Long-life power lead-acid storage battery based on electrolyte-polar plate synergistic modification

Abstract

The invention discloses a long-life power lead-acid storage battery based on electrolyte-polar plate synergistic modification, and relates to the technical field of lead-acid storage batteries. According to the invention, the carbon nanotubes, the potassium sodium tartrate and the sodium sulfate are added into the electrolyte of the lead-acid storage battery, the graphene and the lanthanum oxide are doped into the positive active material, and the surface of the negative electrode is coated with the polypyrrole layer, so that the synergistic modification of the electrolyte and a polar plate is realized; according to the design, the conductivity is remarkably improved, the polar plate vulcanization is inhibited, and the structural stability is enhanced, so that the cycle life and the capacity retention ratio of the battery are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid battery technology, and in particular relates to a high-life power lead-acid battery based on electrolyte-plate synergistic modification. Background Technology

[0002] Lead-acid batteries are widely used in electric bicycles and as starting power for automobiles due to their good charge-discharge performance, safety, stability, and low price. Although lead-acid batteries are widely used, their specific energy and cycle life still need improvement, especially their capacity and lifespan. These performance aspects are generally determined by the active material of the positive electrode plate, and the formulation of the positive electrode paste affects the active material. The formulation of the lead paste can influence the battery's capacity, lifespan, and other performance characteristics. Currently, most lead-acid battery manufacturers use Shimadzu ball milling to prepare lead paste formulations containing 70-80% lead powder, conductive agents, binders, and fibers. Increasing the content of conductive agents, binders, and fibers in the formulation can improve the initial performance of the battery, but it also leads to a decrease in the adhesion strength between the active material and the grid, thus accelerating capacity loss and reducing lifespan. Summary of the Invention

[0003] The purpose of this invention is to provide a high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification. By adding carbon nanotubes, potassium sodium tartrate, and sodium sulfate to the electrolyte, doping graphene and lanthanum oxide into the positive electrode active material, and coating the negative electrode surface with a polypyrrole layer, the synergistic modification of the electrolyte and the plate is achieved, thus solving the problems raised in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] This invention relates to a long-life power lead-acid battery based on electrolyte-plate synergistic modification, wherein the electrolyte has a density of 1.26-1.28 g / cm³. 3 The electrode is formed by adding 0.1-0.5 wt% carbon nanotubes, 0.05-0.1 wt% potassium sodium tartrate, and 0.2-0.5 wt% sodium sulfate to a sulfuric acid solution; the electrode includes a positive electrode and a negative electrode; the active material of the positive electrode is doped with 0.5-1.0 wt% graphene and 0.3-0.6 wt% lanthanum oxide; the surface of the negative electrode is coated with a polypyrrole conductive layer with a thickness of 10-20 μm.

[0006] Furthermore, the carbon nanotubes have a length of 1-5 μm and a diameter of 10-30 nm, which helps to form a stable conductive network, reduce battery internal resistance, and improve high-current discharge performance.

[0007] Furthermore, the grid alloy of the positive electrode plate is a lead-calcium-tin-silver quaternary alloy, wherein the silver content is 0.01-0.03 wt%.

[0008] Furthermore, during the charging process, when the detected internal resistance value is greater than 1.5 times the initial internal resistance value, the charging current is controlled to drop to 0.05C; when the detected internal resistance value is less than 1.2 times the initial internal resistance value again, the charging is controlled to return to 0.1C; this effectively prevents overcharging, reduces gas evolution, protects the electrode structure, and improves charging efficiency and safety.

[0009] Furthermore, during the discharge process, when the voltage drops by more than 1V within 10 seconds, the discharge current is adjusted to 0.5C to avoid deep discharge damaging the battery and improve the stability of the discharge process and the reliability of the battery.

[0010] Furthermore, the fully charged open-circuit voltage of the lead-acid battery is 12.7-12.9V, and the discharge cut-off voltage is ≥11.0V.

[0011] The present invention has the following beneficial effects:

[0012] This invention achieves synergistic modification of the electrolyte and the electrode plates by adding carbon nanotubes, potassium sodium tartrate, and sodium sulfate to the electrolyte, doping graphene and lanthanum oxide into the positive electrode active material, and coating the negative electrode surface with a polypyrrole layer. This design significantly improves conductivity, inhibits electrode plate sulfation, and enhances structural stability, thereby greatly improving the cycle life and capacity retention of the battery.

[0013] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0015] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0016] Electrolyte preparation: Take a solution with a density of 1.27 g / cm³. 3A sulfuric acid solution was prepared by adding 0.3 wt% carbon nanotubes, 0.08 wt% potassium sodium tartrate, and 0.4 wt% sodium sulfate, and then ultrasonically dispersing the solution for 30 minutes to obtain the desired electrolyte. The length of the carbon nanotubes was approximately 2 μm. The addition of carbon nanotubes and potassium sodium tartrate to the electrolyte reduced ohmic polarization and inhibited sulfation.

