Water system double-platform battery and preparation method thereof

Abstract

The invention belongs to the technical field of secondary battery manufacturing, and particularly relates to a water system double-platform battery and a preparation method thereof. The preparation method comprises the following steps: firstly coating negative electrode zinc battery slurry with foamed nickel, coating hydrogen storage alloy slurry after primary drying, and rolling, welding, cutting and cleaning powder after secondary drying to prepare a negative plate; alternately and oppositely superposing the negative plate and the positive plate to prepare a battery cell, performing laser welding on a pole column and a conductive strip group, putting into a shell, sealing a top cover, and injecting liquid; and performing voltage secondary formation to prepare the water-based double-platform battery. The charging amount upper limit and the discharging amount lower limit are set according to the content proportion of the hydrogen storage alloy, and charging and discharging of the battery pack are more intelligently controlled by combining the voltage steep rise / steep drop characteristic in the charging / discharging later period, so that the service life of the battery pack is prolonged, the voltage of the battery in the charging later period is steep, and the hydrogen absorption amount of the hydrogen storage alloy in the later period is relieved; and the service life is prolonged while the expansion rate is reduced, so that the problem of thermal runaway caused by later overcharge of the nickel-metal hydride battery is solved more intelligently, and the method has great industrial value.

Description

Technical Field

[0001] This invention belongs to the field of secondary battery manufacturing technology, specifically relating to an aqueous dual-platform battery and its preparation method. Background Technology

[0002] Aqueous nickel-metal hydride (NiMH) batteries, with a rated voltage of 1.2V, offer advantages such as high safety, long lifespan, high-current charge / discharge capability, and a wide ambient temperature range (-55℃~60℃). They are widely used in rail transit, energy storage in extremely cold regions, and hybrid vehicles. However, NiMH batteries exhibit a voltage drop after full charging, which can lead to misjudgments by management systems. To further improve lifespan, carbon materials are deposited on the negative electrode current collector of NiMH batteries. Chinese patent CN102290244A provides an asymmetric high-power capacitor battery, significantly improving power density. However, one drawback of this patent is its high manufacturing cost. Chinese patent CN103138030A proposes a layered coating of nickel foam as the current collector and carbon materials, reducing manufacturing costs while effectively leveraging the synergistic effect of the capacitor and battery to improve lifespan and output power. However, the charging / discharging voltage characteristics remain unchanged, and there are still issues with uncontrolled group management.

[0003] Aqueous nickel-zinc batteries are also a type of alkaline rechargeable battery with a rated voltage of 1.6V. They have advantages such as low cost and a high operating voltage platform. However, zinc dendrites are prone to form on the negative electrode during use, which can puncture the separator and cause micro-short circuits in the battery. This results in a low number of charge-discharge cycles, and the zinc material has high resistance, leading to poor charge-discharge capability. To improve the charge-discharge capability of the zinc electrode, Chinese patent CN120048863A proposes coating the surface of the zinc active material with another layer. However, the coating thickness is only 2~10μm, which can only be achieved using organic materials or ionic liquids. The process is difficult to operate and cannot solve the problem of service life. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an aqueous dual-platform battery and its preparation method. It is the first to propose and realize a combination of high-voltage platform characteristics and long-life characteristics, ultimately achieving an aqueous dual-platform battery that combines a 1.6 V discharge platform voltage for nickel-zinc batteries and a 1.2 V platform voltage for nickel-metal hydride batteries. The steep rise in the high-voltage platform is used to control the charging and discharging of the nickel-metal hydride batteries, thereby more effectively improving the actual service life of the battery pack. It can also effectively prevent overcharging and over-discharging of the battery during use based on the charge / discharge cutoff voltage, which is of great significance.

[0005] This invention provides a method for preparing an aqueous dual-platform battery, comprising the following steps: a. A negative electrode sheet is made by using foamed nickel-coated zinc battery slurry, drying it once, coating it with hydrogen storage alloy slurry, drying it a second time, rolling, welding, cutting, and cleaning the powder. b. The negative electrode and positive electrode are alternately stacked to form a battery cell, and the electrode post and conductive strip group are laser welded, inserted into the shell, sealed with the top cover, and injected with liquid. c. After voltage-second formation, an aqueous dual-platform battery is manufactured.

[0006] After nickel-metal hydride (NiMH) batteries are assembled and charged and discharged, although individual NiMH cells can withstand overcharging and over-discharging from a safety perspective, this does not take into account the battery life. As a battery pack, lifespan is the top priority on the basis of safety, and shallow charging and discharging is the best solution. However, due to the differences between NiMH battery cells, the management needs to consider the worst-performing cell in the battery pack. However, in the later stages of charging, the charging voltage of NiMH batteries may not only fail to rise but may even drop. If charging continues, it will not only cause overcharging but also thermal runaway.

[0007] On the other hand, both zinc and hydrogen storage alloys are electrode materials, but their physical and electrochemical properties differ. Zinc electrode materials undergo changes in chemical valence during charge-discharge reactions, resulting in poor conductivity. As charge-discharge progresses, uneven current distribution gradually accumulates, causing zinc to aggregate and form small dendrites. This not only disrupts the reversibility of the zinc electrode material but also significantly shortens its lifespan. In contrast, hydrogen storage alloy electrode materials involve the storage and release of hydrogen atoms during charge-discharge reactions. To some extent, hydrogen atoms represent charge transfer. Therefore, hydrogen storage alloys exhibit better conductivity and high current charge-discharge capability. However, as the charging depth increases, the hydrogen storage alloy expands, leading to increased pulverization and shortening its lifespan. Therefore, improving the lifespan of nickel-metal hydride batteries requires controlling the charge level; the charge level should not reach 100%, typically not exceeding 90%.

[0008] Therefore, this invention uses nickel-plated metal mesh foam as the current collector for the negative electrode. First, a zinc battery slurry is coated onto the negative electrode, dried once, and then a hydrogen storage alloy slurry is coated. After a second drying, the negative electrode sheet is rolled, welded, cut, and cleaned to form a sheet. By employing a layered coating method of zinc battery slurry and hydrogen storage alloy slurry, the zinc material and hydrogen storage alloy material are combined in layers. Utilizing the difference in material conductivity and charge / discharge voltage characteristics, this invention proposes and realizes for the first time a combination of high-voltage platform characteristics and long-life characteristics. It achieves a water-based dual-platform battery combining a nickel-zinc battery discharge platform voltage of 1.6 V and a nickel-metal hydride battery platform of 1.2 V. When the charging capacity exceeds the amount of hydrogen storage alloy electrode material, the charging voltage suddenly surges to approximately 1.8 V. This surge in high voltage platform is used to control the charging and discharging of the nickel-metal hydride battery, thereby more effectively improving the actual service life of the battery pack. It can also effectively prevent overcharging and over-discharging of the battery during use based on the charge / discharge cutoff voltage. In the field of uninterruptible power supply system integration, by setting the upper limit of charging capacity and the lower limit of discharging capacity through the proportion of hydrogen storage alloy content, and combining the voltage rise / fall characteristics in the later stages of charging / discharging, more intelligent control of battery pack charging and discharging can be achieved, thereby improving the battery pack's service life. This allows the battery voltage to rise sharply in the later stages of charging and alleviates the amount of hydrogen absorbed by the hydrogen storage alloy in the later stages, reducing the expansion rate and extending the service life. This more intelligently solves the problem of thermal runaway caused by overcharging in the later stages of nickel-metal hydride batteries, and has significant industrial value.

