Assembly equipment and battery production line

Abstract

The utility model discloses assembly equipment and a battery production line. Belongs to the technical field of batteries. The assembling equipment is used for assembling an electrode assembly, and comprises a conveying and heating mechanism which is at least used for conveying and heating a negative electrode used for assembling the electrode assembly; the thickness detector is at least used for detecting the thickness of the anode or the cathode which is not overlapped with the anode used for assembling the electrode assembly after being heated, and the detection position of the thickness detector is located at the downstream of the conveying and heating mechanism; and the stacking device is used for stacking the negative electrodes and assembling the negative electrodes into the electrode assembly, and the stacking device is located at the downstream of the detection position of the thickness detector. Therefore, the charging rate of the battery cells can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an assembling device and a battery production line. BACKGROUND

[0002] New energy batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, battery devices are also increasingly used in the field of energy storage and the like. In new energy vehicles equipped with batteries, battery devices can be used to provide power wholly or partially. In the field of energy storage, battery devices can be installed in energy storage boxes or directly installed at user sides.

[0003] In the related art, the charging rate of a battery monomer is limited. UTILITY MODEL CONTENT

[0004] To solve the above technical problems, the embodiments of the present application provide an assembling device and a battery production line to improve the charging rate of a battery monomer.

[0005] The embodiments of the present application are implemented through the following technical solutions.

[0006] The first aspect of the embodiments of the present application provides an assembling device for assembling an electrode assembly, the assembling device comprising: a conveying and heating mechanism for at least conveying and heating a negative electrode used for assembling the electrode assembly; a thickness detector for at least detecting the thickness of the negative electrode after being heated and before being stacked with a positive electrode used for assembling the electrode assembly, the detection position of the thickness detector being located downstream of the conveying and heating mechanism; and a stacking device for stacking and assembling the negative electrode into the electrode assembly, the stacking device being located downstream of the detection position of the thickness detector.

[0007] In the embodiments of the present application, since the assembling device comprises the conveying and heating mechanism, the conveying and heating mechanism can not only convey the negative electrode to at least the detection position of the thickness detector, but also preheat and pre-expand the negative electrode. Moreover, since the negative electrode itself has a temperature, the negative electrode forms the electrode assembly, and the temperature of the negative electrode inside the electrode assembly is relatively high, thereby heat can be transferred to the separator of the electrode assembly to improve the adhesion of the separator with glue, so that the separator with glue is better bonded with the negative electrode. Furthermore, since the assembling device further comprises the thickness detector, the thickness detector can detect the thickness of the negative electrode after being heated and before being stacked with the positive electrode. If the thickness of the negative electrode entering the front part of the stacking device is inconsistent, an alarm can be given in time to stop and debug, and if the thickness of the negative electrode is basically consistent, the negative electrode enters the stacking device, so that the thickness of the negative electrode stacked by the stacking device at each position tends to be consistent, which can better reduce the limitation of the position with a relatively thin thickness on the negative electrode on the charging rate of the battery monomer, and is conducive to improving the charging rate of the battery monomer.

[0008] In some embodiments, the stacking device comprises a winding device, the assembling device further comprises a roll roller for supporting a roll of the material to be assembled, the material supported by at least one roll roller is the negative electrode, the conveying heating mechanism is located downstream of the roll roller, the conveying heating mechanism comprises a conveying roller set, the conveying roller set comprises at least one conveying roller for conveying the material released by the roll roller, the detection position of the thickness detector is located downstream of the conveying roller set, and the winding device is used for receiving the material conveyed by the conveying roller and winding the received material into an electrode assembly.

[0009] Since the assembling device further comprises a roll roller, the conveying heating mechanism comprises a conveying roller set, and the stacking device comprises a winding device, the negative electrode can be released from the roll roller, conveyed to the detection position of the thickness detector, and then wound into a winding type electrode assembly.

[0010] In some embodiments, the at least one conveying roller is a heating roller.

[0011] Since the at least one conveying roller is a heating roller, the heating roller can heat the as much as possible expanded negative electrode during the conveying of the negative electrode by the conveying roller, the heat transfer path of the heat transferred from the heating roller to the negative electrode is short, the as much as possible expanded negative electrode can be heated by the heating roller as quickly and uniformly as possible, the negative electrode can be heated and expanded as quickly and uniformly as possible, and the thickness of the negative electrode at each position during the stacking by the stacking device tends to be consistent, which can better reduce the limitation of the position with thinner thickness on the charge rate of the battery monomer, and is conducive to improving the charge rate of the battery monomer. Moreover, the separator and the negative electrode can be better bonded during the extrusion of the electrode assembly, the time length of re-heating is shortened, thereby better solving the problem that the separator far from the surface layer in the electrode assembly after assembly needs to be heated for a long time for bonding, and being conducive to improving the production efficiency.

[0012] In some embodiments, the number of conveying rollers is at least four, at least three conveying rollers are heating rollers, at least one conveying roller is a transition roller located between two adjacent heating rollers, at least one heating roller is a first heating roller, the heating roller adjacent to the first heating roller and located upstream of the first heating roller is a second heating roller, the heating roller adjacent to the first heating roller and located downstream of the first heating roller is a third heating roller, and the number of transition rollers between the upstream of the first heating roller and the downstream of the second heating roller is greater than the number of transition rollers between the downstream of the first heating roller and the upstream of the third heating roller.

[0013] The negative electrode is gradually heated from the second heating roller to the third heating roller, the number of transition rollers between the upstream of the first heating roller and the downstream of the second heating roller is large, the first heating roller and the second heating roller are distributed sparsely, the number of transition rollers between the downstream of the first heating roller and the upstream of the third heating roller is small, and the first heating roller and the second heating roller are distributed densely. Therefore, the temperature of the negative electrode increases slowly during the conveying process of the negative electrode on the first heating roller and the second heating roller distributed sparsely, and the negative electrode is prevented from being heated to a high temperature too quickly. During the conveying process of the negative electrode on the second heating roller and the first heating roller away from the stacking device, the temperature of the negative electrode is relatively low, the temperature difference between the negative electrode and the surrounding environment is small, and the heat exchange between the negative electrode and the surrounding environment is reduced, thereby reducing the energy loss and the energy consumption. During the conveying process of the negative electrode on the first heating roller and the third heating roller distributed densely, the part of the negative electrode preheated upstream of the first heating roller is continuously heated by the first heating roller and the second heating roller. Since the first heating roller and the third heating roller are distributed densely, the temperature of the negative electrode is maintained at a high temperature, and the negative electrode is heated to a preset temperature before entering the stacking device for assembly. During the extrusion process of the electrode assembly after the assembly is completed, the high temperature of the negative electrode facilitates the good adhesion between the adhesive isolation member and the negative electrode.

[0014] In some embodiments, the number of transition rollers between the two adjacent heating rollers upstream is greater than or equal to the number of transition rollers between the two adjacent heating rollers downstream.

