Low-temperature electrolyte preparation device and method for zinc-silver reserve battery

Abstract

The invention relates to the technical field of zinc-silver reserve batteries, in particular to a low-temperature electrolyte preparation device and method for a zinc-silver reserve battery, and the method comprises the following steps: S1, preparing a basic electrolyte, S2, preparing a composite functional additive, S3, mixing a composite electrolyte, and S4, carrying out vacuum degassing treatment. The device comprises a mixing tank, a liquid density sensor is arranged in the mixing tank, and an additive feeding assembly is arranged at the top of the mixing tank; a rotation driving part is fixedly connected to the top of the mixing tank and fixedly connected with a rotating shaft, and a first stirring paddle assembly is arranged at the bottom of the rotating shaft; the rotating shaft is sleeved with a sleeve, a second stirring paddle assembly is arranged at the bottom of the sleeve, and a transmission assembly is arranged between the second stirring paddle assembly and the rotating shaft. The electrolyte is prepared by introducing the composite functional additive, the working performance of the zinc-silver battery under the wide temperature range condition is improved, the preparation device in a specific stirring mode is combined for preparation, the mixing efficiency of the additive and the basic electrolyte is guaranteed, and the finished product quality of the low-temperature electrolyte is improved.

Description

Technical Field

[0001] This invention relates to the field of zinc-silver reserve battery technology, and more specifically to a low-temperature electrolyte preparation apparatus and method for zinc-silver reserve batteries. Background Technology

[0002] Zinc-silver backup batteries, as a key special military chemical power source, are widely used in high-precision equipment fields with extremely demanding power supply performance requirements, such as missile guidance systems, torpedo propulsion devices, and aerospace emergency power supplies, due to their significant advantages such as highly stable discharge voltage, excellent voltage accuracy, good inherent safety, and ultra-long storage life (usually exceeding 10 years).

[0003] To meet the reliable operation requirements of zinc-silver backup batteries in a wide temperature range of -20℃ to +50℃, current engineering practices mainly adopt two types of technical solutions: one is an external temperature control system that integrates thin-film heating elements (such as Pt resistance wires) and vacuum insulation layers, such as the heating and insulation system of airborne missile battery packs. This system preheats the battery with an external power source to maintain the fluidity of the electrolyte in a low-temperature environment and ensure the activation response speed. The other type is a mechanically reinforced design that uses a thickened high-strength shell and a built-in pressure relief valve. This design improves the shell's pressure-bearing capacity and pressure relief mechanism to address the problem of increased internal pressure caused by hydrogen evolution at the zinc negative electrode under high-temperature conditions.

[0004] While existing external heating and insulation technologies, along with mechanical reinforcement of the casing, have alleviated the bottleneck of wide-temperature-range environmental adaptability of zinc-silver backup batteries to some extent, they have not yet overcome core technological bottlenecks. For example, adding heating elements and thickening the casing to address low-temperature operating requirements and high-temperature internal pressure issues, while offering advantages in ease of operation and cost control, has led to significant system-level performance losses. Most notably, the additional devices drastically reduce battery energy density, fundamentally conflicting with the equipment's technical demands for miniaturization, lightweight design, and long operating range. Furthermore, and more critically, these external interventions fail to address the fundamental electrochemical contradictions within the battery. At low temperatures, the heating device cannot eliminate the activation lag and capacity decay caused by sluggish electrolyte wetting kinetics and zinc electrode passivation. At high temperatures, the thickened casing cannot suppress the irreversible impact of the continuous corrosion and hydrogen evolution side reaction of the zinc anode on the battery's electrochemical performance and operational safety. Therefore, there is an urgent need for a low-temperature (wide temperature range) electrolyte preparation device and method for zinc-silver backup batteries, and to prepare an electrolyte additive that has the characteristics of high efficiency, broad applicability and low cost, and can be adapted to extreme high and low temperature conditions. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a low-temperature electrolyte preparation apparatus and method for zinc-silver reserve batteries. The method introduces composite functional additives to prepare the electrolyte, improving the performance of zinc-silver batteries under a wide temperature range. Furthermore, it utilizes a preparation apparatus with a specific stirring method to ensure efficient mixing of the additives and the base electrolyte, thereby improving the final quality of the low-temperature electrolyte.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing a low-temperature electrolyte for a zinc-silver storage battery, comprising the following steps: S1. Preparation of basic electrolyte: Under the protection of inert gas, add analytical grade potassium hydroxide solid to deionized water and stir until completely dissolved to prepare a potassium hydroxide solution with a molar concentration of 7 mol / L. Control the solution temperature to not exceed 30℃. S2. Preparation of composite functional additives: Dimethyl sulfoxide is used as a functional additive. Impurities are removed by filtration through a 0.22μm organic phase filter membrane to obtain additive monomers with a purity ≥99.9%. S3. Mixing of composite electrolyte: Under constant temperature of 25℃, the additive monomer prepared in S2 is added to the potassium hydroxide solution prepared in S1 and stirred for 60 min to obtain the composite electrolyte system. S4. Vacuum degassing treatment: Place the compounded electrolyte in an environment with a vacuum degree ≤0.09 MPa for 30 minutes to degas, remove dissolved oxygen and bubbles, and obtain the low-temperature electrolyte for zinc-silver reserve batteries.

