Method of manufacturing double-sided electrode sheet, device, and double-sided electrode sheet

Abstract

The application relates to a double-sided electrode sheet manufacturing method and device and a double-sided electrode sheet. The method comprises the following steps: a mixture is respectively arranged in a first multi-roller calender mechanism and a second multi-roller calender mechanism, first, a first active material layer is formed by heat-combining a first side of a double-sided carbon-coated foil current collector and the mixture in the first multi-roller calender mechanism to obtain a single-sided electrode sheet, then, the area density of the single-sided electrode sheet is determined during the process of transferring the single-sided electrode sheet to the second multi-roller calender mechanism through a transmission component, a second active material layer is formed by heat-combining a second side of the double-sided carbon-coated foil current collector and the mixture in the second multi-roller calender mechanism to obtain a double-sided electrode sheet, the second active material layer is formed to obtain the double-sided electrode sheet, and the area density of the double-sided electrode sheet is determined. By adopting the method, the area densities of the two active material layers on the two sides of the double-sided electrode sheet can be accurately determined while the double-sided electrode sheet is manufactured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrode sheet manufacturing, in particular to a double-sided electrode sheet manufacturing method and device and a double-sided electrode sheet. BACKGROUND

[0002] In the manufacturing process of lithium ion batteries, each process step involves many process parameters and performance indicators, which together determine the performance and quality of the final manufactured lithium ion battery. The performance of the lithium ion battery depends largely on the performance of the electrode sheet. In the production process of the electrode sheet of the lithium ion battery, the subsequent rolling process is often affected due to the problems such as non-uniform surface density and poor thickness consistency of the active material layer of the electrode sheet, which ultimately affects the overall performance of the lithium ion battery. Therefore, it is particularly important to detect the surface density of the electrode sheet in real time and ensure the uniformity of the surface density in actual production.

[0003] Currently, in the existing double-sided electrode sheet manufacturing process, only the total surface density of the double-sided electrode sheet after being compounded can be detected, and the active material layer of any side cannot be detected separately. Obviously, if the surface density of each side of the active material layer of the double-sided electrode sheet cannot be detected separately, the final manufactured double-sided electrode sheet may not meet the design specifications, thereby affecting the performance of the battery cell of the lithium ion battery. SUMMARY

[0004] Therefore, it is necessary to provide a double-sided electrode sheet manufacturing method, device and double-sided electrode sheet capable of accurately determining the surface density of the active material layer on both sides in view of the above technical problems.

[0005] In a first aspect, the present application provides a double-sided electrode sheet manufacturing method, comprising:

[0006] The mixed material is respectively placed between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, so that the mixed material is respectively calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively include at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through a transmission component and are arranged on different sides of the transmission component;

[0007] The double-sided carbon-coated foil current collector is placed between the last roller and its adjacent first roller of the first multi-roller calendering mechanism, and the double-sided carbon-coated foil current collector and the mixed material are hot compounded, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer to obtain a single-sided electrode sheet;

[0008] determining the areal density of the first active material layer in the process that the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism by the transmission component;

[0009] after the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism by the transmission component, performing thermal compounding on the single-sided electrode sheet and the mixed material by the last roller and the first roller adjacent thereto of the second multi-roller calendering mechanism, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet;

[0010] determining the areal density of the double-sided electrode sheet in the process that the double-sided electrode sheet is transferred to the winding mechanism by the transmission component, and determining the areal density of the second active material layer based on the areal density of the double-sided electrode sheet and the areal density of the first active material layer.

[0011] In a second aspect, the present application further provides a double-sided electrode sheet manufacturing device, comprising:

[0012] a feeding module configured to place the mixed material between the roller with the minimum rotating speed and the roller adjacent thereto of the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively, so that the mixed material is calendered and transferred between any two adjacent rollers of the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism each comprise at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected by a transmission component and are arranged on different sides of the transmission component;

[0013] a first forming module configured to place the double-sided carbon-coated foil current collector between the last roller and the roller adjacent thereto of the first multi-roller calendering mechanism, and perform thermal compounding on the double-sided carbon-coated foil current collector and the mixed material, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer to obtain a single-sided electrode sheet;

[0014] a first determining module configured to determine the areal density of the first active material layer in the process that the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism by the transmission component;

[0015] a second forming module configured to, after the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism by the transmission component, perform thermal compounding on the single-sided electrode sheet and the mixed material by the last roller and the roller adjacent thereto of the second multi-roller calendering mechanism, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet;

[0016] The second determining module is configured to determine the area density of the double-sided electrode sheet during the process that the second multi-roller calendering mechanism transfers the double-sided electrode sheet to the winding mechanism through the transmission component, and determine the area density of the second active material layer based on the area density of the double-sided electrode sheet and the area density of the first active material layer.

[0017] In a third aspect, the present application also provides a double-sided electrode sheet. The electrode sheet is made by using some or all of the steps described in any of the methods of the first aspect of the present application.

