Energy storage battery and production process thereof

Abstract

This invention discloses an energy storage battery and its manufacturing process, belonging to the field of solar energy storage battery technology. It includes: a main structure; the main structure includes a battery casing, the top of which is encapsulated with a cover plate, battery terminals installed on both sides inside the cover plate, and a positive electrode plate and a negative electrode plate respectively disposed within the inner cavity of the battery casing, with the positive and negative electrode plates alternately arranged. This invention redesigns the shape of the positive and negative electrode plates, using a three-dimensional wave structure to increase the contact area between the positive and negative electrode plates and the electrolyte, thereby improving the oxidation-reduction reaction rate. Subsequently, the grid alloy composition and positive electrode lead paste formulation are optimized, utilizing a lead-calcium-tin-aluminum system to suppress grid corrosion, improve conductivity, refine grains, reduce microcracks, enhance the alloy's creep resistance, and improve the battery's capacity recovery rate and cycle life after deep discharge, thus optimizing the battery's performance.

Description

Technical Field

[0001] This invention relates to the field of solar energy storage battery technology, specifically to an energy storage battery and its manufacturing process. Background Technology

[0002] Solar storage batteries are the application of "storage batteries" in solar photovoltaic power generation. Four types are used: lead-acid maintenance-free batteries, ordinary lead-acid batteries, gel batteries, and alkaline nickel-cadmium batteries. In China, the most widely used solar storage batteries are lead-acid maintenance-free batteries and gel batteries. These two types of batteries are well-suited for reliable solar power systems, especially unattended workstations, due to their inherent maintenance-free characteristics and low environmental pollution.

[0003] Solar energy storage batteries need to provide continuous power even in the absence of sunlight, such as powering streetlights. However, when the mains power supply is insufficient or there is continuous cloudy or rainy weather, the batteries are prone to prolonged deep discharge (depth of discharge > 80%), leading to the following problems:

[0004] Defects of traditional plate grid alloys:

[0005] In conventional lead-calcium alloys (such as Pb-Ca-Sn), the tin content is insufficient (usually <1wt%), which leads to irreversible sulfation of the grid after deep discharge, resulting in lattice structure destruction and decreased electron transport efficiency.

[0006] Positive electrode lead paste active material failure:

[0007] Traditional lead paste formulations lack anti-sulfurization components (such as antimony trioxide and stannous sulfate). The active material (PbO2) is difficult to reduce after being converted to PbSO4 at high discharge rates, resulting in a capacity recovery rate of less than 85%.

[0008] Process parameter limitations:

[0009] The existing paste temperature (<70℃) and curing conditions (short-term high-temperature stage) cannot fully activate the additives in the lead paste, resulting in low electrode porosity (<45%) and poor electrolyte permeability. Summary of the Invention

[0010] The purpose of this invention is to provide an energy storage battery and its manufacturing process. By redesigning the outer surface structure of the electrode plates and adopting a three-dimensional wavy surface, the contact area between the positive and negative electrode plates and the electrolyte is increased. At the same time, the grid alloy composition (lead-calcium-tin-aluminum system) and the positive electrode lead paste formula (containing antimony trioxide, stannous sulfate, etc.) are optimized. Combined with high temperature and multi-stage curing process of paste, the capacity recovery rate and cycle life of the battery after deep discharge are significantly improved, so as to solve the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: an energy storage battery, comprising:

[0012] Main structure;

[0013] The main structure includes a battery casing, the top of which is encapsulated with a cover plate. Battery terminals are installed on both sides inside the cover plate. A positive electrode plate and a negative electrode plate are respectively arranged in the inner cavity of the battery casing. The positive electrode plate and the negative electrode plate are arranged alternately. The positive electrode plate and the negative electrode plate are respectively connected to the battery terminals through connectors. The surface of the positive electrode plate is wavy. The negative electrode plate is parallel to the side of the positive electrode plate facing the positive electrode plate.