[0007] The above approach has the following beneficial effects: 1. Dimethyl sulfoxide (DMSO) is used as a functional additive. DMSO has a large number of hydrogen and oxygen atoms, which can effectively disrupt the hydrogen bond network of the electrolyte, lower the freezing point of the electrolyte, improve the fluidity of the electrolyte, and enhance the activation speed of the battery under low temperature conditions.

[0008] 2. DMSO, as an additive, can slow down the self-corrosion hydrogen evolution reaction of the electrode and inhibit electrode passivation by adsorbing onto the surface of the zinc negative electrode.

[0009] Furthermore, in the mixing of the additive monomer and potassium hydroxide solution in S3, the volume ratio of the additive monomer is 2% to 5% of the total volume of the composite electrolyte system.

[0010] Beneficial effects: This ratio range ensures that the highly polar sulfoxide groups in dimethyl sulfoxide are fully inserted into the hydrogen bond network of the base electrolyte, effectively disrupting the hydrogen bonding between water molecules to lower the freezing point and improve low-temperature fluidity. At the same time, it allows a sufficient number of additive molecules to be directionally adsorbed onto the zinc anode surface to form a complete physical isolation layer. Controlling the proportion to within 5% avoids the decrease in electrolyte ionic conductivity or the obstruction of ion transport at the electrode interface caused by excessive additives, ensuring that the electrolyte system has both good electrochemical activity and stability over a wide temperature range, achieving synergistic optimization of low-temperature rapid activation, high-temperature safety protection, and overall performance.

[0011] Furthermore, a low-temperature electrolyte preparation apparatus for zinc-silver storage batteries, based on the process characteristics of the composite electrolyte mixing in the above-mentioned low-temperature electrolyte preparation method for zinc-silver storage batteries, includes a mixing tank, a solution inlet pipe connected to the top of the mixing tank, a liquid density sensor installed inside the mixing tank, a controller connected to the liquid density sensor signal, and an additive dispensing component installed at the top of the mixing tank for storing additives and regulating the dispensing amount, the additive dispensing component being connected to the controller signal. The outside of the mixing tank is equipped with a temperature regulating component for controlling the mixing environment temperature, and the temperature regulating component is connected to the controller signal. A rotary drive is fixedly connected to the top of the mixing tank. The output shaft of the rotary drive passes through the inner top wall of the mixing tank and extends into the mixing tank. The output shaft of the rotary drive is coaxially fixedly connected to a rotating shaft that coincides with the axis of the mixing tank. A first stirring paddle assembly for dispersing additives is provided at the bottom of the rotating shaft. A sleeve is rotatably connected to the top wall of the mixing tank on the outside of the rotating shaft. A second stirring paddle assembly for uniformly agitating the solution is provided at the bottom of the sleeve. A transmission assembly for driving the rotating shaft to rotate on the second stirring assembly is provided between the second stirring paddle assembly and the rotating shaft. The bottom of the mixing tank is connected to an outlet.

[0012] The technical principle of the above scheme is as follows: the prepared basic electrolyte is added to the mixing tank through the solution inlet pipe, and then the additive dosing component and the temperature regulation component are coordinated and controlled by the controller. Combined with the real-time feedback of the liquid density in the mixing tank by the liquid density sensor, the additive is accurately added. The temperature regulation component is used to achieve constant temperature control of the mixing environment of the additive and the basic electrolyte. At the same time, regarding the mixing and stirring, the rotating drive component drives the rotating shaft to drive the first stirring paddle assembly for local dispersion. The rotating shaft drives the sleeve and the second stirring paddle assembly through the transmission component to achieve overall tumbling. The dual stirring system works together to complete the electrolyte mixing process.

[0013] The above-mentioned device has the following beneficial effects: 1. Based on the volatile nature of dimethyl sulfoxide and the requirement for precise control of its volume ratio of 2% to 5%, a first stirring component is used to form a local high-shear flow field to achieve rapid dispersion of DMSO microdroplets. This is combined with a second stirring component to promote the overall circulation of the electrolyte, pushing the locally dispersed microdroplets to various areas of the mixing tank, avoiding agglomeration and promoting molecular-level uniform mixing. The synergistic effect of the two components not only ensures precise control of the additive volume ratio but also achieves macroscopic uniformity and microscopic dispersion of the additive with the base electrolyte, thereby ensuring the high quality of the electrolyte preparation product.

[0014] 2. The temperature control component regulates the temperature inside the mixing tank. Combined with real-time feedback from the temperature sensor and dynamic adjustment by the controller, it maintains a constant temperature in the mixing environment to suppress evaporation loss and ensures that the actual amount of additives added deviates from the target proportion within the allowable range.

[0015] 3. The synergistic effect of the first and second stirring components ensures rapid dispersion and macroscopic uniform mixing of DMSO droplets, while avoiding the continuous heat accumulation caused by the overall high-speed rotation of conventional high-shear stirring, thus significantly reducing the risk of evaporation loss of DMSO due to local overheating.

[0016] Furthermore, the additive dispensing assembly includes a storage box and a metering pump fixedly connected to the top wall of the mixing tank. The storage box is filled with additive monomers. The storage box is connected to the input end of the metering pump, and the output end of the metering pump is connected to an additive dispensing pipe. The additive dispensing pipe extends through the side wall of the mixing tank into the mixing tank.

[0017] Beneficial effects: The additive monomers are stored in the storage box, and the metering pump extracts a quantitative amount of additive according to the controller instructions and injects it into the mixing tank through the additive injection pipe, forming a closed-loop injection control. This enables precise control of the amount of additive injected, ensuring that the volume fraction of DMSO remains stable within the design range of 2% to 5%. This ensures that its core mechanisms, such as breaking hydrogen bonds of water molecules and forming an electrode isolation layer, are functioning stably, and improves the consistency of electrolyte performance over a wide temperature range.

