Rare earth new power electrode sheet, its preparation method and battery prepared therefrom

Abstract

The present invention belongs to the technical field of secondary battery manufacturing, and specifically relates to a rare earth new power electrode plate, a preparation method thereof, and a battery prepared therefrom. The current collector nickel foam is pre-pressed and rolled, with a white edge reserved on one side, and then it is drawn into the welding platform; the nickel-plated steel strip is cut into several sections, and each section is laser-welded to the white edge of the current collector nickel foam respectively. After pre-pressing, double-sided tape is attached. The length of each section of the nickel-plated steel strip is an integer multiple of the width of the electrode plate; it is drawn into the slurry spraying station to spray the slurry; it is drawn into the drying chamber for drying and rolling; it is transversely cut, and after the tab forming and cutting, the electrode plate is obtained. In the present invention, the nickel-plated steel strip is pre-welded to the current collector nickel foam in sections, and the slurry spraying feeding method is adopted to reduce the pollution of the slurry to the tape. Subsequently, the tabs are formed by laser cutting, realizing the on-line direct forming of the electrode plate and the tab to prepare the electrode plate, achieving the on-line continuous production and integrated preparation of the electrode plate, having the advantages of high production efficiency and being more intelligent, and high tape utilization rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of secondary battery manufacturing, and particularly relates to a rare earth new power electrode sheet, a preparation method thereof, and a battery prepared therefrom. Background Art

[0002] The large-capacity aqueous secondary battery has the advantages of high safety, long life, and a wide environmental temperature range (-55°C to 60°C), and has been widely used. However, the battery core of the large-capacity aqueous secondary battery is composed of alternating positive and negative electrode sheets, and the efficient production of high-quality electrode sheets has always been a key process in the production process.

[0003] In the prior art, usually after the electrode plate is produced, the conductive electrode ear is specially welded to form an electrode sheet. During the production process of the electrode plate, tape is required to ensure that the reserved white edge is not contaminated. Before the production of the electrode plate, the tape needs to be removed, and there is a risk of tearing the white edge during the removal process and a need for an operator to watch. After welding the electrode ear, a new tape needs to be pasted again. Therefore, this kind of welding has problems such as many turnover processes, low manual efficiency, and tape utilization rate lower than 50%. There is also an end-face welding process, in which the whole roll of nickel-plated steel strip is pre-welded on the white edge of the nickel foam, but it has defects such as being only applicable to the production of negative electrode sheets and the electrode sheet thickness cannot be too thick. If a method for directly forming the electrode plate and the electrode ear online can be developed, it can be applied to both the positive and negative electrodes, and can also adapt to different thicknesses, which has great industrial and commercial value. Summary of the Invention

[0004] The prior art prepares the electrode sheet by first manufacturing the electrode plate and then specially welding the electrode ear alone, which has problems such as many processes and low production efficiency. In view of the deficiencies of the prior art, the purpose of the present invention is to provide a preparation method for a rare earth new power electrode sheet, which can realize the online direct forming of the electrode plate and the electrode ear to prepare the electrode sheet, realize the online continuous production and integrated preparation of the electrode sheet, has the advantages of high production efficiency and more intelligent production, high tape utilization rate, and can be applied to both the positive and negative electrodes, and can also adapt to different thicknesses; the present invention also provides a rare earth new power electrode sheet prepared by this preparation method; the present invention also provides a battery prepared from this electrode sheet.

[0005] The present invention provides a preparation method for a rare earth new power electrode sheet, comprising the following steps:

[0006] (1) Pre-press the current collector nickel foam, with one side of the current collector nickel foam reserved with a white edge, and enter the welding platform through traction;

[0007] (2) Cut the nickel-plated steel strip into several sections, and respectively use laser welding on the white edge of the current collector nickel foam obtained in step (1), and perform double-sided taping after pre-pressing; the length of each section of the nickel-plated steel strip is an integer multiple of the width of the electrode plate;

[0008] (3) It is drawn into the spraying slurry station to spray slurry;

[0009] (4) It is drawn into the drying chamber for drying, and after coming out, it is roll-pressed;

[0010] (5) It is transversely cut, and then after the tab forming and cutting, the electrode sheet is obtained.