[0014] The main structure also includes an electrolyte filled into the inner cavity of the battery casing.

[0015] Preferably, the inner cavity of the battery casing has a limiting slot, and the outer sides of the positive and negative plates are fixed with limiting blocks, which are engaged in the limiting slot.

[0016] Based on an energy storage battery, a manufacturing process for the energy storage battery is also provided, comprising the following steps:

[0017] S1. Material Selection: Choose a suitable battery casing;

[0018] S2. Preparation of positive and negative electrode grids

[0019] (I) Fabrication of the positive electrode grid

[0020] The positive electrode grid uses a lead-calcium alloy, which includes the following raw materials: calcium, tin, aluminum and lead, and the mass percentage of each raw material is: calcium 0.075-0.09wt%, tin 1.25-2.25wt%, aluminum 0.02-0.06wt%, and the remainder is metallic lead. The positive electrode grid material is mixed, melted and processed into the grid shape.

[0021] (II) Fabrication of the negative electrode grid

[0022] Preparation of S3, positive and negative electrode lead paste

[0023] (I) Preparation of positive electrode lead paste

[0024] Material preparation

[0025] The raw materials include: antimony trioxide, potassium sulfate, stannous sulfate, colloidal graphite, acetic acid, formulated water, recycled powder, short fiber, and lead powder;

[0026] The mass percentages of various raw materials are as follows: antimony trioxide 0.1-0.3wt%, potassium sulfate 0.2-0.3wt%, stannous sulfate 0.3-0.5wt%, colloidal graphite 0.1-0.3wt%, synthetic acid 10-13wt%, formulated water 9-10wt%, recycled powder 3-5wt%, short fiber 0.08-0.1wt%, and the remainder is lead powder with an oxidation degree of 72-77%.

[0027] Preparation before applying ointment

[0028] The raw materials are screened, impurities removed, dried, and weighed, and then ground in sequence.

[0029] Processing of Ointments

[0030] Various raw materials are added sequentially into the paste mixing machine and stirred to form a paste-like mixture.

[0031] Processing of positive electrode plates

[0032] The prepared paste is applied to the grid, then cured at high temperature, followed by shaping of the positive electrode plate.

[0033] Process it;

[0034] (II) Preparation of negative electrode lead paste

[0035] S4. Install the processed positive and negative plates inside the battery casing, then inject electrolyte, and seal the top of the battery casing with the cover plate.

[0036] S5. Perform charging and discharging tests on the assembled energy storage battery.

[0037] Preferably, in step S2, the lead-calcium alloy is prepared by first weighing various raw materials according to their mass ratios, then adding the raw materials into a furnace and continuously processing the furnace to melt and mix the various raw materials. The liquid mixed metal is then filtered and the liquid metal solution is poured into a mold to form a metal sheet or grid structure. The metal sheet is then machined, or the grid structure is directly polished.

[0038] Preferably, in step S2, the furnace melting temperature is 450-480℃, argon gas is introduced for protection to form a liquid alloy solution, and then cooling intervention is performed during the casting process to maintain a cooling rate of 10-15℃ / min to obtain a uniform α-Pb solid solution structure.

[0039] Preferably, in step S3, the recycled powder is sieved through a 200-mesh screen, the short fibers are selected from polyester fibers with a length maintained at 0.5-1 mm, and the PbO content in the lead powder is ≥70%.

[0040] Preferably, during the processing of S3 and the paste, the addition of raw materials is divided into three stages:

[0041] (I) Dry Mixing Stage

[0042] Main solid raw materials: lead powder, antimony trioxide, potassium sulfate, stannous sulfate, recycled powder.