[0018] Furthermore, the outlet of the additive input pipe located inside the mixing tank adopts a slanted structure at a 45° angle to the inner wall of the mixing tank.

[0019] Beneficial effects: The 45° angled cut structure allows the additives to flow out obliquely along the inner wall of the mixing tank, reducing liquid flow impact and avoiding air entrainment, reducing the probability of bubble generation, preventing bubbles from hindering the uniform wetting of the electrodes by the electrolyte, and ensuring the stability of the discharge voltage platform and the activation response speed.

[0020] Furthermore, the temperature control component includes a temperature control jacket layer and a pump component. The temperature control jacket layer is fixedly sleeved on the outside of the mixing tank. A first electromagnetic regulating valve and a second electromagnetic regulating valve are connected to the temperature control jacket layer. The first electromagnetic regulating valve is connected to the output end of the pump component, the second electromagnetic regulating valve is connected to an outlet pipe, and the input end of the pump component is connected to an inlet pipe. A temperature sensor is fixedly connected inside the mixing tank, and the temperature of the liquid flowing into the inlet pipe is controlled within 20-25℃.

[0021] Beneficial effects: By circulating 20-25℃ constant temperature water through the temperature control jacket layer and pump components, combined with real-time feedback from the temperature sensor, the controller adjusts the electromagnetic regulating valve to control the heat exchange rate, maintain a constant mixing environment temperature, avoid abnormal electrolyte density and changes in additive efficiency caused by temperature fluctuations, ensure the consistency of hydrogen bonding between DMSO and water molecules and electrode adsorption effect, and improve the stability of the electrolyte system.

[0022] Furthermore, the first impeller assembly includes several turbine-type impellers fixedly connected to the rotating shaft, and the turbine-type impellers are evenly distributed along the circumference of the rotating shaft.

[0023] Beneficial effects: The turbine-type stirring blades are distributed circumferentially along the rotating shaft. The high-speed rotation creates a local high-shear flow field, which quickly disperses DMSO droplets to avoid local agglomeration, promotes uniform dispersion of additives at the molecular level, reduces the concentration gradient of the mixture, ensures the consistency of its concentration in different areas of the electrolyte, and enhances the micro-dispersion effect.

[0024] Furthermore, the transmission assembly includes an input gear, a transmission gear, and an output gear ring. The input gear is coaxially sleeved and fixed on the rotating shaft. A connecting rod is rotatably connected to the top surface of the transmission gear. The connecting rod is fixedly connected to the inner top wall of the mixing tank. The output gear ring is rotatably connected to the bottom end of the sleeve. The two sides of the transmission gear mesh with the input gear and the output gear ring, respectively.

[0025] Beneficial effects: Through the meshing transmission of the input gear, transmission gear and output gear ring, the power of the rotating shaft is transmitted to the sleeve, realizing the linkage between the second stirring paddle assembly and the rotating shaft. The gear transmission realizes the same source drive of the first stirring assembly and the second stirring assembly, ensuring the matching of local shear and overall circulation, improving mixing efficiency and avoiding the mixing dead zone problem of traditional single stirring mode.

[0026] Furthermore, the second stirring assembly includes an anchor-type stirring blade and a rotating drum. The top of the rotating drum is fixedly connected to the bottom of the output toothed ring, the anchor-type stirring blade is fixedly connected to the side wall of the rotating drum, and a scraper is fixedly connected to the outside of the anchor-type stirring blade. The scraper is made of polytetrafluoroethylene material and is attached to the inner wall of the mixing tank. The shape of the anchor-type stirring blades corresponds to the cross-sectional shape of the mixing tank.

[0027] Beneficial effects: The anchor-type stirring blades are matched with the cross-sectional shape of the mixing tank, and the outer PTFE scraper is attached to the tank wall. The anchor structure reduces the dead corners of the stirring and scrapes off the liquid attached to the wall, avoiding residues that affect the concentration ratio. The PTFE material is resistant to strong alkali corrosion and DMSO swelling, ensuring the purity of the electrolyte and the stability of the zinc negative electrode, and preventing performance degradation caused by the introduction of impurities.

[0028] Furthermore, the input gear, transmission gear, and output gear ring all have the same module, but the number of teeth on the input gear is less than the number of teeth on the output gear ring. This results in the anchor-type stirring blade connected to the output gear ring rotating at a lower speed than the turbine-type stirring blade connected to the input gear.

[0029] Beneficial effects: The gear transmission ratio design makes the anchor impeller rotate at a lower speed than the turbine impeller. The low-speed anchor impeller achieves overall circulation inside the vessel, pushing the DMSO droplets generated by the high-speed turbine impeller to each area, avoiding local agglomeration and promoting uniform distribution. At the same time, it suppresses the DMSO evaporation caused by traditional high-shear heat generation, ensuring the accuracy of volume fraction control.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] Figure 1 This is a schematic flowchart of the preparation method in the embodiment of the low-temperature electrolyte preparation apparatus and method for zinc-silver reserve batteries of the present invention; Figure 2 This is a schematic diagram of the molecular structure of DMSO in the embodiments of the low-temperature electrolyte preparation apparatus and method for zinc-silver storage batteries of the present invention; Figure 3 This is an isometric view of the overall structure of the preparation device in the embodiment of the low-temperature electrolyte preparation device and method for zinc-silver reserve batteries of the present invention; Figure 4 This is an isometric sectional view of the mixing tank in an embodiment of the low-temperature electrolyte preparation apparatus and method for zinc-silver reserve batteries of the present invention; Figure 5 This is a partial cross-sectional view of the transmission component in an embodiment of the low-temperature electrolyte preparation apparatus and method for zinc-silver reserve batteries of the present invention.

