Square battery liquid injection and exhaust device and its application

Abstract

The present invention belongs to the field of lithium-ion batteries, and specifically relates to a square battery liquid injection and exhaust device and its application. It includes a square battery unit, a liquid injection and exhaust unit, and a base support unit; the square battery unit includes a square battery, a positive electrode connecting piece connected to the positive pole of the square battery, a negative electrode connecting piece connected to the negative pole of the square battery, and an injection hole; the positive electrode connecting piece and the negative electrode connecting piece directly or indirectly serve as terminals for battery charge and discharge output or input; the liquid injection and exhaust channel includes a liquid storage tube, and an exhaust ball valve and a liquid injection tube respectively connected to the upper and lower ends of the liquid storage tube; a sealing rubber plug matching the liquid injection hole is provided at the lower end of the liquid injection tube. The present invention provides a square battery liquid injection and exhaust device, which has a scientific structural design. By combining liquid injection, exhaust pre-formation and formation, the electrolyte inside the high energy density battery cell can be kept full, and the generated gas can be discharged through this device to reduce and eliminate lithium precipitation inside the battery cell.

Description

Technical Field

[0001] The invention belongs to the field of lithium-ion batteries, and in particular relates to a square battery liquid injection and exhaust device and application thereof. Background Art

[0002] In recent years, lithium-ion batteries have been widely used in the field of new energy vehicles. With the continuous development of new energy vehicles, lithium-ion batteries with high energy density, long life and high safety have also become the main research direction in the field of lithium-ion battery technology.

[0003] As the energy density increases, the compaction density of the anode and cathode sheets inside the battery cell will further increase, and the battery cell's electrolyte retention will decrease. During the pre-formation and formation of the battery, if the electrode sheets inside the battery cell are not filled with electrolyte or the gas generated cannot be discharged, problems such as poor anode interface state, uneven anode surface reaction, and poor solid electrolyte (SEI) film formation will occur, which will further affect the battery cycle life. More seriously, it will cause the anode potential to drop and lithium deposition to occur on the anode surface, which will cause safety problems. Based on the above problems, it is difficult to further improve the battery cycle life and safety performance while ensuring the improvement of battery energy density, making it difficult for high energy density batteries to be widely promoted and used. . Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a square battery liquid filling and exhaust device and its application.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A square battery liquid injection and exhaust device, comprising a square battery unit, a liquid injection and exhaust unit and a base support unit;

[0007] The square battery unit comprises a square battery, a positive electrode connecting piece connected to the positive electrode column of the square battery, a negative electrode connecting piece connected to the negative electrode column of the square battery, and a liquid injection hole; the positive electrode connecting piece and the negative electrode connecting piece directly or indirectly serve as the battery charging and discharging output or input terminal;

[0008] The liquid injection and exhaust passage comprises a liquid storage pipe, and an exhaust ball valve and a liquid injection pipe respectively connected to the upper and lower ends of the liquid storage pipe; a sealing rubber plug matching the liquid injection hole is arranged at the lower end of the liquid injection pipe;

[0009] The base bracket unit includes a bottom plate, a slot arranged on the bottom plate for holding the square battery, and a column; a support plate and a limit plate are arranged on the column; an oil-free bushing is arranged on the support plate to match and connect with the liquid storage tube; a copper sleeve is arranged on the limit plate to match and connect with the liquid injection tube.

[0010] The injection tube is sleeved with a spring body, the spring body and the injection tube are coaxial, and the spring body is used to clamp the sealing rubber plug and the injection hole.

[0011] The upper end of the liquid storage tube is connected to the exhaust ball valve through an adapter.

[0012] The liquid storage tube is connected to the liquid level display tube via a flexible joint.

[0013] The liquid storage pipe is provided with a liquid discharge valve.

[0014] The present invention also includes an application of the square battery liquid injection and exhaust device, which is used to study the relationship between the liquid injection volume and the battery cycle life and to analyze the gas composition and content of gas generated at different stages.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a square battery liquid filling and exhaust device, which has a scientific structural design. By combining liquid filling, exhaust pre-formation and formation, the electrolyte inside the high energy density battery cell can be kept full, and the generated gas can be discharged through this device, thereby reducing and eliminating lithium precipitation inside the battery cell, which has great practical significance for improving the service life of the battery cell.