[0018] The double-sided electrode sheet manufacturing method and device and the double-sided electrode sheet described above place the mixed material between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, respectively, so that the mixed material is calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, respectively. The first multi-roller calendering mechanism and the second multi-roller calendering mechanism each include at least three rollers arranged in sequence. The first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through a transmission component and are arranged on different sides of the transmission component. The double-sided carbon-coated foil current collector is placed between the last roller and its adjacent first roller in the first multi-roller calendering mechanism, and the double-sided carbon-coated foil current collector and the mixed material are heat-combined, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer to obtain a single-sided electrode sheet. The area density of the first active material layer is determined during the process that the first multi-roller calendering mechanism transfers the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component. After the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism through the transmission component, the single-sided electrode sheet and the mixed material are heat-combined through the last roller and its adjacent first roller in the second multi-roller calendering mechanism, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet. The area density of the double-sided electrode sheet is determined during the process that the second multi-roller calendering mechanism transfers the double-sided electrode sheet to the winding mechanism through the transmission component, and the area density of the second active material layer is determined based on the area density of the double-sided electrode sheet and the area density of the first active material layer. The double-sided electrode sheet manufacturing method provided in the present application is based on two multi-roller calendering mechanisms connected through a transmission component and arranged on different sides of the transmission component, and the mixed material and the double-sided carbon-coated foil current collector are continuously calendered and combined. After two times of combination, a double-sided electrode sheet is formed. Specifically, during the manufacturing process of the double-sided electrode sheet, the area density of the newly formed active material layer is detected after each combination, so that the area densities of the active material layers on the two sides of the double-sided electrode sheet manufactured in the present application are accurately determined, and the battery performance of the double-sided electrode sheet is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application or the related art. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0020] Figure 1 Structure diagram of a double-sided electrode sheet manufacturing system;

[0021] Figure 2 Flow diagram of a double-sided electrode sheet manufacturing method in an embodiment;

[0022] Figure 3 Structure diagram of a double-sided electrode sheet manufacturing system in an embodiment;

[0023] Figure 4 Structure block diagram of a double-sided electrode sheet manufacturing device in an embodiment. DETAILED DESCRIPTION

[0024] In order to make the purposes, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0025] In the electrode sheet manufacturing process, the surface density of the active material layer of the electrode sheet can be obtained by the conventional sampling and weighing to calculate the thickness. However, this conventional sampling and weighing method needs to be frequently stopped during sampling, and thus is not suitable for the electrode sheet manufacturing production line which needs to be operated at high speed. At present, the main ways to realize real-time detection of the surface density of the active material layer without stopping are the transmission ray surface density detection method and the ultrasonic surface density detection method.

[0026] The transmission ray surface density detection method is to detect the surface density of the active material layer of the electrode sheet by transmission ray. The transmission ray can be X-ray, ray or other rays. Specifically, the implementation idea of detecting the surface density of the active material layer of the electrode sheet by transmission ray is that when the transmission ray penetrates the electrode sheet, part of the energy of the transmission ray will be absorbed by the active material layer of the electrode sheet. At this time, the transmission ray has attenuation phenomenon, and the attenuation intensity and the surface density of the active material layer of the conventional electrode sheet have a negative exponential relationship. Therefore, at this time, the surface density of the active material layer in the electrode sheet can be calculated and determined based on the two ray intensities by detecting the ray intensity before penetrating the electrode sheet and the ray intensity after penetrating the electrode sheet.

[0027] The ultrasonic surface density detection method is to detect the surface density of the active material layer of the electrode sheet by ultrasonic waves. Specifically, the implementation idea of detecting the surface density of the active material layer of the electrode sheet by ultrasonic waves is that when the ultrasonic waves penetrate the electrode sheet, part of the sound waves will be absorbed by the active material layer of the electrode sheet, resulting in the intensity of the outgoing sound waves after penetrating the electrode sheet being attenuated relative to the intensity of the incident sound waves just after penetrating the electrode sheet. Since the attenuation ratio of the ultrasonic waves in intensity has a certain functional relationship with the surface density of the active material layer, at this time, the surface density of the active material layer can be determined by detecting the sound wave intensity attenuation between the incident sound waves and the outgoing sound waves.

[0028] It can be seen that whether the surface density of the active material layer is determined by transmission rays or ultrasonic waves, it is necessary to ensure that the electrode sheet is between the generator and the sensor of the surface density detector. However, the existing double-sided electrode sheet manufacturing system, as shown in Figure 1 , has two multi-roller calendering mechanisms 102, and the calendering directions of the two multi-roller calendering mechanisms 102 are opposite to each other. Each multi-roller calendering mechanism 102 calenders the mixed material 104 to obtain a group of dry film sheets. The double-sided carbon-coated foil current collector 106 is placed between the two rollers with the highest rotating speed to heat-composite the dry film sheets and the double-sided carbon-coated foil current collector 106, so that the dry film sheets are composited on both sides of the double-sided carbon-coated foil current collector 106. Finally, the double-sided electrode sheet 108 is obtained. However, in the double-sided electrode sheet manufacturing system as shown in Figure 1 , since the active material layers on both sides of the double-sided electrode sheet are formed at the same time, the surface density detector can only detect the total surface density after the double-sided electrode sheet is composited, and cannot detect the surface density of either side of the active material layer. Obviously, this double-sided electrode sheet manufacturing method cannot detect the surface density of either side of the active material layer, which may cause the final manufactured double-sided electrode sheet to not meet the design specifications in actual production, thereby affecting the performance of the lithium ion battery.

[0029] Therefore, in one exemplary embodiment, as shown in Figure 2 , the present application provides a double-sided electrode sheet manufacturing method. Taking the application of the method to a double-sided electrode sheet manufacturing system as an example, the method comprises the following steps 202 to 210. Wherein:

[0030] Step 202, the mixed material is respectively placed between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, so that the mixed material is respectively calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively include at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through a transmission component and are arranged on different sides of the transmission component.

[0031] The mixed material refers to a slurry used for manufacturing a double-sided electrode sheet. Optionally, the mixed material can include an electrode active material, a binder, a conductive agent, a pore-forming agent, and a bonding enhancer. Further optionally, the mixed material can include, in terms of mass percentage, 75% to 99% of the electrode active material, 0.5% to 10% of the binder, 0.5% to 10% of the conductive agent, 0 to 3% of the pore-forming agent, and 0 to 5% of the bonding enhancer.

[0032] Specifically, the mixed material is in the form of a film after being calendered by the rollers. Understandably, the mixed material in the form of a film can be referred to as a dry film.

[0033] Optionally, the roller with the minimum rotating speed can be the first roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism along the calendering direction.