[0011] As a current collector, nickel foam has the advantage of strong adhesion to battery active materials, but it also has the disadvantage of elongation after roll-pressing. This is also the technical bottleneck that the existing technology has always wanted to achieve integrated electrode sheet forming but has never been able to achieve. In the present invention, the nickel-plated steel strip cannot be welded entirely on the white edge of the current collector nickel foam because nickel foam has elongation after subsequent roll-pressing, while the nickel-plated steel strip does not elongate, and the overall baseband (the baseband refers to the nickel foam welded with the nickel-plated steel strip) will be deformed or even curled, resulting in the scrapping of the electrode plate. The present invention solves the problem of asynchronous elongation of the nickel-plated steel strip and nickel foam by cutting the nickel-plated steel strip into several sections and welding them on the white edges of the current collector nickel foam in a segmented welding manner. The feeding method of spraying slurry is adopted to reduce the pollution of the slurry to the tape. Subsequently, the tabs are formed by laser cutting, realizing the on-line direct forming of the electrode plate and the tab to prepare the electrode sheet, achieving the on-line continuous production of the electrode sheet, and realizing the integrated electrode sheet forming. Among them, the length of each section of the nickel-plated steel strip is an integer multiple of the width of the electrode plate, that is, each cutting is not necessarily along the junction of two sections of the nickel-plated steel strip, but using this length of the nickel-plated steel strip can ensure that the last cut is at the junction of two sections of the nickel-plated steel strip during cutting. For example, if the width of the electrode plate is 100 mm and the length of the nickel-plated steel strip is an integer multiple of 100 mm, taking 300 mm as an example, then when the baseband is delivered, the cutting knife will quickly cut three times during subsequent cutting, and the last cut is at the junction of two sections of the nickel-plated steel strip. To prevent difficult rectification, only one side of the nickel foam has a reserved white edge, with a high yield. It cannot have white edges on both sides or in the middle. The method of spraying slurry can effectively solve the problem of slurry polluting the surface of the tape.

[0012] If the number of pores in the nickel foam is too large and the pore diameter is too small, it is not easy to spray the battery slurry, and the spraying pressure increases, resulting in easy breakage of the substrate tape during movement; if the number of pores is too small and the pore diameter is too large, too much battery slurry is filled, and it is easy to crack after final rolling. The selection factor of the nickel foam thickness is directly related to the number of pores. If it is too thick, the diameter of each roll of nickel foam will be too large, making it difficult to operate in production; if it is too thin, it is difficult to control the incoming quality of the nickel foam. The width of the nickel foam is considered based on the plate size and elongation. If the width is too small, the strength of the nickel foam will be greatly reduced, making it difficult to adapt to continuous production; if the width is too large, the absolute value of the lateral elongation increases, and the lateral deformation of the plate after rolling exceeds the upper limit alarm value, increasing the probability of plate rejection. Based on considerations such as subsequent welding and pre-pressing of the nickel-plated steel strip, preferably, in step (1), the number of pores in the current collector nickel foam is 90 - 120 ppi, the thickness is 0.7 - 2.4 mm, and the width is 60 - 300 mm.

[0013] A width of 8 - 10 mm is reserved on one side of the nickel foam as the overlapping area for welding with the nickel-plated steel strip, which is also called the white edge. To prevent difficult alignment, only one side of the nickel foam has a white edge, with a high yield rate. It cannot have white edges on both sides or in the middle. The area where the battery material adheres (i.e., the area where the slurry is sprayed in step (4)) is called the non-white edge. The white edge needs to be welded to the nickel-plated steel strip. After the porous nickel foam is pre-pressed and rolled, its density increases, increasing the contact surface with the nickel-plated steel strip, which is beneficial for subsequent laser welding. However, the white edge cannot be pressed too thin, otherwise the mechanical strength of the white edge will decrease and it is easy to tear. The pre-pressing of the non-white edge is mainly to control the amount of slurry per unit area, thereby controlling the final specific gravity per unit area. The pre-pressing thickness needs to be determined according to the requirements of the subsequent plate, and it cannot be too thick. If it is too thick, there will be too much slurry, and it is easy to crack during subsequent rolling. It cannot be too thin either, otherwise the amount of applied slurry will be small and the battery capacity will be too low. Preferably, in step (1), the pre-pressing roll is: pre-press the current collector nickel foam, pre-press the width of one side of the current collector nickel foam to 8 - 10 mm as the white edge, the pre-pressing thickness of the white edge is 0.2 - 0.5 mm, and the pre-pressing thickness of the non-white edge is 0.5 - 0.9 mm.

