Tool for improving liquid injection efficiency

Abstract

The utility model discloses a tool for improving liquid injection efficiency, which relates to the technical field of battery cell liquid injection and comprises a constant-temperature heating water tank, a water heating pipe, a vertical liquid injection pipe, a transverse liquid injection pipe I and a transverse liquid injection pipe II, a semicircular bent pipe is arranged between the first transverse liquid injection pipe and the second transverse liquid injection pipe, a switch control valve is arranged on the semicircular bent pipe, a hollow pipeline with the closed upper end is arranged on the top of the vertical liquid injection pipe, and a water heating pipe is arranged on the outer wall of the vertical liquid injection pipe in a winding mode. Two ends of the water heating pipe are respectively communicated with a water inlet and a water outlet of the constant-temperature heating water tank. The utility model aims to shorten the temperature difference between the processes so as to shorten the process time on one hand, and promote electrolyte infiltration on the other hand.

Description

Technical Field

[0001] The utility model relates to the technical field of battery core liquid injection, and in particular to a tool for improving liquid injection efficiency. Background Art

[0002] Lithium / sodium ion battery is a secondary battery that can be repeatedly charged and discharged. It is composed of anode and cathode poles, isolation membrane, electrolyte, mechanical parts and other main components. At present, the volume of lithium / sodium ion battery is getting bigger and bigger, and the energy density requirements of the battery are getting higher and higher, but the test on the manufacturing process is also getting greater and greater. First, the theoretical remaining space inside the battery with high energy density has been compressed to the extreme, so it is difficult to inject liquid; second, the main material is a high-pressure dense material with a very small porosity, which is not conducive to the infiltration of the electrolyte; third, the surface density basically tends to be designed with higher thickness, so the infiltration path of the electrolyte is lengthened.

[0003] The above three reasons combined greatly increase the difficulty of injection and wetting, and also cause the process to be prone to poor wetting and lithium precipitation, thus affecting the cycle performance and safety performance of the battery cell. The current traditional process is that the battery cell needs to be cooled for a period of time after high-temperature baking before injection, and then high-temperature infiltration for more than ten hours. The biggest time-wasting point here is that the battery cell needs to be heated to about 100 degrees to dry the water and then cool the battery cell to about 15 degrees before injection. After injection, it needs to be heated to about 45 degrees for infiltration. This process of heating, cooling, and heating again will waste at least one or two hours. In addition, the electrolyte is taken out of the cold storage warehouse, and its temperature is within 10 degrees. Such a low-temperature electrolyte directly enters the battery cell with a relatively high temperature, and its infiltration effect will be greatly reduced. Due to the low storage temperature of the electrolyte and the low temperature of the injection room, electrolyte crystals are easily formed at the injection port and around the injection port, which will contaminate the battery cell to be injected next, and will corrode the injection machine in the long run. Utility Model Content

[0004] The purpose of the utility model is to provide a tool for improving the liquid injection efficiency, so as to overcome the above-mentioned defects in the prior art.

[0005] A tool for improving injection efficiency, comprising a constant temperature heating water tank, a water heat pipe, a vertical injection pipe, a horizontal injection pipe 1 and a horizontal injection pipe 2, wherein the horizontal injection pipe 1 is vertically arranged on the vertical injection pipe, a semicircular elbow is arranged between the horizontal injection pipe 1 and the horizontal injection pipe 2, a switch control valve is arranged on the semicircular elbow, a section of a hollow pipe with a closed upper end is arranged on the top of the vertical injection pipe, a water heat pipe is wound around the outer wall of the vertical injection pipe, and both ends of the water heat pipe are respectively connected to the water inlet and outlet of the constant temperature heating water tank.

[0006] Preferably, the water heat pipe is serpentinely wound on the vertical liquid injection pipe.

[0007] Preferably, the winding starting point of the water heat pipe is 50-60 cm above the injection port of the vertical injection pipe.

[0008] Preferably, the length of the transverse injection tube 1 is 10-30 cm.

[0009] Preferably, the water temperature in the water heat pipe is 42-48°C.

[0010] Preferably, the diameter of the hollow pipe is the same as that of the vertical injection pipe and its length is 30-60 cm.

