Lead-acid storage battery with ultra-long cycle life and preparation method thereof

Abstract

The invention relates to the field of storage batteries, and provides a lead-acid storage battery with an ultra-long cycle life and a preparation method thereof. A battery jar of the lead-acid storage battery is integrally sealed, a first valve hole is formed in an upper cover of the battery jar, and a second valve hole is formed in the lower surface of a base; openings in two ends of a hollow connecting piece are respectively communicated with the valve hole I and the valve hole II; gas generated by the battery jar circularly flows back to the battery jar through the connecting piece; the part, connected with the first valve hole, of the connecting piece is called a first connecting part, a third valve hole is formed in the first connecting part, the valve opening pressure of the third valve hole is 35-40 kPa, and the valve closing pressure of the third valve hole is 23-28 kPa; a fourth valve hole is formed in the upper surface of a base of the battery jar, a first rubber cap is arranged in the fourth valve hole, the valve opening pressure is 15-20 kPa, and the valve closing pressure is 8-10 kPa. The structure of the battery is improved, so that gas circularly moves in the battery, acid layering caused by sedimentation of high-density acid is reduced, and the lead-acid storage battery with long cycle life is obtained. The invention also provides a preparation method of the lead-acid storage battery.

Description

Technical Field

[0001] The invention relates to the field of storage batteries, and in particular to a lead-acid storage battery with an ultra-long cycle life and a preparation method thereof. Background Art

[0002] The battery life is generally between 2-3 years. How to extend the life of power batteries has become one of the key areas of technical competition among major power battery manufacturers. Thermal runaway and sulfation are important causes of lead-acid battery failure. Patent CN118073531A discloses a method for using trace nanostructured PbO@MWCNTs composite materials as negative electrode additives to improve the high-rate cycle life of lead-acid batteries under partial charge conditions. The PbO@MWCNTs composite material is obtained by pyrolyzing a lead citrate precursor at 450°C; carbon black, lignin and barium sulfate are mixed to form a preliminary mixture, lead powder is added to the preliminary mixture to form a raw material mixture, and then the composite material is dispersed in water and added to the above raw material dry mixture at one time to obtain a mixture, which is stirred evenly, and dilute sulfuric acid is added and mechanically stirred to obtain an acidic lead paste; the acidic lead paste is applied to the negative plate grid and cured to obtain a negative plate lead-acid battery under high-rate partial charge operation. The invented method effectively alleviates the sulfation of the negative plate, thereby improving the cycle life of the lead-acid battery; however, the preparation of the negative electrode additive is complicated and costly. Therefore, an ideal solution is needed. Summary of the invention

[0003] The invention provides a lead-acid storage battery with an ultra-long cycle life and a preparation method thereof, which improves the battery structure so that gas forms a cyclic motion inside the battery, reduces acid stratification caused by the precipitation of high-density acid, and obtains a lead-acid storage battery with a long cycle life.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A lead-acid storage battery with an ultra-long cycle life, wherein the battery slot is sealed as a whole, the upper cover of the battery slot is provided with a valve hole 1, and the lower surface of the base is provided with a valve hole 2; openings at both ends of a hollow connecting piece are respectively connected to the valve hole 1 and the valve hole 2, and the gas generated by the battery slot circulates back to the battery slot through the connecting piece; the part where the connecting piece is connected to the valve hole 1 is called the connecting part 1, and the connecting part 1 is provided with a valve hole 3, and the valve opening pressure of the valve hole 3 is 35-40kPa, and the valve closing pressure is 23-28kPa; the upper surface of the base of the battery slot is provided with a valve hole 4, and a rubber cap 1 is installed in the valve hole 4, and the valve opening pressure is 15-20kPa, and the valve closing pressure is 8-10kPa.

[0005] Preferably, the top of the rubber cap is 0.5-1 mm away from the upper surface of the battery slot base.

[0006] Preferably, the connector is mounted on the outer side of the battery container, and is C-shaped, with two ends bent and sealedly connected to the upper surface of the upper cover and the lower surface of the base of the battery container respectively.

[0007] Preferably, the battery compartment is divided into a plurality of cells, and each cell is provided with at least one valve hole 1, valve hole 2 and a connecting piece.

[0008] Preferably, the valve opening pressure of valve hole three is 40 kPa and the valve closing pressure is 25 kPa.

