A lead-acid battery with extended life based on a suspension structure

Abstract

The application relates to the field of battery design, and discloses a lead-acid battery with prolonged service life based on a suspension structure; the battery comprises a battery shell, a cover body arranged at the upper end of the battery shell, positive plates and negative plates arranged in the battery shell, and a closed cavity formed by a bottom and a top cover plate; the positive plates are suspendedly installed through a top suspension mode, a vertical height H is reserved between the bottom end of the battery plate and the bottom of the battery; the lower end of the positive plate and the lower end of the negative plate form a height difference; the upper end of the positive plate is provided with at least one hanging lug; support rods are arranged in the closed cavity, and the hanging lug of each positive plate is hung on the support rod; the hanging lug is in a ring-shaped, U-shaped or circular open structure; through the positive suspension optimization structure, the reliability of the battery can be improved, and the probability of faults of the battery in the use process is reduced.

Description

Technical Field

[0001] This invention relates to the field of battery design technology, and more particularly to a lead-acid battery with an extended lifespan based on a suspension structure. Background Technology

[0002] Lead-acid batteries, as widely used electrochemical energy storage devices, play an important role in fields such as communications, power, automotive starting, and backup power. Their working principle relies on the reversible chemical reaction between the positive and negative electrode active materials and the electrolyte. However, during long-term charge-discharge cycles, a series of physical and chemical changes inevitably occur inside the battery, severely affecting its service life and operational reliability.

[0003] During repeated charge and discharge cycles, the positive electrode plate undergoes phenomena such as active material expansion, structural corrosion, and dendrite growth, leading to a gradual increase in its overall size—a phenomenon known as "positive electrode growth." In traditional structures, both the positive and negative electrodes are directly attached to the bottom of the battery casing, with the positive electrode plate only able to grow upwards within the confined space. As the number of cycles increases, the expanded positive electrode active material continuously accumulates upwards, potentially compressing or even damaging the top sealing structure of the battery, causing electrolyte leakage and premature battery failure. Furthermore, active material detached during charge and discharge, commonly known as "lead slag," deposits at the bottom of the battery. With both positive and negative electrodes attached to the bottom, this can easily come into contact with both electrodes simultaneously, forming a conductive path and causing an internal short circuit, further exacerbating safety hazards.

[0004] Meanwhile, lead-acid batteries also undergo water electrolysis during operation, producing hydrogen and oxygen. Although some of these gases can be reduced back to water at the negative electrode via oxygen recombination, a small amount escapes from the top of the battery, leading to continuous water loss from the electrolyte. As the water content decreases, the negative electrode plate gradually dries out, significantly increasing internal resistance. This not only reduces battery capacity and output efficiency but also accelerates electrode sulfation, shortening the overall lifespan. Traditional battery cover structures lack effective gas recovery mechanisms and cannot effectively suppress water loss, limiting battery performance in maintenance-free or long-life applications.

[0005] While existing technologies have made improvements in material formulation and manufacturing processes to address the aforementioned issues, significant shortcomings remain in structural design, making it difficult to fundamentally solve the problems of mechanical damage caused by cathode growth and water loss due to gas escape. Therefore, a novel battery structure design is urgently needed that can effectively accommodate the volume changes of the cathode plate during cycling, avoiding damage to the casing's sealing structure, and efficiently recover escaped gases and convert them back into electrolyte, thereby significantly extending battery life and improving safety and reliability. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a lead-acid battery with extended lifespan, employing the following technical solution: A lead-acid battery with extended lifespan based on a suspension structure, comprising a battery casing, a cover at the upper end of the battery casing, and a positive electrode plate and a negative electrode plate disposed inside the casing. The battery casing is formed by a bottom cover and a top cover plate to create a sealed chamber. The positive electrode plate is suspended from the top, maintaining a vertical height H between the bottom end of the electrode plate and the bottom of the battery. The lower end of the positive electrode plate forms a height difference with the lower end of the negative electrode plate. At least one hanging lug is provided at the upper end of the positive electrode plate. A support rod is provided within the sealed chamber, and the hanging lug of each positive electrode plate is attached to the support rod. The hanging lug has an annular, U-shaped, or circular opening structure.

