CN115084665A - Method for improving compaction density of lithium battery pole piece - Google Patents

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a method for improving the compaction density of a lithium battery pole piece. The technical scheme is provided mainly aiming at the problems that the compactness of slurry for processing the pole piece is not high, the absorption of the pole piece on electrolyte is influenced and the like: the preparation method of the lithium battery comprises the following steps: s1, tabletting; s1.1, conveying the slurry into a coating machine head body; s1.2, processing the pole piece coated with the slurry by an ultrasonic generator; s1.3, drying and processing the oven body to obtain a lithium battery pole piece; s1.4, rolling the pole piece by a rolling roller; s2, assembling; and S3, activating. The pole piece preparation equipment disclosed by the invention is high in integration level and convenient to use, carries out ultrasonic vibration treatment on the pole piece, improves the consistency of the pole piece, improves the compaction density, facilitates the rolling of the pole piece, enhances the absorption of the pole piece on electrolyte, reduces the usage amount of a solvent, improves the baking efficiency of the pole piece, reduces the cost input of an oven, saves the energy consumption, and is mainly applied to a coating process in the production process of a lithium ion battery.

Description

A method for improving the compaction density of lithium battery pole pieces

technical field

The invention relates to the technical field of lithium ion batteries, in particular to a method for improving the compaction density of lithium battery pole pieces.

Background technique

As the power source of new energy electric vehicles, lithium-ion power batteries have developed rapidly in recent years with the popularity of electric vehicles. Lithium-ion power batteries are mainly composed of positive electrodes, negative electrodes, separators and electrolytes. The main manufacturing processes are filming, assembly, and activation. Production is to coat the positive and negative active materials on the substrate in the form of slurry, and then cut into a size and shape suitable for assembly; assembly is to install the cut pole pieces into the battery shell after winding or stacking. The internal connection of the battery is carried out by welding; the activation is to inject electrolyte into the assembled battery, and then carry out chemical charging. After forming, the battery is equivalent to being activated and can be used for repeated charging and discharging.

The patent "CN102299370B" proposes "a lithium-ion power battery and a preparation method of a lithium-ion power battery". In this scheme, when the positive or negative pole pieces are processed, the slurry is passed through an automatic feeding system, coating The machine is evenly coated on the aluminum foil, and the battery pole pieces can be obtained after baking at 80 °C for 12 hours, rolling and slitting in a vacuum environment. However, the traditional coating slurry takes a long time to dry in the oven, the processing cycle of the pole piece 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 piece. Method for compaction density of battery pole pieces.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems in the background technology that the density of the slurry processed by the pole piece is not high, the long drying cycle of the pole piece causes the cost to increase, and affects the absorption of the electrolyte by the pole piece. A method for improving the compaction density of a lithium battery pole piece.

The technical solution of the present invention: a method for improving the compaction density of a lithium battery pole piece, including a preparation method of a lithium battery, and the preparation method of the lithium battery includes the following steps:

S1, film production; the equipment for film production includes: a coating machine head body, a mounting frame, an oven body and a winding roller, and a plurality of groups of guide rollers for guiding the transmission of the substrate are installed on the coating machine head body. , an ultrasonic generator is installed in the mounting rack, the mounting rack 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;

S1.1. Prepare the positive and negative active materials separately, process and mix the two different active materials separately, in the form of slurry, and transport the slurry into the coating machine head body;

S1.2. A mounting frame is set between the coating machine head body and the oven body, and the surface of the substrate is evenly coated with slurry through the coating machine head body, and combined with the ultrasonic generator in the mounting frame to coat the slurry The pole piece processing of the material;

S1.3, the substrate processed by the ultrasonic generator enters the oven body through the front-end output area of the oven body for drying and processing to obtain a lithium battery pole piece;

S1.4. After the drying is completed, the pole piece in the output area of the rear end of the oven body is wound up by the winding roller;

S2. Assembling; cutting the pole pieces after coating the slurry and drying in S1, and wrapping or stacking the cut pole pieces into the lithium ion battery case, and the internal connection of the battery is carried out by welding;

S3. Activation; inject electrolyte into the battery assembled in S2, and then perform chemical charging to activate the battery.

Preferably, the inner wall of the mounting frame is provided with a transverse plate for installing the ultrasonic generator, the top of the ultrasonic generator is provided with a contact plate fixed and horizontally installed on the inner wall of the mounting frame, and the outer diameter of the contact plate is larger than that of the ultrasonic generator. the top area of the device.

