contact point to the negative electrode membrane, and the clearance gap can isolate the positive electrode and the negative electrode of the battery unit to avoid battery short circuit.

[0012] In some embodiments, the battery cell may further include a positive electrode contact point, which is electrically connected to the positive electrode membrane, so that the positive electrode membrane can be easily connected to other battery cells or electrical appliances, thereby realizing the charging and discharging of the battery cell.

[0013] In some embodiments, the negative electrode membrane may be circular or polygonal. In this way, the area ratio of the positive electrode membrane to the negative electrode membrane may be calculated according to the ratio of the gram capacity of the positive and negative electrode materials of the battery cell, so that positive electrode membranes and negative electrode membranes of different shapes may be selected.

[0014] In some embodiments, the positive electrode membrane may include a first positive electrode sub-membrane and a second positive electrode sub-membrane, and at least a portion of the negative electrode membrane is disposed between the first positive electrode sub-membrane and the second positive electrode sub-membrane. In this way, the battery unit can also make the space layout reasonable under the condition that the area of ​​the positive electrode membrane is larger than the area of ​​the negative electrode membrane, thereby fully improving the space utilization rate of the battery unit.

[0015] In some embodiments, the first positive sub-membrane, the second positive sub-membrane and the negative electrode diaphragm can all be regular hexagons, and the negative electrode diaphragm can include: a first edge and a second edge and a third edge adjacent to the first edge, the second edge is arranged opposite to the edge of the first positive sub-membrane, and the third edge is arranged opposite to the edge of the second positive sub-membrane.

[0016] In this way, the negative electrode membrane can be reasonably embedded between the first positive electrode sub-membrane and the second positive electrode sub-membrane to avoid space waste.

[0017] In some embodiments, the first positive electrode sub-membrane and the second positive electrode sub-membrane have the same area. In this way, compared with the positive electrode membrane surrounding the negative electrode membrane, the material ratio between the positive electrode membrane and the negative electrode membrane is more convenient to calculate.

[0018] In some embodiments, a receiving gap is formed between the positive electrode membrane and the negative electrode membrane, and the battery cell may further include an electrolyte disposed in the receiving gap.

[0019] Traditional battery cells require a diaphragm to separate the positive and negative electrodes to prevent short circuits inside the battery cells. During the manufacturing process, the diaphragm may wrinkle, fold or draw, causing lithium deposition, brown spots and safety issues. The accommodation gap between the positive and negative electrode diaphragms can be used to separate the positive and negative electrodes without a diaphragm, thus avoiding the problems caused by the diaphragm.

[0020] In some embodiments, the electrolyte is a gel electrolyte or a solid electrolyte.

[0021] Since the conductivity of gel electrolytes is usually higher than that of traditional liquid electrolytes, this can help the battery charge and discharge quickly and increase the energy density of the battery. Gel electrolytes are less likely to splash during use, thereby improving battery safety.

[0022] Solid electrolytes are less flammable and safer than liquid electrolytes. Solid electrolytes also have a wider operating temperature range, allowing the battery to operate normally under extreme conditions, allowing the battery cells to cope with high or low temperature environments.

[0023] In a second aspect, the present application also provides a flexible battery, which may include the above-mentioned battery cell.

[0024] In some embodiments, the flexible battery may further include a substrate, and the positive electrode film and the negative electrode film are both disposed on the substrate. In this way, the substrate may serve as a carrier of the battery unit, facilitating the fixing and installation of the battery unit.

[0025] In some embodiments, a conductive member is further included between the substrate and the positive electrode membrane and the negative electrode membrane. The conductive member can collect the current generated by the active material of the battery to form a larger current for external output, thereby enhancing the conductivity of the battery.

[0026] In some embodiments, the conductive member includes a conductive carbon tube film, which has excellent conductivity, good strength and toughness, and can withstand large stretching and bending without affecting conductivity, thereby preventing tearing due to bending or folding.

[0027] In some embodiments, the orthographic projections of the positive electrode film and the negative electrode film on the substrate are located within the orthographic projection of the conductive carbon tube film on the substrate.

[0028] Since the conductive member is used to collect the current generated by the active material of the battery to form a larger current for external output, the conductive carbon tube film needs to be in full contact with the active material. The positive and negative electrode membranes on the substrate are located within the positive projection of the conductive carbon tube film on the substrate, so that the positive and negative electrode membranes can be fully in contact with the conductive carbon tube film, thereby improving the performance of the flexible battery.

[0029] In some embodiments, the substrate is made of polyethylene terephthalate (PET). PET is a resin with a smooth and glossy surface, excellent physical and mechanical properties in a wide temperature range, and can be used at a temperature of up to 120°C. It has excellent electrical insulation, and has good creep resistance, fatigue resistance, friction resistance, and dimensional stability.