[0043] Add the solid raw materials to the paste mixer and mix thoroughly;

[0044] (II) Wet Mixing Stage

[0045] Add water first: Add 10%-13% of the total weight of the dry mixed raw materials with deionized water, stir for 10 minutes to ensure that the materials are initially moistened;

[0046] Add acid later: Slowly add acetic acid (H2SO4, density 1.25 g / cm³). 3 The dosage is 8%-10% of the dry mixed raw materials, and the acid addition time is controlled at 10-15 minutes;

[0047] Special additives: Colloidal graphite is added, usually at the same time as lead powder, and short fibers are added in the later stage of wet mixing;

[0048] (III) Final Mixing Stage

[0049] Add the remaining deionized water and acid to the paste mixer in sequence, and stir until the temperature of the lead paste drops below 45 degrees Celsius to ensure the reaction is stable.

[0050] Preferably, in the lead paste processing in S3, the highest temperature of the lead paste is 74-76℃, and the duration of the high temperature is controlled within 3-5 minutes.

[0051] Preferably, the S3 positive electrode plate lead paste is cured in three stages: the first stage is at 75°C for 9-10 hours, the second stage is at 60°C for 12 hours, and the third stage is at room temperature for 24 hours.

[0052] Preferably, a comparative example is added to the S5 charging and discharging test, comparing different formulation ratios of lead paste with the traditional formulation ratio.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] 1. This invention redesigns the shape of the positive and negative electrode plates, using a three-dimensional wave structure to increase the contact area between the positive and negative electrode plates and the electrolyte, thereby improving the redox reaction rate. Subsequently, the grid alloy composition and positive electrode lead paste formulation are optimized, utilizing a lead-calcium-tin-aluminum system to suppress grid corrosion, improve conductivity, refine grains, reduce microcracks, enhance the alloy's creep resistance, and improve the battery's capacity recovery rate and cycle life after deep discharge, thus optimizing the battery's performance.

[0055] 2. This invention improves the performance of the positive electrode plate and increases the battery capacity after full discharge by improving the composition, ratio and preparation process of the positive electrode plate. Attached Figure Description

[0056] Figure 1 This is a three-dimensional structural diagram of the main body structure of the energy storage battery of the present invention;

[0057] Figure 2 This is a three-dimensional structural diagram of the main body of the energy storage battery of the present invention.

[0058] Figure 3 This is a three-dimensional structural diagram of the positive and negative electrode plates of the present invention.

[0059] The following are labeled in the diagram: 1. Battery casing; 2. Cover plate; 3. Battery terminal; 4. Positive plate; 5. Negative plate; 6. Connector; 7. Limiting slot; 8. Limiting block. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] This invention provides, for example Figures 1-3 The energy storage battery shown includes:

[0062] Main structure;

[0063] The main structure includes a battery casing 1, a cover plate 2 encapsulated on the top of the battery casing 1, battery terminals 3 installed on both sides inside the cover plate 2, a positive electrode plate 4 and a negative electrode plate 5 respectively arranged in the inner cavity of the battery casing 1, the positive electrode plate 4 and the negative electrode plate 5 are arranged alternately, the positive electrode plate 4 and the negative electrode plate 5 are respectively connected to the battery terminals 3 through connectors 6, the surface of the positive electrode plate 4 is wavy, and the negative electrode plate 5 is parallel to the side of the positive electrode plate 4 facing each other.

[0064] The main structure also includes the electrolyte filled into the inner cavity of the battery casing 1;

[0065] Through three-dimensional wave-shaped electrode design:

[0066] After 200 cycles, the crack density decreased to <3 cracks / cm². 2 (Traditional structure > 15 lines / cm) 2 );

[0067] The utilization rate of active substances is increased by 12% (by increasing the reaction surface area).

[0068] The surfaces of the positive electrode plate 4 and the negative electrode plate 5 are wavy (wavelength 4-6mm, wave height 1.2-1.8mm). The stress distribution is optimized through finite element simulation. The peak of the wavy structure on the positive electrode plate 4 corresponds to the trough of the wavy structure on the negative electrode plate 5.

[0069] A gradient thinning zone is set at the edge of the electrode (the thickness gradually changes from 2.0 mm at the center to 1.2 mm at the edge) to alleviate expansion stress.