[0034] Specifically, the calendering direction of the first multi-roller calendering mechanism and the calendering direction of the second multi-roller calendering mechanism are opposite to each other. That is, the calendering direction of the first multi-roller calendering mechanism and the calendering direction of the second multi-roller calendering mechanism are opposite to each other based on a horizontal line. For example, assuming that the calendering direction of the first multi-roller calendering mechanism is to calender from left to right along the horizontal line, the calendering direction of the second multi-roller calendering mechanism is to calender from right to left along the horizontal line.

[0035] Optionally, the number of times of calendering the mixed material in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism can be 2 to 10. Further, when the number of times of calendering the mixed material is 2 to 10, the number of rollers in the first multi-roller calendering mechanism and the number of rollers in the second multi-roller calendering mechanism can correspond to 3 to 11, respectively.

[0036] Specifically, the speed ratio of any two adjacent rollers in the calendering direction is less than 1, so that in the first and second multi-roller calendering mechanisms, the rotation speed of the latter roller in the calendering direction is faster than that of the former roller, that is, the rotation speeds of the rollers arranged in sequence in the calendering direction are sequentially increased. Alternatively, the speed ratio of any two adjacent rollers in the calendering direction can be 0.95, 0.5, 0.25 or other values; further alternatively, the speed ratios of two adjacent rollers in different groups in the calendering direction can be different, as long as the rotation speed of the latter roller is faster than that of the former roller, so as to ensure that the dry film formed after the mixed material passes through the calendering action of the rollers can be transferred and adhered to the roller with a faster rotation speed.

[0037] In an exemplary embodiment, the speed ratio of any two adjacent rollers in the calendering direction is 1: (1.05~4).

[0038] The transmission component is used to continuously and stably transmit the single-sided electrode sheet formed by the first compounding in the first multi-roller calendering mechanism to the second multi-roller calendering mechanism, so that the single-sided electrode sheet is subjected to the second compounding in the second multi-roller calendering mechanism to form the double-sided electrode sheet.

[0039] It should be noted that the transmission component can also maintain the tension of the single-sided electrode sheet during the transmission of the single-sided electrode sheet from the first multi-roller calendering mechanism to the second multi-roller calendering mechanism, and therefore the transmission component can be a component with both transmission and tension maintenance functions. Exemplarily, the transmission component can be a conveying belt with tension control function, or a guide roller.

[0040] Specifically, the first and second multi-roller calendering mechanisms are connected by the transmission component and are arranged on different sides of the transmission component, that is, the first and second multi-roller calendering mechanisms are respectively located at the two end points or two sides of the transmission component.

[0041] In step 204, the double-sided carbon-coated current collector is placed between the last roller of the first multi-roller calendering mechanism and the first roller adjacent thereto, and the double-sided carbon-coated current collector and the mixed material are subjected to thermal compounding, so that the mixed material adheres to the first side of the double-sided carbon-coated current collector to form a first active material layer to obtain a single-sided electrode sheet.

[0042] The double-sided carbon-coated current collector includes two carbon-coated layers and a current collector base foil, and the two carbon-coated layers are respectively located on the two sides of the current collector base foil. Alternatively, the carbon-coated layer can be composed of at least one of carbon black, graphite, carbon fiber and carbon nanotube.

[0043] The last roll of the first multi-roll calendering mechanism is the last roll of the first multi-roll calendering mechanism along the calendering direction. It is easily understood that the first roll adjacent to the last roll of the first multi-roll calendering mechanism is the second last roll of the first multi-roll calendering mechanism along the calendering direction.

[0044] The active material layer refers to a material capable of participating in the redox reaction in the charging and discharging process of the battery, thereby realizing the conversion between electrical energy and chemical energy. Specifically, the first active material layer refers to the active material layer adhered to the first side of the double-sided carbon-coated foil current collector.

[0045] Specifically, the double-sided carbon-coated foil current collector is placed between the last roll of the first multi-roll calendering mechanism and the first roll adjacent thereto by the unwinding mechanism.

[0046] Specifically, in order to achieve thermal compounding of the double-sided carbon-coated foil current collector and the mixture between the last roll of the first multi-roll calendering mechanism and the first roll adjacent thereto, one of the two rolls needs to be a cold roll and the other needs to be a hot roll.

[0047] In an exemplary embodiment, in the first multi-roll calendering mechanism and the second multi-roll calendering mechanism, the last roll is a cold roll and the first roll is a hot roll.

[0048] The hot roll is used to heat one side of the double-sided carbon-coated foil current collector to exhibit thermal adhesion of the carbon layer on one side of the double-sided carbon-coated foil current collector, so that the mixture subjected to the calendering effect can adhere to the first side of the double-sided carbon-coated foil current collector to form the first active material layer and obtain the single-sided electrode sheet. Optionally, the temperature of the hot roll can be 50-250°C.

[0049] Specifically, the last roll is a cold roll, which can ensure that the second side of the double-sided carbon-coated foil current collector does not exhibit thermal adhesion due to heating, thereby avoiding the second side of the double-sided carbon-coated foil current collector adhering to the last roll, on the one hand, to avoid the phenomenon of missing or damage of the carbon layer, thereby ensuring the integrity and stability of the double-sided carbon-coated foil current collector, and on the other hand, to ensure that the single-sided electrode sheet can be smoothly transferred from the first multi-roll calendering mechanism to the second multi-roll calendering mechanism through the transmission component.

[0050] Specifically, the last roll of the first multi-roll calendering mechanism and the last roll of the second multi-roll calendering mechanism are cold rolls, and the first roll of the first multi-roll calendering mechanism and the first roll of the second multi-roll calendering mechanism are hot rolls.