[0030] In some embodiments, a plurality of battery cells are provided, and a plurality of battery cell arrays are arranged on the substrate, so that the energy density of the flexible battery can be increased, thereby improving the performance of the flexible battery.

[0031] In some embodiments, when multiple battery cells are connected in parallel, the positive contact points and the negative contact points in the multiple battery cells are respectively connected to form positive and negative common terminals to serve as the positive and negative electrodes of the flexible battery, or when multiple battery cells are connected in series, the positive contact points and the negative contact points in the multiple battery cells are connected in sequence, and the positive and negative common terminals are formed from head to tail to serve as the positive and negative electrodes of the flexible battery.

[0032] When multiple battery cells are connected in parallel, the capacity of the flexible battery can be increased, thereby having a greater power storage capacity. Moreover, when multiple battery cells are connected in parallel, when one of the battery cells fails, the other battery cells can work normally. When multiple battery cells are connected in series, the voltage of the flexible battery can be increased, so that the flexible battery can meet higher voltage requirements under lower current conditions, thereby improving the safety of the flexible battery.

[0033] In some embodiments, the flexible battery may further include a fixing plate, the fixing plate is fixedly connected to the substrate, and the battery unit is disposed between the fixing plate and the substrate. In this way, the fixing plate can encapsulate the flexible battery and fix the battery unit on the substrate to prevent the battery unit from being displaced.

[0034] In a third aspect, the present application also provides a battery pack that may include the above-mentioned flexible battery.

[0035] In some embodiments, the battery pack may include a housing, a housing is formed inside the housing, a plurality of flexible batteries are disposed in the housing, and the plurality of flexible batteries are electrically connected. In this way, the housing can be used to fix the flexible battery, and the plurality of flexible batteries can be connected in series or in parallel to improve the performance of the battery pack, thereby meeting different power requirements of users.

[0036] In some embodiments, a plurality of flexible batteries are stacked, so that the flexible batteries can be integrated in thickness, and a high voltage or a greater energy density per unit volume of the battery pack can be achieved by connecting in series or in parallel.

[0037] In some embodiments, a plurality of flexible batteries are bent and arranged in an array on the bottom wall of the accommodating space. In this way, by bending the flexible batteries, the space required for the flexible batteries can be reduced, and the flexible batteries can be arranged more tightly in the battery pack, thereby increasing the energy density per unit volume in the battery pack.

[0038] In a fourth aspect, the present application further provides a vehicle, which may include the above-mentioned battery pack. It should be noted that the technical effects brought about by the implementation methods of the second aspect, the third aspect and the fourth aspect can all refer to the technical effects brought about by the corresponding implementation methods in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 One of the structural schematic diagrams of a battery unit provided in an embodiment of the present application;

[0041] Figure 2 A second structural schematic diagram of a battery unit provided in an embodiment of the present application;

[0042] Figure 3 A third structural schematic diagram of a battery unit provided in an embodiment of the present application;

[0043] Figure 4 A schematic diagram of the structure of a preset battery unit;

[0044] Figure 5 One of the structural schematic diagrams of a flexible battery provided in an embodiment of the present application;

[0045] Figure 6 for Figure 5 The second structural schematic diagram of the flexible battery shown;

[0046] Figure 7 for Figure 5 The third structural schematic diagram of the flexible battery shown;

[0047] Figure 8 One of the structural schematic diagrams of a battery pack provided in an embodiment of the present application;

[0048] Fig. 9 A second structural schematic diagram of a battery pack provided in an embodiment of the present application;

[0049] Fig.10A schematic diagram of a battery cell mold provided in an embodiment of the present application;

[0050] Fig.11 A flow chart of a method for preparing a flexible battery provided in an embodiment of the present application.

[0051] Reference numerals: 100, battery cell; 1000, flexible battery;

[0052] 10. Positive electrode diaphragm; 101. Avoidance gap; 11. First positive electrode sub-diaphragm; 12. Second positive electrode sub-diaphragm; 13. Positive electrode diaphragm mold; 20. Negative electrode diaphragm; 201. First edge; 202. Second edge; 203. Third edge; 21. Negative electrode diaphragm mold; A. Free area; 30. Positive electrode contact point; 40. Negative electrode contact point; 50. Accommodation gap; 60. Substrate; 70. Conductive member; 70A. Conductive carbon tube film; 80. Fixing plate; 110. Positive electrode; 120. Negative electrode; 90. Shell; 91. Accommodation space. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside" and the like indicate directions or positional relationships based on the directions or relative positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. Unless otherwise specified, the above-mentioned directional description can be flexibly set in the process of actual application under the condition that the relative positional relationship shown in the accompanying drawings is satisfied.

[0055] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the embodiments of the present invention, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, article or device including the element.

[0058] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0059] With the rapid development of battery technology, integrated batteries have great advantages in improving battery energy density, flexibility and optimizing battery performance.