[0032] The reference numerals in the accompanying drawings include: 1. Mixing tank; 2. Solution inlet pipe; 3. Storage box; 4. Metering pump; 5. Additive inlet pipe; 6. Temperature control jacket layer; 7. Pump component; 8. First electromagnetic regulating valve; 9. Second electromagnetic regulating valve; 10. Inlet pipe; 11. Outlet pipe; 12. Rotary drive component; 13. Rotary shaft; 14. Turbine impeller; 15. Sleeve; 16. Input gear; 17. Transmission gear; 18. Output gear ring; 19. Connecting rod; 20. Anchor impeller; 21. Rotary drum; 22. Scraper belt; 23. Liquid outlet. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The following detailed description illustrates the specific implementation method: Example 1: Existing wide-temperature-range application technologies for zinc-silver backup batteries mainly rely on external heating (adding heating elements to cope with low temperatures) and mechanical reinforcement (thickening the casing to resist high-temperature internal pressure). Adding mechanical reinforcement or external heating devices significantly reduces battery energy density and conflicts with the requirements for miniaturization, lightweighting, and long-range operation. Furthermore, it fails to resolve the fundamental electrochemical contradictions within the battery, namely, slow electrolyte wetting at low temperatures, activation lag and capacity decay caused by zinc electrode passivation, and irreversible damage to performance and lifespan due to continuous corrosion and hydrogen evolution side reactions of the zinc anode at high temperatures. Therefore, this embodiment provides a method for preparing a low-temperature electrolyte for zinc-silver backup batteries, specifically as follows: Figure 1 As shown, it includes the following steps: S1. Preparation of basic electrolyte: Under the protection of inert gas, add analytical grade potassium hydroxide solid to deionized water and stir until completely dissolved to prepare a potassium hydroxide (KOH) solution with a molar concentration of 7 mol / L. Control the solution temperature to not exceed 30℃.

[0037] S2. Preparation of composite functional additives: Dimethyl sulfoxide (DMSO) is used as a functional additive. Impurities are removed by filtration through a 0.22μm organic phase filter membrane to obtain an additive monomer with a purity ≥99.9%. The molecular structure of the additive monomer contains a sulfoxide group S=O and two methyl groups -CH3.

[0038] S3. Mixing of the composite electrolyte: Under constant temperature of 25℃, the additive monomer prepared in S2 is added to the potassium hydroxide solution prepared in S1 and stirred for 60 min to obtain the composite electrolyte system. The volume ratio of the additive monomer is 2%~5% of the total volume of the composite electrolyte system. This ratio range ensures that the strongly polar sulfoxide groups in dimethyl sulfoxide are fully inserted into the hydrogen bond network of the basic electrolyte, effectively destroying the hydrogen bond interaction between water molecules to lower the freezing point and improve low-temperature fluidity. At the same time, it allows a sufficient number of additive molecules to be directionally adsorbed on the zinc anode surface to form a complete physical isolation layer. Controlling the ratio to within 5% can avoid the decrease in electrolyte ionic conductivity or the obstruction of ion transport at the electrode interface due to excessive additives, ensuring that the electrolyte system has good electrochemical activity and stability in a wide temperature range, and achieving synergistic optimization of low-temperature rapid activation, high-temperature safety protection, and overall performance.

[0039] S4. Vacuum Degassing Treatment: The compounded electrolyte is placed in an environment with a vacuum degree ≤0.09 MPa for 30 minutes to remove dissolved oxygen and bubbles, thus obtaining the low-temperature electrolyte for zinc-silver reserve batteries. Vacuum degassing treatment can effectively remove dissolved oxygen and bubbles from the electrolyte. The removal of dissolved oxygen can inhibit the oxidation side reaction between dissolved oxygen and zinc electrode, avoiding the loss of electrode active material and the aggravation of passivation. The elimination of bubbles can improve the uniform wettability of the electrolyte to the electrode, prevent local activation difficulties or uneven reactions caused by bubble blockage, and thus ensure the rapid activation efficiency of the battery in low-temperature environment and the stability of the discharge voltage platform in a wide temperature range. At the same time, it reduces the fluctuation of electrolyte flow caused by bubbles, extends battery storage and cycle life, and improves overall electrochemical performance and safety of use.

[0040] The special feature is that, in the electrolyte preparation proposed in this embodiment, the addition of DMSO improves the electrolyte performance through the following mechanism: Regarding the low-temperature improvement mechanism, the highly polar sulfoxide groups in DMSO insert into the electrolyte hydrogen bond network, disrupting the hydrogen bonding between water molecules (as shown in the appendix). Figure 2 The schematic diagram of the DMSO molecular structure shown significantly reduces the freezing point and improves the fluidity of the electrolyte, enabling the battery to be quickly activated even at low temperatures (-10℃), while also alleviating zinc electrode passivation and ensuring the stability of the discharge voltage platform. Regarding the high-temperature protection mechanism, during the discharge process, DMSO is directionally adsorbed onto the surface of the zinc negative electrode, forming a physical isolation layer that blocks the direct contact between water molecules and active zinc, thus inhibiting the hydrogen evolution reaction (2H2O + 2e-). - →H2+2OH - This reduces the hydrogen evolution rate under high-temperature conditions and lowers the internal pressure of the battery during use, thus eliminating high-temperature safety hazards.