[0011] Preferably, the transverse injection pipe 1 and the transverse injection pipe 2 are coaxially arranged and the distance between them is 20 cm.

[0012] Preferably, the water heat pipe is made of soft material and has a diameter of 5 cm.

[0013] The utility model has the following advantages:

[0014] 1. Based on the original equipment, the tooling adds a water heat pipe that can be wrapped around the vertical injection pipe at the upper end of the injection port. The purpose of this water heat pipe is to heat the electrolyte to be injected into the battery cell. The water in the water heat pipe flows from bottom to top. The water temperature in the configured constant temperature heating water tank is controlled at 45±3℃. The water flows out from the lower end and flows into the upper end to form circulating water with the water in the water heat pipe. If the water temperature is too high, the electrolyte will deteriorate and it is easy to cause the low-boiling point components in the electrolyte to volatilize. If the water temperature is too low, the effect of promoting electrolyte infiltration cannot be achieved.

[0015] 2. The tooling adds an additional section of a hollow pipe with a closed upper end at the upper end of the vertical injection pipe. The purpose is to prevent the electrolyte from expanding in volume after heating, and to prevent the electrolyte from releasing a small amount of volatile components after being heated at low temperatures, which will re-liquefy and merge into the electrolyte again after being cooled at the upper end.

[0016] 3. A lower semicircular elbow is added between the horizontal injection pipe 1 and the horizontal injection pipe 2 to separate the cold and hot electrolytes and prevent the heated electrolyte from affecting the electrolyte behind. A switch control valve is added to the semicircular elbow so that after a batch of injection is completed, the switch control valve is closed first and then the heated electrolyte is drained. Using the heated electrolyte to drain the pipe can flush the pipe and prevent crystallization corrosion of the electrolyte leaking at the tail end. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0018] Figure 2 It is a box plot comparing the cell capacity distribution of Example 1 of the utility model and Comparative Example 1.

[0019] Figure 3It is a box plot comparing the internal resistance distribution of the battery cells of Example 1 of the utility model and Comparative Example 1.

[0020] Among them: 1. vertical liquid injection pipe, 2. horizontal liquid injection pipe 1, 3. horizontal liquid injection pipe 2, 4. semicircular elbow, 5. switch control valve, 6. hollow pipe, 7. water heat pipe, 8. constant temperature heating water tank. DETAILED DESCRIPTION

[0021] 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.

[0022] like Figure 1 As shown, tooling preparation is carried out: modification is carried out on one of the injection machines in the test line:

[0023] 1. Add a constant temperature heating water tank 8 to the injection port of the vertical injection pipe 1, wind a water heat pipe 7 made of soft material with a diameter of 5 cm at 50-60 cm near the injection port, and then cover the water heat pipe 7 with a layer of insulation film to reduce energy loss.

[0024] 2. Then weld a section of hollow pipe 6 with closed upper end on the upper end of vertical injection pipe 1. The diameter of the pipe is consistent with that of vertical injection pipe 1. Its length is between 30-60cm, depending on the spare space at the upper end of the workshop. Here, 40cm is selected.

[0025] 3. The length of the horizontal injection pipe 2 on the side of the vertical injection pipe 1 is set to 10-30cm, and a distance of 20cm is maintained between it and the horizontal injection pipe 3. Then, it is connected to the horizontal injection pipe 2 3 through a semicircular elbow 4 with the same diameter as the horizontal injection pipe 2, and then a switch control valve is installed on the horizontal injection pipe 2 3.

[0026] 4. After the installation is completed, test the sealing of each pipeline, connect the water inlet and outlet of the constant temperature heating water tank 8 to the two ends of the water heat pipe 7, and then test the heating temperature effect of the water heat pipe 7. If the conditions are met, put it into experimental verification.

[0027] Example 1:

[0028] Experimental verification process:

[0029] 1. Prepare 50 300Ah lithium iron phosphate aluminum shell batteries to be baked, and then put them into the baking oven with the temperature set to 100±5℃. The baking is stopped after the water content is qualified.

[0030] 2. Take the baked battery out of the baking oven and place it in the cooling area. Then record the time from when the battery is taken out to when the battery temperature drops to 50±3℃ as t1.

