A method for improving the compaction density of lithium battery pole pieces
By using an ultrasonic generator to vibrate the wet coating in the processing of lithium battery electrodes, the problem of insufficient slurry compaction density is solved, the density of the electrodes and electrolyte absorption capacity are improved, and the cost and energy consumption are reduced.
Patent Information
- Application Number
- CN202210913564.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-01
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2042-08-01
AI Technical Summary
During the processing of traditional lithium battery electrode sheets, the compaction density of the slurry is not high, resulting in a long drying cycle, increasing costs, and affecting the absorption effect of the electrode sheet on the electrolyte.
The ultrasonic generator is introduced in the production process, and the wet coating is evenly distributed through ultrasonic vibration, which improves the compaction density of the pole sheet, and reduces slurry waste through the circulation tank and the collection box, and optimizes the distance between the pole sheet and the ultrasonic generator to enhance Vibration effect.
The compaction density of the electrode sheet is improved, which facilitates the absorption of rolling pressure and electrolyte, reduces the use of solvents, improves baking efficiency and equipment efficiency, and reduces costs and energy consumption.
Smart Images
Figure CN115084665B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lithium ion batteries, and in particular to a method for improving the compaction density of lithium battery pole pieces. Background Art
[0002] As the power source of new energy electric vehicles, lithium-ion power batteries have developed rapidly in recent years with the popularization of electric vehicles. Lithium-ion power batteries are mainly composed of positive electrodes, negative electrodes, diaphragms and electrolytes, and the main manufacturing processes are film making, assembly and activation. Film making is to coat the positive and negative active materials on the substrate in the form of slurry, and then cut them into sizes and shapes suitable for assembly; assembly is to install the cut pole pieces into the battery housing after winding or stacking, and the internal connection of the battery is carried out by welding; activation is to inject electrolyte into the assembled battery, and then charge it. After formation, the battery is equivalent to being activated and can be repeatedly charged and discharged.
[0003] Patent "CN102299370B" proposes "a lithium-ion power battery and a method for preparing a lithium-ion power battery". In this scheme, when processing the positive or negative electrode, the slurry is evenly coated on the aluminum foil through the automatic feeding system and the coating machine, and then baked at 80°C for 12 hours in a vacuum environment, and then rolled and cut to obtain the battery electrode. However, the traditional method of coating the slurry takes a long time to dry in the oven, the electrode processing cycle is long, and the compaction density of the slurry is not high, which is not conducive to the absorption of the electrolyte by the electrode; in view of this, we propose a method to improve the compaction density of lithium battery electrode. Summary of the invention
[0004] The purpose of the present invention is to propose a method for increasing the compaction density of lithium battery pole pieces in order to address the problems in the background technology such as low density of the slurry for pole piece processing, long pole piece drying cycle resulting in increased costs, and influence on the pole piece's absorption of electrolyte.
[0005] The technical solution of the present invention is a method for improving the compaction density of a lithium battery pole piece, including a method for preparing a lithium battery, wherein the method for preparing a lithium battery comprises the following steps:
[0006] S1, film making; the film making equipment includes: a coating machine head body, a mounting frame, an oven body and a winding roller, the coating machine head body is equipped with multiple groups of guide rollers for guiding substrate transmission, an ultrasonic generator is installed in the mounting frame, the mounting frame is located in the front output area of the oven body, and the rear output area of the oven body is provided with a winding roller;
[0007] S1.1. Prepare positive and negative active materials respectively, and process and mix the two different active materials separately into a slurry form, and transport the slurry into the coating machine head body;
[0008] S1.2. A mounting frame is provided between the coating machine head body and the oven body, the slurry is evenly applied to the surface of the substrate through the coating machine head body, and the electrode coated with the slurry is processed in combination with the ultrasonic generator in the mounting frame;
[0009] S1.3. The substrate treated by the ultrasonic generator enters the oven body through the front output area of the oven body for drying to obtain a lithium battery electrode;
[0010] S1.4. After drying is completed, the electrode in the output area at the rear end of the oven body is rolled up by a winding roller;
[0011] S2, assembling; cutting the electrode sheets coated with slurry and dried in S1, and winding or stacking the cut electrode sheets and installing them into the lithium-ion battery housing, and the internal connection of the battery is carried out by welding;
[0012] S3, activation: injecting electrolyte into the battery assembled in S2, and then performing formation charging to activate the battery.