[0041] The following experiments were conducted based on the preparation method proposed in this embodiment. (1) Experimental objective: Verify whether the low-temperature electrolyte (containing dimethyl sulfoxide (DMSO) additive) prepared by the method described in this embodiment can: 1. Improve the problems of slow electrolyte wetting at low temperatures and activation lag and capacity decay caused by zinc electrode passivation; 2. Suppress the hydrogen evolution side reaction of continuous corrosion of zinc anode and reduce the risk of internal pressure under high temperature environment; 3. Without relying on external heating or mechanical reinforcement devices, avoid the decrease in battery energy density and meet the requirements for equipment miniaturization and lightweighting.

[0042] (2) Experimental steps 1. Sample preparation Experimental group: Electrolyte prepared using the method in Example 1 Control group: conventional electrolyte (7 mol / L KOH solution, without DMSO additive, prepared by conventional stirring).

[0043] 2. Battery assembly Zinc-silver reserve battery casings of the same specifications were selected and divided into two groups: Experimental group batteries: Injected with the electrolyte from the above-mentioned experimental group; Control group battery: injected with conventional electrolyte (control group).

[0044] Three parallel samples were prepared for each group to ensure that the electrode materials, diaphragms, and assembly processes were completely consistent.

[0045] 3. Performance Testing Low-temperature activation and capacity testing (-10℃): Place the battery in a low-temperature chamber (-10℃) for 2 hours and record the activation time from activation trigger to voltage reaching the rated value (e.g., 10V). The discharge capacity and capacity retention rate were recorded by superimposing a 0.5C constant current with a 5C pulse discharge (compared with the capacity at room temperature of 25℃).

[0046] High-temperature hydrogen evolution and safety test (45℃): The battery was stored in a 45°C constant temperature chamber for 2 hours, and then discharged. The amount of hydrogen evolution was collected and measured by water displacement method. Detect changes in the battery's internal pressure (using a pressure sensor) and the rate of discharge capacity decay after storage.

[0047] Energy density verification: By comparing the volumetric energy density (total discharge energy / battery volume) of the two battery groups, we can verify whether the experimental group avoids the energy density decrease caused by external devices.

[0048] (3) Experimental data

[0049] (4) Experimental conclusions 1. The activation time (3 s) of the experimental group at -10℃ was 50% shorter than that of the control group (6 s), and the capacity retention rate (63%) was significantly higher than that of the control group (45%). This proves that DMSO reduces the freezing point and improves low-temperature fluidity by destroying the hydrogen bond network of the electrolyte, and at the same time, it adsorbs on the zinc anode to inhibit passivation, effectively solving the problems of "slow low-temperature wetting, delayed activation and capacity decay".

[0050] 2. The amount of hydrogen evolution at high temperature in the experimental group (5.3 mL) was only 35% of that in the control group (9.3 mL), and the increase in internal pressure (0.4 MPa) was much lower than that in the control group (0.7 MPa). This indicates that the physical isolation layer formed by DMSO on the zinc anode surface effectively blocks the hydrogen evolution reaction, thus solving the core contradiction of increased internal pressure and irreversible performance damage caused by high-temperature zinc anode corrosion and hydrogen evolution.

[0051] 3. The energy density of the experimental group (140 Wh / L) was significantly higher than that of the control group (120 Wh / L), proving that the method does not require external heating or mechanical reinforcement devices, avoiding the defect of the traditional solution where additional devices would reduce the energy density, and meeting the requirements of equipment miniaturization and lightweighting.

[0052] Example 2: The difference from Example 1 is that this example proposes a low-temperature electrolyte preparation apparatus for zinc-silver storage batteries. This apparatus is based on the process characteristics of composite electrolyte mixing in the low-temperature electrolyte preparation method for zinc-silver storage batteries described in Example 1, specifically as follows: Figure 3 As shown, including mixing tank 1, due to the special characteristics of the composite electrolyte with added DMSO, the volume ratio of the additive monomers and the mixing environment temperature need to be strictly controlled during the mixing process: Regarding the volume ratio control of additive monomers, in this embodiment, a solution inlet pipe 2 (for adding potassium hydroxide solution) is connected to the top of the mixing tank 1. A liquid density sensor is fixedly connected inside the mixing tank 1 by screws, and the liquid density sensor signal is connected to a controller. By detecting the real-time density of the solution in the mixing tank 1, and using the quantitative relationship between the solution density and the amount of DMSO added, combined with the density of the basic electrolyte and the target concentration, the amount of DMSO to be added is calculated to achieve precise compounding of the composite electrolyte system.