[0014] If the nickel-plated steel strip is too thin, it is difficult to produce the nickel-plated steel strip, the procurement cost increases sharply, and its own stiffness is low. When grasping each section of the nickel-plated steel strip in the production process, it is easy to bend, resulting in a large left-right deviation; if it is too thick, on the one hand, a large increase in laser welding power is required to penetrate, increasing equipment investment, and on the other hand, the weight increases too much, reducing the mass specific energy of the battery. The width of the nickel-plated steel strip is determined according to the requirements of the pole piece. As a preferred solution, the nickel-plated steel strip cannot be too narrow. If it is too narrow, there are too few protruding ends of the formed tab, which cannot meet the welding requirements with the pole column. It cannot be too wide either, as it will increase the ineffective space inside the battery, indirectly reducing the volume specific energy of the battery. Preferably, in step (2), the thickness of the nickel-plated steel strip is 0.05 - 1.5 mm, and the width is 15 - 35 mm.

[0015] In step (2), the nickel-plated steel strip is cut into several sections. Each section of the nickel-plated steel strip should not be too long. On the one hand, there is a certain upper limit on the size for the robot to grasp. On the other hand, it needs to be controlled within the upper limit range of elongation. Thirdly, the subsequent cutting frequency and the width of the electrode plate also need to be considered. Usually, the cutting is continuous cutting of 2 or 3 or multiple pieces before the baseband is pulled forward, that is, intermittent continuous movement. Therefore, the length of each section of the nickel-plated steel strip is a multiple of 2N or 3N times the width of the electrode plate. Preferably, in step (2), the length of each section of the nickel-plated steel strip is 300 - 1000 mm, which is 2N times or 3N times the width of the electrode plate, and N is an integer from 1 to 9 in Arabic numerals.

[0016] Preferably, in step (2), the laser welding is carried out by continuous spot welding to form a weld seam, that is, dot-shaped continuous welding, and the appearance is a straight line. To increase conductivity, there are two weld seams. The weld seams are parallel to the long side of the nickel-plated steel strip. To avoid heat concentration, there is a certain gap between the two weld seams. The maximum width of the white edge is only 10 mm, and the width of the weld seam itself is 2 - 3 mm. Therefore, the distance between the two weld seams cannot be too far, preferably 2 - 3 mm. After welding, there will be certain burrs on the surface. Pre-pressing can eliminate the burrs, and then sticking a tape can completely eliminate the hidden danger of burrs and prevent burr micro-short circuit.

[0017] Preferably, in step (3), the slurry is sprayed on both sides. After the nickel-plated steel strip is welded and the tape is stuck, since the tape needs to be continuously used later, in order to minimize the attachment of the slurry, spraying on both sides can effectively solve the problem of slurry contaminating the surface of the tape. Currently, the aqueous slurry is usually sprayed on one side, and the other side is negative pressure suction. This is likely to cause the baseband to shift to one side during the forward movement of the baseband, posing a risk of tape breakage. Spraying on both sides makes the forces on both sides uniform.

[0018] Preferably, in step (4), the drying chamber is a two-way vertical drying chamber. The two-way vertical drying chamber is composed of an ascending drying zone and a descending drying zone. The ascending drying zone and the descending drying zone are parallel to each other and perpendicular to the ground, and are divided into 4 - 6 temperature drying zones. There are 2 - 3 drying zones in the ascending section and 2 - 3 drying zones in the descending section. The sprayed slurry needs to be quickly dried. To avoid the uneven surface of the baseband caused by the slurry sagging phenomenon, the drying area is divided into multiple sections, which is conducive to uniform temperature control. Using the vertical up and down method is convenient for drying. On the one hand, it reduces the overall length of the equipment. On the other hand, due to the characteristics of the aqueous slurry, the vertical drying method is fast and uniform, and is also conducive to the rapid discharge of the water vapor generated by drying, improving the drying efficiency and the drying quality of the slurry.

[0019] If the drying temperature of the aqueous slurry is too high, it is easy to cause too fast drying speed, the surface of the slurry becomes hard and is prone to cracking; if the drying temperature is too low, the moisture in the slurry is not easy to volatilize. Preferably, the drying temperature in all drying zones of the present invention is within 90-145°C. The starting drying zone has a high temperature, and the starting drying zone temperature is preferably within 120-145°C. The temperature in the middle drying zone alternates between high and low, and the temperature difference between the front and rear drying zones is 5-15°C, which can form a temperature and atmosphere fluctuation, facilitating the discharge of water vapor. The temperature in the end drying zone is low, and the temperature in the end drying zone is preferably 90-110°C, avoiding cracking caused by the fast cooling speed after the slurry is dried.