[0013] Preferably, the inner wall of the mounting frame is provided with a horizontal plate for mounting the ultrasonic generator, and the top of the ultrasonic generator is provided with a contact plate fixedly and horizontally mounted on the inner wall of the mounting frame, and the outer diameter of the contact plate is larger than the top area of the ultrasonic generator.
[0014] Preferably, a plurality of longitudinally arranged flow slots 1 are provided on the top of the contact plate, and one end of the plurality of flow slots 1 converges and is connected to a flow slot 2 located on the top of the contact plate.
[0015] Preferably, the depth of the circulation groove 2 is greater than the depth of the circulation groove 1, the bottom of the circulation groove 2 is connected to a feed pipe, the other end of the feed pipe is sealed and connected to a collection box installed on the transverse plate, and a liquid outlet pipe is installed on the collection box.
[0016] Preferably, a mounting plate movably mounted in a mounting frame is provided on the top of the contact plate, an adjustment mechanism located above the contact plate is provided below the mounting plate, a screw is rotatably connected to the mounting plate, a lifting plate is rotatably connected to the bottom of the screw, and sliders are connected to both side walls of the lifting plate.
[0017] Preferably, the bottom of the mounting plate is connected to limiting clamping plates located on both sides of the lifting plate, and the two limiting clamping plates are provided with sliding grooves along their height directions, and the sliding blocks are slidably connected to the inner walls of the sliding grooves.
[0018] Preferably, connecting plates are connected to both sides of the mounting plate, connecting ports are opened on both sides of the mounting frame, and the inner diameter of the connecting plates is matched with the inner diameter of the connecting ports.
[0019] Preferably, two groups of storage grooves are opened on one side wall of the connecting plate, and the inner wall of the storage groove is slidably connected with a pull block, and one end of the pull block located inside the storage groove is connected to a limiting rod, and the limiting rod is slidably connected to the inner wall of the storage groove, and the vertical section of the storage groove is a "T"-shaped groove.
[0020] Preferably, a plurality of rotating grooves are provided at the bottom of the lifting plate, and rotating rollers are rotatably installed in a plurality of groups of the rotating grooves. A wire on one side of the ultrasonic generator is electrically connected to a controller, and the controller is detachably connected to the outer wall of the mounting frame.
[0021] Preferably, a plurality of observation ports are installed on one side of the oven body, and the base material in S1 is either copper or aluminum.