[0070] Simultaneously optimize the grid skeleton structure:

[0071] Central area, diamond grid (grid size 3x3mm) 2 Increase the strength of mechanical supports; compressive strength > 80 Pa.

[0072] In the edge region, radial ribs (rib width 0.8-1.2mm) suppress electrode deformation (electrode warpage after cycling <0.5mm / m);

[0073] The grid skeleton is made of lead alloy, and then a conductive polymer layer (20-50 μm thick) is coated on the surface of the lead alloy to reduce the cross-sectional resistivity (contact resistance < 0.1 mΩ·cm). 2 ).

[0074] Battery terminal 3 is a copper-aluminum composite terminal with a thermal conductivity greater than 350-350 W / m·K. It has a 2mm diameter micro heat pipe embedded inside and is filled with acetone to achieve rapid thermal equilibrium and keep the temperature difference within 2℃.

[0075] The table shows the technical effects and comparative data.

[0076] Performance indicators Structure of the present invention Traditional structure Cycle life (DOD100%) 620 times (capacity > 80%) 200 times (capacity < 70%) Plate crack density <![CDATA[2.8 lines / cm 2 > <![CDATA[16.3 lines / cm 2 > Temperature uniformity ΔT = 1.5℃ ΔT = 8.2℃ acid concentration gradient <![CDATA[0.08g / cm 3 ]]> <![CDATA[0.92g / cm 3 ]]>

[0077] like Figure 2 As shown,

[0078] A limiting slot 7 is provided in the inner cavity of the battery casing 1. A limiting block 8 is fixed on the outer side of the positive plate 4 and the negative plate 5. The limiting block 8 is engaged in the limiting slot 7. By providing a limiting slot 7 in the inner cavity of the battery casing 1, the positive plate 4 and the negative plate 5 are limited by the limiting block 8 to prevent them from contacting each other.

[0079] Based on an energy storage battery, a manufacturing process for the energy storage battery is also provided, comprising the following steps:

[0080] S1. Material Selection: Select a suitable battery casing 1;

[0081] S2. Preparation of positive and negative electrode grids

[0082] (I) Fabrication of the positive electrode grid

[0083] The positive electrode grid uses a lead-calcium alloy, which includes the following raw materials: calcium, tin, aluminum and lead, and the mass percentage of each raw material is: calcium 0.075-0.09wt%, tin 1.25-2.25wt%, aluminum 0.02-0.06wt%, and the remainder is metallic lead with a purity of ≥99.99%. The positive electrode grid material is mixed, melted and processed into the grid shape.

[0084] Calcium is preferably 0.08 wt% and is used to enhance the creep resistance of the alloy. The fine and uniformly distributed grain structure can increase the grain boundary area, hinder dislocation movement, and improve the creep resistance. At the same time, the presence of precipitated phases can also effectively hinder dislocation movement and enhance the creep resistance.

[0085] Tin is added at a rate of 1.8 wt%, which inhibits grid corrosion and improves conductivity, effectively enhancing the electrolyte's resistance to corrosion of lead-calcium alloy grids, thereby strengthening the plates.

[0086] Aluminum is added preferentially at 0.04 wt% to refine the grains, reduce the generation of microcracks, and improve the creep resistance of the alloy.

[0087] (II) Fabrication of the negative electrode grid

[0088] The negative electrode grid uses the same composition and structure as the traditional negative electrode grid.

[0089] After deep discharge, conventional lead-calcium alloy grids develop cracks at the grid-active material interface due to stress concentration and oxidation, further accelerating the shedding of active material (experiments show that the active material loss rate of conventional grids is >10% after 20 cycles). Adopting an improved positive electrode grid formulation and structure can effectively increase the reversible conversion rate of PbSO4 in the electrode (greater than 95%, compared to <70% for conventional grids).

[0090] Under DOD100% conditions, the improved battery has a cycle life of more than 500 cycles and a capacity retention rate of more than 80%, far exceeding the cycle life of traditional batteries which is less than 200 cycles.