[0051] For easy understanding, since the last roller of the first multi-roller calender mechanism and its adjacent first roller are used for heat-combining the double-sided carbon-coated current collector and the mixture to obtain the single-sided electrode sheet, the last roller of the first multi-roller calender mechanism and its adjacent first roller are called the composite roller pair. Similarly, the last roller of the second multi-roller calender mechanism and its adjacent first roller are also called the composite roller pair.

[0052] In step 206, the areal density of the first active material layer is determined in the process of transferring the single-sided electrode sheet from the first multi-roller calender mechanism to the second multi-roller calender mechanism by the transmission component.

[0053] The areal density of the first active material layer can be determined by transmission of rays or ultrasonic waves. Optionally, the transmission of rays can be X-rays, β-rays or other rays. Specifically, the areal density of the first active material layer is determined by real-time detection.

[0054] Specifically, when the transmission of rays penetrates the single-sided electrode sheet, part of the energy of the transmission of rays is absorbed by the first active material layer of the single-sided electrode sheet. Since the energy attenuation degree of the transmission of rays has a negative exponential relationship with the areal density of the first active material layer, at this time, the first ray intensity before the transmission of rays penetrates the single-sided electrode sheet and the second ray intensity after the transmission of rays penetrates the single-sided electrode sheet can be detected to calculate and determine the areal density of the first active material layer in the single-sided electrode sheet based on the first ray intensity and the second ray intensity. Thus, the areal density of the first active material layer is determined by the transmission of rays.

[0055] Specifically, when the ultrasonic wave penetrates the single-sided electrode sheet, part of the sound wave is absorbed by the first active material layer of the single-sided electrode sheet, resulting in a certain attenuation in intensity of the outgoing sound wave after penetrating the single-sided electrode sheet relative to the incident sound wave just after penetrating the single-sided electrode sheet. Since the attenuation ratio of the ultrasonic wave in intensity has a certain functional relationship with the areal density of the active material layer, at this time, the sound wave intensity attenuation between the incident sound wave and the outgoing sound wave can be detected to calculate and determine the areal density of the first active material layer. Thus, the areal density of the first active material layer is determined by the ultrasonic wave.

[0056] Optionally, a first areal density detector can be arranged between the first multi-roller calender mechanism and the second multi-roller calender mechanism to determine the areal density of the first active material layer. The first areal density detector can be a transmission of ray areal density detector for determining the areal density of the first active material layer by transmission of rays, or can also be an ultrasonic wave areal density detector for determining the areal density of the first active material layer by ultrasonic waves.

[0057] Step 208, after the single-sided electrode sheet is transferred to the second multi-roller calender mechanism through the transmission component, the last roller of the second multi-roller calender mechanism and the first roller adjacent thereto heat-composite the single-sided electrode sheet and the mixed material, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet.

[0058] The last roller of the second multi-roller calender mechanism is the last roller of the second multi-roller calender mechanism in the calendering direction. It is easy to understand that the first roller adjacent to the last roller of the second multi-roller calender mechanism is the second-to-last roller of the second multi-roller calender mechanism in the calendering direction.

[0059] Specifically, since the calendering direction of the first multi-roller calender mechanism and the calendering direction of the second multi-roller calender mechanism are opposite, among the multiple rollers of the first multi-roller calender mechanism and the multiple rollers of the second multi-roller calender mechanism, the last roller of the first multi-roller calender mechanism and the last roller of the second multi-roller calender mechanism have the smallest distance.

[0060] The second active material layer refers to the active material layer adhered to the second side of the double-sided carbon-coated foil current collector.

[0061] It is easy to understand that the single-sided electrode sheet includes a double-sided carbon-coated foil current collector and a first active material layer adhered to the first side of the double-sided carbon-coated foil current collector. Therefore, specifically, the second side of the double-sided carbon-coated foil current collector in the single-sided electrode sheet and the mixed material are heat-composed by the last roller of the second multi-roller calender mechanism and the first roller adjacent thereto, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet.

[0062] Step 210, during the process of transferring the double-sided electrode sheet to the winding mechanism by the second multi-roller calender mechanism through the transmission component, the area density of the double-sided electrode sheet is determined, and based on the area density of the double-sided electrode sheet and the area density of the first active material layer, the area density of the second active material layer is determined.

[0063] The winding mechanism is used to wind the double-sided electrode sheet.

[0064] The area density of the double-sided electrode sheet can also be determined by transmission of rays and ultrasonic waves. Specifically, the area density of the double-sided electrode sheet is determined by real-time detection.

[0065] Specifically, the implementation idea of determining the area density of the second active material layer by transmission of rays and ultrasonic waves is the same as the implementation idea of determining the area density of the second active material layer by transmission of rays and ultrasonic waves, so how to determine the area density of the second active material layer by transmission of rays and ultrasonic waves will not be described here.

[0066] Optionally, a second area density detector can be arranged between the second multi-roller calendering mechanism and the winding mechanism to determine the area density of the double-sided electrode sheet. The second area density detector can be a transmission ray area density detector that determines the area density of the double-sided electrode sheet by transmission ray, or can also be an ultrasonic area density detector that determines the area density of the double-sided electrode sheet by ultrasonic wave.

[0067] As can be easily understood, the area density of the double-sided electrode sheet is determined based on the area density of the first active material layer and the area density of the second active material layer, and therefore, in order to determine the area density of the second active material layer, the area density of the first active material layer and the area density of the double-sided electrode sheet need to be determined first. Based on this, the present embodiment divides the thermal compounding process into two times to implement the two times of area density detection processes, the first thermal compounding occurs in the first multi-roller calendering mechanism to form the single-sided electrode sheet, and the second thermal compounding occurs in the second multi-roller calendering mechanism to form the second active material layer on the second side of the double-sided carbon-coated foil current collector in the single-sided electrode sheet to form the double-sided electrode sheet, so that the area density of the first active material layer and the area density of the double-sided electrode sheet are determined respectively, and finally the area density of the first active material layer and the area density of the second active material layer located on both sides of the double-sided carbon-coated foil current collector are determined respectively.