[0015] Since the number of transition rollers between the two adjacent heating rollers upstream is greater than or equal to the number of transition rollers between the two adjacent heating rollers downstream, the number of heating rollers of the conveying roller group upstream of the conveying material can be set to be smaller, and the number of heating rollers of the conveying roller group downstream of the conveying material can be set to be larger. Therefore, the number of heating rollers for heating the material upstream of the conveying material is small, the temperature of the negative electrode increases slowly during the conveying process of the negative electrode on the heating rollers, the heat exchange between the negative electrode and the surrounding air is reduced, thereby reducing the energy loss and the energy consumption. Moreover, the number of heating rollers for heating the negative electrode upstream of the conveying negative electrode is large, the more heating rollers can heat the negative electrode, the negative electrode can maintain a high temperature near the stacking device, the negative electrode is heated to a high temperature before entering the stacking device for assembly, and the adhesive isolation member is more easily adhered to the negative electrode.

[0016] In some embodiments, the heating roller comprises a first roller body, and a first heater located in the first roller body, the first heater heating the first roller body.

[0017] The heating roller is composed of the first roller body and the first heater located in the first roller body, and has a simple structure and low manufacturing cost.

[0018] In some embodiments, the first roller body comprises a roller body sidewall enclosing the first heater, and the roller body sidewall is configured to contact the negative electrode transported by the conveying roller.

[0019] Since the roller body sidewall encloses the first heater and the roller body sidewall is configured to contact the negative electrode transported by the conveying roller, the temperature of the roller body sidewall is uniform, thereby making the negative electrode uniformly heated, keeping the degree of rebound of the negative electrode heated as consistent as possible, and reducing the negative impact of the local performance difference of the negative electrode on the overall battery cell.

[0020] In some embodiments, the conveying and heating mechanism further comprises a heating device located between the downstream of the conveying roller group and the upstream of the detection position of the thickness detector.

[0021] The heating device can heat the negative electrode before thickness detection, so as to pre-expand the negative electrode. Moreover, the heating device can be added to the original assembly equipment, and the adaptability of the heating device to the old equipment is relatively high, and the overall modification scheme is relatively simple and low in cost.

[0022] In some embodiments, the number of the roll-up rollers is at least two, each roll-up roller is provided with a corresponding conveying and heating mechanism, and the stacking device further comprises a merging roller configured to stack the positive electrode and the negative electrode, the merging roller being located between the downstream of the detection position of the thickness detector and the upstream of the winder.

[0023] Since the number of the roll-up rollers is at least two, each roll-up roller is provided with a corresponding conveying and heating mechanism, the positive electrode and the negative electrode can be heated simultaneously, the total heating time of the positive electrode and the negative electrode before the electrode assembly is wound is reduced, the heat treatment rate of the positive electrode and the negative electrode is improved, and the manufacturing efficiency of the electrode assembly is further improved. Since the assembly equipment further comprises the merging roller configured to receive and merge the materials released by the at least two roll-up rollers, and the detection position of the thickness detector is located upstream of the merging roller, the merging roller can merge the positive electrode and the negative electrode that have been heat treated and passed the thickness detection, and the winding of the positive electrode and the negative electrode after merging is facilitated.

[0024] In some embodiments, the number of the roll-up rollers is at least three, at least one roll-up roller is configured to support the positive electrode, at least one roll-up roller is configured to support the negative electrode, and at least one roll-up roller is configured to support the separator, and the conveying and heating mechanisms corresponding to the at least two roll-up rollers are respectively provided with the thickness detectors.

[0025] Since the conveying and heating mechanisms corresponding to the at least two roll-up rollers are respectively provided with the thickness detectors, the heated positive electrode and the heated negative electrode can be respectively subjected to the thickness detection, which further improves the consistency of the thickness of the positive electrode and the negative electrode before winding, improves the alignment accuracy between the positive electrode and the negative electrode during winding or merging, and reduces the probability of tab misplacement.

[0026] The second aspect of the present application provides a battery production line, the battery production line comprising the assembling device of the first aspect.

[0027] Since the battery production line comprises the assembling device, the thickness of the negative electrode at each position after being stacked by the stacking device can be made substantially uniform, the limitation of the position with thinner thickness on the negative electrode on the charge rate of the battery monomer can be reduced, and the charge rate of the battery monomer can be improved. The beneficial effects of the present application include: since the assembling device comprises the conveying and heating mechanism, the conveying and heating mechanism can not only convey the negative electrode to the detection position of the thickness detector, but also preheat and pre-expand the negative electrode. Moreover, since the negative electrode itself has a temperature, the negative electrode forms an electrode assembly, and the temperature of the negative electrode inside the electrode assembly is higher, thereby heat can be transferred to the separator of the electrode assembly to improve the adhesion of the separator with adhesive, and the adhesive separator is better bonded with the negative electrode. Moreover, since the assembling device further comprises the thickness detector, the thickness of the negative electrode after being heated and before being stacked with the positive electrode can be detected. If the thickness of the negative electrode entering the front part of the stacking device is inconsistent, an alarm can be given in time to stop and debug, and if the thickness of the negative electrode is substantially uniform, the negative electrode enters the stacking device, so that the thickness of the negative electrode at each position after being stacked by the stacking device can be made substantially uniform, the limitation of the position with thinner thickness on the negative electrode on the charge rate of the battery monomer can be reduced, and the charge rate of the battery monomer can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the same figures. In the drawings:

[0029] Figure 1 A structural schematic diagram of the assembling device provided for some embodiments of the present application is shown in FIG. 1.

[0030] Figure 2 A structural schematic diagram of the assembling device provided for some other embodiments of the present application is shown in FIG. 2.

[0031] Figure 3 A structural schematic diagram of the assembling device provided for some other embodiments of the present application is shown in FIG. 3.

[0032] Figure 4 A structural schematic diagram of the assembling device provided for some other embodiments of the present application is shown in FIG. 4.

[0033] BRIEF DESCRIPTION OF DRAWINGS

[0034] 10, assembling device; 1, material; 2, material roll; 3, conveying roller group; 31, conveying roller; 311, heating roller; 3111, first heating roller; 3112, second heating roller; 3113, third heating roller; 312, transition roller; 4, stacking device; 41, winder; 42, merging roller; 6, thickness detector; 7, heating device. DETAILED DESCRIPTION

[0035] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and the above description of drawings are intended to cover non-exclusive inclusion.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0038] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents the "or" relationship between the front and rear associated objects.

[0040] In the description of the embodiments of the present application, the directions or positional relationships indicated by the technical terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential" and the like are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, operate or be used in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0041] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mount", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0042] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical term "contact" should be understood in a broad sense, which can be direct contact or contact through an intermediate medium layer, which can be contact between two objects in contact without interaction force, or contact between two objects in contact with interaction force.

[0043] In the following, the present application will be described in detail.