[0007] The lead-acid battery is provided with a catalytic reaction battery cover on the top. The catalytic reaction battery cover integrates a catalytic recombination functional chamber, which is used to recombine the escaped hydrogen and oxygen in situ into water and return it to the sealed chamber.

[0008] Furthermore, the positive electrode plate is made of a lead-calcium-tin-aluminum alloy material that is integrally cast.

[0009] Furthermore, the support rod is located on the inner lower surface of the top of the battery casing, and the hanging ear is sleeved on the outer periphery of the support rod, so that the positive electrode plate is suspended in the air.

[0010] Furthermore, the surface of the ear loop is treated with phosphate passivation; the support rod is made of acid-resistant engineering plastic or glass fiber reinforced polypropylene, with an outer diameter of 3 mm to 8 mm.

[0011] Furthermore, the vertical height gap H is 2 mm to 8 mm in size; the bottom of the battery is a one-piece injection-molded closed structure without perforations or current collectors, made of modified polypropylene or ABS engineering plastic, with a smooth inner surface and no protruding structures.

[0012] Furthermore, the edge of the negative electrode plate is covered with an acid-resistant polymer layer, which is EPDM rubber, fluororubber, or chlorosulfonated polyethylene, with a thickness of 0.2 mm to 0.5 mm.

[0013] Furthermore, a separator is provided between the positive and negative electrode plates, and the separator is made of microporous rubber, AGM, or composite multilayer film material.

[0014] Furthermore, the catalytic reaction battery cover is a three-layer composite structure, consisting of an outer sealing cover, a middle catalytic reaction chamber, and an inner gas guiding layer from top to bottom; the inner wall of the middle catalytic reaction chamber is provided with a catalyst layer, and the bottom is provided with an inclined guiding groove and a capillary return liquid channel.

[0015] Furthermore, the catalyst layer comprises platinum nanoparticles with a particle size of 2 nm to 5 nm and a loading of 0.5 wt% to 2.0 wt%, and the co-catalyst is palladium or ruthenium, with a content of 10% to 30% of the platinum mass; the capillary return channel is made of hydrophilic ceramic or porous silica, with an inner diameter of 0.3 mm to 0.8 mm.

[0016] Furthermore, the positive electrode plate 31 is made of lead-calcium-tin-aluminum alloy with a Ca content of 0.06 wt% to 0.10 wt%, a Sn content of 1.0 wt% to 1.5 wt%, an Al content of ≤0.02 wt%, and the balance being lead; the negative electrode plate 32 adopts a thickness gradient design, with the grid thickness near the bottom region being 0.1 mm to 0.3 mm greater than that in the upper region.

[0017] This invention addresses the structural and chemical defects of existing lead-acid batteries during long-term charge-discharge cycles, such as top cover cracking due to longitudinal growth of the positive electrode plate, internal short circuits caused by lead slag settling at the bottom, and negative electrode dryness and failure due to continuous loss of electrolyte moisture. It provides a lead-acid battery with an extended lifespan based on a suspension structure. This battery, by reconstructing the internal electrode plate support method and the top gas management mechanism, forms a triple-layered protection system of physical containment, electrical isolation, and chemical regeneration, fundamentally improving the battery's cycle stability, sealing reliability, and maintenance-free performance.

[0018] In this invention, by optimizing the positive electrode suspension structure, the reliability of the battery can be increased and the probability of battery failure during use can be reduced. This not only improves the safety of the battery, but also reduces the battery scrapping and after-sales costs caused by the growth of the positive electrode plate.