[0009] Preferably, the valve hole three is equipped with a rubber cap two to realize the opening and closing of the valve.

[0010] Preferably, the battery tank is filled with an electrolyte, which does not contain colloidal substances, colloidal substances that do not contain colloidal additives and silica colloidal substances (or Dedong colloidal substances), because the present invention creates a circulating movement inside the battery, and not adding colloidal substances can reduce the impact of colloidal clogging of pipelines or adhesion of rubber caps caused by the gas circulating movement.

[0011] Preferably, the electrolyte includes concentrated sulfuric acid, pure water, and anhydrous sodium sulfate.

[0012] Preferably, a cover plate is provided at the top of the lead-acid battery, and the cover plate is located above the upper cover and the connector.

[0013] The present invention also provides a method for preparing the lead-acid battery, comprising the following steps: 1) Install the rubber cap 1 into the valve hole 4, put the electrode group into the battery slot, cover the upper cover and seal it, and assemble; 2) Align the openings at both ends of the connector with valve hole 1 and valve hole 2 respectively and install it on the battery slot, and seal the openings around the connector to be sealed and connected to the battery slot; 3) Add electrolyte into the battery tank through the valve hole three times, and then connect and form a qualified battery; 4) A pressure control structure is installed in valve hole 3 of the qualified battery.

[0014] Preferably, in step 1), the sealant is used in a curing kiln to seal the upper cover, and the temperature of the curing kiln is 50-55°C.

[0015] Preferably, the assembly of step 1) includes terminal welding and dispensing of colored glue, and the temperature of the colored glue after passing through a curing kiln is 48-53°C.

[0016] Preferably, in step 3), the electrolyte is added by a vacuum negative pressure method, and the interior of the battery is evacuated to a negative pressure value of 0.08-0.095 MPa.

[0017] Preferably, step 3) wiring formation is carried out in a cooling water tank.

[0018] Preferably, the structure for controlling the pressure in step 4) is rubber cap 2.

[0019] Preferably, after step 4), the residual dirt on the surface of the battery is removed, and then a cover sheet is firmly combined with the upper cover of the battery container to obtain a lead-acid storage battery.

[0020] Therefore, the beneficial effects of the present invention are: improving the battery structure so that the gas forms a circulating motion inside the battery, reducing the acid stratification caused by the sedimentation of high-density acid, the battery cycle life is longer than that of existing conventional batteries, the battery water loss during the cycle use process is less than that of existing batteries, and the acid density consistency at different positions of the partition is better after 250 cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an exploded diagram of a lead-acid battery.

[0022] Figure 2 This is the assembly diagram of the battery slot and connectors.

[0023] Figure 3 This is a structural diagram of the battery compartment without the cover.

[0024] Figure 4 This is a structural diagram of the bottom of the battery compartment.

[0025] Figure 5 It is a structural diagram of the battery slot base.

[0026] Figure 6 This is a structural diagram of the battery compartment cover.

[0027] Figure 7 It is an inverted diagram of the connector.

[0028] In the figure: 1. battery slot, 2. base, 21. valve hole four, 22. valve hole two, 23. rubber cap one, 3. upper cover, 31. valve hole one, 4. connecting piece, 41. vertical part, 42. bending part one, 421. opening one, 422. valve hole three, 43. bending part two, 431. opening two, 44. rubber cap two, 5. cover plate, 6. pole group. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below through specific embodiments.

[0030] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the embodiments, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, parts are all weight parts, temperatures are expressed in ° C or at ambient temperature, and pressures are atmospheric pressure or near atmospheric pressure. There are many variations and combinations of reaction conditions (such as component concentrations, desired solvents, solvent mixtures, temperatures, pressures, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method, and only reasonable routine experiments will be required to optimize such method conditions.