[0044] In the related art, the electrode assembly includes a positive electrode, a negative electrode and a separator, and the separator is arranged between the positive electrode and the negative electrode. During the charging process of the battery monomer, the negative electrode of the electrode assembly will expand. The negative electrode will be heated by a conveying heating mechanism before being stacked with the positive electrode on the stacking device to make the negative electrode produce a certain pre-expansion. After the positive electrode, the negative electrode and the separator are assembled into an electrode assembly, the electrode assembly or the negative electrode is installed into the shell of the battery monomer. The pre-expansion of the negative electrode makes the further expansion of the electrode assembly or the negative electrode during the charging and discharging process of the battery monomer smaller. However, during the heating process of the negative electrode by the conveying heating mechanism, due to uneven heating or interference of other external factors, the different pre-expansion amounts of the negative electrode can cause uneven thickness of the negative electrode. The pre-expansion amount of the negative electrode is smaller at the position with smaller thickness, the space of the electrode assembly at the position with smaller thickness of the negative electrode is smaller, the negative electrode is denser at the corresponding position, and the electrolyte is more difficult to infiltrate into the corresponding position of the negative electrode, causing larger local resistance and limiting the charging rate of the battery monomer.

[0045] It should be noted that the charging rate is an index for measuring the charging speed of the battery, and the charging rate of the battery cell is the ratio of the charging current of the battery cell to the rated capacity of the battery cell.

[0046] For example, the charging rate of 1C means that the battery cell is fully charged in one hour. For example, the rated capacity of the battery cell is 25 Ah, the charging current of the battery cell is 25 A, and the charging rate of the battery cell is 1C.

[0047] For example, the material of the negative electrode is graphite, and the carriers of the electrolyte are embedded in the graphite during the charging process to expand the negative electrode.

[0048] For example, the carrier of the electrolyte can be a lithium ion.

[0049] For example, the material of the negative electrode is graphite, and the negative electrode is heated to a relatively thin position with a smaller pre-expansion amount. The graphite particles in this position are relatively dense, and the electrolyte is difficult to infiltrate between the graphite particles, resulting in a larger local resistance. During the charging process, it is difficult for lithium ions to be embedded in the graphite, and the charging rate is limited.

[0050] It is found through research that a thickness detector can be added to the assembly equipment, the detection position of the thickness detector is set before a stacking device used for stacking and assembling the negative electrode into an electrode assembly, the thickness of the negative electrode before stacking is detected by the thickness detector, if the thickness of the negative electrode entering the front part of the stacking device is inconsistent, an alarm can be sent to stop the machine for debugging in time, if the thickness of the negative electrode is basically consistent, the negative electrode enters the stacking device, so that the thickness of the negative electrode stacked by the stacking device is basically consistent at each position, which can better reduce the limitation of the position with a relatively thin thickness on the charging rate of the battery cell, and is conducive to improving the charging rate of the battery cell.

[0051] Based on such a design concept, the embodiment of the present application provides an assembly equipment for assembling an electrode assembly, the assembly equipment comprising: a conveying and heating mechanism, which is used for at least conveying and heating a negative electrode used for assembling the electrode assembly; a thickness detector, which is used for at least detecting the thickness of the negative electrode after being heated and before being stacked with a positive electrode used for assembling the electrode assembly, and the detection position of the thickness detector is located downstream of the conveying and heating mechanism; and a stacking device, which is used for stacking and assembling the negative electrode into the electrode assembly, and the stacking device is located downstream of the detection position of the thickness detector.

[0052] Since the assembling device comprises the conveying and heating mechanism, the conveying and heating mechanism can not only convey the negative electrode to the detection position of the thickness detector, but also preheat and pre-expand the negative electrode. Moreover, since the negative electrode itself has a temperature, the temperature of the negative electrode inside the electrode assembly is relatively high, thereby heat can be transferred to the separator of the electrode assembly to improve the adhesion of the separator, and the separator with adhesive is better bonded with the negative electrode. Moreover, since the assembling device further comprises the thickness detector, the thickness detector can detect the thickness of the negative electrode after being heated and before being overlapped with the positive electrode. If the thickness of the negative electrode entering the front part of the overlapping device is inconsistent, an alarm can be given in time to stop and adjust, and if the thickness of the negative electrode is basically consistent, the negative electrode enters the overlapping device, so that the thickness of the negative electrode overlapped by the overlapping device at each position is basically consistent, which can better reduce the limitation of the position with relatively thin thickness on the charging rate of the battery monomer, and is beneficial to improving the charging rate of the battery monomer. The battery production line provided by the embodiments of the present application can be used for manufacturing battery devices or battery monomers, but is not limited thereto.

[0053] The battery apparatus mentioned in the embodiments of the present application can comprise one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can comprise a plurality of battery cells connected in series, in parallel or in a mixed connection through a busbar component.

[0054] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by binding a plurality of battery cells with a cable tie.

[0055] In some embodiments, the battery apparatus can be a battery pack comprising a box body and one or more battery cell assemblies accommodated in the box body.

[0056] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0057] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells in the box body.

[0058] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0059] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During charging and discharging of the battery cell, active ions are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can function to prevent short circuiting of the positive and negative electrodes, while allowing the active ions to pass through. The active ions can be lithium ions, for example.

[0060] In some embodiments, the positive electrode can be a positive electrode tab, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0061] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0062] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material on a polymer material base material.

[0063] As an example, the metal material can be aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, etc.

[0064] As an example, the polymer material base material can be a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.

[0065] As an example, the positive electrode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, embodiments of the present application are not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination with two or more. As an example of the lithium-containing phosphates, at least one of lithium iron phosphate (e.g., LiFePO4 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon can be used, but the present application is not limited thereto.

[0066] In some embodiments, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. When the foamed metal is used as the positive electrode, the surface of the foamed metal can be free of positive electrode active material, or can be provided with positive electrode active material. As an example, the foamed metal can be filled or / and deposited with a lithium source material, potassium metal or sodium metal. The lithium source material can be lithium metal and / or lithium-rich material.

[0067] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0068] As an example, the negative electrode current collector can employ a metal foil, foamed metal or composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, titanium, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. The composite current collector can be formed by forming a metal material on a polymer material base material. In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0069] As an example, the metal material can be copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.

[0070] As an example, the polymer material base material can be a base material such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.

[0071] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited in the embodiments of the present application, and any publicly known porous structure separator film having good chemical stability and mechanical stability can be selected.

[0072] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0073] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is provided between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0074] In some embodiments, the battery cell further includes an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of the electrolyte is not particularly limited in the embodiments of the present application, and can be selected as needed. The electrolyte can be in a liquid state, a gel state or a solid state.

[0075] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0076] As an example, the separators can be continuously arranged, and arranged between any adjacent positive electrode tab or negative electrode tab in a winding manner.

[0077] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, etc.

[0078] In some embodiments, the electrode assembly is provided with a tab, which can guide the current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0079] In some embodiments, the electrode assembly has a stacked structure.

[0080] As an example, a plurality of positive electrode tabs and a plurality of negative electrode tabs can be arranged alternately.

[0081] In some embodiments, the battery cell can include a housing. The housing encapsulates the electrode assembly and other components such as electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell, a composite metal shell, or an aluminum-plastic film, etc.