[0009] The negative electrode of this invention uses nickel-foamed metal mesh as the current collector. First, a zinc battery slurry is coated onto the negative electrode, and after drying, a hydrogen storage alloy slurry is coated onto it. Because zinc materials will generate zinc dendrites during charging and discharging, there is a certain rate problem. The higher the degree of charging and discharging of the zinc electrode, the faster the zinc dendrites grow. The smaller the charge and discharge range, the slower the zinc dendrites grow. In addition, there is a layer of hydrogen storage alloy electrode material covering the outside. The probability of zinc dendrites penetrating the thick layer of hydrogen storage alloy material is even lower because the content of the zinc dendrites is less than half or less of the hydrogen storage alloy material. There is also a separator on the outside between the positive and negative electrodes. In this way, the micro short circuit problem caused by zinc dendrites can be completely eliminated.

[0010] Further analysis of the electrochemical mechanism reveals that if zinc electrode material and hydrogen storage alloy electrode material are directly mixed together and fabricated into an electrode sheet, although there will be some voltage rise in the later stages of charging, increasing the capacity to some extent, the zinc dendrites generated by the zinc electrode material during charging and discharging will directly pierce the separator and create micro-short circuits, thus significantly shortening the lifespan. Therefore, this invention chooses to separately coat the zinc electrode material and the hydrogen storage alloy material, and through a double-layer coating, with the hydrogen storage alloy electrode material on the surface of the zinc electrode material, it is possible to both utilize the voltage characteristics of the zinc material and prevent the micro-short circuit problem caused by zinc dendrites. MH+OHˉ—— M+H2O+2eˉ -0.829 V The charge / discharge equations for the negative electrode material of a nickel-zinc battery are as follows: Zn + 2OHˉ —— Zn(OH)2 + 2eˉ -1.215 V In summary, considering the reactions at the two half-electrodes of the negative electrode, the overall electrochemical reaction mechanism can be deduced as follows: Figure 4 As shown: In the initial stage of charging, the charging reaction rate of zinc is lower than the hydrogen absorption rate of the hydrogen storage alloy. In the later stage of charging, due to the zinc material being close to the current collector, the electron conduction speed is fast. On the other hand, the resistance to hydrogen diffusion into the interior of the hydrogen storage alloy increases, and the charging reaction rate of zinc gradually exceeds the hydrogen absorption rate of the hydrogen storage alloy. This causes a sharp rise in charging voltage, highlighting the voltage characteristics of nickel-zinc batteries in the later stage of charging. If the voltage in the later stage of charging can be controlled, the zinc material can be gradually activated with a smaller current. As a result, the voltage rise of nickel-zinc batteries will be more obvious and faster during use. This allows for better judgment by the battery management system to limit voltage and control charging amount, preventing the battery pack from being overcharged.

[0011] Preferably, the negative electrode zinc battery slurry in step a comprises a mixture of zinc material, carboxymethyl cellulose binder, polytetrafluoroethylene, carbon powder, nickel powder, and pure water in a mass ratio of 68~69:2~2.1:1.5~1.6:1.5~1.6:1:25~26; the zinc material is at least one of zinc oxide and zinc. The hydrogen storage alloy slurry mentioned in step a is a mixture of hydrogen storage alloy, catalyst, binder carboxymethyl cellulose, polytetrafluoroethylene, carbon powder, nickel powder, and pure water in a mass ratio of 49~50:19~20:2~2.1:1.5~1.6:1.5~1.6:1:25~26; the catalyst is one or more of yttrium oxide, cerium oxide, lanthanum oxide, ytterbium oxide, cobalt tetroxide, and iron tetroxide.

[0012] Preferably, the hydrogen storage alloy is A2B7 type alloy powder. A2B7 type alloy powder is a main electrode material in the preparation process of hydrogen storage alloy slurry, used to improve the discharge efficiency of the battery at extreme temperatures.

[0013] Preferably, the mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry in step a is 1~3:7~9. Zinc battery materials are prone to generating zinc dendrites during charging and discharging, which can puncture the separator, causing micro-short circuits in the battery and significantly affecting its service life. Hydrogen storage alloy materials are expensive. Adding a portion of zinc battery material can save material costs without reducing the battery's usable capacity and can also increase the battery voltage in the later stages of charging. In battery packs, the sharp voltage rise in the later stages of charging can serve as an indicator voltage to signal the end of charging. However, the amount of zinc battery material cannot be too high; excessive zinc content leads to uncontrollable zinc dendrite formation, while insufficient content results in an indistinct charging and discharging voltage plateau, affecting subsequent pack management.

[0014] Preferably, the welding in step a is resistance welding or laser melting segment welding. If ultrasonic welding is used, which is continuous end-face welding, the appearance is straight, and tape is applied after welding to eliminate micro-short circuits. However, ultrasonic welding can only be intermittent segment welding, and nickel foam has a three-dimensional structure and high hardness, making it easy to break. In addition, during continuous segment welding, joints are easily formed, which can easily cause jamming in the production process, resulting in low production efficiency and welding defects (nickel fracture). The present invention uses resistance welding or laser melting segment welding, which can achieve effective contact between nickel-plated steel strip and nickel foam, greatly reducing the internal resistance of electronic conductivity. Also, because less heat is generated, the tape application step can be eliminated.

[0015] Step a employs resistance welding or laser melting segment welding processes to reduce battery internal resistance and improve charge / discharge performance. Resistance welding or laser melting segment welding enables surface contact between nickel-plated steel strips and nickel foam. Traditional ultrasonic welding uses continuous segment welding, which has low welding efficiency, is prone to adhesion, and the number of welding attempts decreases exponentially with increasing contact area. However, the baseband production line is a moving transmission line. Using resistance welding or laser melting segment welding can be synchronized with baseband production and can achieve online electrode formation during subsequent cutting, realizing integrated production and greatly reducing turnover steps. Because nickel foam is relatively hard but has low mechanical strength, ultrasonic welding at high-frequency power is prone to cracking. Although using ultra-thin nickel-plated steel strips can improve ultrasonic welding penetration life and welding stability, the cost of ultra-thin nickel-plated steel strips is actually five times higher than that of conventional strips.

[0016] The welding described in step a is the welding of the electrode plate to the conductive strip. The conductive strip has a thickness of less than 0.5~1 mm and a width of 5~6 mm. The conductive strip within this range is very rigid and can be divided into two large groups, making it convenient to weld each group together using resistance welding or laser melting segment welding. Then, the bottom of the electrode post is sandwiched in the middle, and the molten metal at the top of the conductive strip group on both sides is melted by laser and fused to the bottom of the electrode post.