[0022] Compared with the prior art, the present invention has the following beneficial technical effects:
[0023] 1. The present invention can release ultrasonic waves of appropriate intensity and frequency by adding an ultrasonic generator in the film making process. The electrode pieces after coating by the coating head body are still in a wet electrode state before entering the oven body. At this time, the electrode pieces first pass through the ultrasonic generator, and the ultrasonic generator is set to an appropriate intensity and frequency, so that the wet coating is distributed more evenly and compactly under the vibration of the ultrasonic wave. The electrode pieces after ultrasonic vibration are not only convenient for baking, but also can improve the compaction density of the electrode pieces, facilitate rolling, and are also beneficial to the absorption of electrolyte by the electrode pieces after injection, thereby improving the overall consistency of the battery;
[0024] 2. The present invention collects the slurry falling down through the flow slot 1, the flow slot 2 and the collection box when the ultrasonic vibrating pole piece flows through the contact plate arranged above the ultrasonic generator, so as to collect and reuse the slurry, reduce the waste of slurry, and avoid the top of the ultrasonic generator from being polluted and difficult to clean;
[0025] 3. The present invention pushes the coated pole piece downward according to the rotation of the screw by setting the adjustment mechanism, so that the distance between the pole piece and the ultrasonic generator can be adjusted, so that the ultrasonic wave emitted by the ultrasonic generator has a better effect;
[0026] 4. The present invention facilitates disassembly and maintenance of the mounting plate and the adjustment mechanism through the arrangement of the mounting plate, the connecting plate and the connecting port, or replaces the mounting plate with different distances between the two limit clamps according to the different widths of the pole piece, so as to fully contact the pole piece with the bottom of the lifting plate and improve the fit of the pole piece when it is pushed downward;
[0027] 5. In summary, the electrode preparation equipment of the present invention has high integration and is easy to use. It can perform ultrasonic vibration treatment on the electrode to improve the consistency of the electrode, increase the compaction density, facilitate the rolling of the electrode, enhance the absorption of the electrolyte by the electrode, reduce the use of solvents, improve the baking efficiency of the electrode, and at the same time reduce the cost investment of the oven and save energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is the front view of the equipment for film production;
[0029] Figure 2 yes Figure 1 Schematic diagram of the mounting plate and adjustment mechanism structure;
[0030] Figure 3 yes Figure 2 A schematic diagram of the structure of the flip state;
[0031] Figure 4 yes Figure 1 A schematic diagram of the structure of an ultrasonic generator and a contact plate;
[0032] Figure 5 It is a flow chart of the preparation method of lithium battery.
[0033] Reference numerals:
[0034] 1. Coating head body; 2. Guide roller; 3. Mounting frame;
[0035] 4. Oven body; 41. Inlet; 42. Observation port;
[0036] 5. Winding roller; 6. Ultrasonic generator;
[0037] 7. Contact plate; 71. Flow slot 1; 72. Flow slot 2; 73. Feed pipe; 74. Collection box;
[0038] 8. Adjustment mechanism; 81. Lifting plate; 82. Rotating roller; 83. Screw rod; 84. Sliding block;
[0039] 9. Mounting plate; 91. Limiting card plate; 92. Slide groove; 93. Connecting plate; 931. Storage groove; 932. Pull block; 933. Limiting rod;
[0040] 10. Connection port. DETAILED DESCRIPTION
[0041] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.
[0042] Example
[0043] like Figure 1-5As shown, the present invention proposes a method for improving the compaction density of a lithium battery pole piece. Compared with the first embodiment, this embodiment also includes a method for preparing a lithium battery. Figure 5 , the preparation method of the lithium battery comprises the following steps:
[0044] S1, film making; the film making equipment includes: a coating head body 1, a mounting frame 3, an oven body 4 and a winding roller 5, and a plurality of guide rollers 2 for guiding the transmission of the substrate are installed on the coating head body 1.