[0060] In the manufacturing field of lithium-ion batteries or sodium-ion batteries, interdigitated membrane electrodes are a common battery structure with a symmetrical geometric structure for the positive and negative electrodes.

[0061] However, under reasonable compaction conditions, the difference in the gram capacity of the positive and negative electrodes will lead to inconsistent coating thickness of the positive and negative electrodes. As a result, the different thicknesses of the positive and negative electrodes will lead to poor integration stability of the battery unit, and because thicker electrodes will occupy a larger space, resulting in low space utilization.

[0062] Based on this, an embodiment of the present application provides a battery cell. By making the area of ​​the positive electrode diaphragm larger than the area of ​​the negative electrode diaphragm, the thickness of the positive electrode diaphragm can be reduced so that the thickness of the positive electrode diaphragm is the same as that of the negative electrode diaphragm, thereby enhancing the stability of the battery cell integration. The thickness of the positive electrode diaphragm is the same as that of the negative electrode diaphragm, and when integrated in the thickness direction, no space waste will occur, thereby increasing the utilization of the space.

[0063] Please refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 This is one of the structural schematic diagrams of a battery unit 100 provided in an embodiment of the present application. Figure 2 This is a second structural schematic diagram of a battery unit 100 provided in an embodiment of the present application. Figure 3 The third structural schematic diagram of a battery cell 100 provided in an embodiment of the present application, the battery cell 100 may include a positive electrode membrane 10 and a negative electrode membrane 20, and the positive electrode membrane 10 and the negative electrode membrane 20 are located in the same plane and are spaced apart.

[0064] Due to the difference in the positive and negative electrode materials of the battery, their gram capacity is different. Usually, the gram capacity of the negative electrode material is greater than that of the positive electrode material. For example, the negative electrode is a graphite negative electrode or a silicon (Si) negative electrode, so the volume of the negative electrode material is usually greater than that of the positive electrode material. If the amount of negative electrode material is too much, it will cause material waste and increase manufacturing costs. If the amount of negative electrode material is too little, it may cause a series of safety problems such as lithium precipitation.

[0065] Therefore, the area of ​​the positive electrode membrane 10 of the battery cell 100 provided in the embodiment of the present application is larger than the area of ​​the negative electrode membrane 20 .

[0066] Since the positive electrode diaphragm 10 and the negative electrode diaphragm 20 are located in the same plane, the volume of the electrode material is equal to the product of the area and thickness of the electrode diaphragm. Therefore, by making the area of ​​the positive electrode diaphragm 10 larger than the area of ​​the negative electrode diaphragm 20, the thickness of the positive electrode diaphragm 10 can be made the same as the thickness of the negative electrode diaphragm 20. In this way, when the battery unit 100 is integrated in the thickness direction, the stability is better and no space is wasted, thereby improving space utilization.

[0067] In some embodiments, the material of the positive electrode film 10 may include: a ternary material (abbreviated as NCM) containing metal nickel (NI), cobalt (CO) and manganese (Mn), and the material of the negative electrode film 20 may include a graphite main material. NCM batteries can provide more power while keeping the battery volume and weight relatively small, which can improve the cruising range of electric vehicles, and NCM batteries can withstand a large number of charge and discharge cycles, which can extend the service life of the battery.

[0068] In other embodiments, the material of the positive electrode membrane 10 may include lithium iron phosphate (LiFePO4, referred to as LFP), and the material of the negative electrode membrane 20 may include a graphite main material. Since LiFePO4 has high thermal stability and chemical stability, it is not easy to cause thermal runaway reaction, self-decomposition or oxidation reaction. Therefore, the LFP battery can maintain stable performance in a high temperature environment, thereby reducing the risk of fire, explosion, etc. caused by overheating.

[0069] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of a preset battery cell 100. Since the area of ​​the positive electrode diaphragm 10 is larger than that of the negative electrode diaphragm 20, if the positive electrode diaphragm 10 and the negative electrode diaphragm 20 are arranged opposite to each other, in the plane direction, due to the larger area of ​​the positive electrode diaphragm 10, there will be a vacant area A on the negative electrode diaphragm 20 at the corresponding position of the positive electrode diaphragm 10 with respect to the central axis of the battery cell 100, resulting in space waste.

[0070] Therefore, please refer to Figure 1 and Figure 2 In some embodiments of the present application, the positive electrode membrane 10 can be arranged around the negative electrode membrane 20. In this way, the waste of space in the plane direction can be avoided, and the battery unit 100 can maintain a symmetrical configuration as a whole, so that the space arrangement is more reasonable and the space utilization rate is improved.

[0071] Since the positive electrode membrane 10 is arranged around the negative electrode membrane 20, it is inconvenient to connect the negative electrode membrane 20 with other battery cells 100 or electrical appliances. Therefore, in some embodiments of the present application, the battery cell 100 may further include a negative electrode contact point 40, and the negative electrode contact point 40 is electrically connected to the negative electrode membrane 20. In this way, the negative electrode contact point 40 is electrically connected to the negative electrode membrane 20, which can facilitate the connection of the negative electrode membrane 20 with other battery cells 100 or electrical appliances, so that the battery cell 100 can be charged and discharged.

