A soft package sodium-ion battery electrolyte infiltration method

Abstract

The application discloses a soft package sodium ion battery electrolyte infiltration method and relates to the technical field of lithium batteries, and has the beneficial effect that compared with the high-temperature standing / conventional standing of the traditional scheme, the application adopts the operation process of alternately rolling the battery soft package TD and MD directions under a certain pressure, makes the electrolyte quickly infiltrate the surface of the battery cell in the up-down and left-right directions in a large area, and then vibrates at a certain frequency and amplitude, so that the electrolyte fully penetrates into the core body corner position, the traditional electrolyte infiltration difficult area can be quickly infiltrated, the standing time is significantly reduced, and the infiltration effect is improved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a method for impregnating a soft-pack sodium-ion battery with an electrolyte. Background Technology

[0002] Sodium is one of the most abundant elements on Earth. Its working principle is similar to that of lithium-ion batteries, and it boasts advantages such as low cost, good safety, and long-term large-scale storage, attracting increasing attention from researchers. However, sodium-ion batteries also suffer from drawbacks such as poor cycle performance, gas expansion during high-temperature storage, and low initial efficiency, which restricts their widespread application. The electrolyte, as one of the key materials in sodium-ion power batteries, has a significant impact on the battery's cycle performance and high / low temperature performance. Among the three main components of the electrolyte, the formulations of sodium salt and solvent remain relatively unchanged; additives are the key factor in improving the performance of sodium-ion batteries. Therefore, developing additives that meet the performance requirements of sodium-ion batteries is of great significance for electrolytes. Furthermore, as battery capacity and area increase, the requirements for wetting become more stringent; poor wetting severely affects performance. In view of this, it is indeed necessary to provide a technical solution to address the aforementioned problems. Summary of the Invention

[0003] The purpose of this invention is to provide an electrolyte wetting method that can improve the uniformity of cell wetting, increase the wetting speed of electrolyte on cell, and improve battery production efficiency and cell performance in order to solve the above problems.

[0004] The present invention achieves the above objectives through the following technical solutions:

[0005] A method for impregnating a soft-pack sodium-ion battery with an electrolyte includes the following steps:

[0006] Step S1: Inject electrolyte into the battery pouch and let it stand to wet the battery cells inside the battery pouch;

[0007] Step S2: Place the electrolyte-filled battery cell into the rolling device for hot rolling and cold rolling: First, use a temperature of 60℃~80℃ to perform hot rolling in the TD direction, so that the electrolyte accumulated at the head and tail of the battery cell can quickly enter the inside of the cell. Then, use a temperature of 25℃~35℃ to perform cold rolling in the MD direction, so that the electrolyte that has entered the inside of the cell can quickly and evenly wet the upper and lower sides. The battery cell is rolled alternately in the TD and MD directions. The number of rolling times in the TD direction is N, and the number of rolling times in the MD direction is M. The rolling temperature increases by 10℃ each time to ensure the heat loss caused by rolling and to keep the rolling temperature consistent each time.

[0008] Step S3: After the battery cell is placed in the fixture, the battery cell is transferred to a high-temperature vibration table for vibration in the TD and MD directions: First, the battery cell is vibrated in the TD direction, then in the MD direction. The battery cell is vibrated alternately in the TD and MD directions. The vibration time in the TD direction is T1, the vibration time in the MD direction is T2, and the alternating vibration period is S times.

[0009] Step S4: After vibration is complete, vacuum seal the battery pack.

[0010] Step S5: Allow the battery pack to stand for a second time to obtain a battery semi-finished product.

[0011] Preferred setting temperature: 40℃~50℃.

[0012] Preferably, the vibration frequency of the battery in the TD direction is 20 Hz to 40 Hz, the vibration frequency in the MD direction is 40 Hz to 60 Hz, the T1 time is 10-15 min, the T2 time is 20-25 min, and the alternation period S is 3-5 times.

[0013] Preferably, the settling time for the battery during the second settling period is 2 to 4 hours.

[0014] Preferably, the rolling pressure in the TD direction of the battery is 1-2 kg, the rolling pressure in the MD direction is 2-3 kg, the number of rolling cycles N in the TD direction is 5-7 times, and the number of rolling cycles M in the MD direction is 8-10 times.