[0091] Preparation of S3, positive and negative electrode lead paste

[0092] (I) Preparation of positive electrode lead paste

[0093] Material preparation

[0094] The raw materials include: antimony trioxide, potassium sulfate, stannous sulfate, colloidal graphite, acetic acid, formulated water, recycled powder, short fiber, and lead powder;

[0095] The mass percentages of various raw materials are as follows: antimony trioxide 0.1-0.3wt%, potassium sulfate 0.2-0.3wt%, stannous sulfate 0.3-0.5wt%, colloidal graphite 0.1-0.3wt%, synthetic acid 10-13wt%, formulated water 9-10wt%, recycled powder 3-5wt%, short fiber 0.08-0.1wt%, and the remainder is lead powder with an oxidation degree of 72-77%.

[0096] Antimony trioxide can inhibit the crystal growth of PbSO4; potassium sulfate improves the ionic conductivity of the electrolyte; stannous sulfate promotes the reduction reaction of PbO2; colloidal graphite helps to enhance the conductive network of the electrode plates; and acetic acid (H2SO4, density 1.25 g / cm³) 3 The system controls the acidity of the lead paste; it uses formulated water to adjust the fluidity of the lead paste, facilitating paste processing and maintaining the moisture content of the plates to prevent micro-cracks from forming due to reduced moisture content; it uses recycled powder as filler to reduce costs, and short fibers to improve the mechanical strength of the plates; it also eliminates the need for expensive additives (such as carbon nanotubes), reducing costs by 50% compared to lithium-ion battery solutions. The introduction and use of recycled powder reduces lead pollution, and the improved lead-acid battery production line is compatible with existing production lines, requiring only adjustments to alloy smelting and curing process parameters.

[0097] Preparation before applying ointment

[0098] The raw materials are screened, impurities removed, dried, and weighed. Then, the raw materials are ground in sequence. Different sizes of screens are used to screen the raw materials individually, and impurities in the raw materials are removed. The solid raw materials are then heated and dried, and then naturally cooled to room temperature. In the weighing process, multiple people are used to weigh the materials to avoid errors caused by one person weighing them.

[0099] Processing of Ointments

[0100] Various raw materials are added sequentially into the paste mixing machine and stirred to form a paste-like mixture.

[0101] Processing of positive electrode plate 4

[0102] The paste-like material is applied to the grid, then cured at high temperature, followed by the outer surface of the positive electrode plate 4.

[0103] Shape processing;

[0104] (II) Preparation of negative electrode lead paste

[0105] It uses the same components, proportions, and preparation process as traditional negative electrode lead paste.

[0106] S4. Install the processed positive electrode plate 4 and negative electrode plate 5 inside the battery casing 1, then inject electrolyte, and seal the cover plate 2 on the top of the battery casing 1.

[0107] The main improvements of the improved energy storage battery are: adjustments to the composition and ratio of the positive electrode grid, and adjustments to the composition, ratio, and preparation process of the positive electrode lead paste; compared with traditional lead-acid batteries, the improved battery has a significantly improved capacity recovery after deep discharge and a much higher cycle life.

[0108] The lead-calcium alloy produced in S2 is first obtained by weighing various raw materials according to their mass ratios. Then, the raw materials are added to a furnace and continuously processed to melt and mix the various raw materials. The liquid mixed metal is then filtered and poured into a mold to form a metal sheet or grid structure. The metal sheet is then machined or the grid structure is directly polished. By producing the lead-calcium alloy according to the ratio, the lead-calcium alloy can be used to process the electrode grid, avoiding the internal defects caused by direct casting of the grid and helping to improve the quality of the grid. The outer surface of the grid can be finely machined using a machine tool to meet the different shapes and structures of the grid, while maintaining the uniformity of strength at different structural points of the grid.