[0053] Based on the calculation results of DMSO dosage, the top of mixing tank 1 is equipped with an additive dispensing component for storing additives and regulating their dosage. Figure 3 and Figure 4As shown, the additive dispensing assembly includes a storage box 3 and a metering pump 4, which are fixed to the outer top wall of the mixing tank 1 by screws. The storage box 3 is filled with additive monomers. The storage box 3 is connected to the input end of the metering pump 4, and the output end of the metering pump 4 is connected to an additive injection pipe 5. The metering pump 4 is connected to the controller. The additive injection pipe 5 extends through the side wall of the mixing tank 1 into the mixing tank 1. The controller drives the metering pump 4 to extract additive monomers from the storage box 3 according to a quantitative amount (calculated based on the solution density) and deliver them into the mixing tank 1 through the additive injection pipe 5. At the same time, the real-time density signal in the mixing tank 1 is fed back to the controller. The controller dynamically adjusts the metering pump 4 by comparing the deviation between the actual density and the target density. The driving parameters of metering pump 4 are adjusted to correct the DMSO dosage, achieving closed-loop control. This design ensures that the initial DMSO dosage meets the calculation requirements through precise control of metering pump 4, and dynamically compensates for concentration fluctuations during the mixing process through real-time density feedback. This keeps the volume ratio of DMSO stably controlled within the design range of 2% to 5%, ensuring that its core mechanisms, such as the strong polar sulfoxide groups fully disrupting hydrogen bonds in water molecules to lower the freezing point and directional adsorption to form an isolation layer to inhibit hydrogen evolution reaction, are stably functioning. Ultimately, this guarantees the rapid activation performance of the composite electrolyte at -10℃ and the safety protection effect at 50℃, improving the stability and reliability of zinc-silver backup batteries in a wide temperature range.

[0054] In particular, such as Figure 4 As shown, the outlet of the additive injection pipe 5 located in the mixing tank 1 adopts a 45° angled structure with respect to the inner wall of the mixing tank 1. The 45° angled structure allows the additive monomer to flow out obliquely along the inner wall of the mixing tank 1 to reduce liquid flow impact and avoid air entrainment, thereby reducing the probability of bubble generation during the injection process (too many bubbles will hinder the uniform wetting of the electrode by the electrolyte, leading to local activation difficulties, uneven reaction and fluctuations in the discharge voltage plateau).

[0055] Regarding temperature control of the mixing environment, this embodiment provides a temperature regulating component for temperature control of the mixing environment on the outside of the mixing tank 1. The temperature regulating component is signal-connected to the controller and includes a temperature control jacket layer 6 and a pump component 7, such as... Figure 4As shown, the temperature-controlled jacket 6 is fixedly fitted onto the outside of the mixing tank 1 by fasteners (temperature-controlled water flows inside the temperature-controlled jacket 6 to exchange heat with the mixing tank 1 and achieve temperature control). A first electromagnetic regulating valve 8 and a second electromagnetic regulating valve 9 are connected to the temperature-controlled jacket 6. The first electromagnetic regulating valve 8 is connected to the output end of the pump component 7, and the second electromagnetic regulating valve 9 is connected to a water outlet pipe 11 (the first electromagnetic regulating valve 8 and the second regulating valve are used to regulate and adapt the flow rate of the liquid used to control the temperature within the temperature-controlled jacket 6, i.e., the rate of heat exchange). The input end of the pump component 7 is connected to a water inlet pipe 10. A temperature sensor is fixedly connected inside the mixing tank 1 by bolts, and the temperature of the liquid flowing into the water inlet pipe 10 is controlled within 20-25℃. The controller, based on the real-time temperature feedback from the temperature sensor inside the mixing tank 1, controls the operation of the first electromagnetic regulating valve 8, the second electromagnetic regulating valve 9, and the pump component 7. This allows the 20-25℃ constant temperature water introduced through the inlet pipe 10 to circulate within the temperature control jacket layer 6 and exchange heat with the mixing tank 1, thereby regulating the mixing environment temperature. This stable electrolyte mixing temperature environment ensures the consistency of hydrogen bond breaking between DMSO and water molecules and the adsorption effect on the electrode surface. It also prevents abnormal electrolyte density caused by temperature fluctuations from affecting the accuracy of DMSO dosing. Simultaneously, it ensures that the electrolyte maintains stable physicochemical properties (such as viscosity and ionic conductivity) during the mixing process, ensuring the performance stability of the composite electrolyte system in a wide temperature range.

[0056] To ensure the performance of the prepared low-temperature electrolyte, the mixing of DMSO and KOH solutions must simultaneously meet the requirements of "macroscopic uniformity" (i.e., no stratification) and "microscopic dispersion" (DMSO molecules uniformly inserted into the KOH hydrogen bond network). However, traditional high-shear stirring can easily lead to local overheating and volatilization of DMSO (boiling point 189℃), while low-speed stirring cannot break the interfacial tension between DMSO and KOH solutions.

[0057] Based on the aforementioned requirements for stirring, the special feature of this embodiment is that it combines... Figure 3 , Figure 4 and Figure 5As shown, a rotating drive component 12 (preferably a servo motor) is bolted to the top of the mixing tank 1. The output shaft of the rotating drive component 12 passes through the inner top wall of the mixing tank 1 and extends into the mixing tank 1. The output shaft of the servo motor is coaxially fixed to a rotating shaft 13 that coincides with the axis of the mixing tank 1 via a coupling. A first stirring paddle assembly is provided at the bottom of the rotating shaft 13. The first stirring paddle assembly includes several turbine-type stirring blades 14 that are fused and fixed to the rotating shaft 13. The several turbine-type stirring blades 14 are evenly distributed along the circumference of the rotating shaft 13. By forming a local high-shear flow field in the region of the turbine-type stirring blades 14, DMSO is quickly dispersed into the base electrolyte to avoid local agglomeration of additive monomers and reduce the probability of concentration gradients formed in the mixture during the mixing process. This promotes the molecular-level uniform dispersion of DMSO in the electrolyte and ensures the consistency of its concentration in each region of the mixing tank 1.

