A low-temperature-resistant dual-chamber acid-base decoupled zinc-air flow battery and application thereof

Abstract

The application relates to an anti-low-temperature dual-chamber acid-base decoupling zinc-air flow battery and application thereof, and belongs to the technical field of battery energy storage. The anti-low-temperature dual-chamber acid-base decoupling zinc-air flow battery adopts anti-low-temperature acid-base decoupling electrolytes, namely H3PO4+C2H6O2 (cathode acid chamber) and ZnCl2+NiCl2+C2H6O2+KOH (anode alkali chamber). The dual-chamber structure realizes partition regulation and control of electrolyte environments on the air cathode side and the zinc anode side, and ion conduction isolation components are utilized to realize charge transmission and acid-base electrolyte isolation, so that direct mixing of electrolytes on the two sides is avoided. The flow circulation unit can promote electrolyte flow, relieve problems such as electrolyte viscosity rise, ion transmission limitation and local concentration polarization at low temperatures and the like. The application can improve the battery performance, discharge stability and cycle service life of the zinc-air flow battery in a low-temperature environment, and can be used for low-temperature energy storage and standby power supply devices.

Description

Technical Field

[0001] This invention belongs to the field of battery energy storage technology, and specifically relates to a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery and its application. Background Technology

[0002] In zinc-air flow batteries, the electrolyte plays a crucial role in determining the battery reaction pathway, low-temperature ion transport, the reversibility of zinc deposition / dissolution processes, and electrode side reactions, thus directly affecting the battery's discharge voltage, cycle stability, and low-temperature performance. A suitable electrolyte system can regulate the solvation environment and interfacial reaction processes on the zinc anode side, reduce the effects of electrolyte freezing and limited mass transfer under low-temperature conditions, and improve the stability of zinc-air flow batteries during repeated charge-discharge cycles.

[0003] Existing zinc-air batteries mostly use a single alkaline electrolyte, which is prone to problems such as increased viscosity, restricted ion migration, increased polarization, and even icing at low temperatures. Simultaneously, the zinc anode is susceptible to hydrogen evolution, dendrite growth, and surface passivation in alkaline environments, leading to reduced zinc utilization and decreased cycle performance. In traditional single-chamber zinc-air batteries, the air cathode and zinc anode share the same electrolyte, making it difficult to separately regulate the electrolyte environment for oxygen reduction / oxygen evolution reactions on the air cathode side and zinc deposition / dissolution reactions on the zinc anode side. Furthermore, under low-temperature conditions, the oxygen reaction kinetics on the air cathode side decrease, while the interfacial side reactions and mass transfer limitations on the zinc anode side intensify, both contributing to reduced battery output voltage and insufficient cycle stability. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of electrolyte freezing, limited ion transport, increased discharge polarization, hydrogen evolution, dendrite growth and surface passivation in existing zinc-air flow batteries under low-temperature conditions, and to provide a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery and its application.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The present invention discloses a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery comprising an acidic cathode chamber and an alkaline anode chamber, and employing a low-temperature resistant dual-chamber acid-base decoupled electrolyte, which includes an acidic electrolyte and an alkaline electrolyte; the acidic cathode chamber contains an acidic electrolyte, and the alkaline anode chamber contains an alkaline electrolyte; The acidic electrolytes include H3PO4, C2H6O2, and H2O; Furthermore, by volume ratio, C2H6O2:H2O = (1~5):(4~8); in acidic electrolytes, the molar concentration of H3PO4 is 1~3 mol / L.

[0006] The alkaline electrolytes include ZnCl2, NiCl2, C2H6O2, KOH, and H2O; Furthermore, by volume ratio, C2H6O2:H2O = (1~4):(4~7); in the alkaline electrolyte, the molar concentration of ZnCl2 is 0.1mol / L, the molar concentration of NiCl2 is 0.01mol / L, and the molar concentration of KOH is 6mol / L; preferably, by molar ratio, ZnCl2:NiCl2:KOH = 0.1:0.01:6.