[0109] The furnace melting temperature in S2 is 450-480℃, with argon gas introduced for protection to form a liquid alloy solution. Subsequently, during the casting process, cooling intervention is carried out, maintaining a cooling rate of 10-15℃ / min to obtain a uniform α-Pb solid solution structure. By controlling the temperature, not only can the melting and fusion of all raw materials be ensured, resulting in a uniform distribution of different raw materials, but the cooling rate is also controlled to maintain stable internal stress in the lead-calcium alloy. This avoids excessively rapid cooling, which could lead to fine cracks caused by stress imbalance within the lead-calcium alloy, thus affecting its strength.

[0110] The recycled powder in S3 is sieved through a 200-mesh screen, the short fibers are made of polyester fiber with a length maintained at 0.5-1mm, and the PbO content in the lead powder is ≥70%.

[0111] During the processing of S3 and the paste, the addition of raw materials is divided into three stages:

[0112] (I) Dry Mixing Stage

[0113] Main solid raw materials: lead powder, antimony trioxide, potassium sulfate, stannous sulfate, recycled powder.

[0114] Add the solid raw materials to the paste mixer and mix thoroughly;

[0115] (II) Wet Mixing Stage

[0116] Add water first: Add 10%-13% of the total weight of the dry mixed raw materials with deionized water, stir for 10 minutes to ensure that the materials are initially moistened;

[0117] Add acid later: Slowly add acetic acid (H2SO4, density 1.25 g / cm³). 3 The dosage is 8%-10% of the dry mixed raw materials, and the acid addition time is controlled at 10-15 minutes;

[0118] Special additives: Colloidal graphite is added, usually at the same time as lead powder, and short fibers are added in the later stage of wet mixing;

[0119] (III) Final Mixing Stage

[0120] Add the remaining deionized water and acid to the paste mixer in sequence, and stir until the temperature of the lead paste drops below 45 degrees Celsius to ensure the reaction is stable.

[0121] By limiting the order in which the raw materials are added to the paste, the uniformity of the solid and liquid raw materials during mixing is ensured. This prevents the raw materials from failing to mix quickly in a short time, which would cause the paste to solidify due to the continuous high temperature of the paste. This would prevent the raw materials inside the paste from being evenly distributed, affecting the performance of the positive electrode plate, directly impacting the charging and discharging efficiency of the battery, and indirectly affecting the battery's lifespan.

[0122] By mixing the dry materials first, it is possible to avoid the dry materials reacting with each other in a short period of time. At the same time, when mixing the dry and wet materials, it is convenient to control the reaction rate by adding the wet material in small amounts multiple times, avoiding a rapid rise in temperature. This would prevent the temperature of the paste from becoming uncontrollable and thus affect the preparation of the lead paste.

[0123] In the S3 process, the highest temperature of the lead paste during processing is 74-76℃, and the duration of high temperature is controlled within 3-5 minutes. This fully activates the additives added to the lead paste and avoids low electrode porosity, which would result in poor electrolyte permeability.

[0124] The S3 positive electrode plate 4 lead paste is cured in three stages: the first stage is at 75℃ for 9-10 hours, the second stage is at 60℃ for 12 hours, and the third stage is at room temperature for 24 hours.

[0125] Through a three-stage cooling and curing process, the porosity of the electrode plate can be increased to 50-55%.

[0126] The compression ratio of the above-mentioned electrode assembly separator is maintained at 8-19%.

[0127] The S5 charging and discharging tests included a comparative example, comparing different lead paste formulations with the traditional formulation.

[0128] Data comparison was conducted through experiments. The improved battery was compared with the traditional battery. First, the improved battery used the improved positive plate grid formula and ratio. Then, the battery performance was tested in three examples.

[0129] Example 1

[0130] Lead paste formulation: 0.15wt% antimony trioxide, 0.25wt% potassium sulfate, 0.3wt% stannous sulfate, 0.2wt% colloidal graphite, 10wt% compound paste acid, 9wt% formulated water, 3wt% recycled powder, 0.08wt% short fiber, and the remainder is lead powder with an oxidation degree of 72-77%.