[0019] In this invention, the positive electrode plate suspension structure and the battery cover with catalyst can also extend the battery life, which means that under the same working environment, the battery can maintain a good working condition for a longer period of time. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a lead-acid battery in the prior art;

[0021] Figure 2 This is a schematic diagram of the lead-acid battery structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the internal structure of the lead-acid battery of the present invention;

[0023] Figure 4 This is a partially enlarged structural schematic diagram of the positive and negative electrode plates of the present invention;

[0024] Figure 5 This is a schematic diagram of the positive electrode plate of the present invention;

[0025] Figure 6 This is a schematic diagram of the internal structure of the lead-acid battery of the present invention from another perspective;

[0026] Figure 7 This is a partially enlarged structural diagram of the internal structure of the lead-acid battery of the present invention from another perspective. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0029] This invention discloses a lead-acid battery with extended lifespan based on a suspension structure, comprising a battery casing 1, a cover 2 at the upper end of the battery casing 1, and a positive electrode plate 31 and a negative electrode plate 32 disposed inside the casing. The battery casing 1 is characterized by: a sealed chamber formed by a bottom cover and a top cover; the positive electrode plate 31 being suspended from the top, with a vertical height H maintained between the bottom end of the electrode plate and the bottom of the battery; a height difference between the lower end of the positive electrode plate 31 and the lower end of the negative electrode plate 32; at least one hanging lug 311 at the upper end of the positive electrode plate 31; a support rod 4 disposed within the sealed chamber, with each hanging lug of the positive electrode plate abutting the support rod 4; and the hanging lug 31 having an annular, U-shaped, or circular opening structure.

[0030] In this invention, the top of the lead-acid battery is provided with a catalytic reaction battery cover 6, which integrates a catalytic recombination functional chamber for in-situ recombination of the escaped hydrogen and oxygen into water and returning it to the sealed chamber.

[0031] In a preferred embodiment, the positive electrode plate 31 is made of a lead-calcium-tin-aluminum alloy material integrally cast; the support rod 4 is located on the inner lower surface of the top of the battery casing 1, and the hanging ear 31 is sleeved on the outer periphery of the support rod 4, so that the positive electrode plate 31 is suspended in the air; the surface of the hanging ear 31 is treated with phosphate passivation; the support rod 4 is made of acid-resistant engineering plastic or glass fiber reinforced polypropylene, and its outer diameter is 3 mm to 8 mm; the vertical height gap H is 2 mm to 8 mm; the bottom of the battery is an integral injection-molded closed structure without perforations or current collectors, made of modified polypropylene or ABS engineering plastic, with a flat inner surface and no protruding structure.

[0032] In this invention, the negative electrode plate 32 is covered with an acid-resistant polymer layer at its edge. The polymer layer is EPDM rubber, fluororubber, or chlorosulfonated polyethylene with a thickness of 0.2 mm to 0.5 mm. A separator 33 is also provided between the positive electrode plate 31 and the negative electrode plate 32. The separator 33 is made of microporous rubber, AGM, or composite multilayer film material.

[0033] In a preferred embodiment, the catalytic reaction battery cover 6 has a three-layer composite structure, comprising, from top to bottom, an outer sealing cover, a middle catalytic reaction chamber, and an inner gas guiding layer; the inner wall of the middle catalytic reaction chamber is provided with a catalyst layer, and the bottom is provided with an inclined guiding groove and a capillary return liquid channel; the catalyst layer contains platinum nanoparticles with a particle size of 2 nm to 5 nm and a loading of 0.5 wt% to 2.0 wt%, and the co-catalyst is palladium or ruthenium, with a content of 10% to 30% of the platinum mass; the capillary return liquid channel is made of hydrophilic ceramic or porous silica, with an inner diameter of 0.3 mm to 0.8 mm.

[0034] In this invention, the positive electrode plate 31 is made of lead-calcium-tin-aluminum alloy with a composition of 0.06 wt% to 0.10 wt% Ca, 1.0 wt% to 1.5 wt% Sn, ≤0.02 wt% Al, and the balance being lead; the negative electrode plate 32 adopts a thickness gradient design, with the grid thickness near the bottom region being 0.1 mm to 0.3 mm greater than that of the upper region.