[0007] The C2H6O2 is used to reduce the risk of low-temperature freezing of the acidic electrolyte and the alkaline electrolyte, and to improve the liquid phase mass transfer performance of the air electrode side under low-temperature conditions.

[0008] The ZnCl2 is used to provide zinc ions to the alkaline electrolyte.

[0009] The NiCl2 is used to form nickel-containing interface species on the zinc anode side. These nickel-containing interface species are used to regulate the zinc deposition and dissolution process on the zinc anode surface and to reduce the polarization of the zinc anode reaction.

[0010] The nickel-containing interface species include at least one of metallic nickel, nickel hydroxide, and nickel hydroxyl oxide.

[0011] The present invention relates to a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery, wherein the acidic electrolyte is disposed on the air cathode side of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery, and the alkaline electrolyte is disposed on the zinc anode side of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery, the two being isolated from each other to achieve acid-base decoupling of the reaction environments on the air cathode side and the zinc anode side in the zinc-air flow battery.

[0012] The aforementioned low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery includes a battery body, an air cathode, a zinc anode, an acidic cathode chamber, an alkaline anode chamber, an ion conduction isolation component, a flow circulation component, and the aforementioned low-temperature resistant dual-chamber acid-base decoupled electrolyte.

[0013] The ion conduction isolation component is disposed between the acidic cathode chamber and the alkaline anode chamber, and is used for ion conduction and to prevent the acidic electrolyte and alkaline electrolyte from mixing directly; The air cathode is disposed on one side of the cathode acid chamber, and the zinc anode is disposed on one side of the anode alkaline chamber; The cathode acidic chamber is provided with an acidic electrolyte, which includes H3PO4 and C2H6O2; The anode alkaline chamber is provided with an alkaline electrolyte, which includes ZnCl2, NiCl2, C2H6O2 and KOH; The liquid circulation assembly is connected to the acidic cathode chamber and the alkaline anode chamber respectively, and is used to drive the independent circulation of acidic electrolyte and alkaline electrolyte.

[0014] Furthermore, the air cathode includes a gas diffusion layer, a catalyst layer, and a current collection layer, with the catalyst layer in contact with the acidic electrolyte.

[0015] Furthermore, the ion conduction isolation component is one of a bipolar membrane, a cation exchange membrane, an anion exchange membrane, or a composite ion exchange membrane.

[0016] Furthermore, the liquid circulation assembly includes a cathode storage unit, an anode storage unit, a circulation pump, and a circulation pipeline. The cathode storage unit is connected to the cathode acid chamber, and the anode storage unit is connected to the anode alkaline chamber.

[0017] The aforementioned low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery is applicable to temperatures as low as -25°C.

[0018] The aforementioned low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery has a discharge voltage of 1.4V~1.6V, which far exceeds the discharge voltage value in the same field, achieving a significant increase in discharge voltage.

[0019] The aforementioned low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery has a current density of 5 mA / cm² at room temperature. -2 Under these conditions, it can operate stably for 105 hours with a stable discharge voltage of approximately 1.50 V, and can also cycle stably for 100 hours.

[0020] Simulating actual industrial backup power applications under ambient temperature conditions, firstly at 20 mAcm... -2 Under these conditions, after fast charging for 2 hours and retaining power for 8 hours, at 5mAcm -2 Under certain conditions, it can be slowly discharged at 1.50 V for 6 hours and then run stably for 60 hours.

[0021] Under low temperature conditions of -25°C, simulating actual industrial backup power applications, the first step was to test at 20 mAcm. -2 Under these conditions, after 2 hours of fast charging, the charging voltage can be maintained at 2.5V, and at 5mA / cm. -2 Under these conditions, maintain a high voltage of 1.50 V and allow it to slowly discharge for 6 hours.