[0058] Furthermore, in this embodiment, a sleeve 15 is rotatably connected to the top wall of the mixing tank 1 and fitted outside the rotating shaft 13, in conjunction with... Figure 4 and Figure 5 As shown, the bottom of the sleeve 15 is provided with a second stirring paddle assembly for uniformly agitating the solution. A transmission assembly is provided between the second stirring paddle assembly and the rotating shaft 13 for rotating the rotating shaft 13 around the second stirring paddle assembly. The transmission assembly includes an input gear 16, a transmission gear 17, and an output gear ring 18 (the connection relationship between the input gear 16, the transmission gear 17, and the output gear ring 18 is as follows...). Figure 5As shown), the input gear 16 is coaxially sleeved and fixed on the rotating shaft 13 (the input gear 16 is driven to rotate by the rotating shaft 13). The top surface of the transmission gear 17 is rotatably connected to the connecting rod 19 through the bearing. The connecting rod 19 is fused and fixed to the inner top wall of the mixing tank 1 (the transmission gear 17 can only rotate on its own, and its spatial position is limited). The output gear ring 18 is rotatably connected to the bottom end of the sleeve 15 through the bearing. The two sides of the transmission gear 17 are respectively meshed with the input gear 16 and the output gear ring 18 (the rotation of the input gear 16 is transmitted to the output gear ring 18 through the transmission gear 17). Based on this, the second stirring assembly includes an anchor-type stirring blade 20 and a rotating drum 21. The top end of the rotating drum 21 is welded to the bottom end of the output gear ring 18 (the rotation of the output gear ring 18 drives the rotating drum 21 to rotate). The anchor-type stirring blade 20 is fused to the side wall of the rotating drum 21. (The rotation drives the anchor-type stirring blade 20 to rotate). A scraper 22 is fixedly connected to the outside of the anchor-type stirring blade 20 (the scraper 22 is used to remove the liquid adhering to the side wall of the mixing tank 1). The scraper 22 is made of polytetrafluoroethylene (the advantage of the polytetrafluoroethylene material is that it is resistant to high-concentration strong alkali KOH corrosion without releasing metal ions to avoid accelerating the self-corrosion of the zinc negative electrode, and it is resistant to swelling by polar organic solvent DMSO without introducing organic impurities, thereby ensuring the purity of the electrolyte system and the stability of the zinc negative electrode). The scraper 22 is attached to the inner wall of the mixing tank 1. The shape of the anchor-type stirring blade 20 corresponds to the cross-sectional shape of the mixing tank 1 (the anchor-type stirring blade 20 can fit against the tank wall to reduce the stirring dead angle and improve the mixing uniformity. At the same time, the scraper 22 efficiently removes the liquid adhering to the wall to avoid residue affecting the stability of the electrolyte concentration).

[0059] Specifically, in this embodiment, the input gear 16, transmission gear 17, and output gear ring 18 all have the same module. The number of teeth in the input gear 16 is less than the number of teeth in the output gear ring 18. This results in the anchor stirring blade 20 connected to the output gear ring 18 rotating at a lower speed than the turbine stirring blade 14 connected to the input gear 16. This design enables the anchor stirring blade 20 (rotating drum 21) to achieve overall circulation of the electrolyte to be mixed in the mixing tank 1 at a low speed of 80-120 rpm. It also pushes the DMSO microdroplets formed by the local high-shear dispersion generated by the turbine stirring blade 14 (rotating shaft 13) at a high speed of 300-400 rpm to various areas of the mixing tank 1, avoiding local agglomeration of microdroplets and promoting their uniform distribution in the electrolyte. This achieves efficient mixing of DMSO from microdroplet dispersion to overall uniformity.

[0060] Through the synergistic effect of turbine-type stirring blade 14 (local shear stirring) and anchor-type stirring blade 20 (overall stirring and tumbling), the macroscopic mixing uniformity of the electrolyte system is ensured, and the microscopic dispersion effect of DMSO is achieved. At the same time, by suppressing the heat accumulation in the traditional high-shear stirring process, the risk of insufficient control accuracy of 2%~5% volume fraction of DMSO due to evaporation loss is reduced, thereby ensuring the accurate realization of the target ratio.

[0061] The bottom of mixing tank 1 is connected to a liquid outlet 23, such as... Figure 4 As shown, the mixed electrolyte can be discharged under gravity, avoiding residue at the bottom of the tank that could cause concentration ratio deviations in subsequent batches.

[0062] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a low-temperature electrolyte for zinc-silver reserve batteries, characterized in that, Includes the following steps: S1. Preparation of basic electrolyte: Under the protection of inert gas, add analytical grade potassium hydroxide solid to deionized water and stir until completely dissolved to prepare a potassium hydroxide solution with a molar concentration of 7 mol / L. Control the solution temperature to not exceed 30℃. S2. Preparation of composite functional additives: Dimethyl sulfoxide is used as a functional additive. Impurities are removed by filtration through a 0.22μm organic phase filter membrane to obtain additive monomers with a purity ≥99.9%. S3. Mixing of composite electrolyte: Under constant temperature of 25℃, the additive monomer prepared in S2 is added to the potassium hydroxide solution prepared in S1 and stirred for 60 min to obtain the composite electrolyte system. S4. Vacuum degassing treatment: Place the compounded electrolyte in an environment with a vacuum degree ≤0.09 MPa for 30 min to degas, remove dissolved oxygen and bubbles, and obtain the low-temperature electrolyte for zinc-silver reserve batteries.

