Battery cell negative pressure heating water removal device

Abstract

The utility model discloses a negative pressure heating and dewatering device for a battery cell, and relates to the technical field of battery cell production and processing, the negative pressure heating and dewatering device comprises a tool clamp, a control system, a box body, a side heating plate and a low heating plate, and the negative pressure heating and dewatering device can realize the function of quickly drying and dewatering an electrode slice in the battery cell; through contact type independent heating, the heating waiting time is shortened, the heating rate is increased, and the process productivity is improved; negative pressure pumping is performed on a single battery cell, so that energy consumption is reduced, and efficiency is improved; a single battery cell is subjected to negative pressure and heating treatment, so that the uniformity of the effect is guaranteed, and the first-pass yield is improved; the operation function of independently vacuumizing a certain battery or several batteries is achieved, and energy consumption is effectively saved. According to the device, the battery can be rapidly heated under the negative pressure condition, the production and manufacturing rework rate is greatly reduced, the production efficiency is further improved, and the product yield is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery core production and processing, and in particular to a battery core negative pressure heating and water removal device. Background Art

[0002] Lithium-ion batteries have high energy density, which is about 6-7 times that of lead-acid batteries. They have long service life, high rated voltage and wide adjustable range. They are suitable for assembly of various electrical equipment and have strong high-power bearing capacity. They are widely used in high-intensity starting and acceleration power supply for various electric vehicles. They have performance advantages such as light weight and small size.

[0003] The battery manufacturing process includes three main parts: electrode preparation (mixing, coating, drying, solvent recovery, rolling, cutting, electrode vacuum drying), battery assembly (stacking or winding, welding, shelling, sealing, baking, liquid injection, etc.) and battery electrochemical activation (pre-charging, formation, aging, etc.). The manufacturing cost accounts for a large proportion of the cost of lithium batteries.

[0004] The baking process in the battery manufacturing process is a baking process for the purpose of removing moisture, activating electrode materials and removing volatiles, so as to improve the performance and safety of the battery. Heating and baking the battery has the following advantages:

[0005] 1. Remove moisture. In the process of manufacturing lithium batteries, various raw materials and solvents may contain some moisture. The presence of moisture will interfere with the chemical reaction inside the battery and cause various safety problems. By heating and baking, the moisture can be evaporated to ensure a dry environment inside the battery.

[0006] 2. Activate electrode materials: Activate the positive and negative electrode materials of lithium batteries under specific conditions to improve the chemical properties of the raw materials. By heating and baking, the activation of electrode materials is accelerated, giving them good electrochemical reaction capabilities.

[0007] 3. Remove volatiles: The materials or coatings used in the manufacturing process contain some volatile organic matter. By heating and baking, the organic matter can be removed to improve battery safety.

[0008] The existing baking process uses heating wire resistance heating, which conducts heat through the air and bakes the battery as a whole without contact. The process is as follows: select the process operation page → click the process editing page → set the temperature value → set the upper and lower limit protection temperature → click to start heating, and at the same time, start vacuuming the entire box, set the time to 8h → after the test time is reached, take out the test sample, and take out the battery electrode for water content testing. The test batteries completed by this method have a high proportion of unqualified water content, and the rework rate needs to reach more than 36%. The reworked batteries need to be baked twice, and the test time needs to be extended. The time setting is generally increased to 16h to 24h. The reworked batteries need to repeat the water content test, which is time-consuming and labor-intensive, and the production test efficiency is low. Utility Model Content

[0009] The purpose of the utility model is to provide a negative pressure heating and water removal device for a battery cell to overcome the above-mentioned defects in the prior art.

[0010] A negative pressure heating and water removal device for battery cells, comprising a fixture, a control system, a box body, a side heating plate and a low heating plate, wherein the front side of the box body is hinged with a box door via a hinge, a low heating plate is provided in the box body, the side heating plate is provided on the side of the low heating plate, the fixture is provided on the low heating plate and is used to clamp the battery cells, the vacuum air pipe in the box body is connected to a vacuum pump, a branch air pipe connected to the vacuum air pipe via an air pressure control valve is provided above each low heating plate, and the control system is electrically connected to the low heating plate, the side heating plate, the vacuum pump and the air pressure control valve.