[0017] Preferably, step a is as follows: the negative electrode zinc battery slurry is coated with a continuous wet method using foamed nickel, and then dried with hot air in five temperature zones of 110℃-110℃-130℃-120℃-100℃. The baseband surface is coated with a hydrogen storage alloy slurry, and then dried with hot air in four temperature zones of 130℃-120℃-120℃-100℃. The negative electrode sheet is then formed by continuous rolling, online ultrasonic powder cleaning, laser welding of long conductive strips and white edges of the electrode plate, and online continuous longitudinal and transverse cutting.

[0018] Preferably, the voltage dichotomy in step c is constant current charging and constant voltage charging, with the cutoff voltage and cutoff time corresponding to each other: 0.2 C constant current charging for 3.5~4.5 h, followed by 1.8 V constant voltage charging for 2 h, resting for 10 minutes, and then discharging at 0.2 C to the cutoff voltage of 1.2 V to achieve charging and discharging and thoroughly activate the battery. The ratio of hydrogen storage alloy slurry to negative electrode zinc battery slurry directly corresponds to the constant current charging time. For example, if the hydrogen storage alloy battery material accounts for 70% (data 1 is the product of the mass of hydrogen storage alloy in the hydrogen storage alloy slurry and its specific capacity, and data 2 is the product of the mass of zinc material in the negative electrode zinc battery slurry and its specific capacity; the ratio of data 1 to data 2 is the content of hydrogen storage alloy battery material, which is a proportional value. Since both have the same specific capacity, a 70% hydrogen storage alloy battery material content means that the mass of hydrogen storage alloy in the hydrogen storage alloy slurry accounts for 70% of the total mass of hydrogen storage alloy in the hydrogen storage alloy slurry and zinc material in the negative electrode zinc battery slurry), then a 0.2 C constant current charging for 3.5 hours, followed by a 1.8 V constant voltage charging for 2 hours, completes the formation. The constant voltage charging time is uniformly 2 hours to activate the zinc battery material. The upper limit of constant current charging is the amount of hydrogen storage alloy battery material used, charging to the actual capacity value of the hydrogen storage alloy. The content of hydrogen storage alloy battery material is at least 70% and at most 90% (that is, the mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 1~3:7~9). Specifically, when the hydrogen storage alloy battery material accounts for 70%, it requires 0.2 C constant current charging for 3.5 hours; when the hydrogen storage alloy battery material accounts for 90%, it requires 0.2 C constant current charging for 4.5 hours. The actual capacity of the hydrogen storage alloy is typically 320 mAh / g. Based on the content of hydrogen storage alloy in the electrode, the overall capacity is derived, and thus the current setting value is derived. The current for constant current charging and constant current discharging is calculated as: mass of hydrogen storage alloy in the hydrogen storage alloy slurry  hydrogen storage alloy specific capacity  charging charge. The mass of the hydrogen storage alloy is expressed in grams, the specific capacity of the hydrogen storage alloy is expressed in mAh / g, the charging charge is expressed in C, and the current is expressed in Ah. For example: if the hydrogen storage alloy content (mass) is 1000g, and the hydrogen storage alloy specific capacity is 320mAh / g, then the hydrogen storage alloy capacity of this battery is 320 Ah. Based on a current setting of 0.2C... That is, the charging and discharging current is 64A.

[0019] Other formation processes include constant current throughout, constant current charging followed by constant voltage charging for 1-3 hours, and constant current followed by float charging for 1-3 hours. For nickel-metal hydride and nickel-zinc batteries, constant current charge-discharge formation is commonly used in the industry, the difference being the magnitude and duration of the constant current charge-discharge current and the charge-discharge cutoff voltage, all aimed at fully activating the battery. Constant current charging followed by constant voltage charging for 1-3 hours is mainly used for lithium-ion batteries. This is because lithium-ion batteries rely on lithium-ion intercalation. In the later stages of charging, the resistance to lithium-ion intercalation is very high. If a constant current is continued at this point, not only will the battery not be able to charge properly, but the high resistance and internal resistance will also lead to energy loss through battery heating. Failure to fully activate lithium-ion batteries can actually increase safety risks, and the voltage will continue to rise slowly, exceeding the safety limit of lithium-ion batteries, further deteriorating the battery, and even decomposing the electrolyte, leading to safety problems. Therefore, during the formation process, constant voltage charging is used in the later stages of charging. Under constant voltage, the current is charged at a very small value, slowly embedding lithium ions deep into the electrode material, thereby fully activating them. Constant current followed by float charging is used for lead-acid and nickel-cadmium batteries because the vent valves of lead-acid and nickel-cadmium batteries are open, resulting in large voltage fluctuations, so they can only be float charged; while the vent valves of nickel-metal hydride, nickel-zinc, and lithium-ion batteries are all closed.

[0020] The novel battery provided by this invention, if charged with constant current throughout the entire process, cannot fully activate the zinc electrode material and will also lead to overcharging of the hydrogen storage alloy electrode material. Float charging is also not feasible, as the vent valve is closed, and the charge level is difficult to calculate and control. This invention uses constant current charging to charge the hydrogen storage alloy electrode material, and then sets a voltage limit of 1.8V on the zinc electrode material for constant voltage charging. This is based on the fact that the zinc electrode has a relatively high voltage, and that its poor conductivity and slow electrochemical reaction rate result in a smaller acceptable charge / discharge current. Therefore, the zinc electrode material is activated under a smaller current.

[0021] During the charging process, the hydrogen storage alloy absorbs hydrogen rapidly in the early stages, but the diffusion rate gradually decreases in the later stages. Simultaneously, the electrochemical reaction rate of the zinc material gradually catches up, or even surpasses, the hydrogen storage alloy, resulting in a rapid increase in the overall battery charging voltage in the later stages of charging. Therefore, the first stage employs constant current charging (0.2 C constant current charging for 3.5-4.5 h), setting the charging amount based on the amount of active material in the hydrogen storage alloy. Then, constant voltage charging (1.8 V constant voltage charging for 2 h) is implemented, with additional time for charge control, thereby achieving the formation of a dual-platform battery. This invention uses the above-mentioned constant current and constant voltage charging for two-stage formation to prepare an aqueous dual-platform battery, ultimately achieving an aqueous dual-platform battery combining a nickel-zinc battery discharge platform voltage of 1.6 V and a nickel-metal hydride battery platform of 1.2 V. This effectively prevents overcharging and over-discharging during use based on the charge / discharge cutoff voltage. In practical control, the charging amount is set based on the hydrogen storage alloy content, and a charging stop command is issued based on the voltage rise characteristic of the zinc material. This method features low material cost and simple control.

[0022] The method for preparing the positive electrode sheet in step b is as follows: using foamed nickel coated positive electrode slurry, drying, rolling, welding, cutting, and cleaning the powder to make a positive electrode sheet, and packaging it in a separator bag. Preferably, the positive electrode slurry is a mixture of spherical nickel hydroxide, carboxymethyl cellulose binder, polytetrafluoroethylene, carbon powder, and pure water; the spherical nickel hydroxide is zinc-doped spherical nickel hydroxide or zinc-doped cobalt-coated spherical nickel hydroxide.