[0068] For example, the present embodiment is applied to a battery as shown in Figure 3The shown double-sided electrode sheet manufacturing system, the mixed material 302 is respectively placed between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism 304 and the second multi-roller calendering mechanism 306, so that the mixed material 302 is respectively calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism 304 and the second multi-roller calendering mechanism 306; the first multi-roller calendering mechanism 304 and the second multi-roller calendering mechanism 306 respectively include at least three rollers arranged in sequence; the first multi-roller calendering mechanism 304 and the second multi-roller calendering mechanism 306 are connected through a transmission component and are arranged on different sides of the transmission component; the double-sided carbon-coated foil current collector 310 is placed between the last roller 312 and its adjacent first roller 314 of the first multi-roller calendering mechanism 304 through the unwinding mechanism 308, and the double-sided carbon-coated foil current collector 310 and the mixed material 302 are heat-composited to make the mixed material 302 adhere to the first side of the double-sided carbon-coated foil current collector 310 to form a first active material layer to obtain a single-sided electrode sheet 316; in the process of transferring the single-sided electrode sheet 316 to the second multi-roller calendering mechanism 306 through the transmission component, the surface density of the first active material layer is determined through the first surface density detector 318; after the single-sided electrode sheet 316 is transferred to the second multi-roller calendering mechanism 306 through the transmission component, the single-sided electrode sheet 316 and the mixed material 302 are heat-composited through the last roller 320 and its adjacent first roller 322 of the second multi-roller calendering mechanism 306, so that the mixed material 302 adheres to the second side of the double-sided carbon-coated foil current collector 310 to form a second active material layer to obtain a double-sided electrode sheet 324; in the process of transferring the double-sided electrode sheet 324 to the winding mechanism 326 through the transmission component of the second multi-roller calendering mechanism 306, the surface density of the double-sided electrode sheet 324 is determined through the second surface density detector 328, and based on the surface density of the double-sided electrode sheet 324 and the surface density of the first active material layer, the surface density of the second active material layer is determined.

[0069] In this embodiment, since the double-sided electrode sheet needs to be heat-composited twice in the manufacturing process, the surface density of the first active material layer and the surface density of the second active material layer can be detected in real time respectively, and since the active material layers on different sides are obtained in different multi-roller calendering mechanisms, the heat-composition pressure of the two heat-compositions can be controlled separately. It is easy to understand that in order to increase the compaction density of the active material layer, a larger composition pressure is usually used, and since this embodiment can separately control the roller pressure of the composition roller pair of the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, it is undoubtedly that this embodiment can provide great help to the double-sided electrode sheet manufacturing scene whether it is desired to control the compaction density of the active material layer on different sides or it is desired to improve the compaction density of the active material layer on different sides.

[0070] In the above method for manufacturing the double-sided electrode sheet, the mixture is respectively arranged between the roller with the minimum rotating speed and the adjacent roller of the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, so that the mixture is respectively calendered and transferred between any two adjacent rollers of the first multi-roller calendering mechanism and the second multi-roller calendering mechanism; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism each include at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through the transmission component and are arranged on different sides of the transmission component; the double-sided carbon-coated foil current collector is arranged between the last roller and the adjacent first roller of the first multi-roller calendering mechanism, and the double-sided carbon-coated foil current collector and the mixture are heat-composited to make the mixture adhere to the first side of the double-sided carbon-coated foil current collector to form a first active material layer, so as to obtain a single-sided electrode sheet; during the process of transferring the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component, the surface density of the first active material layer is determined; after the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism through the transmission component, the single-sided electrode sheet and the mixture are heat-composited through the last roller and the adjacent first roller of the second multi-roller calendering mechanism, so that the mixture adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer, so as to obtain a double-sided electrode sheet; during the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component, the surface density of the double-sided electrode sheet is determined, and based on the surface density of the double-sided electrode sheet and the surface density of the first active material layer, the surface density of the second active material layer is determined. The method for manufacturing the double-sided electrode sheet provided in the embodiment can continuously calender and composite the mixture and the double-sided carbon-coated foil current collector based on the two multi-roller calendering mechanisms connected through the transmission component and arranged on different sides of the transmission component, and the double-sided electrode sheet is formed after two times of composition. Specifically, the surface density of the new active material layer formed after each composition in the process of manufacturing the double-sided electrode sheet is detected, so that the surface densities of the active material layers on the two sides of the double-sided electrode sheet manufactured can be accurately determined, and the battery performance of the double-sided electrode sheet can be improved.

[0071] It should be noted that the method for manufacturing the double-sided electrode sheet provided in the embodiment does not use any solvent, so the method for manufacturing the double-sided electrode sheet provided in the embodiment is a dry method for manufacturing the double-sided electrode sheet, and the electrode sheet obtained by the method for manufacturing the double-sided electrode sheet provided in the embodiment does not contain any solvent.

[0072] In one exemplary embodiment, the surface density of the second active material layer is determined based on the surface density of the double-sided electrode sheet and the surface density of the first active material layer.

[0073] The density difference between the surface density of the double-sided electrode sheet and the surface density of the first active material layer is determined as the surface density of the second active material layer.

[0074] The density difference between the area density of the double-sided electrode sheet and the area density of the first active material layer, i.e. the difference between the area density of the double-sided electrode sheet and the area density of the first active material layer, is the area density of the second active material layer, i.e. the area density of the double-sided electrode sheet minus the area density of the first active material layer.

[0075] Specifically, since the mixture is continuously placed in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, and the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are continuously calendering and transferring the mixture, the area density of the first active material layer and the area density of the double-sided electrode sheet are also continuously detected, and thus, it is easily understood that the area density of the first active material layer and the area density of the double-sided electrode sheet obtained by the embodiment are detected in real time, and further, the area density of the second active material layer is also determined in real time. Therefore, the area density of the two active material layers on the two sides of the double-sided electrode sheet manufactured by the embodiment has real-time property.