[0020] Preferably, in step (4), the rolling pressure is 80-400t. The base belt dried out, after being corrected for deviation, generally has a temperature of 40-50°C and enters the roll press, and is rolled into a base belt of a certain thickness under a certain pressure. According to the requirements of the active material of the battery material, the thickness of the electrode sheet, and the compaction density, different pressures are set. Usually, the pressure for the positive electrode sheet is relatively low, and the lowest can be 80t. If it is too low, the binding degree between the active material materials of the electrode plate is insufficient, affecting the life of the electrode sheet; the pressure for the negative electrode is relatively high, up to 400t. If it is too high, the equipment investment is too high, and the negative active material particles are also easily crushed too much, affecting the battery rate performance.

[0021] Preferably, step (5) is: perform transverse cutting according to the set parameters. The cut electrode plates are scanned by a vision device. The qualified electrode plates enter the laser cutting station through a robotic arm, and after the tab forming cutting, the electrode sheets are prepared. The electrode plates cut transversely are rectangular or square. During the cutting process, for example, the first sheet at the start is generally used as a waste sheet. In subsequent intermittent continuous cutting, some electrode plates are cut into oblique sheets, and are monitored online by a vision device. The non-conforming ones are grabbed and placed aside for manual processing; the qualified cut electrode plates are directly grabbed by the robotic arm and placed on the laser cutting station, and the tab forming cutting is performed by a laser cutting machine. After the cutting is completed, the electrode sheets are prepared. Preferably, the electrode plates cut out in step (5): the width is 50-120mm, the length is 65-330mm, and the thickness is 0.16-0.4mm. The length of the electrode plate = the width of the nickel foam + the width of the nickel-plated steel strip - the overlapping part, and the overlapping part is also the width of the white edge; the corresponding prepared electrode sheets: the width is 50-120mm, the length is 65-330mm, and the thickness is 0.16-0.4mm.

[0022] The present invention also provides a rare earth new power source electrode sheet prepared by any of the above preparation methods.

[0023] Using the above method can be applicable to the preparation of positive and negative electrodes, and is also applicable to the preparation of different thicknesses, all with a high yield.

[0024] The present invention also provides a battery prepared from the above-mentioned rare-earth new power electrode sheet. The preparation process adopts the existing process. The rare-earth new power electrode sheet enters the subsequent powder cleaning process, and the positive and negative electrode sheets and the separator are alternately laminated into an electric core, and then through shelling, liquid injection, sealing, and formation, a finished battery is manufactured.

[0025] In summary, the present invention has the following advantages:

[0026] (1) As a current collector, nickel foam has the advantage of strong adhesion of battery active materials, but it also has the disadvantage of elongation after rolling, which is also the technical bottleneck that the existing technology has been trying to achieve integrated electrode sheet forming but has never been able to achieve. In the present invention, the nickel-plated steel strip cannot be welded entirely on the white edge of the current collector nickel foam because nickel foam has elongation after subsequent rolling, while the nickel-plated steel strip does not elongate, and the overall baseband will be deformed or even curled, resulting in the scrapping of the electrode plate. The present invention solves the problem of asynchronous elongation of the nickel-plated steel strip and nickel foam by cutting the nickel-plated steel strip into several sections and welding them on the white edge of the current collector nickel foam in a segmented welding manner, that is, pre-welding the nickel-plated steel strip in segments with the current collector nickel foam. By adopting the feeding method of spraying slurry, the pollution of the slurry to the tape is reduced. Subsequently, the tab is formed by laser cutting, realizing the on-line direct forming of the electrode plate and the tab to prepare the electrode sheet, realizing the on-line continuous production of the electrode sheet, and realizing the integrated electrode sheet forming.

[0027] (2) Compared with the prior art, which manufactures the electrode plate first and then welds the tab separately to prepare the electrode sheet, the present invention also has the advantages of high production efficiency and more intelligent production.

[0028] (3) To prevent difficult rectification, only one side of the nickel foam is reserved with a white edge, and the yield is high.