2. The method for preparing a low-temperature electrolyte for a zinc-silver reserve battery according to claim 1, characterized in that, In the mixing of additive monomers and potassium hydroxide solution in S3, the volume ratio of additive monomers is 2% to 5% of the total volume of the composite electrolyte system.

3. A low-temperature electrolyte preparation apparatus for zinc-silver storage batteries, based on the process characteristics of composite electrolyte mixing in the low-temperature electrolyte preparation method for zinc-silver storage batteries according to any one of claims 1-2, characterized in that, Includes a mixing tank (1), the top of the mixing tank (1) is connected to a solution inlet pipe (2), the mixing tank (1) is equipped with a liquid density sensor, the liquid density sensor signal is connected to a controller, the top of the mixing tank (1) is equipped with an additive dispensing component for storing additives and regulating the amount of additives dispensed, the additive dispensing component is connected to the controller signal; The mixing tank (1) is equipped with a temperature regulating component for regulating the mixing environment temperature on the outside, and the temperature regulating component is connected to the controller signal; A rotating drive (12) is fixedly connected to the top of the mixing tank (1). The output shaft of the rotating drive (12) passes through the inner top wall of the mixing tank (1) and extends into the mixing tank (1). The output shaft of the rotating drive (12) is coaxially fixedly connected to a rotating shaft (13) that coincides with the axis of the mixing tank (1). The bottom of the rotating shaft (13) is provided with a first stirring paddle assembly for dispersing additives. A sleeve (15) is rotatably connected to the top wall of the mixing tank (1) on the outside of the rotating shaft (13). A second stirring paddle assembly for uniformly stirring the solution is provided at the bottom of the sleeve (15). A transmission assembly for driving the rotating shaft (13) to rotate between the second stirring paddle assembly and the rotating shaft (13) is provided. The bottom of the mixing tank (1) is connected to the liquid outlet (23).

4. The low-temperature electrolyte preparation apparatus for zinc-silver reserve batteries according to claim 3, characterized in that, The additive dispensing assembly includes a storage box (3) and a metering pump (4) fixedly connected to the top wall of the mixing tank (1). The storage box (3) is filled with additive monomers. The storage box (3) is connected to the input end of the metering pump (4). The output end of the metering pump (4) is connected to an additive inlet pipe (5). The additive inlet pipe (5) extends through the side wall of the mixing tank (1) into the mixing tank (1).

5. The low-temperature electrolyte preparation apparatus for zinc-silver reserve batteries according to claim 4, characterized in that, The outlet of the additive input pipe (5) located inside the mixing tank (1) adopts a slanted structure with a 45° angle to the inner wall of the mixing tank (1).

6. The low-temperature electrolyte preparation apparatus for zinc-silver storage batteries according to claim 5, characterized in that, The temperature control assembly includes a temperature control jacket layer (6) and a pump component (7). The temperature control jacket layer (6) is fixedly sleeved on the outside of the mixing tank (1). A first electromagnetic regulating valve (8) and a second electromagnetic regulating valve (9) are connected to the temperature control jacket layer (6). The first electromagnetic regulating valve (8) is connected to the output end of the pump component (7). The second electromagnetic regulating valve (9) is connected to the water outlet pipe (11). The input end of the pump component (7) is connected to the water inlet pipe (10). A temperature sensor is fixedly connected inside the mixing tank (1), and the temperature of the liquid flowing into the water inlet pipe (10) is controlled within 20-25℃.

7. The low-temperature electrolyte preparation apparatus for zinc-silver reserve batteries according to claim 6, characterized in that, The first impeller assembly includes several turbine-type impellers (14) fixedly connected to the rotating shaft (13), and the several turbine-type impellers (14) are evenly distributed along the circumference of the rotating shaft (13).

8. The low-temperature electrolyte preparation apparatus for zinc-silver storage batteries according to claim 7, characterized in that, The transmission assembly includes an input gear (16), a transmission gear (17), and an output gear ring (18). The input gear (16) is coaxially sleeved and fixed on the rotating shaft (13). A connecting rod (19) is rotatably connected to the top surface of the transmission gear (17). The connecting rod (19) is fixedly connected to the inner top wall of the mixing tank (1). The output gear ring (18) is rotatably connected to the bottom end of the sleeve (15). The two sides of the transmission gear (17) mesh with the input gear (16) and the output gear ring (18) respectively.

9. The low-temperature electrolyte preparation apparatus for zinc-silver reserve batteries according to claim 8, characterized in that, The second stirring assembly includes an anchor-type stirring blade (20) and a rotating drum (21). The top of the rotating drum (21) is fixedly connected to the bottom of the output toothed ring (18). The anchor-type stirring blade (20) is fixedly connected to the side wall of the rotating drum (21). A scraper (22) is fixedly connected to the outside of the anchor-type stirring blade (20). The scraper (22) is made of polytetrafluoroethylene material and is attached to the inner wall of the mixing tank (1). The shape of the anchor-type stirring blade (20) corresponds to the cross-sectional shape of the mixing tank (1).

10. The low-temperature electrolyte preparation apparatus for zinc-silver reserve batteries according to claim 9, characterized in that, The input gear (16), transmission gear (17) and output gear ring (18) have the same module. The number of teeth of the input gear (16) is less than the number of teeth of the output gear ring (18). As a result, the rotational speed of the anchor-type stirring blade (20) connected to the output gear ring (18) is lower than the rotational speed of the turbine-type stirring blade (14) connected to the input gear (16).

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