[0031] Example A lead-acid battery is a storage battery whose electrodes are mainly made of lead and its oxides, and whose electrolyte is a sulfuric acid solution. When the lead-acid battery is in the discharged state, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead; in the charged state, the main components of the positive and negative electrodes are both lead sulfate. Thermal runaway and sulfation are important causes of lead-acid battery failure. Sulfation is a chemical change that causes the lead sulfate grains on the two poles of the lead-acid battery to become coarse and hard due to the change in the solubility of lead sulfate in sulfuric acid media of different temperatures and concentrations. It is difficult for coarse-grained lead sulfate to be converted into the positive electrode active material lead dioxide and the negative electrode active material sponge-like metallic lead through the dissolution-deposition process during charging, which reduces the capacity of the battery or even damages it. The present invention makes structural improvements to obtain a lead-acid battery with an ultra-long cycle life. 1. A lead-acid battery with ultra-long cycle life The lead-acid battery includes a battery container 1, a connector 4 and a cover plate 5. The battery container 1 is sealed as a whole, and the upper cover 3 of the battery container 1 is provided with a valve hole 1 31, and the lower surface of the base 2 is provided with a valve hole 22; the openings at both ends of a hollow connector 4 are respectively connected to the valve hole 1 31 and the valve hole 22, and the gas generated by the battery container 1 circulates back to the battery container 1 through the connector 4; the part where the connector 4 is connected to the valve hole 1 31 is called the connecting part 1, and the connecting part 1 is provided with a valve hole 3 422, and the valve opening pressure of the valve hole 3 422 is 35-40kPa and the valve closing pressure is 23-28kPa; the upper surface of the base 2 of the battery container 1 is provided with a valve hole 4 21, and the valve hole 4 21 is equipped with a rubber cap 1 23, and the valve opening pressure is 15-20kPa and the valve closing pressure is 8-10kPa. The cover plate 5 is located above the upper cover 3 and the connector 4, that is, located at the top of the lead-acid battery. The specific structure is described as follows: The battery container 1 is enclosed by a side wall and a base 2, and the interior is evenly divided into a plurality of single cells by a plurality of vertical partitions, and the top of the opening is sealed by a top cover. The battery container 1 is filled with an electrolyte, and the electrolyte does not contain a colloid substance. The colloid substance includes a colloid additive and a silica colloid (or a Dedong colloid), etc. Because the present invention creates a circulating motion inside the battery, not adding a colloid substance can reduce the effect of colloid blocking the pipeline or sticking to the rubber cap caused by the gas circulating motion. Preferably, the electrolyte includes concentrated sulfuric acid, pure water, and anhydrous sodium sulfate.

[0032] The base 2 of the battery container 1 is a flat plate with a certain thickness and a hollow interior. The upper surface of the base 2 is located inside the battery container 1, and a valve hole 21 is provided on the upper surface. The valve hole 21 is sealed with a rubber cap 23. After sealing, the top of the rubber cap 23 is 0.5-1mm away from the upper surface of the bottom of the battery container 1. The valve opening pressure is 15-20kPa and the valve closing pressure is 8-10kPa. When the gas pressure generated by the single cell inside the battery reaches the preset pressure, the rubber cap 23 is lifted up, and the gas enters the single cell inside the battery through the bottom of the battery container 11. When the gas pressure generated by the single cell inside the battery is less than the preset pressure, the rubber cap 23 falls to seal the valve hole, and the gas is prohibited from entering the single cell inside the battery. The lower surface of the base 2 is located outside the battery container 1, and a valve hole 22 is provided on the lower surface to facilitate communication with the outside world.

[0033] The upper cover 3 of the battery container 1 is used to cover and seal the upper surface of the battery container 1. The upper cover 3 is provided with a valve hole 31 which runs longitudinally through the upper cover 3 for adding acid and facilitating the connection of the connector 4. The gas generated during the use of the battery overflows from the valve hole 31.

[0034] The connector 4 is composed of a vertical portion 41 in the middle and bent portions at both ends. The entire interior is hollow and gas can flow. The connector 4 is installed on the outer side of the battery container 1. The lower surface of the bent portion at the upper end of the connector 4 is sealed with the upper surface of the upper cover 3, and the lower surface is provided with an opening 421 that is connected to the valve hole 1 31. The upper surface of the bent portion at the upper end of the connector 4 is also provided with a valve hole 3 422, which is sealed by a rubber cap 3. The upper surface of the bent portion at the lower end of the connector 4 is sealed with the lower surface of the base 2 of the battery container 1, and the upper surface is provided with an opening 431 that is connected to the valve hole 2 22.