Preferably, the top of the contact plate is provided with a plurality of flow grooves one vertically arranged, and one end of the plurality of flow grooves is converged and connected to the flow groove two located on the top of the contact plate.

Preferably, the depth of the second circulation groove is greater than the depth of the first circulation groove, the bottom of the second circulation groove is connected with a feeding pipe, and the other end of the feeding pipe is sealed with a collection box installed on the horizontal plate, A liquid outlet pipe is installed on the collection box.

Preferably, the top of the contact plate is provided with a mounting plate that is movably installed in the mounting frame, the lower part of the mounting plate is provided with an adjustment mechanism located above the contact plate, the mounting plate is rotatably connected with a screw, the screw A lift plate is rotatably connected to the bottom of the lift plate, and sliders are connected to the two side walls of the lift plate.

Preferably, the bottom of the mounting plate is connected with limit cards located on both sides of the lift plate, and two limit cards are provided with sliding grooves along the height direction thereof, and the sliding blocks are connected to the inner walls of the sliding grooves. Slide to connect.

Preferably, two sides of the mounting plate are connected with connecting plates, two sides of the mounting frame are provided with connecting ports, and the inner diameter of the connecting plates is adapted to the inner diameter of the connecting ports.

Preferably, a side wall of the connecting plate is provided with two sets of storage slots, the inner wall of the storage slot is slidably connected with a pull block, and one end of the pull block located inside the storage slot is connected to a limit rod, and the limit The rod is slidably connected with the inner inner wall of the receiving groove, and the vertical section of the receiving groove is a "T"-shaped groove.

Preferably, the bottom of the lift plate is provided with a plurality of rotating grooves, a plurality of sets of rotating grooves are rotatably installed with rotating rollers, one side of the ultrasonic generator is electrically connected with a controller, and the controller is connected to the mounting frame. The outer wall is detachably connected.

Preferably, a plurality of observation ports are installed on one side of the oven body, and the base material in S1 is any one of copper material or aluminum material.

Compared with the prior art, the present invention has the following beneficial technical effects:

1. The present invention can release ultrasonic waves of appropriate intensity and frequency through the ultrasonic generator added in the filming process, and the pole pieces are still in the state of wet pole pieces before the pole pieces coated by the coating machine head body enter the oven body. At this time, the pole piece first passes through the ultrasonic generator, and the ultrasonic generator is set to the appropriate intensity and frequency, so that the wet coating is distributed more uniformly and compactly under the ultrasonic vibration. The pole piece after ultrasonic vibration is not only easy to bake, but also can improve the compaction density of the pole piece, which is convenient for rolling, and is also beneficial to the absorption of the electrolyte by the pole piece after liquid injection, and improves the overall consistency of the battery;

2. In the present invention, when the contact plate set above the ultrasonic generator flows through the ultrasonically vibrated pole piece, the falling slurry is collected by the first and second flow grooves and the collection box, and is used for collection and reuse. , reduce the waste of slurry, and at the same time avoid the pollution of the top of the ultrasonic generator, which is not easy to clean;

3. The present invention pushes the coated pole piece downward according to the rotation of the screw through the setting of 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;

4. The present invention facilitates dismantling and overhauling the mounting plate and the adjusting mechanism through the setting of the mounting plate, the connecting plate and the connecting port, or replacing the mounting plate with different distances between the two limit card plates according to the different widths of the pole pieces, It is used for the full contact between the pole piece and the bottom of the lifting plate to improve the fit of the pole piece when pushed down;

5. To sum up, the pole piece preparation equipment of the present invention has a high degree of integration and is easy to use, and the ultrasonic vibration treatment of the pole piece improves the consistency of the pole piece, improves the compaction density, facilitates the rolling of the pole piece, and enhances the effect of the pole piece on the electrolyte. The absorption of , reduce the amount of solvent used, improve the baking efficiency of the pole piece, while reducing the cost of the oven, saving energy.

Description of drawings

Fig. 1 is the front view of the equipment of film production;

Fig. 2 is the structural schematic diagram of the mounting plate and the adjustment mechanism of Fig. 1;

Fig. 3 is the structural representation of the inversion state of Fig. 2;

Fig. 4 is the structural representation of the ultrasonic generator and the contact plate of Fig. 1;

FIG. 5 is a flow chart of a preparation method of a lithium battery.