[0031] 3. Liquid injection: Push the cooled battery cell to the liquid injection position, start the liquid injection process, and record the time from the start of liquid injection to the end of liquid injection as t2. After the liquid injection is completed, first close the switch control valve at the semicircular elbow, then empty the remaining electrolyte in the vertical liquid injection pipe and the horizontal liquid injection pipe, and stop the water circulation heating in the constant temperature heating water tank and the water heat pipe.

[0032] 4. Transfer the battery cells to a high temperature (45±5℃) static room for soaking. After a period of time, disassemble the battery cells to confirm whether the battery cells are soaked. After soaking, record the time from the start to the end of soaking as t3. All time records are summarized in Table 1.

[0033] 5. Carry out normal formation, aging, sealing, capacity separation and other tests on the battery cells. At the same time, compare the electrical performance of the battery cells to prevent the tooling process from having a negative impact on the electrical performance. See the performance comparison. Figure 1-2 .

[0034] Comparative Example 1:

[0035] Experimental verification process:

[0036] 1. Prepare 50 300Ah lithium iron phosphate aluminum shell batteries to be baked, and then put them into the baking oven with the temperature set to 100±5℃. The baking is stopped when the water content is qualified.

[0037] 2. Take the baked battery out of the baking oven and place it in the cooling area. Then record the time from when the battery is taken out to when the battery temperature drops to 25±5℃ as t1.

[0038] 3. Liquid injection: Push the cooled battery cell to the liquid injection position, start the liquid injection process, and record the time from the start to the end of liquid injection as t2.

[0039] 4. Transfer the battery cells to a high temperature (45±5℃) static room for soaking. After a period of time, disassemble the battery cells to confirm whether the battery cells are soaked. After soaking, record the time from the start to the end of soaking as t3. All time records are summarized in Table 1.

[0040] 5. Carry out normal formation, aging, sealing, capacity division and other tests on the battery cells.

[0041] Table 1: Comparison of process time

[0042] project Cooling time t1 / h Injection time t2 / h Infiltration time t3 / h Total time T Example 1 0.32 0.08 7.5 7.90 Comparative Example 1 0.8 0.18 8.6 9.58

[0043] Compared with comparative example 1, embodiment 1 can save 1.68 hours, or more than 100 minutes, in total time, which is a significant time saving. From the data, it can be seen that the tooling process of the present application has no significant effect on the electrical performance of the battery cell, but it is unexpectedly found that the consistency of the electrical performance is improved, which may be related to the more thorough infiltration.

[0044] 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 tool for improving injection efficiency, comprising a constant temperature heating water tank, characterized in that: It also includes a water heat pipe, a vertical injection pipe, a horizontal injection pipe 1 and a horizontal injection pipe 2. The horizontal injection pipe 1 is vertically arranged on the vertical injection pipe. A semicircular elbow is arranged between the horizontal injection pipe 1 and the horizontal injection pipe 2. A switch control valve is arranged on the semicircular elbow. A section of a hollow pipe with a closed upper end is arranged on the top of the vertical injection pipe. A water heat pipe is wound around the outer wall of the vertical injection pipe. Both ends of the water heat pipe are respectively connected to the water inlet and outlet of the constant temperature heating water tank.

2. A tool for improving injection efficiency according to claim 1, characterized in that: The water heat pipe is arranged in a serpentine shape on the vertical liquid injection pipe.

3. A tool for improving injection efficiency according to claim 2, characterized in that: The winding starting point of the water heat pipe is 50-60 cm above the injection port of the vertical injection pipe.

4. A tool for improving injection efficiency according to claim 1, characterized in that: The length of the transverse injection tube 1 is 10-30 cm.

5. The tooling for improving injection efficiency according to claim 1 is characterized in that: The diameter of the hollow pipe is the same as that of the vertical injection pipe and its length is 30-60 cm.

6. The tooling for improving injection efficiency according to claim 1 is characterized in that: The first transverse injection pipe and the second transverse injection pipe are coaxially arranged and the distance between them is 20 cm.

7. The tooling for improving injection efficiency according to claim 1 is characterized in that: The water heat pipe is made of soft material and has a diameter of 5 cm.

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