[0035] 2. A method for preparing a lead-acid battery with ultra-long cycle life The lead-acid battery is obtained by assembling, adding electrolyte and the like. The steps include: (1) Sealing inside the battery compartment 1: Select a rubber cap 23 that matches the size of the valve hole 21. The opening pressure of the rubber cap 23 is 15-20 kPa and the closing pressure is 8-10 kPa. Use tweezers to reach deep into the battery compartment 1, pinch the rubber cap so that its opening faces downward and covers the valve hole 21. After sealing, the top of the rubber cap should be 0.5-1 mm away from the upper surface of the bottom of the battery compartment 1 (the bottom of the electrode group 6) to prevent the electrode group 6 from pressing on the rubber cap to prevent the gas from lifting the rubber cap and affecting the gas from entering the single cell from the bottom.

[0036] (2) Sealing of battery slot 1: Subsequent assembly operations such as inserting the pole group 6 into the slot, sealing the upper cover 3, welding the terminals and applying colored glue can be completed using the current mature process. The difference from the existing assembly process is that the battery is equipped with a rubber cap. In order to avoid long-term high temperature and accelerated aging of the rubber cap, the temperature of the curing kiln for the sealant of the upper cover 3 is set at 50-55°C (65°C in the current production process), and the temperature of the curing kiln for the colored glue is set at 48-53°C (60°C in the current production process).

[0037] (3) Installation of the connector 4: The connector 4 is installed on the side of the battery container 1 to obtain a dry battery. The upper and lower openings of the connector 4 correspond to the valve hole 1 31 and the valve hole 2 22 respectively, and the periphery of the upper and lower openings is sealed with the battery container 1 so that gas can only enter the connector 4 to avoid leakage during use.

[0038] (4) Acid addition: Add electrolyte of density and amount required by the process to the dry cell obtained in step (3), the electrolyte includes concentrated sulfuric acid, pure water, anhydrous sodium sulfate and other ingredients. Different from the current production process, the added electrolyte does not contain colloidal additives and colloidal substances such as silica colloidal (or Dedong colloidal). Because the present invention creates a circulating motion inside the battery, not adding colloidal substances can reduce the impact of colloidal clogging of pipelines or adhesion of rubber caps caused by the gas circulation process. The installation of the acid pot of the dry cell is different from the current process in that the acid pot is installed on the valve hole three 422 on the upper part of the connector 4, rather than the traditional installation on the valve hole one 31 of the upper cover 3 of the battery container 1; the acid addition adopts vacuum negative pressure (negative pressure value 0.08-0.095MPa) to vacuum the inside of the battery and add acid to accelerate the diffusion of the electrolyte in the partition.

[0039] (5) Formation: After the acid is added, the battery enters the cooling water tank as quickly as possible for wiring and formation. Through the gas communication between the battery interior and the connector 4, part of the generated gas is discharged from the acid pot to the outside through the valve hole 1 31, and the other part passes through the connector 4 and then re-enters the battery through the valve hole 2 22 at the bottom of the battery, stirring the internal acid, reducing the acid stratification caused by the precipitation of high-density acid, improving the reaction effect, increasing the gas cathode absorption reaction at the negative electrode, and reducing the battery water loss caused by gas loss. The purpose of reducing the cost can be achieved by reducing the amount of acid added to reduce the battery formation charge amount.

[0040] (6) After the formation, the qualified battery is covered with a rubber cap 2 44 of a specified size on the valve hole 3 422 to prevent the plate from being oxidized by long-term exposure to the air. After cleaning to remove the residual acid on the surface of the battery, the battery cover 3 is firmly bonded to the battery cover 3 using ultrasound or chloroform, and a lead-acid battery with an ultra-long cycle life of the corresponding model is obtained. Ultrasonic capping is a commonly used automated equipment, and chloroform, scientifically known as trichloromethane, is often used to manually stick the capping.

[0041] Example 1 A lead-acid battery with an ultra-long cycle life, the structure of which is as follows Figure 1 and 2 As shown, it is assembled from a battery slot 1, a connector 4 and a cover sheet 5. The top of the battery slot 1 is sealed by an upper cover 3, and the connector 4 is installed on the same side of the battery slot 1, and the two ends of the connector 4 are bent to respectively abut against the upper surface of the upper cover 3 and the lower surface of the battery slot 1. The specific structure is described as follows: like Figure 3 As shown, the battery container 1 is surrounded by side walls and a base 2 to form a rectangular parallelepiped with an open top, and the interior of the battery container 1 is evenly divided into six cells by vertical partitions. An upper cover 3 is provided above the battery container 1.