Reference number:

1. Coating head body; 2. Guide roller; 3. Mounting frame;

4. Oven body; 41. Import; 42. Observation port;

5. Winding roller; 6. Ultrasonic generator;

7. Contact plate; 71. Flow tank one; 72. Flow tank two; 73. Feeding pipe; 74. Collection box;

8. Adjustment mechanism; 81, Lifting plate; 82, Rotating roller; 83, Screw; 84, Slider;

9. Mounting plate; 91. Limit card plate; 92, Chute; 93, Connecting plate; 931, Storage slot; 932, Pull block; 933, Limit rod;

10. Connection port.

Detailed ways

The technical solutions of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

Example

As shown in Figures 1-5, 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. Referring to Figure 5, the lithium battery The preparation method includes the following steps:

S1, film production; the production equipment includes: the coating machine head body 1, the mounting frame 3, the oven body 4 and the winding roller 5, the coating machine head body 1 is installed with a plurality of groups of guides for guiding the transmission of the substrate Roll 2.

The inner wall of the mounting frame 3 is provided with a horizontal plate for installing the ultrasonic generator 6, one side of the ultrasonic generator 6 is electrically connected with a controller, and the controller is detachably connected to the outer wall of the mounting frame 3, and the controller is used to control the ultrasonic generation. Start and stop of the generator 6, and the ultrasonic generator 6 can use the existing ultrasonic generator with adjustable frequency and vibration intensity. As shown in Figure 4, the top of the ultrasonic generator 6 is provided with a contact plate 7 that is fixed and horizontally installed on the inner wall of the mounting frame 3, and the top of the contact plate 7 is provided with a mounting plate 9 that is movably installed in the mounting frame 3. The outer diameter is larger than the top area of the ultrasonic generator 6, and the top of the contact plate 7 is provided with a plurality of flow grooves one 71 arranged longitudinally, and one end of the plurality of flow grooves 71 is converged and connected to the flow groove two 72 located on the top of the contact plate 7, The depth of the second flow tank 72 is greater than the depth of the first flow tank 71. The second flow tank 72 is used to temporarily store the slurry gathered in the first flow tank 71. The other end of the pipe 73 is sealed and connected with a collection box 74 installed on the horizontal plate, and the slurry flows into the collection box 74 through the conveying pipe 73 for collection. The sealing plug, the transverse plate and the bottom of the ultrasonic generator 6 are detachably connected. As shown in FIG. 2 , an adjustment mechanism 8 located above the contact plate 7 is arranged below the mounting plate 9 , a screw 83 is rotatably connected to the mounting plate 9 , and limit cards located on both sides of the lifting plate 81 are connected to the bottom of the mounting plate 9 . On the plate 91, the two limit cards 91 are provided with chute 92 along their height direction, the two side walls of the lifting plate 81 are connected with the slider 84, and the slider 84 is slidably connected with the inner wall of the chute 92; as shown in Figure 3 As shown, the bottom of the screw 83 is rotatably connected with a lifting plate 81, the bottom of the lifting plate 81 is provided with a plurality of rotating grooves, and rotating rollers 82 are rotatably installed in the plurality of groups of rotating grooves. The entire adjustment mechanism 8 can be replaced according to the width of the pole piece to ensure sufficient contact between the rotating roller 82 and the pole piece, so that the pole piece is located in the space between the two limit cards 91 and circulates, so that the limit card 91 restricts the pole piece to the top center position of the ultrasonic generator 6, so that the slurry coated outside the pole piece receives uniform vibration, and the compactness of the pole piece is improved.

As shown in FIG. 2 and FIG. 3 , connecting plates 93 are connected on both sides of the mounting plate 9 , and connecting ports 10 are opened on both sides of the mounting frame 3 . The inner diameter of the connecting plate 93 is adapted to the inner diameter of the connecting port 10 . One side wall of 93 is provided with two sets of storage slots 931, the inner wall of the storage slot 931 is slidably connected with a pull block 932, and one end of the pull block 932 located inside the storage slot 931 is connected to a limit rod 933, the limit rod 933 and the storage slot 931 The inner walls are slidably connected, 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.

As shown in FIG. 1, the mounting rack 3 is located in the front-end output area of the oven body 4, and the rear-end output area of the oven body 4 is provided with a winding roller 5;

S1.1. Prepare the positive and negative active materials separately, process and mix the two different active materials separately, in the form of slurry, and transport the slurry into the coating machine head body 1. The base material is copper or It is any kind of aluminum material;

S1.2. A mounting frame 3 is set between the coating machine head body 1 and the oven body 4 , and the surface of the substrate is uniformly coated with slurry through the coating machine head body 1 , and combined with the ultrasonic generator in the mounting frame 3 6. Treatment of pole pieces coated with slurry;

S1.3, the substrate processed by the ultrasonic generator 6 enters the oven body 4 for drying and processing through the front-end output area of the oven body 4, and a plurality of observation ports 42 are installed on one side of the oven body 4 to observe the pole pieces The drying effect is obtained, and the lithium battery pole piece is obtained;

S1.4, after the drying is completed, the pole piece in the output area of the rear end of the oven body 4 is wound up by the winding roller 5;

S2. Assembling; cutting the pole pieces after coating the slurry and drying in S1, and wrapping or stacking the cut pole pieces into the lithium ion battery case, and the internal connection of the battery is carried out by welding;

S3. Activation; inject electrolyte into the battery assembled in S2, and then perform chemical charging to activate the battery.