[0072] In some embodiments of the present application, the positive electrode membrane 10 is arranged around the negative electrode membrane 20, and a clearance gap 101 is formed on the positive electrode membrane 10, and the negative electrode contact point 40 is electrically connected to the negative electrode membrane 20 through the clearance gap 101. In this way, it is convenient to connect the negative electrode contact point 40 with the negative electrode membrane 20, and the clearance gap 101 can isolate the positive electrode and the negative electrode of the battery unit 100 to avoid battery short circuit.

[0073] In some embodiments of the present application, the battery cell 100 may further include a positive electrode contact point 30, and the positive electrode contact point 30 is electrically connected to the positive electrode film 10. In this way, the positive electrode contact point 30 is electrically connected to the positive electrode film 10, which can facilitate the connection of the positive electrode film 10 with other battery cells 100 or electrical appliances, thereby realizing the charging and discharging of the battery cell 100.

[0074] In addition, the area of ​​the positive electrode contact point 30 and the negative electrode contact point 40 may be larger than the area of ​​the connection line between the membrane and the contact point, so that the battery unit 100 is easily positioned during integration.

[0075] In a possible structural design, such as Figure 1As shown, the negative electrode membrane 20 may be circular, and the positive electrode membrane 10 may be annular. The annular positive electrode membrane 10 is arranged around a circle, and the positive electrode membrane 10 and the negative electrode membrane 20 are arranged at intervals.

[0076] In another possible structural design, the negative electrode membrane 20 may be a polygon, and the positive electrode membrane 10 may be a hollow polygon, and the shape of the empty space in the middle may also be the polygon. In this way, the hollow polygonal positive electrode membrane may be arranged around the polygonal negative electrode membrane 20. For example, Figure 2 As shown, the negative electrode membrane 20 may be a square, and the positive electrode membrane 10 may be a hollow square. The positive electrode membrane 10 and the negative electrode membrane 20 are spaced apart.

[0077] In this way, the area ratio of the positive electrode membrane 10 to the negative electrode membrane 20 can be calculated according to the ratio of the capacity of different positive electrode materials and negative electrode materials of the battery unit 100, so that positive electrode membranes 10 and negative electrode membranes 20 of different shapes can be selected.

[0078] Please refer to Figure 3 In some other embodiments of the present application, the positive electrode membrane 10 may include a first positive electrode sub-membrane 11 and a second positive electrode sub-membrane 12 , and at least a portion of the negative electrode membrane 20 is disposed between the first positive electrode sub-membrane 11 and the second positive electrode sub-membrane 12 .

[0079] In this way, the battery unit 100 can also make the spatial layout reasonable under the condition that the area of ​​the positive electrode membrane 10 is larger than the area of ​​the negative electrode membrane 20, thereby fully improving the space utilization rate of the battery unit 100.

[0080] In some embodiments of the present application, the first positive sub-membrane 11, the second positive sub-membrane 12 and the negative electrode diaphragm 20 are all regular hexagons, and the negative electrode diaphragm 20 may include a first edge 201 and a second edge 202 and a third edge 203 adjacent to the first edge 201, the second edge 202 is arranged opposite to the edge of the first positive sub-membrane 11, and the third edge 203 is arranged opposite to the edge of the second positive sub-membrane 12.

[0081] In this way, the negative electrode membrane 20 can be reasonably embedded between the first positive electrode sub-membrane 11 and the second positive electrode sub-membrane 12 to avoid space waste.

[0082] In some embodiments of the present application, the first positive sub-membrane 11 and the second positive sub-membrane 12 have the same area. In this way, compared with the positive electrode membrane 10 surrounding the negative electrode membrane 20, the material ratio of the positive electrode membrane 10 and the negative electrode membrane 20 is easier to calculate.

[0083] Exemplarily, the areas of the first positive electrode sub-membrane 11 , the second positive electrode sub-membrane 12 and the negative electrode membrane 20 are all the same. In this way, the material of the positive electrode membrane 10 can be twice that of the negative electrode membrane 20 .

[0084] Please refer to Figure 1 , Figure 2 and Figure 3 In some embodiments of the present application, a receiving gap 50 is formed between the positive electrode membrane 10 and the negative electrode membrane 20 , and the battery cell 100 may further include an electrolyte disposed in the receiving gap 50 .

[0085] Since the conventional battery cell 100 needs to use a diaphragm to separate the positive and negative electrodes to prevent short circuits inside the battery cell 100, during the manufacturing process, the diaphragm may cause lithium deposition, brown spots and safety problems due to wrinkling, folding or drawing. The accommodation gap 50 between the positive electrode film 10 and the negative electrode film 20 can separate the positive and negative electrodes without using a diaphragm, thereby avoiding the problems caused by the diaphragm.