[0029] (4) Adopting the method of spraying slurry can effectively solve the problem of slurry polluting the surface of the tape.

[0030] (5) Both the positive and negative electrodes of the present invention can be applied and can also adapt to different thicknesses, with a wide range of applications.

[0031] (6) The utilization rate of the tape in the present invention is almost 100%, which is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the process flow chart of the preparation method of the rare-earth new power electrode sheet of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following further illustrates the present invention in conjunction with embodiments.

[0034] Embodiment 1

[0035] A preparation method of a rare-earth new power electrode sheet includes the following steps:

[0036] (1) Select nickel foam with 100 ppi pore count, 2.0 mm thickness, and 200 mm width as the current collector. Pre-roll the nickel foam current collector, and pre-press one side of the nickel foam current collector to a width of 9 mm as the white edge, with the pre-pressed thickness of the white edge being 0.4 mm and the pre-pressed thickness of the non-white edge being 0.7 mm. Then, it is drawn into the welding platform through traction.

[0037] (2) Select nickel-plated steel strips with 1.0 mm thickness and 22 mm width. Cut the nickel-plated steel strips into several segments, with the length of each segment of nickel-plated steel strip being 300 mm, which is 3 times the width of the electrode plate. Laser weld them to the white edge of the nickel foam current collector obtained in step (1) by spot welding to form welds. Weld two welds, with the welds being parallel to the long side of the nickel-plated steel strip, and the distance between the two welds being 3 mm. After pre-pressing, apply double-sided tape.

[0038] (3) Through traction, enter the slurry spraying station for double-sided slurry spraying.

[0039] (4) Through traction, enter the drying chamber for drying. The drying chamber is a two-way vertical drying chamber, which is composed of an ascending drying zone and a descending drying zone. The ascending drying zone and the descending drying zone are parallel to each other and perpendicular to the ground, and are divided into 6 temperature drying zones in total. There are 3 drying zones in the ascending section and 3 drying zones in the descending section. The temperature of the starting drying zone is high, and the temperature of the middle drying zones alternates between high and low. The temperature of each temperature zone from ascending to descending is: 140 ± 2 °C, 125 ± 2 °C, 130 ± 2 °C, 115 ± 2 °C, 120 ± 2 °C, 105 ± 2 °C. After coming out, roll press with a rolling pressure of 200 t.

[0040] (5) Perform horizontal cutting according to the set parameters. The cut electrode plates: width 100 mm, length 213 mm, thickness 0.3 mm; the corresponding prepared electrode sheets: width 100 mm, length 213 mm, thickness 0.3 mm. The cut electrode plates are scanned by a vision device. The qualified electrode plates enter the laser cutting station through a robotic arm, and after ear forming and cutting, electrode sheets are prepared.

[0041] For the electrode sheets manufactured through this embodiment, the tape utilization rate is increased from 46% in the prior art to 98.5%. The separate welding process of the ears in the prior process is directly cancelled. Originally, a single electrode sheet production line with the separate ear welding process required 16 welding devices corresponding to two substrate coating production lines. Each welding device required two workers, one responsible for operating the welding device and turnover, and one responsible for ear sorting, substrate powder cleaning, and electrode sheet weight balancing. Plus 6 people in the substrate coating production line (including two tape tearing workers in the two substrate coating production lines), a total of 38 people were required.

[0042] In this embodiment, the tape tearing station is eliminated, and the corresponding number of workers is 0. A separate pole piece welding machine is not required. After the substrate is produced and tested and qualified, it directly enters the laser cutting pole piece forming pole piece station through a robot arm. The whole is automated and connected, and the number of automated monitoring personnel is increased by 1. The manual turnover of welding from substrate to pole piece is also omitted. The number of workers in a pole piece production line is reduced to 6 people, and the number of manual turnover times of pole pieces is reduced by 50%. The yield rate of this embodiment reaches 98.5%.

[0043] The prepared pole pieces enter the subsequent powder cleaning process, and the positive and negative pole pieces and separators are alternately stacked into battery cells, which are then shelled, injected, sealed, and formed to produce finished batteries.