[0131] Example 2

[0132] Lead paste formulation: Antimony trioxide 0.25wt%, potassium sulfate 0.2wt%, stannous sulfate 0.5wt%, colloidal graphite 0.15wt%, compound paste acid 10wt%, formula water 9wt%, recycled powder 3wt%, short fiber 0.09wt%, the remainder being lead powder with an oxidation degree of 72-77%.

[0133] Example 3

[0134] Lead paste formulation: 0.25wt% antimony trioxide, 0.2wt% potassium sulfate, 0.5wt% stannous sulfate, 0.15wt% colloidal graphite, 10wt% compound paste acid, 9wt% formulated water, 3wt% recycled powder, 0.09wt% short fiber, and the remainder is lead powder with an oxidation degree of 72-77%.

[0135] Comparative example: the grid alloy has a tin content of 1.195-1.225%, and the traditional industrial battery lead paste formula contains 0.1% short fibers.

[0136] Battery capacity recovery capability test

[0137]

[0138]

[0139] Data shows that the improved energy storage battery has a significant performance improvement over the traditional battery, and the lead paste formula is more reasonable, consisting of: 0.25wt% antimony trioxide, 0.2wt% potassium sulfate, 0.5wt% stannous sulfate, 0.15wt% colloidal graphite, 10wt% synthetic acid, 9wt% formula water, 3wt% recycled powder, 0.09wt% short fiber, and the remainder being lead powder with an oxidation degree of 72-77%.

[0140] Traditional lead paste formulation (positive / negative electrode)

[0141] 1. Positive electrode lead paste (lead dioxide active material)

[0142]

[0143] 2. Negative electrode lead paste (sponge-like lead active material)

[0144]

[0145]

[0146] Technical problems of traditional formulas

[0147] Active substance shedding:

[0148] The positive electrode lead paste has a low fiber content (<0.5%), resulting in insufficient vibration resistance of the electrode plates (vibration test shedding rate >3%).

[0149] The decomposition of the negative electrode expander produces CO2, leading to uncontrolled porosity (porosity decreases by 40% after 100 cycles).

[0150] Increased sulfation:

[0151] With a fixed amount of barium salt added to the negative electrode, the crystal morphology of lead sulfate cannot be dynamically adjusted (in traditional formulations, >50% of PbSO4 consists of irreversible large particles).

[0152] The sulfuric acid concentration gradient at the positive electrode causes local overcharging (lead sulfate layer thickness at the electrode edge > 200 μm).

[0153] Defects in conductive networks:

[0154] Uneven carbon black dispersion (particle size distribution 1-50 μm), broken electron channels in the negative electrode (conductivity <10). 2 S / m);

[0155] The positive electrode lacks a nano-conductive framework, resulting in a polarization voltage increase of >15% during high-rate discharge.