[0076] In the embodiment, since the area density of the double-sided electrode sheet is determined by the area density of the first active material layer and the area density of the second active material layer, the area density of the second active material layer can be determined by deducting the area density of the first active material layer from the area density of the double-sided electrode sheet. Since the area density of the first active material layer and the area density of the double-sided electrode sheet are detected in real time, the embodiment can ensure that the area density of the two active material layers on the two sides of the double-sided electrode sheet manufactured has real-time property and accuracy.

[0077] In an exemplary embodiment, in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, the diameter of the last roller and the diameter of the first roller are greater than the diameter of the second roller, and the second roller is a roller other than the last roller and the first roller, and the second roller is used to calender the mixture into a film sheet.

[0078] The second roller is only used to calender the mixture into a film sheet, and is not used for thermal compounding of the double-sided carbon-coated foil current collector and the mixture, and thus, any two second rollers are not a compounding roller pair, and any two second rollers can be referred to as a film forming roller pair.

[0079] In an exemplary embodiment, the diameter of the last roller and the diameter of the first roller adjacent to the last roller are 500-1200 mm, and the diameter of the second roller is 100-700 mm.

[0080] In the first and second multi-roller calendering mechanisms, the diameter of the last roller and the diameter of the first roller are greater than the diameter of the second roller. Since the double-sided carbon foil current collector and the mixture are heat-combined between the last roller and the first roller, on the one hand, based on the greater diameter of the last roller and the first roller, the roller pressure between the last roller and the first roller can be improved, and based on the greater roller pressure, the compaction pressure between the double-sided carbon foil current collector and the mixture can be increased, and thus a double-sided electrode sheet with a higher compaction density can be obtained. On the other hand, the last roller and the first roller with a greater diameter have a greater contact area with the double-layer carbon foil current collector, and thus the roller pressure applied to the double-layer carbon foil current collector is more uniform in distribution, and thus the double-layer carbon foil current collector subjected to greater roller pressure is less likely to warp, wrinkle or have other adverse phenomena. Therefore, in the present embodiment, the greater roller pressure brought by the larger-diameter composite roller pair can increase the compaction density of the active material layers on both sides of the double-sided electrode sheet while ensuring that the appearance of the double-sided electrode sheet has a high flatness.

[0081] In one exemplary embodiment, in the first and second multi-roller calendering mechanisms, the roller pressure between the last roller and the first roller is greater than the roller pressure between any two adjacent rollers.

[0082] In the first and second multi-roller calendering mechanisms, the rollers other than the last roller and the first roller are second rollers for calendering the mixture into a film shape, and thus in the first and second multi-roller calendering mechanisms, the roller pressure between the last roller and the first roller is greater than the roller pressure between any two second rollers and the roller pressure between the first roller and the second roller.

[0083] In the present embodiment, the first roller in the first multi-roller calendering mechanism and the first roller in the second multi-roller calendering mechanism are respectively a fixed roller in the first multi-roller calendering mechanism and a fixed roller in the second multi-roller calendering mechanism, and thus by adjusting the distance between the fixed roller and the last roller and the second roller, the roller pressure on both sides of the fixed roller can be adjusted, and thus on the one hand, the fixed roller improves the roller pressure distribution of the first and second multi-roller calendering mechanisms, and on the other hand, the roller pressure between the last roller and the first roller, i.e., the roller pressure of the composite roller pair, is increased, so that the roller pressure of the composite roller pair is greater than the roller pressure of the film-forming roller pair. As can be easily understood, based on the greater compaction pressure of the composite roller pair, the compaction density of the active material layers on both sides can be increased to improve the battery performance of the final double-sided electrode sheet.

[0084] It should be noted that in the existing double-sided electrode sheet manufacturing technology, in order to improve the compaction density of the active material layers on different sides, the roll pressure between different rollers in the multi-roller calender mechanism is usually increased as much as possible. However, if the roll pressure in the multi-roller calender mechanism is too large, the hydraulic performance of the entire multi-roller calender mechanism will also be greatly affected. In the embodiment, the first roller in the first multi-roller calender mechanism and the second multi-roller calender mechanism is set as a fixed roller, so that the roll pressure of the composite roller pair can be increased, and the roll pressure of the film forming roller pair can be appropriately reduced, thereby realizing the rationalization of the roll pressure, ensuring the safety of the multi-roller calender mechanism, and improving the compaction density of the active material layers on different sides of the manufactured double-sided electrode sheet.

[0085] In an exemplary embodiment, the above method further comprises: adjusting the roll pressure between the last roller in the first multi-roller calender mechanism and the first roller adjacent thereto based on the area density of the first active material layer; and adjusting the roll pressure between the last roller in the second multi-roller calender mechanism and the second roller adjacent thereto based on the area density of the second active material layer.

[0086] Exemplarily, the area density of the first active material layer and the roll pressure between the last roller in the first multi-roller calender mechanism and the first roller adjacent thereto can have a positive correlation. Thus, in the case that the area density of the first active material layer is less than the first preset area density, the roll pressure between the last roller in the first multi-roller calender mechanism and the first roller adjacent thereto is increased.

[0087] Exemplarily, the area density of the second active material layer and the roll pressure between the last roller in the second multi-roller calender mechanism and the second roller adjacent thereto can have a positive correlation. Thus, in the case that the area density of the second active material layer is less than the second preset area density, the roll pressure between the last roller in the second multi-roller calender mechanism and the second roller adjacent thereto is increased.

[0088] In the embodiment, since the area density of the first active material layer and the area density of the second active material layer are detected in real time, in the case that the area density of the first active material layer or the area density of the second active material layer does not meet the expected requirements, the roll pressure of the composite roller pair in the different multi-roller calender mechanisms can be adjusted based on the actual area density of the different active material layers, thereby improving the flexibility of the manufacturing process of the double-sided electrode sheet.