[0044] Example 2

[0045] A method for preparing a new rare earth power supply electrode comprises the following steps:

[0046] (1) Selecting nickel foam with a pore number of 90ppi, a thickness of 1.0mm, and a width of 100mm as the current collector, pre-rolling the nickel foam of the current collector, pre-pressing one of the nickel foams of the current collector to a width of 8mm as a white edge, pre-pressing the white edge to a thickness of 0.2mm, and pre-pressing the non-white edge to a thickness of 0.5mm, and then pulling it into the welding platform;

[0047] (2) Select a nickel-plated steel strip with a thickness of 0.1 mm and a width of 15 mm, cut the nickel-plated steel strip into several sections, each section of the nickel-plated steel strip is 500 mm long, which is 10 times the width of the electrode plate, and laser weld them on the white edge of the nickel foam of the current collector obtained in step (1) by spot welding. Weld two welds, the welds are parallel to the long side of the nickel-plated steel strip, and the distance between the two welds is 2 mm. After pre-pressing, double-sided tape is applied;

[0048] (3) After being pulled into the slurry spraying station, slurry is sprayed on both sides;

[0049] (4) After being pulled into the drying room for drying, the drying room is a bidirectional vertical drying room, which is composed of an ascending drying area and a descending drying area. The ascending drying area and the descending drying area are parallel to each other and perpendicular to the ground. There are 6 temperature drying areas in total, 3 drying areas in the ascending section and 3 drying areas in the descending section. The temperature of the starting drying area is high, and the temperature of the middle drying area is high and low alternately. From ascending to descending, the temperature of each temperature area is: 130±2℃, 120±2℃, 125±2℃, 110±2℃, 115±2℃, 100±2℃. After coming out, it is rolled, and the rolling pressure is 80t;

[0050] (5) Perform transverse cutting according to the set parameters. The cut electrode plate has the following characteristics: width 50 mm, length 107 mm, thickness 0.2 mm; the corresponding prepared electrode piece has the following characteristics: width 50 mm, length 107 mm, thickness 0.2 mm; the cut electrode plate is scanned by a visual device, and the qualified electrode plate enters the laser cutting station through a robot, and then the electrode piece is prepared after the ear forming and cutting.

[0051] The pole piece manufactured by this embodiment has a tape utilization rate increased from 48% in the prior art to 98%, directly eliminating the separate welding process of the pole ear in the existing process - the original pole piece production line including the separate welding process of the pole ear requires 24 welding equipment corresponding to two substrate coating production lines, and each welding equipment requires two workers, one responsible for operating the welding equipment and turnover, and one responsible for the pole ear arrangement, substrate powder cleaning and pole piece weighting, plus 6 people in the substrate coating production line (including two tape tearing personnel in the two substrate coating production lines), a total of 54 people are required. This embodiment cancels the tape tearing station, the corresponding number of workers is 0, and no separate pole ear welding machine is required. After the substrate is produced and tested, it directly enters the laser cutting pole ear forming pole piece station through the robot arm. The overall automation is connected, and the number of automated monitoring personnel is increased by 1. The manual turnover of substrate to pole ear welding is also omitted. The number of workers in a pole piece production line is reduced to 6, and the number of manual turnover of pole pieces is reduced by 50%. The yield rate of this embodiment reaches 98%.

[0052] The prepared pole pieces enter the subsequent powder cleaning process, and the positive and negative pole pieces and separators are alternately stacked into battery cells, which are then shelled, injected, sealed, and formed to produce finished batteries.

[0053] Example 3

[0054] A method for preparing a new rare earth power supply electrode comprises the following steps:

[0055] (1) Selecting nickel foam with a pore number of 120ppi, a thickness of 2.4mm, and a width of 300mm as the current collector, pre-rolling the nickel foam of the current collector, pre-pressing one of the nickel foams of the current collector to a width of 10mm as a white edge, pre-pressing the white edge to a thickness of 0.5mm, and pre-pressing the non-white edge to a thickness of 0.9mm, and then pulling it into the welding platform;

[0056] (2) Select a nickel-plated steel strip with a thickness of 1.5 mm and a width of 35 mm, cut the nickel-plated steel strip into several sections, each section of the nickel-plated steel strip is 720 mm long, which is 6 times the width of the electrode plate, and laser weld them on the white edge of the nickel foam of the current collector obtained in step (1) by spot welding. Weld two welds with a distance of 3 mm between the two welds, and apply double-sided tape after pre-pressing;

[0057] (3) After being pulled into the slurry spraying station, slurry is sprayed on both sides;