[0086] In addition, the electrolyte is disposed in the accommodation gap 50 and can be in contact with both the positive electrode membrane 10 and the negative electrode membrane 20 , so that ions can be conducted between both the positive electrode membrane 10 and the negative electrode membrane 20 .

[0087] In some embodiments, the width of the accommodation gap 50 between the positive electrode film 10 and the negative electrode film 20 may be 1-10 μm, and for example, the width of the accommodation gap 50 may be 1 μm, 3 μm, 5 μm, 8 μm or 10 μm. In this way, the space in the plane can be saved.

[0088] In some embodiments of the present application, the electrolyte is a gel electrolyte or a solid electrolyte. The conductivity of the gel electrolyte is usually higher than that of the traditional liquid electrolyte, which helps the battery to charge and discharge quickly, and can also increase the energy density of the battery. The gel electrolyte is not prone to splashing during use, which can improve the safety of the battery. The solid electrolyte is less flammable than the liquid electrolyte, and is safer. The solid electrolyte has a wider operating environment temperature range, which can enable the battery to operate normally under extreme conditions, so that the battery cell 100 can cope with high or low temperature environments.

[0089] Please refer to Figure 5 and Figure 6 , Figure 5 This is one of the structural schematic diagrams of a flexible battery 1000 provided in an embodiment of the present application. Figure 6 for Figure 5 As shown in the second structural schematic diagram of the flexible battery 1000 , the embodiment of the present application further provides a flexible battery 1000 , which may include the above-mentioned battery unit 100 .

[0090] In some embodiments of the present application, the flexible battery 1000 may further include a substrate 60, and the positive electrode film 10 and the negative electrode film 20 are both disposed on the substrate 60. In this way, the substrate 60 may serve as a carrier of the battery unit 100, facilitating the fixing and installation of the battery unit 100.

[0091] The substrate 60 is made of a flexible material, for example, fabric, carbon fiber or resin material. In this way, the substrate 60 has good flexibility and can be bent into any shape or angle, so that the flexible battery 1000 can be closely arranged in the battery pack, thereby improving the space utilization of the battery.

[0092] In some embodiments of the present application, the substrate 60 is made of polyethylene terephthalate (PET). PET is a resin with a smooth and glossy surface, excellent physical and mechanical properties in a wide temperature range, and can be used at a temperature of up to 120°C. It has excellent electrical insulation, and has good creep resistance, fatigue resistance, friction resistance, and dimensional stability.

[0093] In some embodiments of the present application, the flexible battery 1000 may further include a conductive member 70 disposed between the substrate 60 and the positive electrode film 10 and the negative electrode film 20 .

[0094] The conductive member 70 can collect the current generated by the active materials of the battery to form a larger current for external output, thereby enhancing the conductivity of the battery.

[0095] In some embodiments of the present application, the conductive member 70 may include a conductive carbon tube film 70A. The conductive carbon tube film 70A has excellent conductivity, good strength and toughness, and can withstand large stretching and bending without affecting conductivity, so that it will not be torn due to bending or folding.

[0096] In addition, when the conductive carbon tube film 70A is used as a flexible electric heating film for electric heating curing of resin-based composite materials, it has the characteristics of energy saving, high efficiency, low cost, etc.

[0097] In some embodiments of the present application, the orthographic projections of the positive electrode film 10 and the negative electrode film 20 on the substrate 60 are located within the orthographic projection of the conductive carbon tube film 70A on the substrate 60 .

[0098] Since the conductive member 70 is used to collect the current generated by the battery active material to form a larger current for external output, the conductive carbon tube film 70A needs to be in full contact with the active material. The positive electrode film 10 and the negative electrode film 20 are located within the positive projection of the conductive carbon tube film 70A on the substrate 60, so that the positive electrode film 10 and the negative electrode film 20 are in full contact with the conductive carbon tube film 70A, thereby improving the performance of the flexible battery 1000.

[0099] In some embodiments, the positive electrode contact point 30 and the negative electrode contact point 40 may be made of metal materials such as nickel (Ni) or aluminum (Al), or may be directly connected using a conductive carbon tube film 70A.

[0100] In some embodiments of the present application, a plurality of battery cells 100 may be provided, and the plurality of battery cells 100 are arrayed on the substrate 60. In this way, the energy density of the flexible battery 1000 may be increased, thereby improving the performance of the flexible battery 1000.

[0101] In some embodiments of the present application, when multiple battery cells 100 are connected in parallel, the positive contact points 30 and the negative contact points 40 in the multiple battery cells 100 are respectively connected to form positive and negative common terminals to serve as the positive electrode 110 and the negative electrode 120 of the flexible battery 1000 .