[0042] The base 2 of the battery container 1 is a flat plate with a certain thickness and a hollow interior. Figure 4 As shown, the upper surface of the base 2 is located inside the battery slot 1, and a valve hole 21 is provided thereon. The valve hole 21 is sealed with a rubber cap 23, and the valve opening pressure of the rubber cap 23 is kPa and the valve closing pressure is kPa. A valve hole 21 is provided corresponding to the position of each cell, that is, a total of six valve holes 21 are provided, and the position of the valve hole 21 is approximately located at the center of the bottom surface of the cell. Figure 5 As shown, the lower surface of the base 2 is located outside the battery container 1, and is provided with six valve holes 22 for easy communication with the outside world. The six valve holes 22 correspond to the six valve holes 4 21 one by one and are coaxially arranged.

[0043] The top of the battery container 1 is open, and the upper cover 3 is used to cover the upper surface of the battery container 1 for sealing. Figure 6 As shown, the upper cover 3 is provided with a valve hole 31 which runs longitudinally through the upper cover 3 for acid addition and facilitating the connection of the connector 4. The gas generated during the use of the battery escapes from the valve hole 31. A valve hole 31 is provided corresponding to the position of each cell, that is, a total of six valve holes 31 are provided, and the position of the valve hole 31 is approximately located at the center of the upper surface of the cell.

[0044] like Figure 7As shown, the connector 4 is composed of a vertical portion 41 in the middle and bent portions at both ends. The angle between the vertical portion 41 and the bent portion is 90°, and the two bent portions are in the same direction. The connector 4 is C-shaped. The entire interior of the bent portion is hollow, and gas can flow. A connector 4 is provided at the position corresponding to each cell, that is, a total of six connectors 4 are installed, and the position of the vertical portion 41 of the connector 4 is located on the longitudinal center line of the side of the cell.

[0045] The bending part at the upper end of the connector 4 is called bending part 1 42, and the bending part at the lower end is called bending part 2 43. When installing the connector 4, the lower surface of the bending part 1 42 is sealed and fitted with the upper surface of the upper cover 3, the lower surface of the bending part 1 42 is provided with an opening 1 421 which is connected to the valve hole 1 31, and the upper surface of the bending part 1 42 is also provided with a valve hole 3 422 which is sealed by a rubber cap, and the valve hole 3 422 is coaxial with the opening on the lower surface of the bending part 1 42; the upper surface of the bending part 2 43 is sealed and fitted with the lower surface of the base 2 of the battery container 1, and the upper surface of the bending part 1 42 is provided with an opening 2 431 which is connected to the valve hole 22. The valve hole three 422 is equipped with a rubber cap two 44, the opening pressure of the rubber cap two 44 is 40kPa, and the closing pressure is 25kPa (the opening pressure of the rubber cap corresponding to the conventional plastic shell structure is 30kPa), which increases the recycling of the gas generated during the use of the battery, reduces the water loss of the battery, and avoids swelling caused by excessive gas pressure of the battery.

[0046] In order to facilitate the installation of the connector 4, grooves are provided on the battery slot 1 and the upper cover 3, and the number and position of the grooves depend on the number and installation position of the connector 4. The sides of the battery slot 1 and the upper cover 3 are respectively provided with a longitudinal groove 1 and a longitudinal groove 2, which match and penetrate to form a complete longitudinal groove for the installation of the vertical part 41 of the connector 4. The upper surface of the upper cover 3 is provided with a horizontal groove 1 for the installation of the bending part 1 42 of the connector 4; the lower surface of the base 2 is provided with a horizontal groove 2 for the installation of the bending part 2 43 of the connector 4. The longitudinal groove runs through the entire side, that is, the length of the longitudinal groove is consistent with the height of the side and the length of the vertical part 41 of the connector 4. The two ends of the horizontal groove 1 are exactly the top of the longitudinal groove and the valve hole 1 31, and the two ends of the horizontal groove 2 are exactly the bottom of the longitudinal groove and the valve hole 2 22.

[0047] The preparation method of the lead-acid battery of the above structure comprises the following steps: (1) Sealing inside the battery compartment 1: Select a rubber cap 23 that matches the size of the valve hole 21. The opening pressure of the rubber cap 23 is 15 kPa and the closing pressure is 8 kPa. Use tweezers to reach deep into the battery compartment 1, pinch the rubber cap so that its opening faces downward and covers the valve hole 21. After sealing, the top of the rubber cap is 0.8 mm away from the upper surface of the bottom of the battery compartment 1 (the bottom of the pole group 6) to prevent the pole group 6 from pressing on the rubber cap to prevent the gas from lifting the rubber cap and affecting the gas from entering the single cell from the bottom.