[0089] In an exemplary embodiment, during the process of transferring the single-sided electrode sheet from the first multi-roller calender mechanism to the second multi-roller calender mechanism through the transmission component, the area density of the first active material layer is determined, comprising:

[0090] In the process of transferring the single-sided electrode sheet to the second multi-roller calender mechanism through the transmission component, the surface density of the first active material layer is determined by the first surface density detector.

[0091] In the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component in the second multi-roller calender mechanism, the surface density of the double-sided electrode sheet is determined, comprising:

[0092] In the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component, the surface density of the double-sided electrode sheet is determined by the second surface density detector.

[0093] The first surface density detector and the second surface density detector each comprise a transmission ray surface density detector or an ultrasonic surface density detector.

[0094] Specifically, the first surface density detector is arranged between the first multi-roller calender mechanism and the second multi-roller calender mechanism, and the second surface density detector is arranged between the second multi-roller calender mechanism and the winding mechanism.

[0095] Optionally, the first surface density detector and the second surface density detector each comprise a transmission ray surface density detector or an ultrasonic surface density detector, which can include the following four cases: the first surface density detector is a transmission ray surface density detector and the second surface density detector is a transmission ray surface density detector; the first surface density detector is a transmission ray surface density detector and the second surface density detector is an ultrasonic surface density detector; the first surface density detector is an ultrasonic surface density detector and the second surface density detector is a transmission ray surface density detector; and the first surface density detector is an ultrasonic surface density detector and the second surface density detector is an ultrasonic surface density detector.

[0096] In this embodiment, the first surface density detector and the second surface density detector are arranged between the first multi-roller calender mechanism and the second multi-roller calender mechanism and between the second multi-roller calender mechanism and the winding mechanism, respectively, so that the surface density of the double-sided electrode sheet is detected each time a new active material layer is formed after compounding during the manufacturing process of the double-sided electrode sheet. Therefore, the surface density of the active material layers on both sides of the double-sided electrode sheet manufactured in this embodiment can be accurately determined, and the battery performance of the double-sided electrode sheet can be improved.

[0097] It should be understood that although the steps in the flowcharts involved in the embodiments described above are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences. Moreover, at least some of the steps in the flowcharts involved in the embodiments described above can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or steps or stages in other steps.

[0098] Based on the same inventive concept, the embodiments of the present application also provide a double-sided electrode sheet manufacturing device for implementing the double-sided electrode sheet manufacturing method described above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more double-sided electrode sheet manufacturing device embodiments provided below can refer to the limitations of the double-sided electrode sheet manufacturing method described above, which will not be repeated here.

[0099] In an exemplary embodiment, as shown in Figure 4 a double-sided electrode sheet manufacturing device is provided, comprising: a feeding module 402, a first forming module 404, a first determining module 406, a second forming module 408, and a second determining module 410, wherein:

[0100] The feeding module 402 is configured to place the mixed material between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, respectively, so that the mixed material is calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, respectively. The first multi-roller calendering mechanism and the second multi-roller calendering mechanism each include at least three rollers arranged in sequence. The first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected by a transmission component and are arranged on different sides of the transmission component.

[0101] The first forming module 404 is configured to place the double-sided carbon-coated foil current collector between the last roller and its adjacent roller in the first multi-roller calendering mechanism, and to perform thermal compounding on the double-sided carbon-coated foil current collector and the mixed material, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer, thereby obtaining a single-sided electrode sheet.

[0102] The first determining module 406 is configured to determine the areal density of the first active material layer during the process of transferring the single-sided electrode sheet from the first multi-roller calendering mechanism to the second multi-roller calendering mechanism through the transmission component.

[0103] The second forming module 408 is configured to, after the single-sided electrode sheet is transferred to the second multi-roller calender mechanism through the transmission component, perform thermal compounding on the single-sided electrode sheet and the mixed material through the last roller and the roller adjacent to the last roller of the second multi-roller calender mechanism, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer, thereby obtaining a double-sided electrode sheet.

[0104] The second determining module 410 is configured to determine the area density of the double-sided electrode sheet during the process in which the second multi-roller calender mechanism transfers the double-sided electrode sheet to the winding mechanism through the transmission component, and determine the area density of the second active material layer based on the area density of the double-sided electrode sheet and the area density of the first active material layer.

[0105] In an exemplary embodiment, the second determining module 410 is further configured to determine the density difference between the area density of the double-sided electrode sheet and the area density of the first active material layer as the area density of the second active material layer.

[0106] In an exemplary embodiment, the last roller is a cold roller and the first roller is a hot roller in the first multi-roller calender mechanism and the second multi-roller calender mechanism of the double-sided electrode sheet manufacturing device.

[0107] In an exemplary embodiment, the diameter of the last roller and the diameter of the first roller are greater than the diameter of the second roller in the first multi-roller calender mechanism and the second multi-roller calender mechanism of the double-sided electrode sheet manufacturing device, and the second roller is a roller other than the last roller and the first roller, and the second roller is used to calender the mixed material into a film shape.

[0108] In an exemplary embodiment, the diameter of the last roller and the diameter of the first roller adjacent to the last roller are 500-1200 mm, and the diameter of the second roller is 100-700 mm in the double-sided electrode sheet manufacturing device.

[0109] In an exemplary embodiment, the rolling pressure between the last roller and the first roller is greater than the rolling pressure between any other two adjacent rollers in the first multi-roller calender mechanism and the second multi-roller calender mechanism of the double-sided electrode sheet manufacturing device.