[0045] The inner wall of the mounting frame 3 is provided with a horizontal plate for mounting the ultrasonic generator 6. A wire on one side of the ultrasonic generator 6 is electrically connected to a controller. The controller is detachably connected to the outer wall of the mounting frame 3. The controller is used to control the start and stop of the ultrasonic generator 6. The ultrasonic generator 6 can be an existing ultrasonic generator with adjustable frequency and vibration intensity. Figure 4 As shown, the top of the ultrasonic generator 6 is provided with a contact plate 7 fixedly mounted horizontally on the inner wall of the mounting frame 3, and the top of the contact plate 7 is provided with a mounting plate 9 movably mounted in the mounting frame 3. The outer diameter of the contact plate 7 is larger than the top area of the ultrasonic generator 6. The top of the contact plate 7 is provided with a plurality of longitudinally arranged flow slots 71. One end of the plurality of flow slots 71 converges and is connected to a flow slot 72 located on the top of the contact plate 7. The depth of the flow slot 72 is greater than the depth of the flow slot 71. The flow slot 72 is used to temporarily store the slurry gathered in the plurality of flow slots 71. The bottom of the flow slot 72 is connected to a feed pipe 73. The other end of the feed pipe 73 is sealed and connected to a collection box 74 mounted on the horizontal plate, and the slurry flows into the collection box 74 through the feed pipe 73 for collection. The collection box 74 is provided with a liquid outlet pipe, and a sealing plug is provided in the liquid outlet pipe. The horizontal plate is detachably connected to the bottom of the ultrasonic generator 6. As shown Figure 2 As shown, an adjustment mechanism 8 is provided below the mounting plate 9 and is located above the contact plate 7. A screw 83 is rotatably connected to the mounting plate 9. The bottom of the mounting plate 9 is connected to limit clamping plates 91 located on both sides of the lifting plate 81. Slide grooves 92 are provided on the two limit clamping plates 91 along their height direction. Slide blocks 84 are connected to the two side walls of the lifting plate 81. The slide blocks 84 are slidably connected to the inner walls of the slide grooves 92. Figure 3 As shown, the bottom of the screw rod 83 is rotatably connected to a lifting plate 81, and a plurality of rotating grooves are provided at the bottom of the lifting plate 81. Rotating rollers 82 are rotatably installed in the plurality of rotating grooves. The rotating rollers 82 have the same width as the processed pole piece, and the adjusting mechanism 8 can be replaced as a whole according to the width of the pole piece, so as to ensure sufficient contact between the rotating rollers 82 and the pole piece, so that the pole piece is located in the space between the two limiting clamps 91 and flows, so that the limiting clamps 91 limit the pole piece to the top center position of the ultrasonic generator 6, so that the slurry coated on the outside of the pole piece receives uniform vibration, and the density of the pole piece is improved.
[0046] like Figure 2 and Figure 3 As shown, connecting plates 93 are connected to both sides of the mounting plate 9, connecting ports 10 are provided on both sides of the mounting frame 3, the inner diameter of the connecting plate 93 is matched with the inner diameter of the connecting port 10, and two groups of receiving grooves 931 are provided on one side wall of the connecting plate 93, and a pull block 932 is slidably connected to the inner wall of the receiving groove 931, and one end of the pull block 932 located inside the receiving groove 931 is connected to a limiting rod 933, and the limiting rod 933 is slidably connected to the inner wall of the receiving groove 931, and the vertical section of the receiving groove 931 is a "T"-shaped groove, and the vertical section of the pull block 932 is also a "T"-shaped structure.
[0047] like Figure 1 As shown, the mounting frame 3 is located at the front output area of the oven body 4, and the rear output area of the oven body 4 is provided with a winding roller 5;
[0048] S1.1, prepare positive and negative active materials respectively, and process and mix the two different active materials separately into a slurry form, and transport the slurry into the coating head body 1, the substrate is either copper or aluminum;
[0049] S1.2, a mounting frame 3 is arranged between the coating machine head body 1 and the oven body 4, the surface of the substrate is evenly coated with slurry through the coating machine head body 1, and the electrode coated with slurry is processed in combination with the ultrasonic generator 6 in the mounting frame 3;
[0050] S1.3, the substrate treated by the ultrasonic generator 6 enters the oven body 4 through the front output area of the oven body 4 for drying. A plurality of observation ports 42 are installed on one side of the oven body 4 for observing the drying effect of the electrode to obtain the lithium battery electrode;
[0051] S1.4, after drying is completed, the electrode in the output area at the rear end of the oven body 4 is rolled up by the winding roller 5;
[0052] S2, assembling; cutting the electrode sheets coated with slurry and dried in S1, and winding or stacking the cut electrode sheets and installing them into the lithium-ion battery housing, and the internal connection of the battery is carried out by welding;
[0053] S3, activation: injecting electrolyte into the battery assembled in S2, and then performing formation charging to activate the battery.