[0015] Preferably, the roller pressing device includes a base plate with a positioning groove for placing a battery pack in the middle of its upper surface. Columns are fixedly installed at the four corners of the upper surface of the base plate. A first lead screw is threaded through the upper part of the two front columns, with both ends of the first lead screw connected to the column via bearings. A second lead screw is threaded through the lower part of the two rear columns, with both ends of the second lead screw connected to the column via bearings. The right ends of the first and second lead screws are connected by a first transmission belt. The second lead screw is driven to rotate by a first motor. A first movable frame that moves left and right is provided between the first and second lead screws. The front and rear ends of the first movable frame are threaded to the first and second lead screws, respectively. Two first hydraulic cylinders are fixedly installed on the lower surface of the first movable frame. The lower ends of the first hydraulic cylinders are fixedly mounted... The system is equipped with a first connecting block, and a first pressure roller is connected between the first connecting blocks via bearings. A third lead screw is inserted through the lower part of the two left-side columns, with both ends of the third lead screw connected to the columns via bearings. A fourth lead screw is inserted through the lower part of the two right-side columns, with both ends of the fourth lead screw connected to the columns via bearings. The front ends of the third and fourth lead screws are connected via a second transmission belt. The third lead screw is driven to rotate by a second motor. A second movable frame that moves back and forth is provided between the third and fourth lead screws. The left and right ends of the second movable frame are threadedly connected to the third and fourth lead screws, respectively. Two second hydraulic cylinders are fixedly installed on the lower surface of the second movable frame. A second connecting block is fixedly installed at the lower end of each second hydraulic cylinder. A second pressure roller is connected between the second connecting blocks via bearings.

[0016] Preferably, the first pressure roller and the second pressure roller have the same internal structure, both including a cylindrical roller body, and a heating tube is provided inside the roller body. The heating tube is fixed to the inner wall of the roller body by a fixing frame.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the traditional high-temperature standing / conventional standing, the present invention adopts an alternating rolling operation with a certain pressure in the TD and MD directions of the battery soft pack, so that the electrolyte first rapidly wets the surface of the cell in a large area in the up-down and left-right directions, and then through vibration of a certain frequency and amplitude, the electrolyte fully penetrates into the corners of the cell. Areas that are difficult to wet with electrolyte in the traditional way can also be quickly wetted, significantly reducing the standing time and improving the wetting effect. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the rolling and vibration direction of the battery soft pack in the electrolyte impregnation method of the soft pack sodium-ion battery described in this invention.

[0020] Figure 2 This is a first-view perspective three-dimensional structural schematic diagram of the roller pressing device for the electrolyte impregnation method of a soft-pack sodium-ion battery according to the present invention.

[0021] Figure 3 This is a second-view perspective three-dimensional structural schematic diagram of the roller pressing device for the electrolyte impregnation method of a soft-pack sodium-ion battery according to the present invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of the pressure roller in the electrolyte impregnation method for a soft-pack sodium-ion battery as described in this invention.

[0023] The annotations in the attached figures are explained as follows:

[0024] 1. Base plate; 2. Column; 3. First transmission belt; 4. First lead screw; 5. Second lead screw; 6. First motor; 7. Second transmission belt; 8. Third lead screw; 9. Fourth lead screw; 10. First hydraulic cylinder; 11. First pressure roller; 111. Roller body; 112. Fixing frame; 113. Heating tube; 12. First connecting block; 13. Second motor; 14. Second hydraulic cylinder; 15. Second pressure roller; 16. Second connecting block; 17. First moving beam; 18. Second moving beam; 19. Positioning groove. Implementation

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood through the specific circumstances.

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] like Figures 1-4 As shown, a method for impregnating a soft-pack sodium-ion battery with electrolyte includes the following steps:

[0029] Step S1: Inject electrolyte into the battery pouch and let it stand to wet the battery cells inside the battery pouch;

[0030] Step S2: Place the electrolyte-filled battery cell into the rolling device for hot rolling and cold rolling: First, use a temperature of 60℃~80℃ to perform hot rolling in the TD direction, so that the electrolyte gathered at the head and tail of the battery cell (i.e., the electrolyte on the left and right sides) can quickly enter the battery cell. Then, use a temperature of 25℃~35℃ to perform cold rolling in the MD direction, so that the electrolyte that has entered the battery cell can quickly and evenly wet the upper and lower sides. The battery cell is rolled alternately in the TD and MD directions. The number of rolling times in the TD direction is N, and the number of rolling times in the MD direction is M. The rolling temperature increases by 10℃ each time to ensure the heat loss caused by rolling and to keep the rolling temperature consistent each time.