In this embodiment, the slurry is coated on the pole piece through the coating machine head body 1, and the coating machine head body 1 adopts the common common coating: any one of the blade type, the roll coating transfer type and the slit extrusion type Either way, the pole piece is guided by the guide roller 2 through the middle of the contact plate 7 and the adjustment mechanism 8, enters the oven body 4 from the inlet 41, and installs the winding roller 5 in the output area of the rear end of the oven body 4, and the pole piece One end of the sheet is wound;

Before processing the pole piece, select a suitable size of the mounting plate 9 according to the width of the pole piece. Appropriate means that the width of the pole piece is the same as the distance between the two limit clips 91. The purpose of this step is to enable the pole piece to be able to Fully fit with the rotating roller 82 at the bottom of the lifting plate 81, under the guiding and driving of the rotating roller 82, and the setting of the limit card 91, so that the pole piece can be located in the top middle position of the ultrasonic generator 6, and is not in contact with 7 , so that the vibration generated by the ultrasonic generator 6 has a uniform effect on the pole piece. After selecting the appropriate mounting plate 9, install the mounting plate 9 with the mounting frame 3, first slide the pull block 932 along the inner wall of the receiving slot 931, so that the two pull blocks 932 are close to each other, at this time the two limit rods 933 are stored After entering the receiving slot 931, one connecting plate 93 is corresponding to the connecting port 10, and then the pull block 932 is released. It should be noted that there is a rebound spring in the groove of the pull block 932, and the two limit rods 933 are kept away, so that the One connecting plate 93 is installed with one connecting port 10, and then the same method is used, firstly, one connecting plate 93 after installation is pushed along the connecting port 10, so that the other connecting plate 93 corresponds to the other connecting port 10, and the same method is completed. Install.

Before starting the ultrasonic generator 6 for use, the screw 83 is rotated, and the rotation of the screw 83 causes the lifting plate 81 connected with the sliders 84 on both sides to move downward along the chute 92, so that the rotating roller 82 at the bottom of the lifting plate 81 and The pole piece is in contact, and the pole piece is pressed close to the ultrasonic generator 6, so that the pole piece is in contact with the vibration emitted by the ultrasonic generator 6 under the limit of the limit card 91 on both sides and the downward pressing action of the lifting plate 81. more uniform.

At this time, the ultrasonic generator 6 is started, so that the ultrasonic generator 6 is adjusted to the appropriate intensity and frequency, and the pole pieces that have not entered the oven body 4 and the slurry that has not been dried are subjected to ultrasonic vibration treatment, so that the wet coating is vibrated in the ultrasonic wave. The lower distribution is more even and tight. The pole piece after ultrasonic vibration is not only easy to bake, but also can improve the compaction density of the pole piece, which is convenient for rolling, and is also beneficial to the absorption of the electrolyte by the pole piece after liquid injection, and improves the overall consistency of the battery. When the ultrasonic generator 6 ultrasonically treats the pole piece, part of the slurry will fall off the pole piece, and the slurry will be collected in the collection box 74 through the first flow groove 71 and the second flow groove 72 for post-processing. The pole pieces processed by the ultrasonic generator 6 enter the oven body 4 through the inlet 41 for drying, and the pole pieces are dried faster at this time to improve the baking efficiency of the oven body 4 and reduce the use of equipment, and are concentrated through the winding roller 5 collect. Finally, the assembly and activation process is carried out.

The above-mentioned specific embodiments are only preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspiration of the above-mentioned embodiments, those skilled in the art can make various alternative improvements and combinations to the above-mentioned specific embodiments.