[0023] Preferably, the positive electrode is prepared using 300g / m 2 The foamed nickel was continuously wet-coated, and then dried with hot air in five temperature zones (140℃-110℃-120℃-120℃-100℃). The positive electrode sheet was then continuously rolled at 240 t pressure, ultrasonically cleaned online, resistance-welded with long conductive strips and white edges, and continuously cut longitudinally and transversely online. The electrode sheet dimensions were as follows: The weight is 11±0.2 g; then it is packaged in a non-woven fabric diaphragm containing ZrO2.

[0024] Preferably, the electrolyte injected in step b is a solution of 5.5~6.5 mol / L KOH + 0.45~0.55 mol / L LiOH + 0.45~0.55 mol / L NaOH.

[0025] The above method can be used to prepare both positive and negative electrodes, as well as electrodes of different thicknesses, and has a high yield.

[0026] The present invention also provides an aqueous dual-platform battery prepared by the above preparation method.

[0027] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses nickel-metal ore foam as the current collector for the negative electrode. First, a zinc battery slurry is coated onto the negative electrode. After a first drying, a hydrogen storage alloy slurry is coated onto the negative electrode. After a second drying, the negative electrode sheet is rolled, welded, cut, and cleaned. Layered coating is used to combine the zinc material and the hydrogen storage alloy material. Utilizing the difference in material conductivity and charge / discharge voltage characteristics, this invention proposes and realizes for the first time a combination of high-voltage plateau characteristics and long-life characteristics. A water-based dual-plateau battery is prepared through two-stage formation using constant current and constant voltage charging. This ultimately achieves a water-based dual-plateau battery combining a nickel-zinc battery discharge plateau voltage of 1.6 V and a nickel-metal hydride battery plateau of 1.2 V. The steep rise in the high-voltage plateau is used to control the charge and discharge of the nickel-metal hydride battery, thereby more effectively improving the actual service life of the battery pack. It can effectively prevent overcharging and over-discharging of the battery during use based on the charge / discharge cutoff voltage, which is of great significance.

[0028] (2) This invention is based on the discharge platform voltage of nickel-zinc battery (1.6 V) and nickel-metal hydride battery (1.2 V). By using nickel-metal hydride foam as the current collector and double-layer coating on the negative electrode, the two are combined in layers. By utilizing the difference in material conductivity and charge / discharge voltage characteristics, an aqueous dual-platform battery is prepared through voltage-secondary formation. This integrates the advantages of nickel-metal hydride battery (long life, high current charge / discharge capability) and nickel-zinc battery (voltage characteristics at the end of charging) and has low preparation cost. In the battery pack application control, the charging amount is set by the content of hydrogen storage alloy inside the aqueous dual-platform battery in the battery management system control logic. The charging stop command is issued by the voltage rise characteristic of zinc material, thereby controlling the battery pack charge more quickly, preventing overcharging, and greatly extending the service life.

[0029] (3) Compared with existing nickel-metal hydride batteries, the present invention uses zinc material, which reduces material cost. By layering the slurry, a layer of hydrogen storage alloy material is covered on the surface of the zinc material, which eliminates the risk of zinc dendrites puncturing the separator. At the same time, the amount of zinc material introduced is used to control the charging amount of the nickel-metal hydride battery, and the amount of hydrogen absorbed by the hydrogen storage alloy in the later stage is alleviated by the zinc material, thus preventing full charging or overcharging.

[0030] (4) By using ultrasonic roll welding, the conductive strip and the white edge of the baseband are made into contact, which greatly reduces the electronic conduction resistance and solves the problem of heat dissipation at the welding point during subsequent high-current charging and discharging. This is economical and environmentally friendly.

[0031] (5) Through a series of improvements, this invention combines the high voltage plateau characteristics of nickel-zinc batteries with the long life and high current charge-discharge characteristics of nickel-metal hydride batteries to develop a new type of battery with dual plateau voltage characteristics. This new battery has the characteristics of nickel-zinc batteries in the later stage of charging, with a sharp voltage rise, so as to judge the charge of the new battery more quickly. It also stores a portion of the charge through a certain amount of zinc material, which delays the rapid expansion rate of the hydrogen storage alloy in the later stage of charging. This improves the service life of the new battery and can also intelligently solve the problem of thermal runaway caused by overcharging in the later stage of nickel-metal hydride batteries, which is of great practical significance. Attached Figure Description

[0032] Figure 1 This is the charge-discharge curve of Example 1; Figure 2 This is a charge-discharge curve diagram for comparison example 1; Figure 3 This is the charge-discharge curve diagram for Comparative Example 2; Figure 4 This is a schematic diagram of the negative electrode electrochemical reaction mechanism of the present invention. Detailed Implementation

[0033] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0034] Example 1 A method for preparing an aqueous dual-platform battery includes the following steps: a. Preparation of positive and negative electrode slurries, zinc battery negative electrode slurry, and hydrogen storage alloy slurry; Positive electrode slurry: The spherical nickel hydroxide, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, conductive carbon powder, and pure water are mixed in a mass ratio of 70:2:1.5:1.5:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the positive electrode slurry.

[0035] The negative electrode zinc battery slurry is prepared by mixing zinc, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, carbon powder, nickel powder, and pure water in a mass ratio of 68.5:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the zinc battery negative electrode slurry.

[0036] Hydrogen storage alloy slurry: The hydrogen storage alloy (A2B7 type alloy powder): catalyst (mixture of yttrium oxide: cerium oxide: lanthanum oxide: ytterbium oxide: cobalt tetroxide: iron tetroxide in a mass ratio of 1:1:1:1:1:1): binder carboxymethyl cellulose (CMC): polytetrafluoroethylene (PTFE) powder: carbon powder: nickel powder: pure water in a mass ratio of 49:19.5:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours, then left to stand for 24 hours, and then stirred under vacuum for 1-2 hours to form the hydrogen storage alloy slurry.

[0037] b. The positive electrode uses foamed nickel coating positive electrode slurry, which is dried, rolled, ultrasonically welded, cut into electrode sheets, and cleaned to form positive electrode sheets, and then packaged in diaphragm bags. The specific preparation of the positive electrode is as follows: using 320g / m 2 The foamed nickel continuous wet coating positive electrode slurry is dried with hot air in five temperature zones (140℃-110℃-120℃-120℃-100℃), then continuously rolled at 240 t pressure, cleaned with online ultrasonic powder, resistively welded with long conductive strips and white edges, and continuously cut longitudinally and transversely online to form positive electrode sheets. The electrode sheet size is... The weight is 15±0.2 g; then it is packaged in a non-woven fabric diaphragm containing ZrO2.