[0082] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, including a square battery cell, a blade battery cell, a multi-prismatic battery cell such as a hexagonal battery cell, etc. The embodiments of the present application are not particularly limited.

[0083] In some embodiments, the housing includes an end cap assembly and a shell, the shell is provided with an opening, and the end cap assembly closes the opening to form a sealed space for accommodating the electrode assembly and electrolyte, etc. The shell can be provided with one or more openings. The end cap assembly can also be provided with one or more openings.

[0084] In some embodiments, the housing is provided with at least one electrode terminal, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or indirectly connected to the tab through an adapter component. The electrode terminal can be arranged on the end cap assembly, or arranged on the shell.

[0085] In the following, the Figures 1 to 4 Some embodiments of the present application are described in detail.

[0086] The first aspect of the present application provides an assembly device 10, such as Figures 1 to 4As shown, the assembling device 10 is used for assembling the electrode assembly, the assembling device 10 comprises a conveying heating mechanism, a thickness detector 6 and a stacking device 4. The conveying heating mechanism is used for at least conveying and heating the negative electrode used for assembling the electrode assembly. The thickness detector 6 is used for detecting the thickness of the negative electrode after being heated and before being stacked, and the detection position of the thickness detector 6 is located downstream of the conveying heating mechanism. The stacking device 4 is used for stacking and assembling the negative electrode into the electrode assembly, and the stacking device 4 is located downstream of the detection position of the thickness detector 6.

[0087] The conveying heating mechanism is used for both conveying and heating the negative electrode.

[0088] The thickness detector 6 is used for detecting the thickness of the negative electrode after being heated and before being stacked.

[0089] The stacking device 4 is used for stacking the negative electrode into the electrode assembly.

[0090] Exemplarily, the assembling device 10 can also assemble the positive electrode, the separator and the negative electrode into the jelly-roll type electrode assembly.

[0091] Exemplarily, as shown in Figures 1 to 4 As shown, the conveying heating mechanism heats and conveys the negative electrode to the detection position of the thickness detector 6. If the thickness of the negative electrode after being detected is unchanged, the negative electrode with unchanged thickness enters the stacking device 4, and the stacking device 4 stacks and assembles the negative electrode into the electrode assembly. If the thickness of the negative electrode after being detected is changed, an alarm can be given to stop the device for debugging.

[0092] Exemplarily, the assembling device 10 further comprises a cutting device (not shown), which is used for cutting the negative electrode, and in the case that the thickness detector 6 detects that the thickness of the negative electrode is changed, the negative electrode is cut to stop entering the stacking device 4.

[0093] Exemplarily, the thickness detector 6 can be arranged downstream of the conveying heating mechanism and upstream of the stacking device 4.

[0094] Exemplarily, as shown in Figure 3 As shown, the conveying heating mechanism can comprise a set of conveying rollers 3 and a set of heating devices 7. For example, the conveying rollers 3 convey the negative electrode to the heating devices 7, and the heating devices 7 heat the negative electrode. For example, the conveying rollers 3 can comprise a plurality of conveying rollers, and the heating devices 7 can be infrared heating devices.

[0095] Exemplarily, as shown in Figure 1 and Figure 2 As shown, the conveying heating mechanism can comprise a plurality of conveying rollers 31, at least a part of the conveying rollers 31 are heating rollers 311, the conveying rollers 31 are used for conveying the negative electrode, and the heating rollers 311 can convey the negative electrode and have a heating function, which is used for heating the conveyed negative electrode.

[0096] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode. Figure 1 Figure 2 For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode. Figure 4 For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0097] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0098] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode. Figure 1 Figure 4 For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0099] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0100] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode. Figures 1 to 4

[0101] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode. Figure 4 For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0102] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0103] For example, as shown in FIG. 1, the number of the conveying and heating mechanisms can be one group, and the one group of the conveying and heating mechanisms is used for conveying and heating the negative electrode.

[0104] ​​​Exemplarily, the negative electrode, the separator, the positive electrode and the separator are sequentially stacked on the merging roller 42.

[0105] Exemplarily, the stacking device 4 can directly wind and form the separator, the positive electrode and the negative electrode.

[0106] Exemplarily, the stacking device 4 can include a winding device, and the assembly equipment 10 does not provide the merging roller 42, and the winding device is used to directly stack and wind the negative electrode after the thickness detector 6 detection and the positive electrode and the separator into a wound electrode assembly.

[0107] Exemplarily, the stacking device 4 can stack the separator, the positive electrode and the negative electrode, and the separator, the positive electrode and the negative electrode are assembled and formed by other devices.

[0108] In the embodiment of the present disclosure, since the assembly equipment 10 includes the conveying and heating mechanism, the conveying and heating mechanism can not only convey the negative electrode to at least the detection position of the thickness detector 6, but also preheat the negative electrode to make the negative electrode pre-expand. Moreover, since the negative electrode itself has a temperature, the negative electrode forms an electrode assembly, and the temperature of the negative electrode inside the electrode assembly is relatively high, thereby heat can be transferred to the separator of the electrode assembly to improve the adhesion of the separator, and the separator with adhesive is better bonded with the negative electrode. Moreover, since the assembly equipment 10 further includes the thickness detector 6, the thickness detector 6 can detect the thickness of the negative electrode after heating and before stacking with the positive electrode. If the thickness of the negative electrode entering the front part of the stacking device 4 is inconsistent, the equipment can be stopped in time for adjustment, and if the thickness of the negative electrode is basically consistent, the negative electrode enters the stacking device 4, so that the thickness of the negative electrode stacked by the stacking device 4 at each position is basically consistent, which can better reduce the limitation of the position with relatively thin thickness on the negative electrode on the charge rate of the battery monomer, and is beneficial to improve the charge rate of the battery monomer.

[0109] In some embodiments, as shown in Figures 1 to 4 The stacking device 4 includes a winding device 41, and the assembly equipment 10 further includes a material roll roller 2 for supporting a material roll wound by the material 1 to be assembled. The material 1 supported by at least one material roll roller 2 is a negative electrode, and the conveying and heating mechanism is located downstream of the material roll roller 2. The conveying and heating mechanism includes a conveying roller group 3 including at least one conveying roller 31 for conveying the material 1 released by the material roll roller 2. The detection position of the thickness detector 6 is located downstream of the conveying roller group 3, and the winding device 41 is used to receive the material 1 conveyed by the conveying roller 31 and wind the received material 1 into an electrode assembly.

[0110] The winding device 41 is used to wind the positive electrode, the negative electrode and the separator into a wound electrode assembly.

[0111] The material 1 supported by at least one material roll roller 2 is a negative electrode, and the conveying roller 31 is used to convey the material 1 released by the material roll roller 2. The conveyed material 1 can be a negative electrode.

[0112] For example, the material roll 2 releases the material 1, the conveying roller set 3 conveys the material 1 released by the material roll 2, the thickness detector 6 detects the material 1 conveyed by the conveying roller set 3, and the winder 41 winds the material 1 detected by the thickness detector 6 into an electrode assembly.