[0058] (4) After being pulled into the drying room for drying, the drying room is a bidirectional vertical drying room, which is composed of an ascending drying area and a descending drying area, and is divided into 6 temperature drying areas, 3 drying areas in the ascending section, and 3 drying areas in the descending section. The temperature of the starting drying area is high, and the temperature of the middle drying area is high and low alternately. From ascending to descending, the temperature of each temperature area is: 140±2℃, 125±2℃, 130±2℃, 115±2℃, 120±2℃, 105±2℃. After coming out, it is rolled, and the rolling pressure is 100t;

[0059] (5) Perform transverse cutting according to the set parameters. The cut plates have the following characteristics: width 120 mm, length 325 mm, thickness 0.4 mm; the corresponding prepared pole pieces have the following characteristics: width 120 mm, length 325 mm, thickness 0.4 mm; the cut plates are scanned by a visual device, and qualified plates are sent to the laser cutting station by a robot, and then the pole pieces are prepared after the pole ear forming and cutting.

[0060] The pole piece manufactured by this embodiment has a tape utilization rate increased from 47% in the prior art to 99%, directly eliminating the separate welding process of the pole ear in the existing process - the original pole piece production line including the separate welding process of the pole ear requires 12 welding equipment corresponding to two substrate coating production lines, and each welding equipment requires two workers, one responsible for operating the welding equipment and turnover, and one responsible for pole ear arrangement, substrate powder cleaning and pole piece weighting, plus 6 people in the substrate coating production line (including two tape tearing personnel in the two substrate coating production lines), a total of 30 people are required. This embodiment cancels the tape tearing station, the corresponding number of workers is 0, and no separate pole ear welding machine is required. After the substrate is produced and tested, it directly enters the laser cutting pole ear forming pole piece station through the robot arm. The overall automation is connected, and the number of automated monitoring personnel is increased by 1, and the manual turnover of substrate to pole ear welding is also omitted. The number of workers in a pole piece production line is reduced to 6, the number of manual turnover of pole pieces is reduced by 50%, and the yield rate reaches 99%.

[0061] The prepared pole pieces enter the subsequent powder cleaning process, and the positive and negative pole pieces and separators are alternately stacked into battery cells, which are then shelled, injected, sealed, and formed to produce finished batteries.

[0062] Example 4

[0063] A method for preparing a new rare earth power electrode is basically the same as that of Example 1, with the only difference being that step (4) is: after being pulled into a drying chamber for drying, the drying chamber is a common drying equipment, the drying temperature is 100°C, and after coming out, it is rolled, and the rolling pressure is 200t.

[0064] For the electrode sheet manufactured through this embodiment, the utilization rate of the tape is increased from 46% in the prior art to 91.2%, the number of workers is decreased to 7, the turnover times of the electrode sheet are reduced by 50%, and the yield rate reaches 91.2%.

[0065] It can be seen from Examples 1 - 4 that in step (4), a two-way vertical drying chamber is adopted, and compared with using ordinary drying equipment, the yield rate is higher.

[0066] Comparative Example 1

[0067] A preparation method of a rare earth new power source electrode sheet is basically the same as that of Example 1, and the only difference is that: the length of each section of nickel-plated steel strip is 320 mm, and the length is 3.2 times the width of the electrode plate.

[0068] For the electrode sheet manufactured through Comparative Example 1, the yield rate is 72.1%.

[0069] Since the length of each section of nickel-plated steel strip in Comparative Example 1 is 3.2 times the width of the electrode plate, which is not an integer multiple, in step (5) during cutting, there is a junction of two sections of nickel-plated steel strip on some of the cut electrode plates, which are non-conforming products.

[0070] It can be seen from Example 1 and Comparative Example 1 that in step (2), the nickel-plated steel strip is cut into several sections, and the length of each section of nickel-plated steel strip is an integer multiple of the width of the electrode plate. Compared with non-integer multiples, the yield rate is higher.

[0071] Comparative Example 2

[0072] A preparation method of a rare earth new power source electrode sheet is basically the same as that of Example 1, and the only difference is that: in step (1), the two sides of the current collector nickel foam are pre-pressed to a width of 9 mm as white edges, and in step (2), laser welding is carried out by spot welding to form welds on each white edge of the current collector nickel foam obtained in step (1), and two welds are welded on each white edge.