[0102] When multiple battery cells 100 are connected in parallel, the capacity of the flexible battery 1000 can be increased, thereby having a greater power storage capacity. Moreover, when multiple battery cells 100 are connected in parallel, when one of the battery cells 100 fails, the other battery cells 100 can work normally.

[0103] In some embodiments of the present application, when multiple battery cells 100 are connected in series, the positive contact points 30 and the negative contact points 40 in the multiple battery cells 100 are connected in sequence, and the positive and negative common terminals are formed at the head and tail to serve as the positive electrode 110 and the negative electrode 120 of the flexible battery 1000.

[0104] When a plurality of battery cells 100 are connected in series, the voltage of the flexible battery 1000 can be increased, so that the flexible battery 1000 can meet a higher voltage requirement under a lower current condition, thereby improving the safety of the flexible battery 1000 .

[0105] In some embodiments, the plurality of battery cells 100 may be connected in parallel or in series via the conductive carbon tube film 70A.

[0106] It should be noted that the conductive carbon tube film 70A is only provided at the projections of the positive electrode film 10 and the negative electrode film 20 on the substrate 60 and at and between the positive and negative electrode contact points, but not on the entire substrate 60. In this way, a short circuit can be prevented from occurring inside the flexible battery 1000.

[0107] In some embodiments of the present application, multiple battery cells 100 may also be integrated by first connecting in series and then in parallel, so that the energy density of the flexible battery 1000 can be increased, the voltage of the flexible battery 1000 can be increased, and the safety of the flexible battery 1000 can be improved.

[0108] For example, the flexible battery 1000 may include 16 battery cells 100 , and the 16 battery cells 100 are arranged on the substrate 60 in a 4×4 array.

[0109] Among them, the four battery cells 100 in a single row are connected in series, and the positive contact points 30 and the negative contact points 40 in the four battery cells 100 are connected in sequence, and the positive and negative common terminals are formed at the head and tail to serve as the positive electrode 110 and the negative electrode 120 of the flexible battery 1000, that is, the negative electrode contact point 40 of the first battery cell 100 is connected to the positive electrode contact point 30 of the second battery cell 100, and the negative electrode contact point 40 of the second battery cell 100 is connected to the positive electrode contact point 30 of the third battery cell 100. In this way, the four battery cells 100 are connected in sequence, the positive electrode contact point 30 of the first battery cell 100 constitutes the positive electrode of the battery cells 100 in this row, and the negative electrode contact point 40 of the fourth battery cell 100 constitutes the negative electrode of the battery cells 100 in this row.

[0110] The four rows of battery cells 100 are connected in parallel, the positive electrodes of the four rows of battery cells 100 are connected in sequence to form the positive electrode 110 of the flexible battery 1000, and the negative electrodes of the four rows of battery cells 100 are connected in sequence to form the negative electrode 120 of the flexible battery 1000. The positive electrode 110 and the negative electrode 120 are respectively connected to the positive and negative electrodes of the electrical appliance to realize the charging and discharging of the flexible battery 1000.

[0111] In some embodiments, the positive electrode 110 and the negative electrode 120 are respectively disposed on the upper and lower sides of the flexible battery 1000 , so that the positive and negative electrodes can be prevented from contacting each other when the flexible battery 1000 is rolled into a cylinder, thereby preventing an internal short circuit.

[0112] In some embodiments, the positive electrode contact point 30 and the negative electrode contact point 40 are connected through the conductive carbon tube film 70A, so that the conductive efficiency of the battery can be increased and the flexible battery 1000 can be easily bent.

[0113] Please refer to Figure 7, Figure 7 for Figure 5 As shown in the third structural diagram of the flexible battery 1000, in some embodiments of the present application, the flexible battery 1000 may further include a fixing plate 80, which is fixedly connected to the substrate 60, and the battery cell 100 is arranged between the fixing plate 80 and the substrate 60.

[0114] In this way, the fixing plate 80 can encapsulate the flexible battery 1000 and fix the battery unit 100 on the substrate 60 to prevent the battery unit 100 from being displaced.

[0115] In some embodiments, the fixing plate 80 and the substrate 60 can be bonded by glue, and the glue can be epoxy resin AB glue, UV hot melt glue or modified hot melt adhesive film. The glue can be bonded to the edges of the substrate 60 and the fixing plate 80.

[0116] It is understandable that the positive electrode 110 and the negative electrode 120 of the flexible battery 1000 are both located outside the fixing plate 80 , so that the positive electrode 110 and the negative electrode 120 can be easily connected to the electrical appliance.

[0117] In some embodiments, the material of the fixing plate 80 can be the same as that of the substrate 60. For example, the material of the fixing plate 80 is polyethylene terephthalate (PET). In this way, the fixing plate 80 can also be bent or curled.