[0035] In the actual manufacturing process, the battery casing is first prepared. The bottom A of the battery is integrally injection molded from modified polypropylene material, with a smooth inner surface without protrusions, perforations, or current collectors running through it, to ensure that sediment will not accumulate in structural dead corners and cause short circuits. Subsequently, the positive electrode plate 31 and the negative electrode plate 32 are assembled into the casing respectively. The positive electrode plate 31 is cast from a lead-calcium-tin-aluminum alloy (Pb-Ca-Sn-Al), with a Ca content of 0.08 wt%, a Sn content of 1.2 wt%, an Al content of 0.015 wt%, and the balance being lead. 0.3 wt% of multi-walled carbon nanotubes (CNTs, 20 nm in diameter and 3 μm in length) are incorporated into the positive electrode active material to construct a three-dimensional conductive network and improve charge and discharge efficiency. At the same time, 0.5 wt% of barium sulfate (BaSO4) is added as a seed agent to regulate the crystal morphology of PbO2 and inhibit the formation of large particles. In addition, 0.03 wt% of CeO2 rare earth oxide is added to increase the oxygen evolution overpotential and slow down the grid corrosion rate.

[0036] The upper end of the positive electrode plate 31 is integrally cast with a circular lug 31. The lug 31 has an outer diameter of 6 mm and an inner diameter of 4 mm. Its surface is passivated with phosphate to enhance its corrosion resistance and mechanical strength. The support rod 4 is made of glass fiber reinforced polypropylene with an outer diameter of 5 mm. It is vertically fixed to the lower inner surface of the top cover plate and is evenly distributed to ensure the stable suspension of the positive electrode plate 31. After the lug 31 is sleeved on the outer periphery of the support rod 6, a vertical gap H is formed between the bottom end of the positive electrode plate 31 and the bottom A of the battery. The size of the gap is set to 4 ± 1 mm, preferably 4 mm. This gap is sufficient to accommodate the longitudinal elongation of the positive electrode plate caused by the expansion of active material, dendrite growth, or accumulation of corrosion products during long-term charge and discharge cycles, and to prevent upward pressure on the top cover plate, which could lead to sealing failure.

[0037] The negative electrode plate 32 is cast from the same lead-based alloy, but 0.15 wt% sodium lignosulfonate is added to its active material as an expanding agent to inhibit lead sulfate densification. The surface of the negative electrode plate 32 is treated with CF4 plasma to form a hydrophobic-hydrophilic balance structure at the microscale: that is, hydrophobic micro-regions formed by –CF2 and –CF3 fluorine-containing functional groups are alternately distributed with hydrophilic micro-regions in the untreated area, thereby delaying electrolyte loss and improving wettability. The negative electrode plate 32 is placed flat on the upper surface of the bottom A of the battery and fixed by welding or snap-fit. In the vertical projection area of ​​the positive electrode plate 31, a groove with a depth of 0.8 mm and a width slightly larger than the projection width of the positive electrode plate is machined at the corresponding position of the negative electrode plate 32 to form a physical isolation zone to prevent the formation of conductive paths between the positive and negative electrodes by settled lead slag. In addition, the edges of the negative electrode plate 32 are covered with a 0.3 mm thick EPDM polymer layer to further block the edge conductive path. The negative electrode plate 32 also adopts a thickness gradient design, with the plate thickness near the bottom area being 0.2 mm greater than that in the upper area, in order to enhance its impact resistance and deformation resistance.

[0038] The separator 33 is made of AGM (ultra-fine glass fiber) material, ensuring that even if the positive electrode plate 31 sinks slightly due to long-term use, the separator can still completely cover the edge of the electrode plate, maintaining an effective insulation distance between the positive and negative electrodes. The separator assembly wraps around the positive electrode plate 31 and the negative electrode plate 32 to prevent direct contact and has good liquid absorption and retention properties.