[0022] At -25℃, the current density is 5 mA / cm². -2 Under stable cyclic operation for 180 hours, the discharge voltage remained stable at approximately 1.40~1.50 V, which is only slightly different from the stable discharge voltage ΔE=~0.13V under normal temperature cyclic operation.

[0023] The present invention relates to the application of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery in low-temperature energy storage, backup power supply, or emergency power supply devices.

[0024] The present invention discloses a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery and its application. Compared with the prior art, its advantages are as follows: 1. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery of this invention employs a different low-temperature resistant dual-chamber acid-base decoupled electrolyte compared to traditional single alkaline electrolytes. By separating the acidic and alkaline electrolytes, the air cathode side and the zinc anode side are placed in different reaction environments. C2H6O2 is used to improve the electrolyte's antifreeze properties and the zinc ion solvation environment at low temperatures. NiCl2 in the anode alkaline electrolyte can form nickel-containing interface species on the zinc anode side, regulating the zinc deposition / dissolution process on the zinc anode surface, reducing zinc anode polarization, hydrogen evolution side reactions, and surface passivation, thereby increasing the discharge voltage of the zinc-air flow battery. The acidic electrolyte is used to optimize the oxygen reduction reaction environment on the air electrode side, reducing low-temperature oxygen reaction polarization and mitigating the problem of carbonation easily occurring in the alkaline air electrode.

[0025] 2. The method provided by this invention is simple, and the resulting low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery exhibits good low-temperature operational stability. This invention can improve the battery performance, discharge stability, and cycle life of zinc-air flow batteries in low-temperature environments, and can be used in low-temperature energy storage and backup power supply devices.

[0026] 3. This invention achieves zoned regulation of the electrolyte environment on the air cathode side and the zinc anode side through a dual-chamber structure, and utilizes an ion-conduction isolation component to achieve charge transfer and acid-base electrolyte isolation, preventing direct mixing of the electrolytes on both sides and maintaining the pH gradient of the electrolyte by suppressing acid-base neutralization reactions. Simultaneously, the ion-selective transport characteristics of the bipolar membrane in the ion-conduction isolation component reduce ion cross-contamination between different electrolytes, ensuring the stability of the battery under high-voltage discharge mode. The liquid flow circulation unit promotes electrolyte flow and alleviates problems such as increased electrolyte viscosity, limited ion transport, and local concentration polarization at low temperatures. Attached Figure Description

[0027] The accompanying drawings, which constitute a part of this invention, are provided to further illustrate the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0028] Figure 1 This is a schematic diagram of a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery structure provided in an embodiment of the present invention.

[0029] Figure 2 This is an actual working drawing of a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery provided in an embodiment of the present invention.

[0030] Figure 3 The actual appearance color of the acidic and alkaline electrolytes provided in the embodiments of the present invention.

[0031] Figure 4 The cycling curves of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at 25°C and -25°C are shown.

[0032] Figure 5 The discharge polarization curves and discharge power density curves of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0033] Figure 6 The discharge step diagrams at 25°C of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0034] Figure 7 The figure shows the cycle curves of Example 1 under 25°C and -25°C for 2 hours of fast charging and 6 hours of slow discharging.

[0035] Figure 8 The discharge step diagrams at -25°C of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0036] Figure 9 The discharge curve of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at 25°C is shown.

[0037] Figure 10 The discharge curve of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at -25°C is shown.

[0038] Figure 11 SEM images of Example 1, Comparative Example 1, and Comparative Example 2 after immersion at 25°C and -25°C are shown.

[0039] Figure 12 Symmetric cell tests of Example 1, Comparative Example 1, and Comparative Example 2 under alkaline electrolyte conditions at 25°C are shown.

[0040] Figure 13 Symmetric cell tests of Example 1, Comparative Example 1, and Comparative Example 2 under alkaline electrolyte conditions at -25°C are shown.