[0011] Preferably, a plurality of side heating plates are provided and are evenly distributed around the lower heating plate.

[0012] Preferably, the box door is an explosion-proof door.

[0013] Preferably, a door handle is provided on the box door.

[0014] The utility model has the following advantages:

[0015] This application can achieve the function of quickly drying and dehydrating the electrode sheets in the battery cell; through contact-type independent heating, the heating waiting time can be reduced, the heating rate can be increased, and the process capacity can be increased; negative pressure can be pumped on a single battery cell to reduce energy consumption and improve efficiency; negative pressure and heating treatment can be performed on a single battery cell to ensure the uniformity of the effect and improve the first-time pass rate; the operation function of vacuuming a certain battery or several batteries can be realized separately, effectively saving energy consumption. The device of this patent can ensure that the battery is quickly heated under negative pressure conditions, greatly reducing the rework rate of production and manufacturing, thereby improving production efficiency and improving product quality rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a schematic diagram of the overall three-dimensional structure of the utility model.

[0017] Figure 2 This is a schematic diagram of battery sampling of the utility model.

[0018] Among them: 1. Control system; 2. Vacuum air pipe; 3. Box body; 4. Air pressure control valve; 5. Branch air pipe; 6. Box door; 7. Side heating plate; 8. Low heating plate; 9. Door handle. DETAILED DESCRIPTION

[0019] The specific implementation methods of the utility model are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the utility model.

[0020] like Figure 1-2 As shown, the utility model provides a negative pressure heating and water removal device for battery cells, including a fixture, a control system 1, a box body 3, a side heating plate 7 and a low heating plate 8, the front side of the box body 3 is hinged with a box door 6 by a hinge, the box body 3 is provided with a low heating plate 8, the side heating plate 7 is arranged on the side of the low heating plate 8, the fixture is arranged on the low heating plate 8 and is used to clamp the battery cells, the vacuum air pipe 2 in the box body 3 is connected to the vacuum pump, and a branch air pipe 5 connected to the vacuum air pipe 2 through an air pressure control valve 4 is arranged above each low heating plate 8, and the control system 1 is electrically connected to the low heating plate 8, the side heating plate 7, the vacuum pump and the air pressure control valve 4.

[0021] It should be noted that there are a plurality of side heating plates 7 which are evenly distributed around the lower heating plate 8 .

[0022] In addition, the box door 6 is an explosion-proof door, and a door handle 9 is provided on the box door 6 .

[0023] Specific implementation and principle:

[0024] 1. Turn on the power of the whole machine: turn on the power switch of the equipment, enter the control panel, enter the initial page of the touch screen, confirm the required air pressure value, which must be within the document range specified in the process production.

[0025] 2. Turn on the vacuum pump and baking oven: open the main valve on the vacuum air pipe 2, the cooling water pipeline, click the start device, and confirm the process parameters including the air pressure setting value, temperature setting value, and the upper and lower temperature limit protection alarm values.

[0026] 3. Vacuuming: Open the separate air pipe main valve, and at the same time ensure that the air pressure control valve 4 on each branch air pipe on the display page is open.

[0027] 4. Battery heating: Place the battery in the fixture of the test heating plate 7 and the low heating plate, and click to heat.

[0028] 5. Water content: Select the sample battery that has been tested and take the battery electrode to test the water content.

[0029] 6. Cooling after being taken out of the oven: If the water content test result is qualified, the battery is stored in the area to be filled with liquid.

[0030] Comparative Example 1: Baking lithium batteries using traditional methods

[0031] 1. Record the test time to complete a set of battery baking;

[0032] 2. Record the number of process outputs within 24 hours;

[0033] 3. Randomly sample 5 groups of batteries that have been cooled and removed from the furnace for inspection, and record them as sample group 1, sample group 2, sample group 3, sample group 4, and sample group 5;

[0034] 4. Randomly select 3 test samples from each of the 5 groups of production batteries, record battery A, battery B, and battery C, and take pole pieces of the same size at the center of the three batteries for Karl Fischer coulometric moisture meter to test moisture;

[0035] 5. Record the number of unqualified water content tests and calculate the baking rework rate in each group of batteries.