[0048] (2) Sealing of battery slot 1: Subsequent assembly operations such as inserting the pole group 6 into the slot, sealing the upper cover 3, welding the terminals and applying colored glue can be completed using the current mature process. The difference from the existing assembly process is that the battery is equipped with a rubber cap. In order to avoid long-term high temperature and accelerated aging of the rubber cap, the temperature of the curing kiln for the sealant of the upper cover 3 is set at 55°C (65°C in the current production process), and the temperature of the curing kiln for the colored glue is set at 53°C (60°C in the current production process).

[0049] (3) Installation of the connector 4: The connector 4 is installed on the side of the battery container 1 to obtain a dry battery. The upper and lower openings of the connector 4 correspond to the valve hole 1 31 and the valve hole 2 22 respectively, and the periphery of the upper and lower openings is sealed with the battery container 1 so that gas can only enter the connector 4 to avoid leakage during use.

[0050] (4) Acid addition: an electrolyte consisting of concentrated sulfuric acid, pure water and anhydrous sodium sulfate is added to the dry cell obtained in step (3) (any electrolyte not containing colloid in the prior art is feasible). The installation of the acid pot of the dry cell is different from the existing process in that the acid pot is installed on the valve hole 3 422 on the upper part of the connector 4, rather than the conventional installation on the valve hole 1 31 on the upper cover 3 of the battery container 1; the acid is added by vacuum negative pressure (negative pressure value 0.08-0.095MPa) to evacuate the interior of the battery and add acid, thereby accelerating the diffusion of the electrolyte in the partition.

[0051] (5) Formation: After the acid is added, the battery enters the cooling water tank as quickly as possible for wiring and formation. Through the gas communication between the battery interior and the connector 4, part of the generated gas is discharged from the acid pot to the outside through the valve hole 1 31, and the other part passes through the connector 4 and then re-enters the battery through the valve hole 2 22 at the bottom of the battery, stirring the internal acid, reducing the acid stratification caused by the precipitation of high-density acid, improving the reaction effect, increasing the gas cathode absorption reaction at the negative electrode, and reducing the battery water loss caused by gas loss. The purpose of reducing the cost can be achieved by reducing the amount of acid added to reduce the battery formation charge amount.

[0052] (6) After the formation, the qualified battery is covered with a rubber cap 2 44 of a specified size on the valve hole 3 422 to prevent the plate from being exposed to the air for a long time and being oxidized. The opening pressure of the rubber cap 2 44 is 40 kPa and the closing pressure is 25 kPa. After cleaning to remove the residual acid on the surface of the battery, the battery cover 3 is firmly combined with the battery cover 3 by ultrasonic wave, and a lead-acid battery with a super long cycle life of the corresponding model is obtained.

[0053] Example 2 A method for preparing a lead-acid battery, comprising the following steps: (1) Sealing inside the battery compartment 1: Select a rubber cap 23 that matches the size of the valve hole 21. The opening pressure of the rubber cap 23 is 20 kPa and the closing pressure is 10 kPa. Use tweezers to reach deep into the battery compartment 1, pinch the rubber cap so that its opening faces downward and covers the valve hole 21. After sealing, the top of the rubber cap is 1 mm away from the upper surface of the bottom of the battery compartment 1 (the bottom of the pole group 6) to prevent the pole group 6 from pressing on the rubber cap to prevent the gas from lifting the rubber cap and affecting the gas from entering the single cell from the bottom.

[0054] (2) Sealing of battery slot 1: Subsequent assembly operations such as inserting the pole group 6 into the slot, sealing the upper cover 3, welding the terminals and applying colored glue can be completed using the current mature process. The difference from the existing assembly process is that the battery is equipped with a rubber cap. In order to avoid long-term high temperature and accelerated aging of the rubber cap, the temperature of the curing kiln for the sealant of the upper cover 3 is set at 50°C (65°C in the current production process), and the temperature of the curing kiln for the colored glue is set at 48°C (60°C in the current production process).