[0113] For example, as shown in Figure 3 For example, the conveying rollers 31 in the conveying roller set can all be the conveying rollers 31 having the conveying function but not the heating function, and the heating device 7 is arranged downstream of the conveying roller set and heats the material 1 conveyed by the conveying rollers 31.

[0114] For example, as shown in Figure 1 For example, as shown in Figure 2 For example, at least part of the conveying rollers 31 can be the conveying rollers 31 having both the conveying function and the heating function, and the conveying rollers 31 heat and convey the material 1 to the detection position of the thickness detector 6.

[0115] For example, the material roll 2 can be a roll.

[0116] For example, as shown in Figures 1 to 4 For example, the number of the material rolls 2 can be one or more. For example, the number of the material rolls 2 can be one, and one material roll 2 is used to support the negative electrode; or the number of the material rolls 2 can be four, and the four material rolls 2 are respectively used to support the material rolls made of the separators, the positive electrode, the separator and the negative electrode. The relative arrangement positions of the plurality of material rolls 2 are not specifically limited in the present application, as long as the material 1 can be conveyed to the conveying roller set 3.

[0117] For example, the winder 41 can be a winding needle.

[0118] For example, the wound electrode assembly has a flat area and a corner area, and the flat area is arranged with the corner area on opposite sides.

[0119] For example, the material 1 supported by at least one material roll 2 is the negative electrode.

[0120] In the embodiment of the present disclosure, the assembling device 10 further comprises the material roll 2, the conveying heating mechanism comprises the conveying roller set 3, and the stacking device 4 comprises the winder 41, so that the negative electrode can be released from the material roll 2, conveyed, conveyed to the detection position of the thickness detector 6, and then wound into a wound electrode assembly, and the thickness of the wound negative electrode is substantially uniform through the detection of the thickness detection device.

[0121] It can be understood that the assembly device 10 is not limited to assembling the wound electrode assembly. For example, the assembly device 10 can be used to assemble the stacked electrode assembly, and the stacking device 4 includes a stacker for stacking the positive electrode, the separator and the negative electrode into the stacked electrode assembly. For example, the stacker can be a stacking robot.

[0122] In some embodiments, as shown in Figure 1 or Figure 2 The at least one conveying roller 31 is a heating roller 311.

[0123] The heating roller 311 is used to convey and heat the negative electrode.

[0124] For example, the at least one conveying roller 31 having the conveying function but not having the heating function can be replaced by the heating roller 311.

[0125] For example, the at least one heating roller 311 can be added to the original device.

[0126] For example, the at least one conveying roller 31 having the conveying function but not having the heating function can be replaced by the heating roller 311, and the at least one heating roller 311 can be added to the original device.

[0127] Optionally, the number of the heating roller 311 can be one, two, three or four, etc.

[0128] In the embodiments of the present disclosure, since the at least one conveying roller 31 is the heating roller 311, during the conveying of the negative electrode by the conveying roller 31, the heating roller 311 heats the as-unfolded negative electrode as much as possible, the heat transfer path of the heating roller 311 to the negative electrode is relatively short, the as-unfolded negative electrode can be heated by the heating roller 311 as quickly and uniformly as possible, the negative electrode can be heated and expanded as quickly and uniformly as possible, and the thickness of the negative electrode at each position during the stacking by the stacking device tends to be consistent, which can better reduce the limitation of the position with a relatively thin thickness on the negative electrode on the charge rate of the battery monomer, and is conducive to improving the charge rate of the battery monomer. Moreover, the separator and the negative electrode can be better bonded during the extrusion of the electrode assembly, the time length of re-heating is shortened, thereby better solving the problem that the separator far from the surface layer in the electrode assembly after assembly needs to be heated for a long time in order to be bonded, and is conducive to improving the production efficiency.

[0129] In some embodiments, as shown in Figure 1 and Figure 2As shown, the number of conveying rollers 31 is at least four, at least three of the conveying rollers 31 are heating rollers 311, at least one of the conveying rollers 31 is a transition roller located between two adjacent heating rollers 311, at least one of the heating rollers 311 is a first heating roller 311, the heating roller 311 adjacent to the first heating roller 311 and located upstream of the first heating roller 311 is a second heating roller 311, the heating roller 311 adjacent to the first heating roller 311 and located downstream of the first heating roller 311 is a third heating roller 311, and the number of transition rollers 312 between the upstream of the first heating roller 311 and the downstream of the second heating roller 311 is greater than the number of transition rollers 312 between the downstream of the first heating roller 311 and the upstream of the third heating roller 311.

[0130] The transition roller 312 is a conveying roller 31 with conveying function and without heating function.

[0131] The heating roller 311 adjacent to the first heating roller 3111 and located upstream of the first heating roller is a second heating roller 3112, where adjacent refers to the adjacent between the heating rollers 311, and there is no other heating roller 311 between the upstream of the first heating roller 3111 and the downstream of the second heating roller 3112. The material released by the material roll 2 reaches between the first heating roller 3111 after passing through the second heating roller 3112, and does not pass through other heating rollers 311. However, the material released by the material roll 2 can pass through the transition roller 312 after passing through the second heating roller 3112 to reach between the first heating roller 3111.

[0132] The first heating roller 3111 and the third heating roller 3113 are adjacent to each other, where adjacent refers to the adjacent between the two conveying rollers, and there is no other conveying roller between the downstream of the first heating roller 3111 and the upstream of the third heating roller 3113.

[0133] Exemplarily, as shown in Figure 1 The number of transition rollers between the downstream of the first heating roller 3111 and the upstream of the third heating roller 3113 can be zero. In this case, there is no transition roller 312 between the downstream of the first heating roller 3111 and the upstream of the third heating roller 3113.

[0134] Exemplarily, there is no transition roller 312 between the downstream of the first heating roller 3111 and the upstream of the third heating roller 3113, as shown in Figure 1 The first heating roller 3111 and the third heating roller 3113 are adjacent to each other, and the material released by the material roll 2 reaches between the third heating roller 3113 after passing through the first heating roller 3111, and does not pass through other conveying rollers 31.

[0135] Exemplarily, as shown in Figure 1As shown, the number of conveying rollers 31 is at least four. Among them, at least three conveying rollers 31 are heating rollers 311, one heating roller 311 is a first heating roller 3111, another is a second heating roller 3112, and the other is a third heating roller 3113; at least one conveying roller 31 is a transition roller 312, which is located between adjacent heating rollers 311 along the conveying direction of the material 1. The conveying direction of the material 1 refers to the direction in which the material 1 is conveyed from the roll roller 2 to the stacking device via the conveying roller group 3.

[0136] Exemplarily, the number of conveying rollers 31 can be four, five, six, seven or more, etc.

[0137] Exemplarily, the number of heating rollers 311 can be three, four, five, six or more, etc.