[0036] Among them, 5 groups of moisture data were measured by sampling at the center positions of the outside, middle and inside of the battery cells:

[0037]

[0038] 1. The test time of a group of batteries baked by traditional method is 8 hours, the water content is often unqualified, and the rework rate is 36%;

[0039] 2. The traditional method requires preheating of the cavity before heating and baking. The preheating time is 30 minutes. One cavity can store 100 batteries at a time. A single cavity can bake 282 batteries in 24 hours.

[0040] 3. The traditional method of water content testing fails and requires manual injection, which is inefficient.

[0041] Example 1: Baking of lithium batteries using the patented method

[0042] 1. Record the test time to complete a set of battery baking;

[0043] 2. Record the number of process outputs within 24 hours;

[0044] 3. Randomly sample 5 groups of batteries that have been cooled and removed from the furnace for inspection, and record them as sample group 1, sample group 2, sample group 3, sample group 4, and sample group 5;

[0045] 4. Randomly select 3 test samples from each of the 5 groups of production batteries, record battery A, battery B, and battery C, and take pole pieces of the same size at the center of the three batteries for Karl Fischer coulometric moisture meter to test moisture;

[0046] 5. Record the number of unqualified water content tests and calculate the baking rework rate in each group of batteries.

[0047] Among them, 5 groups of moisture data were measured by sampling at three locations: outside, middle and inside the battery cell:

[0048]

[0049] 1. The test time of baking a group of batteries in this patent is 4 hours, the water content is less unqualified, and the rework rate is 0.02%;

[0050] 2. This patent adopts contact-type independent heating, which is started simultaneously with the vacuum device. It only takes 2 minutes to reach the set temperature value. A single cavity can bake out 600 batteries in 24 hours.

[0051] 3. Products that fail the water content test can be reworked independently in the machine directly, with high efficiency and a 100% rework rate.

[0052] Result analysis:

[0053] Comparative Example 1 is a traditional battery baking method. This method takes 8.5 hours to bake a group of batteries. 100 batteries can be baked at a time, and 282 batteries can be baked and produced in 24 hours. The process output rate is low; and the non-contact heating method causes insufficient battery baking, many water content tests fail, and the rework rate is high; the traditional method fails the water content test and needs manual liquid injection, which is inefficient; the average moisture content of the batteries after baking by this method is greater than 0.03μg / g, the water content is relatively high, and it cannot meet the needs of large-scale battery production.

[0054] Embodiment 1 is the baking method of the battery of the present patent. This method only needs 4 hours to bake a group of batteries. 100 batteries can be baked at a time. 600 batteries can be baked and produced in 24 hours, which is 2.1 times that of the traditional method, and the process output rate is high. It adopts three-sided multi-contact heating, and the heating rate is fast. The one-time quality is high. The water content quality rate of the battery in this method is as high as 99.98% or more. The unqualified products in the water content test of this method can be directly reworked independently in the machine, with high rework efficiency and 100% rework quality rate. The average water content of the battery after baking by this method is less than 0.01μg / g, the water content is low, which can meet the needs of large-scale battery production, and is better than the traditional method.

[0055] The utility model is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the utility model, or the concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A negative pressure heating and water removal device for a battery cell, comprising a fixture and a control system (1), characterized in that: The invention also comprises a box body (3), a side heating plate (7) and a low heating plate (8), wherein the front side of the box body (3) is hingedly connected with a box door (6), the box body (3) is provided with a low heating plate (8), the side heating plate (7) is provided on the side of the low heating plate (8), the fixture is provided on the low heating plate (8) and is used to clamp the battery cell, the vacuum air pipe (2) in the box body (3) is connected to a vacuum pump, a branch air pipe (5) connected to the vacuum air pipe (2) through an air pressure control valve (4) is provided above each low heating plate (8), and the control system (1) is electrically connected to the low heating plate (8), the side heating plate (7), the vacuum pump and the air pressure control valve (4).

2. A negative pressure heating and water removal device for battery cells according to claim 1, characterized in that: A plurality of side heating plates (7) are provided and are evenly distributed around the lower heating plate (8).

3. A negative pressure heating and water removal device for battery cells according to claim 1, characterized in that: The box door (6) is an explosion-proof door.

4. A negative pressure heating and water removal device for battery cells according to claim 1, characterized in that: The box door (6) is provided with a door handle (9).

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