[0038] c. The negative electrode is made of nickel-plated steel strip coated with negative electrode zinc battery slurry, dried once and then coated with hydrogen storage alloy slurry. The mass ratio of zinc material in negative electrode zinc battery slurry to hydrogen storage alloy in hydrogen storage alloy slurry is 1:9. After a second drying, it is rolled, ultrasonically welded, longitudinally and transversely cut and laser-cut into shape, and then cleaned to make a negative electrode sheet. The specific preparation of the negative electrode is as follows: using 320g / m 2 The foamed nickel continuous wet coating negative electrode zinc battery slurry is dried with hot air in five temperature zones: 110℃-110℃-130℃-120℃-100℃. Then, the baseband surface is coated with a negative electrode hydrogen storage alloy slurry. The mass ratio of zinc in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 1:9. After hot air drying in four temperature zones: 130℃-120℃-120℃-100℃, the negative electrode sheet is produced by continuous rolling at 350t pressure, online ultrasonic powder removal, laser melting section welding of long conductive strips and electrode plate white edges, and online continuous longitudinal and transverse cutting. The conductive strip thickness is less than 0.5~1 mm, and the width is 5~6 mm. The electrode sheet dimensions are... The weight is 14±0.2g.

[0039] d. Positive and negative electrode sheets are stacked to form a battery cell, the terminal posts are welded, the casing is installed, the top cover is sealed, and electrolyte is injected; The electrolyte solution was 6 mol / L KOH + 0.5 mol / L LiOH + 0.5 mol / L NaOH solution.

[0040] e. First, charge at a constant current of 0.2C and 10A for 4.5 hours, then charge at a constant voltage of 1.8V for 2 hours. After resting for 10 minutes, discharge at a constant current of 0.2C and 10A until the cutoff voltage of 1.2V is reached, thus forming an aqueous dual-platform battery.

[0041] Figure 1 The charging and discharging curves in the final formation step of the 50 Ah model are as follows: constant current charging at 0.2C and 10A for 4.5 hours, then constant voltage charging at 1.8V for 2 hours, resting for 10 minutes, and then discharging at 0.2C and 10A to the cutoff voltage of 1.2V. The graph clearly shows two charging curve plateaus and a sharp voltage change point.

[0042] The dual-platform battery manufactured using this embodiment was subjected to performance testing of 20 50 Ah cells connected in series as a module. The battery pack was charged at 1 C, 50 A to the cutoff voltage of 32 V or 23 V, within the SOC range of 20-90%, and discharged at 3 C, 150 A to the cutoff voltage of 23 V or 20% SOC. After 1000 cycles, the battery showed no liquid leakage, no external deformation, voltage difference of less than 5 mV, and capacity retention of 99%.

[0043] Example 2 A method for preparing an aqueous dual-platform battery includes the following steps: a. Preparation of positive and negative electrode slurries and zinc battery negative electrode slurry; Positive electrode slurry: The ratio of spherical nickel hydroxide, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, conductive carbon powder, and pure water is 70:2:1.5:1.5:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the positive electrode slurry.

[0044] The negative electrode zinc battery slurry is prepared by mixing zinc oxide, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, carbon powder, nickel powder, and pure water in a mass ratio of 68.5:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the zinc battery negative electrode slurry.

[0045] Hydrogen storage alloy slurry: The hydrogen storage alloy (A2B7 type alloy powder): catalyst (cobalt tetroxide: iron tetroxide mixture in a mass ratio of 1:1): binder carboxymethyl cellulose (CMC): polytetrafluoroethylene (PTFE) powder: carbon powder: nickel powder: pure water in a mass ratio of 49:19.5:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, it is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the hydrogen storage alloy slurry.

[0046] b. The positive electrode uses foamed nickel coating positive electrode slurry, which is dried, rolled, ultrasonically welded, cut into electrode sheets, and cleaned to form positive electrode sheets, and then packaged in diaphragm bags. Preparation of positive electrode: using 420g / m 2 The foamed nickel was continuously wet-coated, and then dried with hot air in five temperature zones (140℃-110℃-120℃-120℃-100℃). The positive electrode sheet was then continuously rolled at 240 t pressure, ultrasonically cleaned online, resistance-welded with long conductive strips and white edges, and continuously cut longitudinally and transversely online. The electrode sheet dimensions were as follows: The weight is 36±0.2 g; then it is packaged in a non-woven fabric diaphragm containing ZrO2.

[0047] c. The negative electrode is made of nickel-plated steel strip coated with negative electrode zinc battery slurry, dried once, and then coated with hydrogen storage alloy slurry. The mass ratio of zinc material in negative electrode zinc battery slurry to hydrogen storage alloy in hydrogen storage alloy slurry is 3:7. After a second drying, it is rolled, longitudinally and transversely cut, laser-cut into shape, and cleaned to make a negative electrode sheet. Preparation of negative electrode: using 420g / m 2 The foamed nickel continuous wet coating negative electrode zinc battery paste is dried with hot air in five temperature zones: 110℃-110℃-130℃-120℃-100℃. Then, the baseband surface is coated with a negative electrode hydrogen storage alloy paste. The mass ratio of zinc in the negative electrode zinc battery paste to hydrogen storage alloy in the hydrogen storage alloy paste is 3:7. After hot air drying in four temperature zones: 130℃-120℃-120℃-100℃, the negative electrode sheet is produced by continuous rolling at 350t pressure, online ultrasonic powder removal, laser melting section welding of long conductive strips and electrode plate white edges, and online continuous longitudinal and transverse cutting. The conductive strip thickness is less than 0.5~1 mm, and the width is 5~6 mm. The electrode sheet dimensions are... The weight is 34±0.2g.

[0048] d. Positive and negative electrode sheets are stacked to form a battery cell, the terminal posts are welded, the casing is installed, the top cover is sealed, and electrolyte is injected; The electrolyte solution was 6 mol / L KOH + 0.5 mol / L LiOH + 0.5 mol / L NaOH solution.

[0049] e. First, charge at a constant current of 0.2C and 40A for 3.5 hours, then charge at a constant voltage of 1.8V for 2 hours. After resting for 10 minutes, discharge at 0.2C and 40A until the cutoff voltage of 1.2V is reached, thus forming an aqueous dual-platform battery.

[0050] The dual-platform battery manufactured using this embodiment was used to conduct performance tests on 160 200 Ah batteries connected in series to form an energy storage microgrid. The battery management system was set to operate within a 10-80% SOC range, with the upper and lower voltage limits of the battery pack defined as 256 V and 190 V, respectively. The battery was charged at 0.2C and 40 A until the cutoff voltage of 256 V or 80% SOC was reached, and discharged at 0.2C and 40 A until the SOC of 10% or 190 V was reached. The battery was cycled twice a day. After 600 cycles, there was no liquid leakage, no visible deformation, a voltage difference of less than 12 mV, and a capacity retention rate of 97.5%.

[0051] Example 3 A method for preparing an aqueous dual-platform battery includes the following steps: a. Preparation of positive and negative electrode slurries and zinc battery negative electrode slurry; Positive electrode slurry: The ratio of spherical nickel hydroxide, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, conductive carbon powder, and pure water is 70:2:1.5:1.5:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the positive electrode slurry.

[0052] The negative electrode zinc battery slurry is prepared by mixing zinc oxide, zinc, carboxymethyl cellulose (CMC) binder, polytetrafluoroethylene (PTFE) powder, carbon powder, nickel powder, and pure water in a mass ratio of 34.5:34:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then, the mixture is left to stand for 24 hours and then stirred under vacuum for 1-2 hours to form the zinc battery negative electrode slurry.