[0138] Exemplarily, the number of transition rollers 312 can be one, two, three or more, etc. Among them, the number of transition rollers 312 between adjacent two heating rollers 311 can be one, two, three or more, etc., of course, no transition roller 312 can be arranged between adjacent two heating rollers 311.

[0139] Exemplarily, as shown in Figure 1 As shown, the number of conveying rollers 31 is four, among which three conveying rollers 31 are heating rollers 311, and the other conveying roller 31 is a transition roller 312, which are arranged in sequence along the conveying direction of the material 1.

[0140] Exemplarily, as shown in Figure 2 As shown, the number of conveying rollers 31 is ten, and the arrangement of the rollers along the conveying direction of the material 1 can be conveying roller 31, heating roller 311, transition roller 312, heating roller 311, transition roller 312 and heating roller 311, for example, three conveying rollers 31, one heating roller 311, two transition rollers 312, one heating roller 311, one transition roller 312 and one heating roller 311 are arranged in sequence along the conveying direction of the material 1. Figure 1 and Figure 2 Only the arrangement of the conveying rollers 31 of the conveying roller group 3 in some cases is shown, and the specific arrangement of the conveying rollers 31 can also be other arrangement forms.

[0141] Exemplarily, the number of transition rollers 312 between the first heating roller 3111 and the second heating roller 3112 can be one, two, three, four or five, etc.

[0142] Exemplarily, the number of transition rollers 312 between the first heating roller 3111 and the third heating roller 3113 can be zero, one, two, three or four, etc.

[0143] For example, such as Figure 1 As shown, the number of transition rollers 312 between the first heating roller 3111 and the second heating roller 3112 can be one, and the number of transition rollers 312 between the first heating roller 3111 and the third heating roller 3113 can be zero.

[0144] In this embodiment, the negative electrode is gradually heated from the second heating roller 3112 to the third heating roller 3113. The number of transition rollers 312 between the upstream of the first heating roller 3111 and the downstream of the second heating roller 3112 is relatively large, and the first heating roller 3111 and the second heating roller 3112 are relatively sparsely distributed. The number of transition rollers 312 between the downstream of the first heating roller 3111 and the upstream of the third heating roller 3113 is relatively small, and the first heating roller 3111 and the second heating roller 3112 are relatively densely distributed. This results in a smaller temperature rise of the negative electrode during transport on the sparsely distributed first and second heating rollers. This can alleviate the situation where the negative electrode is heated to a high temperature too quickly. During the transport of the negative electrode away from the second heating roller and the first heating roller of the stacking device, the temperature of the negative electrode is relatively low, and the temperature difference between the negative electrode and the surrounding environment is small. This helps to reduce heat exchange between the negative electrode and the surrounding environment, thereby reducing energy loss and energy consumption. During the conveying of the negative electrode on the relatively densely distributed first and third heating rollers, the portion of the negative electrode preheated upstream of the first heating roller is further heated by the first and second heating rollers. Since the first and third heating rollers are relatively densely distributed, it is beneficial to maintain a high temperature for the negative electrode. When the negative electrode is heated to the preset temperature, it enters the stacking device for assembly. During the extrusion of the assembled electrode assembly, the high temperature of the negative electrode is beneficial to the better adhesion of the adhesive-coated separator to the negative electrode.

[0145] In some embodiments, such as Figure 1 or Figure 2 As shown, the number of transition rollers 312 between two adjacent heating rollers 311 located upstream is greater than or equal to the number of transition rollers 312 between two adjacent heating rollers 311 located downstream.

[0146] For example, the number of transition rollers 312 between two adjacent heating rollers 311 located upstream is equal to the number of transition rollers 312 between two adjacent heating rollers 311 located downstream.

[0147] For example, along the conveying direction of material 1, three heating rollers 311 are arranged in sequence. Among the three heating rollers 311, the number of transition rollers 312 between two adjacent heating rollers 311 located upstream can be one, and the number of transition rollers 312 between two adjacent heating rollers 311 located downstream can also be one.

[0148] For example, such as Figure 1As shown, the number of transition rollers 312 between the two adjacent heating rollers 311 upstream is greater than the number of transition rollers 312 between the two adjacent heating rollers 311 downstream.

[0149] For example, along the conveying direction of the material 1, three heating rollers 311 are arranged in sequence, among the three heating rollers 311, the number of transition rollers 312 between the two adjacent heating rollers 311 upstream can be three, and the number of transition rollers 312 between the two adjacent heating rollers 311 downstream can be two, one or zero. The three heating rollers 311 can be the first heating roller 3111, the second heating roller 3112 and the third heating roller 3113 described above, of course, the three heating rollers 311 can also be other heating rollers.

[0150] For example, along the conveying direction of the material 1, the number of transition rollers 312 between the two adjacent heating rollers 311 is constant or decreases.

[0151] For example, along the conveying direction of the material 1, the number of transition rollers 312 between the two adjacent heating rollers 311 gradually decreases.

[0152] In the embodiments of the present disclosure, since the number of transition rollers 312 between the two adjacent heating rollers 311 upstream is greater than or equal to the number of transition rollers 312 between the two adjacent heating rollers 311 downstream, the number of heating rollers 311 of the conveying roller group 3 located upstream of the conveyed material 1 can be set to be less, and the number of heating rollers 311 of the conveying roller group 3 located downstream of the conveyed material 1 can be set to be more, so that the number of heating rollers 311 for heating the material 1 is less at the upstream of the conveyed material 1, and the temperature rise of the negative electrode is less, which alleviates the heat exchange of the negative electrode with the surrounding air during the conveying process of the heating roller 311, thereby reducing energy loss and energy consumption. Moreover, the number of heating rollers 311 for heating the negative electrode is more at the upstream of the conveyed negative electrode, and the more heating rollers 311 can heat the negative electrode, so that the negative electrode can maintain a higher temperature near the stacking device 4, and the negative electrode enters the stacking device 4 for assembly at a higher temperature, which is more conducive to better adhesion of the adhesive separator to the negative electrode.

[0153] In some embodiments, the heating roller 311 comprises a first roller body and a first heater. The first heater is located in the first roller body, and the first heater heats the first roller body.

[0154] It should be noted that the first roller body and the first heater are both shown.

[0155] During the conveying of the negative electrode, the first roller body contacts the negative electrode and can heat the negative electrode.

[0156] The first heater can be an electromagnetic heater, and can also be other devices with heating function.

[0157] In the embodiment of the present disclosure, the heating roller 311 is composed of the first roller body and the first heater located in the first roller body, and has simple structure and low manufacturing cost.

[0158] In some embodiments, the first roller body includes a roller body side wall, the roller body side wall enclosing the first heater, and the roller body side wall being configured to contact the negative electrode conveyed by the conveying roller 31.

[0159] The roller body side wall enclosing the first heater means that the side wall of the first roller body is enclosed, and the part of the roller body side wall located outside the first roller body and the part of the roller body side wall located inside the first roller body are cut off by the roller body side wall, i.e., the roller body side wall is not provided with a hole that can communicate the inside and outside of the roller body side wall. The area surrounded by the roller body side wall can be in communication with the outside of the roller body side wall through the openings at both ends of the roller body side wall, so that the first heater can be assembled into the area surrounded by the roller body side wall, and the openings at both ends of the area surrounded by the roller body side wall can be closed.