[0054] In this embodiment, the slurry is coated on the electrode through the coating head body 1. The coating head body 1 adopts any one of the common coating methods: scraper type, roller transfer type and slot extrusion type. The electrode is guided by the guide roller 2 and passes through the contact plate 7 and the adjustment mechanism 8, and enters the oven body 4 from the inlet 41. A winding roller 5 is installed in the rear end output area of the oven body 4 to wind up one end of the electrode.
[0055] Before processing the electrode, a mounting plate 9 of suitable size is selected according to the width of the electrode. Suitable means that the width of the electrode is the same as the distance between the two limiting clamps 91. The purpose of this step is to enable the electrode to fully fit with the rotating roller 82 at the bottom of the lifting plate 81. Under the guidance and transmission of the rotating roller 82 and the setting of the limiting clamp 91, the electrode can be located in the middle of the top of the ultrasonic generator 6 and does not contact 7, so that the vibration generated by the ultrasonic generator 6 acts evenly on the electrode. After selecting a suitable mounting plate 9, install the mounting plate 9 and the mounting frame 3. First, slide the pull block 932 along the inner wall of the receiving groove 931 so that the two pull blocks 932 are close to each other. At this time, the two limit rods 933 are received in the receiving groove 931. After one connecting plate 93 corresponds to the connecting port 10, release the pull block 932. It should be noted that a rebound spring is provided in the groove of the pull block 932, which moves the two limit rods 933 away from each other, so that one connecting plate 93 is installed with one connecting port 10. Secondly, use the same method to first push the installed connecting plate 93 along the connecting port 10 so that the other connecting plate 93 corresponds to the other connecting port 10, and the same installation is completed.
[0056] Before starting the ultrasonic generator 6 for use, the screw 83 is rotated. The rotation of the screw 83 causes the lifting plate 81 connected with sliders 84 on both sides to move downward along the guide groove 92, so that the rotating roller 82 at the bottom of the lifting plate 81 contacts the pole piece, pressing the pole piece closer to the ultrasonic generator 6, so that the pole piece is limited by the limiting clamps 91 on both sides and the downward pressing action of the lifting plate 81, and the vibration contact with the ultrasonic generator 6 is more uniform.
[0057] At this time, the ultrasonic generator 6 is started, and the ultrasonic generator 6 adjusts the appropriate intensity and frequency, and the pole pieces that have not entered the oven body 4 and the slurry that has not dried are treated by ultrasonic vibration, so that the wet coating is distributed more evenly and compactly under the vibration of the ultrasonic wave. The pole pieces after ultrasonic vibration are not only convenient for baking, but also can improve the compaction density of the pole pieces, which is convenient for rolling, and is also beneficial to the absorption of electrolyte by the pole pieces after liquid injection, thereby improving the overall consistency of the battery. While the ultrasonic generator 6 is ultrasonically treating the pole pieces, part of the slurry will fall from the pole pieces, and the slurry will be collected into the collection box 74 through the circulation groove 1 71 and the circulation groove 2 72, and then processed and utilized. The pole pieces treated by the ultrasonic generator 6 enter the oven body 4 through the inlet 41 for drying. At this time, the pole pieces are dried faster to improve the baking efficiency of the oven body 4, reduce the use of equipment investment, and are collected centrally through the winding roller 5. Finally, assembly and activation processing are carried out.
[0058] The above specific embodiments are merely preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art may make various alternative improvements and combinations to the above specific embodiments.