[0053] Hydrogen storage alloy slurry: The hydrogen storage alloy (A2B7 type alloy powder): catalyst (mixture of yttrium oxide: cerium oxide: cobalt tetroxide: iron tetroxide in a mass ratio of 1:1:1:1): binder carboxymethyl cellulose (CMC): polytetrafluoroethylene (PTFE) powder: carbon powder: nickel powder: pure water in a mass ratio of 49:19.5:2:1.5:1.5:1:25. The materials are added to a mixer in sequence and stirred at high speed for 2-4 hours. Then it is left to stand for 24 hours, and then stirred under vacuum for 1-2 hours to form the hydrogen storage alloy slurry.

[0054] b. The positive electrode uses foamed nickel coating positive electrode slurry, which is dried, rolled, ultrasonically welded, cut into electrode sheets, and cleaned to form positive electrode sheets, and then packaged in diaphragm bags. Preparation of positive electrode: using 300g / m 2 The foamed nickel was continuously wet-coated, and then dried with hot air in five temperature zones (140℃-110℃-120℃-120℃-100℃). The positive electrode sheet was then continuously rolled at 240 t pressure, ultrasonically cleaned online, resistance-welded with long conductive strips and white edges, and continuously cut longitudinally and transversely online. The electrode sheet dimensions were as follows: The weight is 11±0.2 g; and then it is packaged in a non-woven fabric diaphragm containing ZrO2.

[0055] c. The negative electrode is made of nickel-plated steel strip coated with negative electrode zinc battery slurry, dried once, and then coated with hydrogen storage alloy slurry. The mass ratio of zinc material in negative electrode zinc battery slurry to hydrogen storage alloy in hydrogen storage alloy slurry is 2:8. After a second drying, it is rolled, longitudinally and transversely cut, laser-cut into shape, and cleaned to make negative electrode sheet. Preparation of negative electrode: using 300g / m 2 The foamed nickel continuous wet coating negative electrode zinc battery paste is dried with hot air in five temperature zones: 110℃-110℃-130℃-120℃-100℃. Then, the baseband surface is coated with a negative electrode hydrogen storage alloy paste. The mass ratio of zinc in the negative electrode zinc battery paste to hydrogen storage alloy in the hydrogen storage alloy paste is 2:8. After hot air drying in four temperature zones: 130℃-120℃-120℃-100℃, the negative electrode sheet is produced by continuous rolling at 350t pressure, online ultrasonic powder removal, laser melting section welding of long conductive strips and electrode plate white edges, and online continuous longitudinal and transverse cutting. The conductive strip thickness is less than 0.5~1 mm, and the width is 5~6 mm. The electrode sheet dimensions are... The weight is 10±0.2g.

[0056] d. Positive and negative electrode sheets are stacked to form a battery cell, the terminal posts are welded, the casing is installed, the top cover is sealed, and electrolyte is injected; The electrolyte solution was 6 mol / L KOH + 0.5 mol / L LiOH + 0.5 mol / L NaOH solution.

[0057] e. First, charge at a constant current of 0.2C and 6A for 4 hours, then charge at a constant voltage of 1.8V for 2 hours. After resting for 10 minutes, discharge at 0.2C and 6A until the cutoff voltage of 1.2V is reached, thus forming an aqueous dual-platform battery.

[0058] The dual-platform battery manufactured using this embodiment underwent performance testing with 320 30 Ah cells connected in series as an uninterruptible power supply. The battery pack was charged within a 10-85% SOC range, with the upper and lower voltage limits set at 500 V and 360 V respectively. The 1 C, 30 A charging cutoff voltage was 500 V or 85% SOC, and the 4 C, 120 A discharging cutoff voltage was 190 V or 10% SOC. After 500 cycles, the battery showed no liquid leakage, no visible deformation, a voltage difference of less than 7 mV, and a capacity retention rate of 98.5%.

[0059] Comparative Example 1 A method for preparing an aqueous nickel-metal hydride battery is basically the same as in Example 1, the only difference being that the negative electrode does not have a layered coating of zinc battery slurry. The specific method for preparing the negative electrode sheet is as follows: using 320 g / m... 2 The surface of the foamed nickel-based strip is coated with a negative electrode hydrogen storage alloy slurry. After hot air drying in four temperature zones (130℃-120℃-120℃-100℃), it is continuously rolled under 350t pressure, cleaned with online ultrasonic powder, laser-welded with long conductive strips to the white edges of the electrode plate, and continuously cut in the longitudinal and transverse directions online to form the negative electrode sheet. The electrode sheet size is [missing information]. The weight is 14±0.2g.

[0060] Figure 2 The charging and discharging curves for the final formation step of the 50 Ah battery are as follows: constant current charging at 0.2 C and 10 A for 4.5 h, followed by constant voltage charging at 1.8 V for 2 h, resting for 10 minutes, and then discharging at 0.2 C and 10 A to the cutoff voltage of 1.0 V. It can be clearly seen from the graph that there is only one charging curve plateau, and the voltage rises slightly at the end. This is because the diffusion resistance inside the hydrogen storage alloy particles increases in the later stage of charging, making it difficult for hydrogen atoms to diffuse. It is necessary to further increase the voltage to push them in, but there is no steep voltage change point, and the voltage does not reach 1.8 V, which is completely consistent with the charging and discharging curve characteristics of nickel-metal hydride batteries.

[0061] The battery manufactured using Comparative Example 1 was also subjected to performance testing using 20 50 Ah batteries connected in series as a module. The battery pack was charged at 1 C, 50 A to the cutoff voltage of 32 V or 23 V, respectively, within the 20-90% SOC range. The battery pack was then discharged at 3 C, 150 A to the cutoff voltage of 23 V or 20% SOC. After 1000 cycles, the battery showed no liquid leakage, no visible deformation, a voltage difference greater than 50 mV, and a capacity retention of 85%.

[0062] Since Comparative Example 1 did not have a zinc battery slurry coated with negative electrode, the State of Charge (SOC) was reached first during each charge and discharge cycle, which is a full charge and discharge cycle. However, in Example 1, the charging voltage was reached first during the charging process, which is basically a shallow charge and discharge cycle in actual testing.

[0063] As can be seen from Example 1 and Comparative Example 1, by layering the zinc battery slurry for the negative electrode, not only is the service life of the nickel-metal hydride battery not affected, but also the high voltage characteristics of the battery itself allow the charging cutoff voltage to be brought forward, enabling shallow charging internally and indirectly improving the level of intelligent control. However, the service life of the battery pack was not improved.

[0064] Comparative Example 2 A method for preparing an aqueous nickel-zinc battery is basically the same as in Example 2, the only difference being that the negative electrode does not have a layered hydrogen storage alloy slurry. The specific method for preparing the negative electrode sheet is as follows: using 420 g / m... 2 The foamed nickel continuous wet coating zinc battery slurry is dried with hot air in five temperature zones (110℃-110℃-130℃-120℃-100℃), and then continuously rolled under 350t pressure, with online ultrasonic powder removal, laser welding of long conductive strips to the white edges of the electrode plates, and online continuous longitudinal and transverse cutting to produce negative electrode sheets. The electrode sheet size is... The weight is 34±0.2g.