[0055] (3) Installation of the connector 4: The connector 4 is installed on the side of the battery container 1 to obtain a dry battery. The upper and lower openings of the connector 4 correspond to the valve hole 1 31 and the valve hole 2 22 respectively, and the periphery of the upper and lower openings is sealed with the battery container 1 so that gas can only enter the connector 4 to avoid leakage during use.

[0056] (4) Acid addition: an electrolyte consisting of concentrated sulfuric acid, pure water and anhydrous sodium sulfate is added to the dry cell obtained in step (3). The acid pot of the dry cell is installed differently from the existing process in that the acid pot is installed on the valve hole 3 422 on the upper part of the connector 4, rather than the conventional installation on the valve hole 1 31 on the upper cover 3 of the battery container 1; the acid addition adopts vacuum negative pressure (negative pressure value 0.08-0.095MPa) to evacuate the interior of the battery to add acid, thereby accelerating the diffusion of the electrolyte in the partition.

[0057] (5) Formation: After the acid is added, the battery enters the cooling water tank as quickly as possible for wiring and formation. Through the gas communication between the battery interior and the connector 4, part of the generated gas is discharged from the acid pot to the outside through the valve hole 1 31, and the other part passes through the connector 4 and then re-enters the battery through the valve hole 2 22 at the bottom of the battery, stirring the internal acid, reducing the acid stratification caused by the precipitation of high-density acid, improving the reaction effect, increasing the gas cathode absorption reaction at the negative electrode, and reducing the battery water loss caused by gas loss. The purpose of reducing the cost can be achieved by reducing the amount of acid added to reduce the battery formation charge amount.

[0058] (6) After the formation of qualified batteries, the valve hole 3 422 is covered with a rubber cap 2 44 of a specified size to prevent the plate from being oxidized by long-term exposure to the air. The opening pressure of the rubber cap 2 44 is 35 kPa and the closing pressure is 23 kPa. After cleaning to remove the residual acid on the surface of the battery, the battery cover 3 is firmly combined with the battery cover 3 by ultrasonic wave, and a lead-acid battery of the corresponding model with an ultra-long cycle life is obtained. The battery structure is as follows Figure 1 and Figure 2 shown.

[0059] Performance Testing 1. Battery deformation test The battery structure of Example 1 was tested for deformation under different air pressures. The battery structure of Example 1 is similar to the 6-DZF-20 battery, which is a 1*6 structure with 6 cells arranged in parallel. The bulging of the plastic shell occurs in the side cells. Test method: Use epoxy resin glue to seal the battery slot and the middle cover of the hole. One end of the plastic tube is connected to the air pump, and the other end is installed with a two-way interface. One side is connected to the valve hole of the middle cover, and the other side is connected to the pressure gauge. An adjusting valve is provided between the air pump and the two-way interface. Before the test starts, the maximum length of the plastic shell is measured with a vernier caliper and recorded. Then, the air pump is turned on, and the pressure gauge is read by adjusting the valve to obtain the required test pressure, and maintained for 5-15 seconds. The maximum length of the plastic shell is measured with a vernier caliper. The difference between this length and the length of the plastic shell measured before the start is the deformation of the plastic shell. Since the battery is mostly used at room temperature, the experiment is carried out at room temperature. The test results are shown in Table 1.

[0060] Table 1. Comparison of plastic shell deformation under different air pressures Air pressure 5kPa 10kPa 15kPa 20kPa 25kPa 30kPa Shell deformation 0.09 0.19 0.31 0.46 0.72 0.87 Air pressure 35kPa 40kPa 45kPa 50kPa 55kPa 60kPa Shell deformation 1.10 1.30 1.52 1.69 1.92 2.11 After verifying the deformation of the plastic shell under different air pressures, the verification results are shown in Table 1. When the expansion deformation of the plastic shell exceeds 1.3mm under air pressure > 40kPa, and then the pressure is released to return to zero, the deformation of the plastic shell will decrease, but it cannot be restored. All valve holes three are used as pressure relief devices for the entire battery, so the maximum valve opening pressure of the rubber cap is 40kPa; and the rubber cap used for valve hole four is an important checkpoint for the internal gas circulation movement, and it is necessary to select a rubber cap with a smaller opening and closing valve pressure to enable the gas generated at the top to enter the bottom of the battery faster.