[0039] In this invention, the catalytic reaction battery cover 6 has a three-layer composite structure: from top to bottom, it consists of an outer sealing cover, a middle catalytic reaction chamber, and an inner gas guiding layer. The outer sealing cover is injection molded from high-density polyethylene (HDPE), possessing excellent airtightness and creep resistance. The middle catalytic reaction chamber is a sealed chamber, accounting for 20% of the total volume of the top cover plate. Its inner wall is coated with a catalyst layer containing platinum (Pt) nanoparticles with a particle size of 3 nm and a loading of 1.2 wt%. The co-catalyst is palladium (Pd), with a content of 20% of the Pt mass. The catalyst support is activated carbon with a BET specific surface area of ​​1200 m² / g, which is oxidized with nitric acid to introduce oxygen-containing functional groups, thereby improving metal dispersion and bonding strength. The inner gas guiding layer is a porous polytetrafluoroethylene (PTFE) membrane with a pore size of 150 μm and a porosity of 60%, used to uniformly distribute the gas entering the chamber and reduce flow resistance. The bottom of the catalytic reaction chamber B2 is provided with a guide groove with an inclination angle of 10°. The bottom of the groove is connected to a capillary return channel. This channel is made of hydrophilic porous silica with an inner diameter of 0.5 mm. Through capillary action, the water droplets generated by the catalytic reaction are guided back to the electrolyte area.

[0040] During battery operation, S1: When the battery is being charged, the water in the electrolyte undergoes an electrolytic reaction to generate hydrogen and oxygen; S2: Some of the gas is reduced to water on the surface of the negative electrode, and the remaining gas enters the inner gas guiding layer B3 of the top cover plate B through the safety valve or vent; S3: After being evenly distributed through the PTFE membrane, the gas enters the intermediate catalytic reaction chamber B2. Under conditions of ≤40℃, the Pt-Pd catalyst promotes the recombination reaction of hydrogen and oxygen: H2 + ½O2 → H2O; S4: The generated water vapor condenses into droplets in the chamber and flows into the capillary return channel along the inclined guide groove; S5: Through capillary action, the water droplets are continuously guided back to the electrolyte area, realizing closed-loop regeneration of water. The electrolyte is a 5.1 mol / L sulfuric acid aqueous solution containing 8 g / L colloidal silica (30 nm particle size) to enhance liquid retention and suppress convection; 2 g / L boric acid (H3BO3) is added to buffer pH fluctuations and passivate the grid surface; and 1.2 g / L p-toluenethiophenol is also added to adsorb onto the negative electrode surface to form a protective film and suppress hydrogen evolution side reaction.

[0041] During charge-discharge cycles, the positive electrode plate 31 undergoes longitudinal elongation due to the expansion of active materials, dendrite growth, or accumulation of corrosion products. However, because it is suspended, the elongation direction is mainly downward. The generated dirt, corrosion debris, and lead slag settle downward under gravity and accumulate in the central area of ​​the bottom of the battery, without contacting the edge or sidewall of the negative electrode plate 32. The groove avoidance structure of the negative electrode plate 32 within the positive electrode projection area effectively blocks the conductive path of the settled lead slag between the positive and negative electrodes, preventing the accumulation of micro-short circuits from developing into thermal runaway. At the same time, the sealed battery has no perforated structure at the bottom, eliminating the risk of leakage caused by bottom openings.

[0042] The battery described in this invention was tested under standard deep-cycle conditions (DOD=80%, 25℃): S6: Initial cycle capacity was 100 Ah; S7: After 1200 cycles, the remaining capacity remained above 80 Ah, with cycle life improved by more than 300% compared to the traditional bottom-mounted structure; S8: The leakage failure rate caused by top seal failure was less than 0.5%, a reduction of more than 90% compared to conventional products; S9: The increase in negative electrode polarization resistance after 1000 cycles was only 12%, significantly better than the 48% increase in the control group; S10: The annual electrolyte moisture loss rate was controlled at 1.3%, meeting the long-term operation requirements of maintenance-free batteries. Furthermore, due to the elimination of the bottom current collector through-hole structure, the overall strength of the battery casing is improved. It can operate continuously for 500 hours without structural damage under vibration frequency of 10 Hz and amplitude of 1.5 mm, making it suitable for demanding applications such as vehicle start-stop systems, photovoltaic energy storage, and outdoor communication base stations.