[0017] In addition, the square battery liquid injection and exhaust device provided by the present invention can also be used to explore the relationship between the injection volume and the battery cycle life during the experimental exploration stage, thereby providing guidance and practice for the theoretical calculation of the battery cell injection volume. The gas composition and content of the gas produced at different stages can be analyzed by an external gas chromatography-mass spectrometer (GS-MS), which has great practical significance for many aspects such as square battery design and analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of the device involved in this patent.

[0019] Figure 2 This is a schematic diagram of the appearance of the square battery of the device involved in this patent.

[0020] Figure 3 This is the liquid injection and exhaust channel structure and its cross-sectional view of the device involved in this patent.

[0021] Figure 4 This is a schematic diagram of the base plate support structure of the device involved in this patent.

[0022] Figure 5 This is a schematic diagram of the adapter structure of the device involved in this patent.

[0023] In the figure, 1, square battery unit; 2, liquid filling and exhaust unit; 3, base bracket unit; 1-1, square battery; 1-2, positive electrode connecting piece; 1-3, liquid filling hole; 1-4, negative electrode connecting piece; 2-1, sealing rubber plug; 2-2, spring; 2-3, liquid filling pipe; 2-4, liquid discharge ball valve; 2-5, liquid level display tube; 2-6, hose connector; 2-7, liquid storage pipe; 2-8, adapter; 2-9, exhaust ball valve; 2-10, gas filter element; 3-1, bottom plate; 3-2, reinforcing rib; 3-3, column; 3-4, support plate; 3-5, oil-free bushing; 3-6, copper sliding sleeve; 3-7, limit plate; 3-8, slot. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the best embodiment.

[0025] Figure 1-5 A square battery liquid injection and exhaust device is shown, comprising a square battery unit 1, a liquid injection and exhaust unit 2 and a base support unit 3; the square battery unit comprises a square battery 1-1, a positive electrode connecting piece 1-2 connected to the positive electrode column of the square battery, a negative electrode connecting piece 1-4 connected to the negative electrode column of the square battery, and a liquid injection hole 1-3; the positive electrode connecting piece and the negative electrode connecting piece directly or indirectly serve as the battery charge and discharge output or input terminal;

[0026] The liquid injection and exhaust passage includes a liquid storage tube 2-7, and an exhaust ball valve 2-9 and a liquid injection tube 2-1 respectively connected to the upper and lower ends of the liquid storage tube; a sealing rubber plug 2-1 matching the liquid injection hole is provided at the lower end of the liquid injection tube; a spring body 2-2 is sleeved on the liquid injection tube; the spring body is coaxial with the liquid injection tube. The spring body is used to clamp the sealing rubber plug with the liquid injection hole. The upper end of the liquid storage tube is connected to the exhaust ball valve 2-9 through an adapter 2-8. The liquid storage tube 2-7 is connected to the liquid level display tube 2-5 through a flexible joint 2-6. A drain valve 2-4 is provided on the liquid storage tube.

[0027] Specifically, the liquid storage tube 2-7 is a cylindrical stainless steel tube with a stepped through hole inside, and a plurality of threaded holes of different sizes are opened at both ends and the tube body, which are connected with different connectors through the threaded holes. In this embodiment, the upper end of the liquid storage tube is connected with the adapter 2-8 through a thread, and the lower end is connected with the injection tube through a thread. The discharge ball valve is fixed on the liquid storage tube through a threaded connection and is perpendicular to the liquid storage tube; one end of the hose connector is fixed on the liquid storage tube through an external thread, and the other end is connected with the liquid level display tube through an interference fit. The liquid level display tube is a white transparent polypropylene hose, which is used to observe the electrolyte level in real time; the liquid storage tube passes through an oil-free bushing and forms an axial hole fit with the oil-free bushing;

[0028] The injection tube 2-3 is a cylindrical stainless steel tube with a stepped through hole inside. One end of the tube passes through the copper sleeve to form an axial hole with the copper sleeve, and then is fixed to the liquid storage tube through a threaded connection; the spring is sleeved on the injection tube, coaxial with the injection tube, and is in a compressed state between the injection tube and the copper sleeve; the sealing rubber plug is made of fluororubber, has a through hole, is installed at the front end of the injection tube with an interference fit, and is subjected to the spring force to fit the injection hole of the square battery, with good sealing performance; the adapter has a stepped through hole inside, one end with an external thread is connected and fixed to the liquid storage tube, and the other end with an internal thread is connected and fixed to the exhaust ball valve; the gas filter element 2-10 is placed in the stepped through hole inside the adapter; the exhaust ball valve is fixed to the adapter through a threaded connection, and a quick-plug connector is left at one end for quick connection to the vacuum air pipe.