[0031] Step S3: After the battery cell is placed in the fixture, the battery cell is transferred to a high-temperature vibration table for vibration in the TD and MD directions: First, the battery cell is vibrated in the TD direction, then in the MD direction. The battery cell is vibrated alternately in the TD and MD directions. The vibration time in the TD direction is T1, the vibration time in the MD direction is T2, and the alternating vibration period is S times.

[0032] Step S4: After vibration is complete, vacuum seal the battery pack.

[0033] Step S5: Allow the battery pack to stand for a second time to obtain a battery semi-finished product.

[0034] The battery is placed at a set temperature of 40℃~50℃; the vibration frequency in the TD direction is 20Hz~40Hz, and the vibration frequency in the MD direction is 40Hz~60Hz; the T1 time is 10-15min, the T2 time is 20-25min, and the alternation cycle S is 3-5 times; the battery is placed for a second settling period of 2h~4h; the rolling pressure in the TD direction is 1-2kg, the rolling pressure in the MD direction is 2-3kg, the number of rolling cycles N in the TD direction is 5-7 times, and the number of rolling cycles M in the MD direction is 8-10 times; the rolling device includes a base plate 1, with supports fixedly installed at the four corners of the lower surface of the base plate 1, and the middle of the upper surface of the base plate 1... A positioning groove 19 is provided for placing a battery pack, which prevents the battery pack from sliding during the rolling process. Columns 2 are fixedly installed at the four corners of the upper surface of the base plate 1 for support. A first lead screw 4 passes through the upper part of the two front columns 2, with both ends of the first lead screw 4 connected to the column 2 via bearings. A second lead screw 5 passes through the lower part of the two rear columns 2, with both ends of the second lead screw 5 connected to the column 2 via bearings. The right ends of the first lead screw 4 and the second lead screw 5 are connected by a first transmission belt 3. The second lead screw 5 is driven to rotate by a first motor 6. A first movable frame that moves left and right is provided between the first lead screw 4 and the second lead screw 5, with its front and rear ends respectively connected to the first lead screw 4 and the second lead screw 5. The second lead screw 5 is threaded. Two first hydraulic cylinders 10 are fixedly installed on the lower surface of the first movable frame. A first connecting block 12 is fixedly installed at the lower end of the first hydraulic cylinder 10. A first pressure roller 11 is connected between the first connecting blocks 12 through bearings. A third lead screw 8 is inserted through the lower part of the two columns 2 on the left side. The two ends of the third lead screw 8 are connected to the columns 2 through bearings. A fourth lead screw 9 is inserted through the lower part of the two columns 2 on the right side. The two ends of the fourth lead screw 9 are connected to the columns 2 through bearings. The front ends of the third lead screw 8 and the fourth lead screw 9 are connected by a second transmission belt 7. The third lead screw 8 is driven to rotate by a second motor 13. A second movable frame that moves back and forth is set between the third lead screw 8 and the fourth lead screw 9. The left and right ends of the movable frame are threaded to the third lead screw 8 and the fourth lead screw 9, respectively. Two second hydraulic cylinders 14 are fixedly installed on the lower surface of the second movable frame. A second connecting block 16 is fixedly installed at the lower end of the second hydraulic cylinder 14. A second pressure roller 15 is connected between the second connecting blocks 16 through bearings. The first pressure roller 11 and the second pressure roller 15 have the same internal structure, both including a cylindrical roller body 111. A heating tube 113 is set inside the roller body 111. The heating tube 113 is fixed to the inner wall of the roller body 111 by a fixing frame 112, which is a ceramic block. Because the core is more difficult to vibrate in the MD direction than in the TD direction, the vibration time, vibration frequency and number of roller presses in the above scheme are all greater than those in the TD direction.