[0118] The present application also provides a battery pack, please refer to Figure 8 and Fig. 9 , Figure 8 This is one of the structural schematic diagrams of a battery pack provided in an embodiment of the present application. Fig. 9 This is a second structural schematic diagram of a battery pack provided in an embodiment of the present application. The battery pack may include the above-mentioned flexible battery 1000.

[0119] In some embodiments of the present application, the battery pack may further include a shell 90 , in which a receiving space 91 is formed, and a plurality of flexible batteries 1000 are disposed in the receiving space 91 , and the plurality of flexible batteries 1000 are electrically connected.

[0120] In this way, the shell 90 can be used to fix the flexible battery 1000. A plurality of flexible batteries 1000 can be connected in series or in parallel to improve the performance of the battery pack, thereby meeting different power requirements of users.

[0121] Please refer to Figure 8In some embodiments of the present application, multiple flexible batteries 1000 are stacked. In one possible structural design, multiple flexible batteries 1000 can be stacked vertically, and in another possible structural design, multiple flexible batteries 1000 can be stacked horizontally, which is not further limited in the present application. In this way, the flexible battery 1000 can be integrated in thickness, and by connecting in series or in parallel, a high voltage or a greater energy density per unit volume of the battery pack can be achieved.

[0122] Please refer to Fig. 9 In some other embodiments of the present application, a plurality of flexible batteries 1000 are bent and arranged in an array on the bottom wall of the accommodating space 91. In this way, by bending the flexible battery 1000, the space required for the flexible battery 1000 can be reduced, and the flexible battery 1000 can be arranged more densely in the battery pack, thereby increasing the energy density per unit volume in the battery pack.

[0123] The embodiment of the present application also provides a vehicle, which can be equipped with the above-mentioned battery pack. In this way, the performance, storage capacity and endurance of the vehicle battery can be increased by integrating the flexible battery in the battery pack.

[0124] Please refer to Figures 1 to 11 , Fig.10 A schematic diagram of a battery cell mold provided in an embodiment of the present application, Fig.11 A flowchart of a method for preparing a flexible battery 1000 provided in an embodiment of the present application. The present application also provides a method for preparing a flexible battery 1000, which is used to prepare the flexible battery 1000. The method may include the following steps:

[0125] S1. The positive and negative electrode active materials are mixed with a conductive agent and a binder respectively to prepare positive electrode slurry and negative electrode slurry with a certain viscosity.

[0126] In some embodiments, the positive electrode active material may include a ternary material (referred to as NCM) containing nickel (NI), cobalt (CO) and manganese (Mn). In other embodiments, the positive electrode active material may include lithium iron phosphate (LiFePO4, referred to as LFP).

[0127] S2. Screen the positive electrode slurry and the negative electrode slurry separately and inject them into the spraying pipeline.

[0128] In this way, larger material particles can be filtered out to avoid uneven conductivity of the electrode membrane and thus performance degradation, as well as to avoid the impact of larger material particles on the thickness of the membrane.

[0129] S3, spraying the positive electrode slurry and the negative electrode slurry into the positive electrode membrane mold 13 and the negative electrode membrane mold 21 respectively.

[0130] In some embodiments, the thickness of the positive electrode diaphragm 10 and the negative electrode diaphragm 20 is less than or equal to 100 μm. According to the ratio of the gram capacity of different battery materials, the area ratio of the positive electrode diaphragm 10 and the negative electrode diaphragm 20 is calculated, so that the inner diameter and outer diameter of the positive electrode diaphragm mold 13 and the negative electrode diaphragm mold 21 are adjusted to achieve the adjustment of the battery thickness.

[0131] S4, drying the slurry in the mold and taking out the positive electrode membrane 10 and the negative electrode membrane 20 from the mold.

[0132] S5 , transferring the positive electrode film 10 and the negative electrode film 20 onto the conductive carbon tube film 70A to form a battery unit 100 .

[0133] According to different performance requirements of the battery, steps S3 to S5 may be repeated multiple times to produce multiple battery cells 100 .

[0134] S6. According to different energy density requirements, the battery cells 100 are combined in series or in parallel, so as to achieve high voltage or high energy density of the battery.

[0135] S7, adding electrolyte and encapsulating with fixing plate 80. Dropping electrolyte into the receiving gap 50 between positive electrode membrane 10 and negative electrode membrane 20 can make ions transfer between positive electrode and negative electrode, so as to realize charging and discharging of the battery.

[0136] S8. Transfer the packaged batteries to a suitable temperature for soaking.

[0137] After the impregnation is completed, the flexible battery 1000 is prepared and can be charged and used for the first time.

[0138] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0139] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A battery cell, characterized in that: It comprises a positive electrode membrane (10) and a negative electrode membrane (20) which are arranged at an interval; the positive electrode membrane (10) and the negative electrode membrane (20) are located in the same plane, and the area of ​​the positive electrode membrane (10) is larger than the area of ​​the negative electrode membrane (20).