[0160] In the embodiment of the present disclosure, since the roller body side wall encloses the first heater and the roller body side wall is configured to contact the negative electrode conveyed by the conveying roller 31, the temperature of the roller body side wall is relatively uniform, thereby making the negative electrode uniformly heated and making the degree of negative electrode thermal rebound as uniform as possible, and reducing the negative impact of the local performance difference of the negative electrode on the overall battery cell.

[0161] In some embodiments, the conveying and heating mechanism further includes a heating device 7 located between the downstream of the conveying roller group 3 and the upstream of the detection position of the thickness detector 6.

[0162] The heating device 7 is configured to heat the negative electrode conveyed by the conveying roller 31. The heating device 7 can be an infrared heater.

[0163] In the conveying direction of the negative electrode, the heating device 7 is located between the conveying roller group 3 and the detection position of the thickness detector 6.

[0164] In the embodiment of the present disclosure, the heating device 7 can heat the negative electrode before thickness detection, so as to pre-expand the negative electrode. Moreover, the heating device 7 can be added to the original assembly device 10, and the adaptability of the heating device 7 to the old device is relatively high, and the overall modification scheme is relatively simple and has low cost.

[0165] In some embodiments, the number of the roll of material 2 is at least two, each roll of material 2 is provided with a conveying and heating mechanism, and the stacking device 4 further includes a merging roller 42 located between the downstream of the detection position of the thickness detector 6 and the upstream of the winder 41.

[0166] The merging roller 42 is located between the detection position of the thickness detector 6 and the winder 41 along the conveying direction of the negative electrode.

[0167] For example, the number of the material roll rollers 2 can be two, three or four, etc. In a specific embodiment, the number of the material roll rollers 2 is four, and the four material roll rollers 2 are respectively used to support the material rolls of the positive electrode, the separator, the negative electrode and the separator.

[0168] For example, two of the material roll rollers 2 are respectively provided with a conveying heating mechanism, and the two material roll rollers 2 are respectively used to support the positive electrode and the negative electrode. The positive electrode and the negative electrode are heated by the conveying heating mechanisms and conveyed to the detection position of the thickness detector 6. After being detected by the thickness detector 6, the positive electrode and the negative electrode can be merged with the separator which is not detected by the thickness detector 6 on the merging roller 42. The merging roller 42 merges the materials 1 to form an integral whole.

[0169] For example, four of the material roll rollers 2 are respectively provided with a conveying heating mechanism, and each of the material roll rollers 2 corresponds to each of the conveying heating mechanisms. Each of the conveying heating mechanisms is used to convey the material 1 supported by each of the material roll rollers 2. Each of the conveying heating mechanisms conveys the material 1 to the merging roller 42. The merging roller 42 merges the materials 1 to form an integral whole. The positive electrode and the negative electrode need to pass through the detection of the thickness detector 6 before entering the merging roller 42.

[0170] For example, the positive electrode, the separator, the negative electrode and the separator wound on the merging roller 42 are arranged in a stacked manner on the merging roller 42 to form an unrolled electrode assembly. The positive electrode, the separator, the negative electrode and the separator arranged in a stacked manner on the merging roller 42 are in an unrolled state. The merging roller 42 can convey the positive electrode, the separator, the negative electrode and the separator arranged in a stacked manner in the unrolled state to the winder 41. The winder 41 winds the positive electrode, the separator, the negative electrode and the separator arranged in a stacked manner to form a wound electrode assembly.

[0171] For example, the merging roller 42 can be a roller located on one side of the material 1 as shown in the figure. Of course, the merging roller 42 can also be other structures capable of merging multiple materials 1, as long as it can receive and merge at least two materials 1 released by the material roll rollers 2. Figure 1

[0172] ​Since the number of the material roll 2 is at least two, each material roll 2 is provided with a corresponding conveying heating mechanism, so that the positive and negative electrodes can be heated at the same time, the total heating time of the positive and negative electrodes before the electrode assembly is wound is reduced, the heat treatment rate of the positive and negative electrodes is improved, and the manufacturing efficiency of the electrode assembly is improved. Since the assembly device 10 further comprises a converging roller 42 for receiving and converging the materials 1 released by the at least two material rolls 2, and the detection position of the thickness detector 6 is located upstream of the converging roller 42, the converging roller 42 can converge the positive and negative electrodes that have been heat treated and have passed the thickness detection, and facilitate the winding of the converged positive and negative electrodes.

[0173] In some embodiments, the number of the material roll 2 is at least three, at least one material roll 2 is used to support the positive electrode, at least one material roll 2 is used to support the negative electrode, and at least one material roll 2 is used to support the separator, and at least two conveying heating mechanisms corresponding to the material roll 2 are respectively provided with a thickness detector 6.

[0174] For example, the number of the material roll 2 can be three or four, etc.

[0175] For example, the number of the material roll 2 is three, three material rolls 2 are used to support the positive electrode, the negative electrode and the separator respectively, three material rolls 2 are respectively provided with a corresponding conveying heating mechanism, and the conveying heating mechanisms corresponding to the material rolls 2 used to support the positive and negative electrodes are respectively provided with a thickness detector 6.

[0176] For example, the number of the material roll 2 is four, four material rolls 2 are used to support the positive electrode, the separator, the negative electrode and the separator respectively, four material rolls 2 are respectively provided with a corresponding conveying heating mechanism, and the conveying heating mechanisms corresponding to the material rolls 2 used to support the positive and negative electrodes are respectively provided with a thickness detector 6.

[0177] For example, the material 1 supported by the at least one roll 2 is a positive electrode. In the case where the material 1 is a positive electrode, the positive electrode is wound with other materials 1 to form an electrode assembly, and the electrode assembly is extruded to form a battery cell in a housing. During the extrusion of the electrode assembly, the positive electrode is prone to cracking due to its material and manufacturing process. The conveying and heating mechanism can heat the positive electrode before winding, increase the thickness of the positive electrode, pre-expand the positive electrode, soften the positive electrode before winding to form an electrode assembly, improve the plasticity of the positive electrode, and further improve the ductility of the positive electrode. During the extrusion of the electrode assembly, the positive electrode can withstand greater pressure, reducing the risk of cracking of the positive electrode during extrusion. Moreover, after the positive electrode is heated and rebounded, the rebound degree of the positive electrode is reduced after being heated again, thereby reducing the contribution of the positive electrode rebound to the expansion force of the electrode assembly, effectively reducing the expansion force of the electrode assembly, improving the service life of the battery cell, and the positive electrode itself has a temperature after being heated and rebounded in advance, thereby preheating the inner ring temperature of the electrode assembly, reducing the extrusion time of the electrode assembly, and improving the manufacturing efficiency of the electrode assembly.