[0035] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for impregnating a soft-pack sodium-ion battery with an electrolyte, characterized in that: Includes the following steps: Step S1: Inject electrolyte into the battery pouch and let it stand to wet the battery cells inside the battery pouch; Step S2: Place the electrolyte-filled battery cell into the rolling device for hot rolling and cold rolling: First, use a temperature of 60℃~80℃ to perform hot rolling in the TD direction, so that the electrolyte accumulated at the head and tail of the battery cell can quickly enter the inside of the cell. Then, use a temperature of 25℃~35℃ to perform cold rolling in the MD direction, so that the electrolyte that has entered the inside of the cell can quickly and evenly wet the upper and lower sides. The battery cell is rolled alternately in the TD and MD directions. The number of rolling times in the TD direction is N, and the number of rolling times in the MD direction is M. The rolling temperature increases by 10℃ each time to ensure the heat loss caused by rolling and to keep the rolling temperature consistent each time. Step S3: After the battery cell is placed in the fixture, the battery cell is transferred to a high-temperature vibration table for vibration in the TD and MD directions: First, the battery cell is vibrated in the TD direction, then in the MD direction. The battery cell is vibrated alternately in the TD and MD directions. The vibration time in the TD direction is T1, the vibration time in the MD direction is T2, and the alternating vibration period is S times. Step S4: After vibration is complete, vacuum seal the battery pack. Step S5: Allow the battery pack to stand for a second time to obtain a battery semi-finished product.

2. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 1, characterized in that: The settling temperature is 40℃~50℃.

3. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 1, characterized in that: The vibration frequency of the battery in the TD direction is 20 Hz to 40 Hz, the vibration frequency in the MD direction is 40 Hz to 60 Hz, the T1 time is 10-15 min, the T2 time is 20-25 min, and the alternation period S is 3-5 times.

4. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 1, characterized in that: The battery is allowed to stand for a second time for 2 to 4 hours.

5. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 1, characterized in that: The rolling pressure of the battery in the TD direction is 1-2 kg, the rolling pressure in the MD direction is 2-3 kg, the number of rolling cycles N in the TD direction is 5-7 times, and the number of rolling cycles M in the MD direction is 8-10 times.

6. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 1, characterized in that: The roller pressing device includes a base plate (1), and a positioning groove (19) for placing a battery soft pack is opened in the middle of the upper surface of the base plate (1); columns (2) are fixedly installed at the four corners of the upper surface of the base plate (1); a first lead screw (4) is passed through the upper part of the two front columns (2), and the two ends of the first lead screw (4) are respectively connected to the column (2) through bearings; a second lead screw (5) is passed through the lower part of the two rear columns (2), and the two ends of the second lead screw (5) are respectively connected to the column (2) through bearings; the right ends of the first lead screw (4) and the second lead screw (5) are connected by a first transmission belt (3); the second lead screw (5) is driven to rotate by a first motor (6); a first moving frame that moves left and right is provided between the first lead screw (4) and the second lead screw (5); the front and rear ends of the first moving frame are respectively threaded to the first lead screw (4) and the second lead screw (5); two first hydraulic cylinders (10) are fixedly installed on the lower surface of the first moving frame; a first connecting block is fixedly installed at the lower end of the first hydraulic cylinder (10). (12), the first connecting blocks (12) are connected by bearings to the first pressure roller (11); the lower part of the two columns (2) on the left is provided with a third screw (8), the two ends of the third screw (8) are respectively connected to the column (2) by bearings, the lower part of the two columns (2) on the right is provided with a fourth screw (9), the two ends of the fourth screw (9) are respectively connected to the column (2) by bearings, the front ends of the third screw (8) and the fourth screw (9) are connected by a second transmission belt (7), the third screw (8) is driven to rotate by a second motor (13), a second moving frame that moves back and forth is provided between the third screw (8) and the fourth screw (9), the left and right ends of the second moving frame are respectively threaded to the third screw (8) and the fourth screw (9), two second hydraulic cylinders (14) are fixedly installed on the lower surface of the second moving frame, a second connecting block (16) is fixedly installed at the lower end of the second hydraulic cylinder (14), and a second pressure roller (15) is connected between the second connecting blocks (16) by bearings.

7. The method for impregnating a soft-pack sodium-ion battery with electrolyte according to claim 6, characterized in that: The first pressure roller (11) and the second pressure roller (15) have the same internal structure, both including a cylindrical roller body (111). A heating tube (113) is provided inside the roller body (111), and the heating tube (113) is fixed on the inner wall of the roller body (111) by a fixing frame (112).

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