[0073] For the electrode sheet manufactured through this embodiment, the utilization rate of the tape is increased from 46% in the prior art to 75%, 4 more automated monitoring personnel are needed, the number of workers is decreased to 9, the turnover times of the electrode sheet are reduced by 50%, but the yield rate is only 75%.

[0074] It can be seen from Example 1 and Comparative Example 2 that there is a white edge on only one side of the current collector nickel foam, and laser welding is carried out by spot welding to form welds on the white edge of the current collector nickel foam. Compared with welding on both sides with white edges, the yield rate is higher.

[0075] For those skilled in the art, as described above, it is only the preferred embodiment of the present invention, and it is not a limitation to the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes, such as winding the positive and negative electrodes and the gel separator. However, as long as it does not depart from the technical content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

[0076] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A preparation method of a new rare earth power electrode sheet, characterized in that, It includes the following steps: (1) Pre-roll the current collector foam nickel. One side of the current collector foam nickel reserves a white edge and is drawn into the welding platform through traction; (2) Cut the nickel-plated steel strip into several segments, and respectively use laser welding on the white edge of the current collector foam nickel obtained in step (1). After pre-pressing, double-sided tape is pasted; the length of each segment of the nickel-plated steel strip is an integer multiple of the width of the electrode plate; (3) Enter the slurry spraying station through traction to spray the slurry; (4) Enter the drying chamber through traction for drying, and then roll after coming out; (5) Perform transverse cutting, and then obtain the electrode plate after ear forming cutting; In step (1), the pore number of the current collector foam nickel is 90 - 120 ppi, the thickness is 0.7 - 2.4 mm, and the width is 60 - 300 mm; In step (1), the pre-rolling is as follows: pre-roll the current collector foam nickel, pre-press the width of one side of the current collector foam nickel to 8 - 10 mm as the white edge, pre-press the thickness of the white edge to 0.2 - 0.5 mm, and pre-press the thickness of the non-white edge to 0.5 - 0.9 mm; In step (2), the length of each segment of the nickel-plated steel strip is 300 - 1000 mm, and the length of each segment of the nickel-plated steel strip is 2N times or 3N times the width of the electrode plate, where N is an integer from 1 to 9 in Arabic numerals.

2. The preparation method of the rare earth new power electrode sheet according to claim 1, characterized in that: In step (2), the thickness of the nickel-plated steel strip is 0.05 - 1.5 mm, and the width is 15 - 35 mm.

3. The preparation method of the rare earth new power electrode sheet according to claim 1, characterized in that: In step (2), laser welding is carried out in the way of continuous spot welding to form a weld seam. There are two weld seams, and the distance between the two weld seams is 2 - 3 mm.

4. The preparation method of the rare earth new power electrode sheet according to claim 1, characterized in that: In step (3), the slurry spraying is double-sided spraying.

5. The preparation method of the rare earth new power electrode sheet according to claim 1, characterized in that: In step (4), the drying chamber is a two-way vertical drying chamber, which is composed of an ascending drying area and a descending drying area, and is divided into 4 - 6 temperature drying areas in total. The temperature of the starting drying area is 120 - 145 °C, the temperature of the middle drying areas alternates between high and low, the temperature difference between the front and rear drying areas is 5 - 15 °C, the temperature of the end drying area is 90 - 110 °C, and the drying temperature of all drying areas is within 90 - 145 °C; the rolling pressure in step (4) is 80 - 400 t.

6. The preparation method of the rare earth new power electrode sheet according to claim 1, wherein: Step (5) is as follows: perform transverse cutting according to the set parameters. The cut electrode plate is scanned by a vision device. The qualified electrode plate enters the laser cutting station through a robot arm, and then obtains the electrode plate after ear forming cutting; for the electrode plate cut out in step (5): the width is 50 - 120 mm, the length is 65 - 330 mm, and the thickness is 0.16 - 0.4 mm; for the corresponding electrode plate prepared: the width is 50 - 120 mm, the length is 65 - 330 mm, and the thickness is 0.16 - 0.4 mm.

7. A rare earth new power source electrode plate prepared by the preparation method according to any one of claims 1 - 6.

8. A battery prepared from the rare earth new power electrode sheet according to claim 7, characterized in that: Put the rare earth new power source electrode plate according to claim 7 into the subsequent powder cleaning process. The positive and negative electrode plates and the separator are alternately laminated into an electric core, and then through shelling, liquid injection, sealing, and formation, a finished battery is manufactured.

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