[0061] 2. Battery cycle life and water loss The test method is: GB T 22199.1-2017 Valve-regulated Lead-acid Battery for Electric Powered Vehicles Part 1: 5.12 Cycle Life Test in Technical Conditions. The battery is weighed before the test and after the test. The weight before the start minus the weight after the end is the water loss. The conventional comparison battery used is 6-DZF-20, where 6 refers to the number of cells in the battery, each cell is 2V, and 6 cells are 12V in total. DZF stands for valve-regulated (F) lead-acid battery for electric (D) power-assisted vehicles (Z), and 20 refers to the rated capacity of 20Ah.

[0062] After experimental verification, the cycle life of this patented battery is longer than that of existing conventional batteries, and the battery loses less water during cyclic use than that of existing batteries.

[0063] Cycle life: The test battery has a cycle life of 436 times, and the conventional comparison battery has a cycle life of 352 times, which is 84 cycles more and the cycle life is improved by 23.9%.

[0064] Water loss: The test battery lost 17.5g of water after 350 cycles, while the conventional comparison battery lost 52.5g after 350 cycles, a 67% reduction in water loss.

[0065] After 250 cycles of dissection, the acid density at different locations of the septum was more consistent, and the results are shown in Table 2.

[0066] Table 2. Acid density data of various parts of the partition sampled after battery failure The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A lead-acid battery with an ultra-long cycle life, characterized in that: The battery slot is sealed as a whole, the upper cover of the battery slot is provided with valve hole 1, and the lower surface of the base is provided with valve hole 2; the openings at both ends of a hollow connecting piece are respectively connected to valve hole 1 and valve hole 2, and the gas generated by the battery slot circulates back to the battery slot through the connecting piece; the part where the connecting piece is connected to valve hole 1 is called connecting part 1, and valve hole 3 is provided on connecting part 1, and the opening pressure of valve hole 3 is 35-40 kPa, and the closing pressure is 23-28 kPa; the upper surface of the base of the battery slot is provided with valve hole 4, and a rubber cap 1 is installed in valve hole 4, and the opening pressure of the valve is 15-20 kPa, and the closing pressure of the valve is 8-10kPa.

2. A lead-acid battery with an ultra-long cycle life according to claim 1, characterized in that: The top of the rubber cap is 0.5-1 mm away from the upper surface of the battery slot base.

3. A lead-acid battery with an ultra-long cycle life according to claim 1, characterized in that: The connecting piece is installed on the outer side of the battery slot. The connecting piece is C-shaped, and its two ends are bent and sealedly connected to the upper surface of the upper cover of the battery slot and the lower surface of the base.

4. A lead-acid battery with an ultra-long cycle life according to claim 1, 2 or 3, characterized in that: The battery tank is divided into a plurality of cells, and each cell is provided with at least one valve hole 1, one valve hole 2 and a connecting piece.

5. A lead-acid battery with an ultra-long cycle life according to claim 1, characterized in that: The battery compartment contains electrolyte, which does not contain colloidal substances.

6. The method for preparing a lead-acid battery with an ultra-long cycle life according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) Install the rubber cap 1 into the valve hole 4, put the electrode group into the battery slot, cover the upper cover and seal it, and assemble; 2) Align the openings at both ends of the connector with valve hole 1 and valve hole 2 respectively and install it on the battery slot, and seal the openings around the connector to be connected to the battery slot; 3) Add electrolyte into the battery tank through the valve hole, and then connect and form a qualified battery; 4) A pressure control structure is installed in valve hole 3 of the qualified battery.

7. The method for preparing a lead-acid battery with an ultra-long cycle life according to claim 6, characterized in that: Step 1) Use sealant to seal the upper cover through a curing kiln, and the temperature of the curing kiln is 50-55 ℃.

8. The method for preparing a lead-acid battery with an ultra-long cycle life according to claim 6 or 7, characterized in that: The assembly of step 1) includes terminal welding and dispensing of color glue, and the temperature of the color glue in the curing kiln is 48-53 ℃.

9. The method for preparing a lead-acid battery with an ultra-long cycle life according to claim 6, characterized in that: Step 3) Add electrolyte using vacuum negative pressure method, and evacuate the inside of the battery to a negative pressure value of 0.08-0.095 MPa.

10. The method for preparing a lead-acid battery with an ultra-long cycle life according to claim 6 or 9, characterized in that: After step 4), the residual dirt on the surface of the battery is removed, and then a cover sheet is firmly combined with the upper cover of the battery container to obtain a lead-acid storage battery.

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