[0041] Figure 14 The HER tests of Example 1 and Comparative Example 2 under alkaline electrolyte conditions were presented. Detailed Implementation

[0042] The following description only depicts some exemplary embodiments of the present invention. Those skilled in the art will understand that various modifications can be made to these embodiments without departing from the spirit and scope of the invention. Therefore, the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0043] Unless otherwise stated, the reagents, membrane materials, electrode materials, circulation pumps, tubing, and testing equipment used in this embodiment are all available through conventional commercial channels. In this embodiment, "acidic electrolyte" refers to the electrolyte disposed on the air cathode side, and "alkaline electrolyte" refers to the electrolyte disposed on the zinc anode side. "Acid-base decoupling" means that the acidic and alkaline electrolytes are located in separate chambers, and ion conduction and charge balance are achieved through an ion conduction isolation component, preventing direct mixing.

[0044] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and examples, so as to better understand the solution of the present invention and its advantages in various aspects. However, the specific embodiments and examples described below are for illustrative purposes only and are not intended to limit the present invention.

[0045] The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery provided by this invention includes an acidic cathode chamber, an alkaline anode chamber, an air cathode, a zinc anode, an ion-conducting membrane, a cathode electrolyte circulation assembly, and an anode electrolyte circulation assembly. The acidic cathode chamber contains an acidic electrolyte, which includes H3PO4 and C2H6O2. The alkaline anode chamber contains an alkaline electrolyte, which includes ZnCl2, NiCl2, C2H6O2, and KOH.

[0046] In this invention, H3PO4 is used to provide an acidic oxygen reaction environment for the air cathode side; C2H6O2 is used to reduce the risk of cryogenic freezing of both acidic and alkaline electrolytes and to improve liquid-phase mass transfer performance under cryogenic conditions. ZnCl2 is used to provide zinc ions to the alkaline electrolyte. NiCl2 is used to form nickel-containing interface species on the zinc anode side to regulate the zinc deposition and dissolution process on the zinc anode surface, reducing the risks of zinc anode reaction polarization, hydrogen evolution side reactions, and surface passivation.

[0047] The following examples and comparative examples employ the following detection methods: Battery charge / discharge testing: A constant current charge / discharge test was performed on the low-temperature dual-chamber acid-base decoupled zinc-air flow battery using a battery testing system. Test temperatures included 25°C and -25°C. The discharge current density included 5 mA cm⁻¹. -2 Fast charging current density includes 20 mA cm⁻¹ -2 The voltage change curve over time was recorded during the test.

[0048] Discharge polarization and power density testing: By gradually changing the discharge current density, the battery discharge voltage is recorded, and the corresponding power density is calculated to compare the discharge performance of batteries under different electrolyte systems.

[0049] Step discharge test: The battery is discharged in a step-like manner at different current densities, and the discharge plateau corresponding to different current densities is recorded to evaluate the battery's rate response capability and discharge stability.

[0050] Zinc anode morphology test: After immersing or circulating the zinc anode in the corresponding electrolyte, it is taken out, cleaned with deionized water and ethanol and dried. The surface morphology of the zinc anode is observed using a scanning electron microscope to analyze corrosion, dendrite growth and deposition uniformity.

[0051] Symmetric cell test: Zinc symmetric cells were assembled using two zinc electrodes and constant current deposition / stripping tests were performed at 25°C and -25°C to evaluate the effect of alkaline electrolyte on the reversibility of zinc anode deposition / dissolution.

[0052] Hydrogen evolution reaction test: The hydrogen evolution reaction behavior in different alkaline electrolytes was tested using linear sweep voltammetry to evaluate the inhibitory effect of the electrolyte on the zinc anode side reaction.

[0053] Example 1

[0054] This embodiment prepares a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery, and the specific steps are as follows: Preparation of acidic electrolyte: Mix H3PO4 and C2H6O2 and stir until the solution is homogeneous to obtain the acidic electrolyte for the cathode acid chamber. The resulting acidic electrolyte is in a homogeneous liquid phase and is used for environmental control of the oxygen reduction reaction on the air cathode side.