[0065] Figure 3 The charging and discharging curves for the final formation step of a 200 Ah battery are as follows: constant current charging at 0.2 C and 40 A for 4.5 hours, then constant voltage charging at 1.8 V for 2 hours, resting for 10 minutes, and then discharging at 0.2 C and 40 A to the cutoff voltage of 1.2 V. It can be clearly seen from the graph that there is only one charging curve plateau, without any steep voltage change points. The overall charging voltage plateau is relatively high, and the discharging plateau is also relatively high, which is completely consistent with the charging and discharging curve characteristics of nickel-zinc batteries. The batteries manufactured using this comparative model were also tested in a series of 160 200Ah cells connected to form an energy storage microgrid. The battery management system was set to operate within a 10-80% SOC range, with the upper and lower voltage limits of the battery pack set at 256V and 190V respectively. The system charged the battery at 40A until the cutoff voltage of 256V or 80% SOC was reached, and discharged at 40A until the SOC of 10% or 190V was reached. This cycle was repeated twice a day. After 200 cycles, three cells showed liquid leakage, the battery pack insulation level dropped by three levels, triggering an alarm, the voltage difference exceeded 300 mV, and the capacity retention rate was 38.5%.

[0066] As can be seen from Example 2 and Comparative Example 2, the nickel-zinc battery has a very short lifespan and serious leakage. This is likely due to zinc dendrite growth during charging and discharging causing membrane puncture and micro-short circuits, resulting in high internal pressure and electrolyte leakage from the vent valve. The overall charging and discharging efficiency is also very low. After 600 cycles, the capacity retention rate is less than 50%, rendering it unusable.

[0067] Comparative Example 3 A method for preparing a dual-platform battery is basically the same as in Example 3, the only difference being that the negative electrode is first coated with a hydrogen storage alloy slurry, dried, and then coated with a zinc battery material slurry. The specific method for preparing the negative electrode sheet is as follows: using 300g / m... 2 The foamed nickel-coated negative electrode hydrogen storage alloy slurry is dried with hot air in four temperature zones: 130℃-120℃-120℃-100℃. Then, a continuous wet coating of the negative electrode zinc battery slurry is applied. The mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 2:8. After hot air drying in five temperature zones: 110℃-110℃-130℃-120℃-100℃, the baseband surface is continuously rolled under 350t pressure, subjected to online ultrasonic powder removal, laser welding of long conductive strips to the white edges of the electrode plates, and online continuous longitudinal and transverse cutting to form the negative electrode sheet. The electrode sheet size is... The weight is 10±0.2g.

[0068] The dual-platform battery manufactured using this comparative model was subjected to a performance test of 320 30 Ah batteries connected in series to form an uninterruptible power supply. The battery pack was charged within a range of 10% to 85% SOC, with the upper and lower voltage limits set at 500 V and 360 V respectively. The charging cutoff voltage was 500 V or 85% SOC at 1 C and 30 A. The discharge was carried out at 10% SOC or 190 V at 4 C and 120 A. After 300 cycles, one battery cell leaked liquid, the battery pack insulation level dropped by three levels, triggering an alarm, the voltage difference was greater than 80 mV, and the capacity retention rate was 68.5%.

[0069] As can be seen from Example 3 and Comparative Example 3, the nickel-zinc battery has a very short lifespan and also leaks. This is likely due to zinc dendrite growth during charging and discharging causing membrane puncture, forming micro-short circuits, etc., resulting in high internal pressure, electrolyte leakage from the vent valve, and low overall charging and discharging efficiency. After 300 cycles, the capacity retention rate is less than 70%, rendering it unusable.

[0070] Comparative Example 4 A method for preparing a dual-platform battery is basically the same as in Example 1, except that a mixed slurry is obtained by mixing a zinc battery slurry and a hydrogen storage alloy slurry for the negative electrode, and the negative electrode is coated with this mixed slurry using a nickel-plated steel strip. Specifically, the negative electrode sheet is prepared using a 320 g / m² plate. 2 A mixed slurry was obtained by mixing a zinc battery negative electrode slurry and a hydrogen storage alloy slurry using a continuous wet coating process with nickel foam. The mass ratio and total mass of the zinc battery negative electrode slurry and the hydrogen storage alloy slurry were the same as in Example 1. After hot air drying in five temperature zones (110℃-110℃-130℃-120℃-100℃), the negative electrode sheet was produced by continuous rolling at 350t pressure, online ultrasonic powder removal, laser welding of long conductive strips and white edges of the electrode plate, and online continuous longitudinal and transverse cutting. The electrode sheet size was [missing information]. The weight is 14±0.2g.

[0071] result: The batteries manufactured using Comparative Example 4 were also subjected to performance testing using 20 50 Ah batteries connected in series as a module. The battery pack was charged at 1 C, 50 A to the cutoff voltage of 32 V or 23 V, respectively, within the 20-90% SOC range. The batteries were then discharged at 3 C, 150 A to the cutoff voltage of 23 V or 20% SOC. After 300 cycles, some batteries showed liquid leakage, but no visible deformation. The voltage difference was greater than 200 mV, and the capacity retention was 65%.

[0072] As can be seen from Example 1 and Comparative Example 4, the electrode prepared by mixing negative zinc battery slurry and hydrogen storage alloy slurry has a very short battery life and serious leakage. This is likely because zinc dendrites generated by the zinc electrode material during charging and discharging gradually grow on the electrode surface, making it easier to pierce the separator and create micro-short circuits. This results in high internal pressure, electrolyte leakage from the vent valve, and very low overall charging and discharging efficiency. After 300 cycles, the capacity retention rate is less than 80%, rendering it unusable.

[0073] Comparative Example 5 A method for preparing a dual-platform battery is basically the same as that in Example 1, except that the mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 5:5 (the total mass of the negative electrode zinc battery slurry and the hydrogen storage alloy slurry is the same as that in Example 1, and the electrode weight is the same as that in Example 1).

[0074] The batteries manufactured using Comparative Example 5 were also subjected to performance testing using 20 50 Ah batteries connected in series to form a module. The battery pack was charged to a state of charge (SOC) range of 20-90%, with the upper and lower limits of the battery pack voltage set to 32 V and 23 V, respectively. The batteries were charged at 1 C and 50 A to the cutoff voltage of 32 V or 90% SOC, and discharged at 3 C and 150 A to the cutoff voltage of 23 V or 20% SOC. After 800 cycles, some batteries showed liquid leakage, but no visible deformation. The voltage difference was greater than 100 mV, and the capacity retention rate was 53%.

[0075] As can be seen from Example 1 and Comparative Example 5, although the negative electrode zinc battery slurry and hydrogen storage alloy slurry are coated in layers, the battery pack has a very short service life and serious leakage. This is likely due to an excessive amount of zinc electrode material and an insufficient amount of hydrogen storage alloy battery material. During the charge and discharge process, zinc dendrites gradually grow and slowly penetrate the thin hydrogen storage alloy material layer. This process continues with charge and discharge, eventually piercing the separator and creating a micro-short circuit. This results in high internal pressure, and the electrolyte leaks out from the vent valve. After 800 cycles, the capacity retention rate is less than 60%, rendering the battery unusable.