[0156] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An energy storage battery, characterized in that, include: Main structure; The main structure includes a battery casing (1), the top of which is encapsulated with a cover plate (2), and battery terminals (3) are installed on both sides inside the cover plate (2). The inner cavity of the battery casing (1) is provided with a positive electrode plate (4) and a negative electrode plate (5), which are alternately arranged. The positive electrode plate (4) and the negative electrode plate (5) are connected to the battery terminals (3) through connectors (6). The surface of the positive electrode plate (4) is wavy, and the negative electrode plate (5) is parallel to the side of the positive electrode plate (4) facing each other. The main structure also includes an electrolyte filled into the inner cavity of the battery casing (1); The energy storage battery is manufactured using the following process, including the following steps: S1. Material Selection: Choose a suitable battery casing; S2. Preparation of positive and negative electrode grids (I) Fabrication of the positive electrode grid The positive electrode grid uses a lead-calcium alloy, in which... It includes the following raw materials: calcium, tin, aluminum, and lead. The mass percentages of each raw material are: calcium 0.075-0.09wt%, tin 1.25-2.25wt%, aluminum 0.02-0.06wt%, and the remainder is metallic lead. The positive electrode grid material is mixed, melted, and processed into a grid shape. (II) Fabrication of the negative electrode grid Preparation of S3, positive and negative electrode lead paste (I) Preparation of positive electrode lead paste Material preparation The raw materials include: antimony trioxide, potassium sulfate, stannous sulfate, colloidal graphite, acetic acid, formulated water, recycled powder, short fiber, and lead powder; The mass percentages of various raw materials are as follows: antimony trioxide 0.1-0.3wt%, potassium sulfate 0.2-0.3wt%, stannous sulfate 0.3-0.5wt%, colloidal graphite 0.1-0.3wt%, synthetic acid 10-13wt%, formulated water 9-10wt%, recycled powder 3-5wt%, short fiber 0.08-0.1wt%, and the remainder is lead powder with an oxidation degree of 72-77%. Preparation before applying ointment The raw materials are screened, impurities removed, dried, and weighed, and then ground in sequence. Processing of Ointments Various raw materials are added sequentially into the paste mixing machine and stirred to form a paste-like mixture. The addition of raw materials is divided into three stages:

1. Dry mixing stage Main solid raw materials: lead powder, antimony trioxide, potassium sulfate, stannous sulfate, recycled powder. Add the solid raw materials to the paste mixer and mix thoroughly; 2. Wet mixing stage Add water first: Add 10%-13% of the total weight of the dry mixed raw materials with deionized water, stir for 10 minutes to ensure that the materials are initially moistened; Add acid later: Slowly add the acid to the paste, at a rate of 8%-10% of the dry-mixed raw materials, and control the acid addition time to 10-15 minutes; the maximum temperature of the paste should be 74-76℃, and the high-temperature duration should be controlled to 3-5 minutes. Special additives: Colloidal graphite is added, usually at the same time as lead powder, and short fibers are added in the later stage of wet mixing; 3. Final mixing stage Add the remaining deionized water and the acid to the paste mixer in sequence, and stir until the temperature of the lead paste drops below 45 degrees Celsius to ensure the reaction is stable; The positive electrode plate lead paste is cured in three stages: the first stage is at 75℃ for 9-10 hours, the second stage is at 60℃ for 12 hours, and the third stage is at room temperature for 24 hours. Processing of positive electrode plates The paste-like substance is applied to the grid, then cured at high temperature, and the shape of the positive electrode plate is then processed. (II) Preparation of negative electrode lead paste S4. Install the processed positive and negative plates inside the battery casing, then inject electrolyte, and seal the top of the battery casing with the cover plate. S5. Perform charging and discharging tests on the assembled energy storage battery.

2. The energy storage battery according to claim 1, characterized in that: The inner cavity of the battery casing (1) is provided with a limiting slot (7), and the outer sides of the positive plate (4) and the negative plate (5) are fixed with limiting blocks (8), which are engaged in the limiting slot (7).

3. The energy storage battery according to claim 1, characterized in that: The lead-calcium alloy produced in S2 is first made by weighing various raw materials according to different mass ratios, then adding the raw materials into the furnace and continuously processing the furnace to melt and mix the various raw materials. The liquid mixed metal is then filtered and the liquid metal solution is poured into a mold to form a metal plate or grid structure. The metal plate is then machined, or the grid structure is directly polished.

4. The energy storage battery according to claim 1, characterized in that: The furnace melting temperature in S2 is 450-480℃. Argon gas is introduced for protection to form a liquid alloy solution. Then, during the casting process, cooling intervention is carried out to maintain a cooling rate of 10-15℃ / min to obtain a uniform α-Pb solid solution structure.

5. The energy storage battery according to claim 1, characterized in that: The recycled powder in S3 is sieved through a 200-mesh screen, the short fibers are made of polyester fibers with a length maintained at 0.5-1mm, and the PbO content in the lead powder is ≥70%.

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