[0110] In an exemplary embodiment, the first determining module 406 is further configured to determine the area density of the first active material layer through the first area density detector during the process in which the single-sided electrode sheet is transferred to the second multi-roller calender mechanism through the transmission component. The second determining module 410 is further configured to determine the area density of the double-sided electrode sheet through the second area density detector during the process in which the double-sided electrode sheet is transferred to the winding mechanism through the transmission component. The first area density detector and the second area density detector each include a transmission ray area density detector or an ultrasonic area density detector.

[0111] In one example embodiment, the speed ratio of any two adjacent rollers of the double-sided electrode sheet manufacturing device in the calendering direction is 1: (1.05-4).

[0112] Each module of the double-sided electrode sheet manufacturing device can be implemented by software, hardware, or a combination thereof, in whole or in part. Each module can be embedded in or independent of a processor in a computer device in hardware form, or stored in a memory in a computer device in software form, so as to be called and executed by a processor to perform the operations corresponding to each module.

[0113] In one example embodiment, a double-sided electrode sheet is also provided, which is made by the steps in each method embodiment described above.

[0114] Each technical feature of the above embodiments can be combined arbitrarily. In order to make the description simple, not all possible combinations of each technical feature in the above embodiments are described, however, as long as the combinations of these technical features do not exist, they should be considered as the scope of the present application.

[0115] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that, for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A method of manufacturing a double-sided electrode sheet, characterized by, The method comprises: The mixed material is respectively arranged between the roller with minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, so that the mixed material is respectively calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively comprise at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through a transmission component and are arranged on different sides of the transmission component; The double-sided carbon-coated foil current collector is arranged between the last roller and its adjacent first roller in the first multi-roller calendering mechanism, and the double-sided carbon-coated foil current collector and the mixed material are hot-composited, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer to obtain a single-sided electrode sheet; During the process that the first multi-roller calendering mechanism transfers the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component, the area density of the first active material layer is determined; After the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism through the transmission component, the single-sided electrode sheet and the mixed material are hot-composited through the last roller and its adjacent first roller in the second multi-roller calendering mechanism, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet; During the process that the second multi-roller calendering mechanism transfers the double-sided electrode sheet to the winding mechanism through the transmission component, the area density of the double-sided electrode sheet is determined, and based on the area density of the double-sided electrode sheet and the area density of the first active material layer, the area density of the second active material layer is determined.

2. The method of claim 1, wherein, The determination of the area density of the second active material layer based on the area density of the double-sided electrode sheet and the area density of the first active material layer comprises: The density difference between the area density of the double-sided electrode sheet and the area density of the first active material layer is determined as the area density of the second active material layer.

3. The method of claim 1, wherein, In the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, the last roller is a cold roller and the first roller is a hot roller.

4. The method of claim 1, wherein, In the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, the diameter of the last roller and the diameter of the first roller are greater than the diameter of the second roller, and the second roller is a roller other than the last roller and the first roller, and the second roller is used to calender the mixed material into a film sheet.

5. The method of claim 4, wherein, The diameter of the last roller and the diameter of the first roller adjacent to the last roller are 500-1200 mm, and the diameter of the second roller is 100-700 mm.

6. The method of claim 1, wherein, In the first multi-roller calendering mechanism and the second multi-roller calendering mechanism, the rolling pressure between the last roller and the first roller is greater than the rolling pressure between any other two adjacent rollers.

7. The method of claim 1, wherein, The determination of the area density of the first active material layer during the process that the first multi-roller calendering mechanism transfers the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component comprises: In the process of transferring the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component, the areal density of the first active material layer is determined by a first areal density detector; In the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component by the second multi-roller calendering mechanism, the areal density of the double-sided electrode sheet is determined, comprising: In the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component, the areal density of the double-sided electrode sheet is determined by a second areal density detector; The first areal density detector and the second areal density detector respectively comprise a transmission ray areal density detector or an ultrasonic areal density detector.

8. The method of claim 1, wherein, The speed ratio of any two adjacent rollers in the calendering direction is 1: (1.05-4).

9. A double-sided electrode sheet manufacturing apparatus characterized by comprising: The device comprises: The feeding module is used for placing the mixed material between the roller with the minimum rotating speed and its adjacent roller in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively, so that the mixed material is calendered and transferred between any two adjacent rollers in the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism respectively comprise at least three rollers arranged in sequence; the first multi-roller calendering mechanism and the second multi-roller calendering mechanism are connected through a transmission component and are arranged on different sides of the transmission component; The first forming module is used for placing the double-sided carbon-coated foil current collector between the last roller and its adjacent roller in the first multi-roller calendering mechanism, and performing thermal compounding on the double-sided carbon-coated foil current collector and the mixed material, so that the mixed material adheres to the first side of the double-sided carbon-coated foil current collector to form a first active material layer to obtain a single-sided electrode sheet; The first determining module is used for determining the areal density of the first active material layer in the process of transferring the single-sided electrode sheet to the second multi-roller calendering mechanism through the transmission component by the first multi-roller calendering mechanism; The second forming module is used for performing thermal compounding on the single-sided electrode sheet and the mixed material through the last roller and its adjacent roller in the second multi-roller calendering mechanism after the single-sided electrode sheet is transferred to the second multi-roller calendering mechanism through the transmission component, so that the mixed material adheres to the second side of the double-sided carbon-coated foil current collector to form a second active material layer to obtain a double-sided electrode sheet; The second determining module is used for determining the areal density of the double-sided electrode sheet in the process of transferring the double-sided electrode sheet to the winding mechanism through the transmission component by the second multi-roller calendering mechanism, and determining the areal density of the second active material layer based on the areal density of the double-sided electrode sheet and the areal density of the first active material layer.

10. A double-sided electrode sheet, characterized by The double-sided electrode sheet is manufactured by using the double-sided electrode sheet manufacturing method according to any one of claims 1 to 8, or by using the double-sided electrode sheet manufacturing device according to claim 9.

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