[0043] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A lead-acid battery with extended lifespan based on a suspension structure, comprising a battery casing (1), wherein a cover (2) is provided at the upper end of the battery casing (1), and further comprising a positive electrode plate (31) and a negative electrode plate (32) disposed inside the casing, characterized in that: The battery casing (1) is a sealed chamber formed by a bottom cover and a top cover; the positive electrode plate (11) is suspended by a top suspension method, and a vertical height H is maintained between the bottom end of the battery plate and the bottom of the battery; the lower end of the positive electrode plate (31) and the lower end of the negative electrode plate (32) form a height difference; the upper end of the positive electrode plate (31) is provided with at least one hanging ear (311); a support rod (4) is provided in the sealed chamber, and the hanging ear of each positive electrode plate is attached to the support rod (4); the hanging ear (5) is a ring, U-shaped or circular opening structure; The lead-acid battery is provided with a catalytic reaction battery cover (6) on the top. The catalytic reaction battery cover (6) integrates a catalytic recombination functional chamber, which is used to recombine the escaped hydrogen and oxygen in situ into water and return it to the sealed chamber.

2. The lead-acid battery according to claim 1, characterized in that, The positive electrode plate (31) is made of lead-calcium-tin-aluminum alloy material cast in one piece.

3. The lead-acid battery according to claim 1, characterized in that, The support rod (4) is located on the inner lower surface of the top of the battery casing (1), and the hanging ear (5) is sleeved on the outer periphery of the support rod (4), so that the positive electrode plate (31) is suspended in the air.

4. The lead-acid battery according to claim 1, characterized in that, The surface of the ear loop (5) is treated with phosphate passivation; the support rod (4) is made of acid-resistant engineering plastic or glass fiber reinforced polypropylene with an outer diameter of 3 mm to 8 mm.

5. The lead-acid battery according to claim 1, characterized in that, The vertical height gap H is 2 mm to 8 mm; the bottom of the battery is a one-piece injection molded closed structure without perforations or current collectors, made of modified polypropylene or ABS engineering plastic, with a smooth inner surface and no protruding structures.

6. The lead-acid battery according to claim 1, characterized in that, The negative electrode plate (32) is covered with an acid-resistant polymer layer at its edge. The polymer layer is EPDM rubber, fluororubber or chlorosulfonated polyethylene, and has a thickness of 0.2 mm to 0.5 mm.

7. The lead-acid battery according to claim 1, characterized in that, A separator 33 is provided between the positive electrode plate (31) and the negative electrode plate 32. The separator 33 is made of microporous rubber, AGM or composite multilayer film material.

8. The lead-acid battery according to claim 1, characterized in that, The catalytic reaction battery cover (6) is a three-layer composite structure, which includes an outer sealing cover, a middle catalytic reaction chamber and an inner gas guide layer from top to bottom; the inner wall of the middle catalytic reaction chamber is provided with a catalyst layer, and the bottom is provided with an inclined guide groove and a capillary return liquid channel.

9. The lead-acid battery according to claim 1, characterized in that, The catalyst layer comprises platinum nanoparticles with a particle size of 2 nm to 5 nm and a loading of 0.5 wt% to 2.0 wt%, and the co-catalyst is palladium or ruthenium, with a content of 10% to 30% of the platinum mass; the capillary return channel is made of hydrophilic ceramic or porous silica, with an inner diameter of 0.3 mm to 0.8 mm.

10. The lead-acid battery according to claim 1, characterized in that, The positive electrode plate (31) is made of lead-calcium-tin-aluminum alloy with a Ca content of 0.06 wt% to 0.10 wt%, Sn content of 1.0 wt% to 1.5 wt%, Al content of ≤0.02 wt%, and the balance being lead; the negative electrode plate (12) adopts a thickness gradient design, with the grid thickness near the bottom region being 0.1 mm to 0.3 mm greater than that in the upper region.

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