2. The battery cell according to claim 1, characterized in that: The positive electrode membrane (10) is arranged around the negative electrode membrane (20).

3. The battery cell according to claim 1 or 2, characterized in that: It also includes a negative electrode contact point (40), wherein the negative electrode contact point (40) is electrically connected to the negative electrode membrane (20).

4. The battery cell according to claim 3, characterized in that: The positive electrode diaphragm (10) is arranged around the negative electrode diaphragm (20), and a clearance gap (101) is formed on the positive electrode diaphragm (10); the negative electrode contact point (40) is electrically connected to the negative electrode diaphragm (20) through the clearance gap (101).

5. The battery cell according to claim 1 or 2, characterized in that: It also includes a positive electrode contact point (30), wherein the positive electrode contact point (30) is electrically connected to the positive electrode membrane (10).

6. The battery cell according to claim 1 or 2, characterized in that: The negative electrode membrane (20) is circular or polygonal.

7. The battery cell according to claim 1, characterized in that: The positive electrode membrane (10) comprises a first positive electrode sub-membrane (11) and a second positive electrode sub-membrane (12), and at least a portion of the negative electrode membrane (20) is arranged between the first positive electrode sub-membrane (11) and the second positive electrode sub-membrane (12).

8. The battery cell according to claim 7, characterized in that: The first positive electrode sub-membrane (11), the second positive electrode sub-membrane (12) and the negative electrode membrane (20) are all regular hexagons; The negative electrode membrane (20) comprises: a first edge (201) and a second edge (202) and a third edge (203) arranged adjacent to the first edge (201); the second edge (202) is arranged opposite to the edge of the first positive electrode sub-membrane (11); and the third edge (203) is arranged opposite to the edge of the second positive electrode sub-membrane (12).

9. The battery cell according to claim 8, characterized in that: The first positive electrode sub-membrane (11) and the second positive electrode sub-membrane (12) have the same area.

10. The battery cell according to claim 1 or 2, characterized in that: A receiving gap (50) is formed between the positive electrode membrane (10) and the negative electrode membrane (20); the battery unit also includes an electrolyte arranged in the receiving gap (50).

11. The battery cell according to claim 10, characterized in that: The electrolyte is a gel electrolyte or a solid electrolyte.

12. A flexible battery, characterized in that: A battery cell (100) comprising any one of claims 1 to 11.

13. The flexible battery according to claim 12, characterized in that: It also includes a substrate (60), and the positive electrode membrane (10) and the negative electrode membrane (20) are both arranged on the substrate (60).

14. The flexible battery according to claim 13, characterized in that: It also includes a conductive member (70) disposed between the substrate (60) and the positive electrode membrane (10) and the negative electrode membrane (20).

15. The flexible battery according to claim 14, characterized in that: The conductive element (70) comprises a conductive carbon tube film (70A).

16. The flexible battery according to claim 15, characterized in that: The orthographic projections of the positive electrode film (10) and the negative electrode film (20) on the substrate (60) are located within the orthographic projection of the conductive carbon tube film (70A) on the substrate (60).

17. The flexible battery according to any one of claims 13 to 16, characterized in that: The material of the substrate (60) is polyethylene terephthalate.

18. The flexible battery according to any one of claims 13 to 16, characterized in that: A plurality of the battery cells (100) are provided, and the plurality of the battery cells (100) are arranged in an array on the substrate (60).

19. The flexible battery according to claim 18, characterized in that: When a plurality of the battery units (100) are connected in parallel, the positive electrode contact points (30) and the negative electrode contact points (40) in the plurality of the battery units (100) are respectively connected to form positive and negative common terminals to serve as the positive and negative electrodes of the flexible battery; or When a plurality of the battery cells (100) are connected in series, the positive electrode contact points (30) and the negative electrode contact points (40) in the plurality of the battery cells (100) are connected in sequence, and the positive and negative common terminals are formed at the head and tail to serve as the positive and negative electrodes of the flexible battery.

20. The flexible battery according to any one of claims 13 to 16, characterized in that: It also includes a fixing plate (80), the fixing plate (80) being fixedly connected to the substrate (60), and the battery unit (100) being arranged between the fixing plate (80) and the substrate (60).

21. A battery pack, characterized in that: A flexible battery (1000) comprising any one of claims 12 to 20.

22. The battery pack according to claim 21, characterized in that: include: A housing (90) is formed with a receiving space (91) in the housing (90), a plurality of flexible batteries (1000) are arranged in the receiving space (91), and the plurality of flexible batteries (1000) are electrically connected.

23. The battery pack according to claim 22, characterized in that: A plurality of the flexible batteries (1000) are stacked.

24. The battery pack according to claim 22, characterized in that: The plurality of flexible batteries (1000) are bent and arranged in an array on the bottom wall surface forming the accommodating space (91).

25. A vehicle, characterized in that: A battery pack comprising any one of claims 21-24.

Images