Claims
1. A method for increasing the compaction density of a lithium battery pole piece, comprising a method for preparing a lithium battery, characterized in that: The preparation method of the lithium battery comprises the following steps: S1. Film making; the film making equipment comprises: a coating machine head body (1), a mounting frame (3), an oven body (4) and a winding roller (5); the coating machine head body (1) is equipped with a plurality of guide rollers (2) for guiding the transmission of a substrate; an ultrasonic generator (6) is installed in the mounting frame (3); a horizontal plate for installing the ultrasonic generator (6) is arranged on the inner wall of the mounting frame (3); a contact plate (7) is arranged on the top of the ultrasonic generator (6) and is fixedly and horizontally mounted on the inner wall of the mounting frame (3); the outer diameter of the contact plate (7) is larger than the top area of the ultrasonic generator (6); The mounting frame (3) is located at the front output area of the oven body (4), and a winding roller (5) is provided at the rear output area of the oven body (4); A mounting plate (9) movably mounted in the mounting frame (3) is provided on the top of the contact plate (7); an adjustment mechanism (8) located above the contact plate (7) is provided below the mounting plate (9); a screw rod (83) is rotatably connected to the mounting plate (9); a lifting plate (81) is rotatably connected to the bottom of the screw rod (83); and sliding blocks (84) are connected to the two side walls of the lifting plate (81); The bottom of the mounting plate (9) is connected to limiting clamping plates (91) located on both sides of the lifting plate (81), and the two limiting clamping plates (91) are provided with sliding grooves (92) along their height direction, and the sliding block (84) is slidably connected to the inner wall of the sliding groove (92); The two sides of the mounting plate (9) are connected with connecting plates (93), the two sides of the mounting frame (3) are provided with connecting ports (10), and the inner diameter of the connecting plate (93) is adapted to the inner diameter of the connecting port (10); Two groups of receiving grooves (931) are provided on one side wall of the connecting plate (93), and a pull block (932) is slidably connected to the inner wall of the receiving groove (931), and one end of the pull block (932) located inside the receiving groove (931) is connected to a limiting rod (933), and the limiting rod (933) is slidably connected to the inner wall of the receiving groove (931), and the vertical section of the receiving groove (931) is a "T"-shaped groove; S1.1, prepare positive and negative electrode active materials respectively, and process and mix the two different active materials separately to form a slurry, and transport the slurry to the coating head body (1); S1.2, a mounting frame (3) is arranged between the coating machine head body (1) and the oven body (4), the coating machine head body (1) is used to evenly apply the slurry to the surface of the substrate, and the electrode coated with the slurry is processed in combination with the ultrasonic generator (6) in the mounting frame (3); S1.3, the substrate treated by the ultrasonic generator (6) enters the oven body (4) through the front output area of the oven body (4) for drying, thereby obtaining a lithium battery electrode; S1.4, after drying is completed, the electrode in the output area at the rear end of the oven body (4) is rolled up by the winding roller (5); S2, assembling; cutting the electrode sheets coated with slurry and dried in S1, and winding or stacking the cut electrode sheets and installing them into the lithium-ion battery housing, and the internal connection of the battery is carried out by welding; S3, activation: injecting electrolyte into the battery assembled in S2, and then performing formation charging to activate the battery.
2. A method for improving the compaction density of a lithium battery pole piece according to claim 1, characterized in that: The top of the contact plate (7) is provided with a plurality of longitudinally arranged flow slots 1 (71), and one end of the plurality of flow slots 1 (71) converges and is connected to a flow slot 2 (72) located at the top of the contact plate (7).
3. A method for improving the compaction density of a lithium battery pole piece according to claim 2, characterized in that: The depth of the second circulation groove (72) is greater than the depth of the first circulation groove (71), and the bottom of the second circulation groove (72) is connected to a feed pipe (73), and the other end of the feed pipe (73) is sealedly connected to a collection box (74) installed on the horizontal plate, and a liquid outlet pipe is installed on the collection box (74).
4. A method for improving the compaction density of a lithium battery pole piece according to claim 1, characterized in that: The bottom of the lifting plate (81) is provided with a plurality of rotating grooves, and a plurality of groups of rotating rollers (82) are rotatably installed in the rotating grooves. A wire on one side of the ultrasonic generator (6) is electrically connected to a controller, and the controller is detachably connected to the outer wall of the mounting frame (3).
5. The method for improving the compaction density of a lithium battery pole piece according to claim 1, characterized in that: A plurality of observation ports (42) are installed on one side of the oven body (4), and the base material in S1 is either copper or aluminum.