[0178] Since the at least two roll 2 corresponding conveying and heating mechanism respectively provided with thickness detector 6, thus can respectively detect the thickness of the heated positive electrode and negative electrode, further, improve the consistency of the thickness of the positive electrode and negative electrode before winding, improve the alignment accuracy between the positive electrode and the negative electrode during winding or merging, and further reduce the probability of tab misalignment.

[0179] The second aspect of the present application provides a battery production line, which comprises the assembly device 10 provided in the first aspect.

[0180] Since the battery production line comprises the assembly device 10, the thickness of the negative electrode at each position after being stacked by the stacking device tends to be consistent, which can better reduce the limitation of the position with thinner thickness on the negative electrode on the charge rate of the battery cell, and is conducive to improving the charge rate of the battery cell.

[0181] In a specific embodiment, the tension roller or other roller through which the negative electrode passes is adjusted to a heating roller 311 with magnetic induction heating function. The conveying roller 31 in the conventional winding machine can be directly modified, without the need to add new rollers. However, if all the rollers are modified to heating rollers 311 with magnetic induction heating function, the cost of equipment and modification will be higher, and the temperature inside the winding machine is very high, which is not conducive to the process and monitoring. Therefore, part of the conveying rollers 31 can be modified to over-rollers with magnetic induction heating function, so that the negative electrode can be heated and rebounded in advance, and the negative electrode itself maintains a high temperature, the inner ring temperature of the electrode assembly increases, and the heat pressing time can be reduced, improving the process efficiency.

[0182] In another specific embodiment, the tension roller through which the positive electrode passes in the conventional winding machine is adjusted to be a heating roller 311 with magnetic induction heating function, so as to heat the positive electrode during the passing of the roller, so that the positive electrode is softened by heat before being wound into an electrode assembly, the plasticity of the positive electrode is improved, the positive electrode has greater ductility after being heated, the positive electrode can bear greater pressure during the extrusion of the electrode assembly, and the probability of cracking of the positive electrode in the corner area of the innermost circle of the electrode assembly is reduced.

[0183] The passing roller in the conventional winding machine can be directly modified, without the need to add new rollers or new equipment, the overall modification scheme is relatively simple, the positive electrode has relatively low temperature requirement, only the purpose of softening the positive electrode by heat to improve the plasticity is needed, the adaptability to the old equipment is relatively high, and the scheme can be widely applied. The early rebound of the positive electrode can reduce the rebound of the positive electrode during the use of the electrode assembly, reduce the contribution of the rebound of the positive electrode to the expansion force of the electrode assembly, effectively reduce the expansion force of the electrode assembly, and improve the service life of the battery monomer. In the scheme, the positive electrode itself maintains a relatively high temperature after the early rebound of the positive electrode, the temperature of the inner circle of the electrode assembly can be preheated, and the extrusion time of the electrode assembly is reduced.

[0184] The heating area with infrared heating function is added in the assembly equipment 10, so that the negative electrode and / or the positive electrode are heated and rebounded in advance before being wound into a winding type electrode assembly. The overall equipment occupies a relatively small area, the overall modification scheme is relatively simple, the cost is relatively low, and the adaptability to the old equipment is relatively high. The entire negative electrode and / or positive electrode will be cut off when process abnormalities occur during winding.

[0185] In order to ensure the thickness consistency of the negative electrode and / or the positive electrode, a thickness monitoring device is added before the negative electrode and / or the positive electrode are converged or wound. If the thickness of the negative electrode and / or the positive electrode exceeds the design specification, the machine can be stopped and adjusted in time to effectively control the consistency of the rebound thickness of the negative electrode and / or the positive electrode after being heated. The negative electrode and / or the positive electrode itself maintains a relatively high temperature after the early rebound of the negative electrode and / or the positive electrode, the temperature of the inner circle of the electrode assembly is increased, the heat pressing time can be reduced, and the process efficiency is improved.

[0186] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the present application.

Claims

1. An assembly device, characterized in that, The assembly equipment is used for assembling electrode assemblies and includes: A conveying heating mechanism, at least for conveying and heating the negative electrode used for assembling electrode assemblies; A thickness detector is used to detect at least the thickness of the negative electrode after heating and not stacked with the positive electrode used to assemble the electrode assembly, and the detection position of the thickness detector is located downstream of the conveying heating mechanism; A stacking device for stacking and assembling the negative electrode into an electrode assembly, the stacking device being located downstream of the detection position of the thickness detector.

2. The assembly equipment according to claim 1, characterized in that, The stacking device includes a winder, and the assembly equipment also includes a material roll roller, which is used to support the material to be assembled wound into a roll. At least one of the material roll rollers supports a negative electrode material. The conveying heating mechanism is located downstream of the material roll roller. The conveying heating mechanism includes a conveying roller group, which includes at least one conveying roller for conveying the material released by the material roll roller. The detection position of the thickness detector is located downstream of the conveying roller group. The winder is used to receive the material conveyed by the conveying roller and wind the received material into an electrode assembly.

3. The assembly equipment according to claim 2, characterized in that, At least one of the conveying rollers is a heated roller.

4. The assembly equipment according to claim 3, characterized in that, The number of conveying rollers is at least four, at least three of which are heating rollers, and at least one of which is a transition roller located between two adjacent heating rollers. At least one of the heating rollers is a first heating roller, a heating roller adjacent to and upstream of the first heating roller is a second heating roller, and a heating roller adjacent to and downstream of the first heating roller is a third heating roller. The number of transition rollers between the upstream of the first heating roller and the downstream of the second heating roller is greater than the number of transition rollers between the downstream of the first heating roller and the upstream of the third heating roller.

5. The assembly equipment according to claim 4, characterized in that, The number of transition rollers between two adjacent heating rollers located upstream is greater than or equal to the number of transition rollers between two adjacent heating rollers located downstream.

6. The assembly equipment according to claim 3, characterized in that, The heating roller includes: First roller body; A first heater is located inside the first roller body, and the first heater heats the first roller body.

7. The assembly equipment according to claim 6, characterized in that, The first roller body includes a roller body sidewall that encloses the first heater and is used to contact the negative electrode conveyed by the conveying roller.

8. The assembly equipment according to claim 2, characterized in that, The conveying heating mechanism further includes a heating device located between the downstream of the conveying roller assembly and the upstream of the detection position of the thickness detector.

9. The assembly equipment according to claim 2, characterized in that, The number of material rolls is at least two, and each material roll is provided with the conveying and heating mechanism. The stacking device also includes a merging roller for stacking the positive electrode and the negative electrode. The merging roller is located between the downstream of the detection position of the thickness detector and the upstream of the winder.

10. The assembly equipment according to claim 9, characterized in that, The number of material rolls is at least three, at least one of the material rolls is used to support the positive electrode, at least one of the material rolls is used to support the negative electrode, at least one of the material rolls is used to support the separator, and the conveying heating mechanism corresponding to at least two of the material rolls is respectively equipped with a thickness detector.

11. A battery production line, characterized in that, Includes the assembly equipment according to any one of claims 1 to 10.

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