[0076] Comparative Example 6 A method for preparing a dual-platform battery is basically the same as that in Example 1, except that the mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 1:20 (the total mass of the negative electrode zinc battery slurry and the hydrogen storage alloy slurry is the same as that in Example 1, and the electrode weight is the same as that in Example 1).

[0077] result: The batteries manufactured in Comparative Example 6 were also subjected to performance tests in a module consisting of 20 50 Ah cells connected in series. The battery pack was charged at 1 C and 50 A to the cutoff voltage of 32 V or 90% SOC, and discharged at 3 C and 150 A to the cutoff voltage of 23 V or 20% SOC. After 1000 cycles, the battery showed no liquid leakage, no external deformation, a voltage difference greater than 100 mV, and a capacity retention rate of 83%.

[0078] As can be seen from Example 1 and Comparative Example 6, despite the layered coating of the negative electrode zinc battery slurry and the hydrogen storage alloy slurry, the battery pack lifespan is comparable to that of the nickel-metal hydride battery pack. This is because the zinc battery material is relatively scarce, making it difficult to control during charging and discharging, and some overcharging occurs, resulting in a capacity retention rate of less than 90% after 1000 cycles. The battery pack lifespan has not been improved.

[0079] Comparative Example 7 A method for preparing a dual-platform battery is basically the same as that in Example 1, except that... Step e of the formation process uses constant current charging at 0.2 C and 10 A for 6 hours throughout, without constant voltage charging.

[0080] result: The batteries manufactured using Comparative Example 7 were also subjected to performance testing using 20 50 Ah batteries connected in series as a module. The battery pack was charged to a state of charge (SOC) range of 20-90%, with the upper and lower voltage limits of 32 V and 23 V respectively. The batteries were charged at 1 C and 50 A to the cutoff voltage of 32 V or 90% SOC, and discharged at 3 C and 150 A to the cutoff voltage of 23 V or 20% SOC. After 1000 cycles, the batteries showed no liquid leakage, no external deformation, a voltage difference greater than 150 mV, and a capacity retention rate of 80%.

[0081] Because Comparative Example 7 did not employ constant-voltage charging and instead used constant-current charging throughout, the hydrogen storage alloy was severely overcharged in the later stages of charging, while the zinc battery material remained unactivated. As can be seen from Examples 1 and 7, the lack of a constant-voltage formation process resulted in severe internal overcharging of the battery during the formation stage, leading to premature pulverization of the hydrogen storage alloy material. This significantly impacts the long-term lifespan of the nickel-metal hydride battery. Despite its high-voltage characteristics, which automatically advance the charging cutoff voltage and achieve shallow charging internally, indirectly improving the level of intelligent control, the battery pack's lifespan still decreased too rapidly.

[0082] For those skilled in the art, the above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments, such as using a winding method between the positive and negative electrodes and the gel separator. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, shall still fall within the protection scope of the present invention.

[0083] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing an aqueous dual-platform battery, characterized in that, Includes the following steps: a. A negative electrode sheet is made by using foamed nickel-coated zinc battery slurry, drying it once, coating it with hydrogen storage alloy slurry, drying it a second time, rolling, welding, cutting, and cleaning the powder. b. The negative electrode and positive electrode are alternately stacked to form a battery cell, and the electrode post and conductive strip group are laser welded, inserted into the shell, sealed with the top cover, and injected with liquid. c. After voltage-second formation, an aqueous dual-platform battery is manufactured.

2. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, The negative electrode zinc battery slurry mentioned in step a comprises a mixture of zinc material, carboxymethyl cellulose binder, polytetrafluoroethylene, carbon powder, nickel powder, and pure water in a mass ratio of 68~69:2~2.1:1.5~1.6:1.5~1.6:1:25~26; the zinc material is at least one of zinc oxide and zinc. The hydrogen storage alloy slurry mentioned in step a is a mixture of hydrogen storage alloy, catalyst, binder carboxymethyl cellulose, polytetrafluoroethylene, carbon powder, nickel powder, and pure water in a mass ratio of 49~50:19~20:2~2.1:1.5~1.6:1.5~1.6:1:25~26; the hydrogen storage alloy is A2B7 type alloy powder; the catalyst is one or more of yttrium oxide, cerium oxide, lanthanum oxide, ytterbium oxide, cobalt tetroxide, and iron tetroxide.

3. The method for preparing an aqueous dual-platform battery according to claim 1 or 2, characterized in that, In step a, the mass ratio of zinc material in the negative electrode zinc battery slurry to hydrogen storage alloy in the hydrogen storage alloy slurry is 1~3:7~9.

4. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, The welding described in step a is resistance welding or laser melting section welding; the welding described in step a is welding of the electrode plate and the conductive strip, wherein the thickness of the conductive strip is less than 0.5~1 mm and the width is 5~6 mm.

5. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, Step a is as follows: The negative electrode zinc battery slurry is coated with foamed nickel using a continuous wet coating method. After hot air drying in five temperature zones (110℃-110℃-130℃-120℃-100℃), the baseband surface is coated with hydrogen storage alloy slurry. After hot air drying in four temperature zones (130℃-120℃-120℃-100℃), the negative electrode sheet is made by continuous rolling, online ultrasonic powder cleaning, laser welding of long conductive strips and white edges of the electrode plate, and online continuous longitudinal and transverse cutting.

6. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, The voltage dichotomy in step c is divided into constant current charging and constant voltage charging, with the cutoff voltage corresponding to the cutoff time: 0.2 C constant current charging for 3.5~4.5 h, followed by 1.8 V constant voltage charging for 2 h, resting for 10 minutes, and then discharging at 0.2 C constant current to the cutoff voltage of 1.2 V; wherein, the current for constant current charging and constant current discharging is: the mass of hydrogen storage alloy in the hydrogen storage alloy slurry  the specific capacity of hydrogen storage alloy  the amount of charging charge, where the mass of hydrogen storage alloy is in g, the specific capacity of hydrogen storage alloy is in mAh / g, the amount of charging charge is in C, and the current is in Ah.

7. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, The positive electrode sheet preparation method described in step b is as follows: using foamed nickel coated positive electrode slurry, after drying, rolling, welding, cutting, and powder cleaning, the positive electrode sheet is made and packaged in a separator bag.

8. The method for preparing the aqueous dual-platform battery according to claim 7, characterized in that, The positive electrode slurry is a mixture of spherical nickel hydroxide, carboxymethyl cellulose binder, polytetrafluoroethylene, carbon powder, and pure water; the spherical nickel hydroxide is zinc-doped spherical nickel hydroxide or zinc-doped cobalt-coated spherical nickel hydroxide.

9. The method for preparing the aqueous dual-platform battery according to claim 1, characterized in that, The electrolyte injected in step b is a solution of 5.5~6.5 mol / L KOH + 0.45~0.55 mol / L LiOH + 0.45~0.55 mol / L NaOH.

10. An aqueous dual-platform battery prepared by any one of the preparation methods according to claims 1-9.

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