[0029] The base bracket unit includes a bottom plate 3-1, a slot 3-8 arranged on the bottom plate for holding the square battery, and a column 3-3 fixed on the bottom plate; a support plate 3-4 and a limit plate 3-7 are arranged on the column 3-3; an oil-free bushing 3-5 is arranged on the support plate to match and connect with the liquid storage tube; a copper sleeve 3-6 is arranged on the limit plate 3-7 to match and connect with the injection tube.

[0030] Specifically, the base plate 3-1 is square and placed horizontally, and the column 3-3 is fixed to the base plate by bolts; the reinforcing rib 3-2 is respectively connected and fixed to the base plate and the column by bolts to enhance the stability of the entire device; the support plate is fixed to the column by bolts and is perpendicular to the column. A circular through hole is opened on the support plate, and the oil-free bushing 3-6 passes through the circular through hole of the support plate and is installed on the support plate by interference fit; the limit plate is an L-shaped structure, which is fixed to the column by bolts and is perpendicular to the column. The bolt countersunk hole of the limit plate is groove-shaped, which can conveniently adjust the height of the limit plate; a threaded hole is opened on the limit plate, and the copper sleeve is connected and fixed to the limit plate by threaded connection; the slot is fixed to the base plate by bolts to position and fix the square battery.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of a square battery liquid filling and exhaust device, It is characterized in that It is used to study the relationship between injection volume and battery cycle life and to analyze the gas composition and content of gas produced at different stages; The square battery liquid filling and exhaust device comprises a square battery unit, a liquid filling and exhaust unit and a base support unit; The square battery unit comprises a square battery, a positive electrode connecting piece connected to the positive electrode column of the square battery, a negative electrode connecting piece connected to the negative electrode column of the square battery, and a liquid injection hole; the positive electrode connecting piece and the negative electrode connecting piece directly or indirectly serve as the battery charging and discharging output or input terminal; The liquid injection and exhaust unit comprises a liquid storage tube, and an exhaust ball valve and a liquid injection tube respectively connected to the upper and lower ends of the liquid storage tube; the liquid level display tube is a white transparent polypropylene hose, which is used to observe the electrolyte level in real time; a sealing rubber plug matching the liquid injection hole is arranged at the lower end of the liquid injection tube; the liquid injection tube is a cylindrical stainless steel tube, with a stepped through hole opened inside, one end of which passes through a copper sleeve to form an axial hole with the copper sleeve, and then is fixed to the liquid storage tube by a threaded connection; the spring is sleeved on the liquid injection tube, coaxial with the liquid injection tube, and is in a compressed state between the liquid injection tube and the copper sleeve; the sealing rubber plug is made of fluororubber, has a through hole opened, is installed at the front end of the liquid injection tube by interference fit, and is attached to the liquid injection hole of the square battery under the action of the spring elastic force; The base bracket unit includes a bottom plate, a slot arranged on the bottom plate for holding the square battery, and a column; a support plate and a limit plate are arranged on the column; an oil-free bushing is arranged on the support plate to match and connect with the liquid storage tube; a copper sleeve is arranged on the limit plate to match and connect with the liquid injection tube.

2. Application of the square battery liquid filling and exhaust device according to claim 1, It is characterized in that The upper end of the liquid storage tube is connected to the exhaust ball valve through an adapter.

3. Application of the square battery liquid filling and exhaust device according to claim 1, It is characterized in that The liquid storage tube is connected to the liquid level display tube via a flexible joint.

4. Application of the square battery liquid filling and exhaust device according to claim 1, It is characterized in that The liquid storage pipe is provided with a liquid discharge valve.

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