[0017] Positive electrode plate preparation: Lead paste containing 1.0 wt% graphene and 0.5 wt% lanthanum oxide is coated onto a Pb-Ca-Sn-Ag quaternary alloy grid, and after curing, a porous positive electrode plate is formed; the positive electrode plate is doped with graphene and lanthanum oxide to enhance conductivity and corrosion resistance.

[0018] Negative electrode plate treatment: A 15μm polypyrrole layer is electrochemically deposited on the lead paste surface of the negative electrode plate, and the polypyrrole layer is coated on the negative electrode to block the sulfidation reaction.

[0019] The desired battery is assembled using the electrolyte, negative electrode plate, and positive electrode plate prepared above.

[0020] Taking the existing battery formation process as an example:

[0021] It includes: several alternating charging and discharging cycles during the main charging phase, with a charging current of 0.13–0.27C and a total charging time of 35–55 hours; a discharging current of 0.13–0.27C and a discharging time of 0.5–8 hours; a resting period of 0–3 hours after the main charging phase; a capacity determination discharge after the resting period; and a second stage of charging after the capacity determination discharge, with a charging current of 0.1C and a total charging time of 18–21 hours; the fully charged open-circuit voltage of the lead-acid battery is 12.7–12.9V, and the discharge cutoff voltage is ≥11.0V.

[0022] Based on existing battery formation processes, the battery of this invention, during charging formation, first follows the main charging phase described above. After the main charging phase, it is charged with a 0.1C charging current. When the detected internal resistance value is greater than 1.5 times the initial internal resistance value, the charging current is reduced to 0.05C. When the detected internal resistance value is less than 1.2 times the initial internal resistance value, the charging current is restored to 0.1C. Simultaneously, during the discharge process of the main charging phase, it is initially discharged with a 1C discharge current. When the voltage drops by more than 1V within 10 seconds, the discharge current is adjusted to 0.5C.

[0023] The batteries to be formed by the preparation method of the present invention are formed using the improved process and the original process, respectively, and are labeled as Group A and Group B. The conventional batteries are formed using the improved process and the original process, respectively, and are labeled as Group C and Group D.

[0024] Traditional batteries do not contain carbon nanotubes, potassium sodium tartrate, or sodium sulfate in their electrolyte; the lead paste on the positive electrode of traditional batteries does not contain graphene or lanthanum oxide; and the surface of the negative electrode of traditional batteries does not have a polypyrrole layer.

[0025] The performance of the batteries used in the chemical process was tested, and the results are shown in the table below:

[0026]

[0027]

[0028] Analysis of the above data yields the following results:

[0029] The capacity retention rates of Group A and Group B batteries using the present invention after 500 cycles and after 1000 cycles are significantly higher than those of Group C and Group D batteries using conventional batteries. This indicates that the electrolyte-plate synergistic modification technology of the present invention effectively slows down the capacity decay of the battery in the early stage of cycling and greatly extends the deep cycle life of the battery. At the same time, it can be seen that Group B and Group D are higher than Group A and Group C, respectively. This shows that the intelligent charge and discharge strategy based on internal resistance and voltage monitoring can optimize the reaction process, provide additional protection for the battery, and further delay performance degradation.

[0030] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification, characterized in that: The electrolyte has a density of 1.26-1.28 g / cm³. 3 A sulfuric acid solution is formed by adding 0.1-0.5 wt% carbon nanotubes, 0.05-0.1 wt% potassium sodium tartrate and 0.2-0.5 wt% sodium sulfate; The electrode plates include a positive electrode plate and a negative electrode plate; The positive electrode plate contains 0.5-1.0 wt% graphene and 0.3-0.6 wt% lanthanum oxide as active material; the negative electrode plate is coated with a polypyrrole conductive layer with a thickness of 10-20 μm.

2. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification according to claim 1, characterized in that, The carbon nanotubes have a length of 1-5 μm and a diameter of 10-30 nm.

3. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification according to claim 1, characterized in that, The grid alloy of the positive electrode plate is a lead-calcium-tin-silver quaternary alloy, wherein the silver content is 0.01-0.03 wt%.

4. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification according to claim 1, characterized in that, During the charging process, when the detected internal resistance value is greater than 1.5 times the initial internal resistance value, the charging current is reduced to 0.05C; when the detected internal resistance value is less than 1.2 times the initial internal resistance value, the charging current is restored to 0.1C.

5. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification according to claim 4, characterized in that, During the discharge process, if the voltage drops by more than 1V within 10 seconds, the discharge current is adjusted to 0.5C.

6. A high-lifespan power lead-acid battery based on electrolyte-plate synergistic modification according to claim 5, characterized in that, The lead-acid battery has a fully charged open-circuit voltage of 12.7-12.9V and a discharge cutoff voltage of ≥11.0V.

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