Claims (10)

1. a method for improving the compaction density of lithium battery pole pieces, comprising the preparation method of lithium battery, it is characterized in that: the preparation method of described lithium battery comprises the following steps: S1, film production; the equipment for film production includes: 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 installed with a plurality of groups of guide rollers (2) for guiding the transmission of the base material, an ultrasonic generator (6) is installed in the installation frame (3), and the installation frame (3) is located in the oven body (4). the front-end output area, the rear-end output area of the oven body (4) is provided with a winding roller (5); S1.1. Prepare the positive and negative active materials separately, process and mix the two different active materials respectively, in the form of slurry, and transport the slurry into the coating machine head body (1); S1.2. A mounting bracket (3) is arranged between the coating machine head body (1) and the oven body (4), and the surface of the substrate is uniformly coated with slurry through the coating machine head body (1), and combined with The ultrasonic generator (6) in the mounting frame (3) processes the pole pieces coated with the slurry; S1.3, the substrate processed by the ultrasonic generator (6) enters the oven body (4) through the front-end output area of the oven body (4) for drying and processing to obtain a lithium battery pole piece; S1.4. After the drying is completed, the pole piece in the output area at the rear end of the oven body (4) is wound up by the winding roller (5); S2. Assembling; cutting the pole pieces after coating the slurry and drying in S1, and wrapping or stacking the cut pole pieces into the lithium ion battery case, and the internal connection of the battery is carried out by welding; S3. Activation; inject electrolyte into the battery assembled in S2, and then perform chemical charging to activate the battery. 2. A method of improving the compaction density of a lithium battery pole piece according to claim 1, wherein the inner wall of the mounting frame (3) is provided with a transverse plate for installing the ultrasonic generator (6), so that the The top of the ultrasonic generator (6) is provided with a contact plate (7) fixed and horizontally installed on the inner wall of the mounting frame (3), and the outer diameter of the contact plate (7) is larger than the top area of the ultrasonic generator (6). 3. A method of improving the compaction density of a lithium battery pole piece according to claim 2, wherein a plurality of longitudinally arranged flow grooves one (71) are provided on the top of the contact plate (7), and a plurality of One end of each of the first flow grooves (71) is convergently connected to the second flow groove (72) located at the top of the contact plate (7). 4. A method for improving the compaction density of a lithium battery pole piece according to claim 3, characterized in that the depth of the second flow groove (72) is greater than the depth of the first flow groove (71), and the flow groove The bottom of the two (72) is connected with a material conveying pipe (73), and the other end of the material conveying pipe (73) is sealed with a collection box (74) installed on the horizontal plate, and the collection box (74) is installed on the There is an outlet pipe. 5. A method for improving the compaction density of lithium battery pole pieces according to claim 4, wherein the top of the contact plate (7) is provided with a mounting plate ( 9), an adjustment mechanism (8) located above the contact plate (7) is provided below the mounting plate (9), a screw (83) is rotatably connected to the mounting plate (9), and the screw (83) A lift plate (81) is rotatably connected to the bottom of the lift plate (81), and sliders (84) are connected to both side walls of the lift plate (81). 6. A method for improving the compaction density of a lithium battery pole piece according to claim 5, wherein the bottom of the mounting plate (9) is connected with limit cards located on both sides of the lifting plate (81). (91), the two limit cards (91) are provided with chute (92) along the height direction, and the slider (84) is slidably connected with the inner wall of the chute (92). 7. A method for improving the compaction density of a lithium battery pole piece according to claim 6, characterized in that, connecting plates (93) are connected on both sides of the mounting plate (9), and the mounting frame (3) ) are provided with connection ports (10) on both sides, and the inner diameter of the connection plate (93) is adapted to the inner diameter of the connection port (10). 8 . The method for improving the compaction density of a lithium battery pole piece according to claim 7 , wherein two sets of receiving grooves ( 931 ) are provided on one side wall of the connecting plate ( 93 ). 9 . A pull block (932) is slidably connected to the inner wall of the storage groove (931), and one end of the pull block (932) located inside the storage groove (931) is connected to a limit rod (933), and the limit rod (933) is connected to the storage groove (933). The inner wall of the groove (931) is slidably connected, and the vertical section of the receiving groove (931) is a "T"-shaped groove. 9 . The method for improving the compaction density of a lithium battery pole piece according to claim 5 , wherein a plurality of rotating grooves are opened at the bottom of the lifting plate (81), and multiple sets of rotating grooves rotate in the rotating grooves. 10 . A rotating roller (82) is installed, one side of the ultrasonic generator (6) is electrically connected with a controller, and the controller is detachably connected to the outer wall of the mounting frame (3). 10. The method for improving the compaction density of a lithium battery pole piece according to claim 1, wherein a plurality of observation ports (42) are installed on one side of the oven body (4), and in the S1 The base material is either copper or aluminum.

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