[0055] The electrolyte contains 2 mol / L H3PO4, 10 mL to 50 mL C2H6O2, and 40 mL to 80 mL H2O.

[0056] The optimal composition is as follows: the concentration of H3PO4 in the electrolyte is 2 mol / L, the volume of C2H6O2 is 30 mL, and the volume of H2O is 67 mL.

[0057] Preparation of alkaline electrolyte: ZnCl2, NiCl2, C2H6O2 and KOH are mixed and stirred until the system is homogeneous to obtain an alkaline electrolyte for the anodic alkaline chamber. The obtained alkaline electrolyte is used for reaction control on the zinc anode side, wherein NiCl2 is used to form nickel-containing interface species in situ on the zinc anode side.

[0058] The electrolyte contains ZnCl2 at a concentration of 0.1 mol / L, NiCl2 at a concentration of 0.01 mol / L, C2H6O2 at a volume of 10 mL to 40 mL, KOH at a concentration of 6 mol / L, and H2O at a volume of 40 mL to 70 mL.

[0059] The optimal composition is as follows: ZnCl2 concentration is 0.1 mol / L, NiCl2 concentration is 0.01 mol / L, C2H6O2 volume is 10 mL, KOH concentration is 6 mol / L, and H2O volume is 70 mL.

[0060] Assemble a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery: such as Figure 1 and Figure 2 As shown, an air cathode, an ion conduction isolation component, and a zinc anode are sequentially arranged in the battery body, with the ion conduction isolation component located between the acidic cathode chamber and the alkaline anode chamber. In this embodiment, the ion conduction isolation component uses a bipolar membrane. An acidic electrolyte is injected into the acidic cathode chamber, and an alkaline electrolyte is injected into the alkaline anode chamber, with each electrolyte circulating independently through its respective circulation component.

[0061] Preparation of the air cathode: The air cathode employs a composite structure consisting of a gas diffusion layer, a catalyst layer, and a current collector layer. The catalyst layer is a mixture of an oxygen reduction / oxygen evolution bifunctional catalyst, a conductive agent, and a binder, coated onto the surface of the current collector layer and dried to obtain the air cathode. During assembly, the catalyst layer faces the acidic chamber of the cathode, and the gas diffusion layer faces the air side. The catalyst used for the air cathode is a commercially available catalyst, Pt / C and RuO2, coated on nickel foam at a loading of 1 mg·cm³. -2 The catalyst slurry was prepared by dissolving 35 mg of Pt / C and 35 mg of RuO2 in 960 μl of isopropanol and 40 μl of Nafion solution, respectively, followed by sonication for 2 hours, and then coating it onto nickel foam.

[0062] Preparation of zinc anode: Commercial zinc sheets are used for zinc anode. Before use, they are polished with sandpaper, cleaned with deionized water and ethanol, and dried for later use.

[0063] After assembly, a low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery is obtained.

[0064] Comparative Example 1 This comparative example prepares a zinc-air flow battery with a structure basically the same as that of Example 1, except that NiCl2 is not added to the alkaline electrolyte at the anode. The rest of the battery assembly method, the acidic electrolyte at the cathode, the air cathode, the zinc anode, and the test conditions are the same as in Example 1.

[0065] Comparative Example 2 This comparative example prepares a traditional alkaline electrolyte: KOH and C4H 10 O6Zn dissolved in deionized water yields a solution containing 6 mol / L KOH and 0.2 mol / L C4H. 10 O6Zn is a traditional alkaline electrolyte. The battery structure and electrode preparation method are basically the same as in Example 1.

[0066] Comparative Example 3 In this comparative example, NiSO4·6H2O was used to replace NiCl2. During the electrolysis process, the sulfides produced by NiSO4 can easily cause anodic corrosion.

[0067] Comparative Example 4 In this comparative example, the volume of C2H6O2 in the acidic electrolyte was 10 mL, and the electrolyte froze at -25℃.

[0068] Comparative Example 5 In this comparative example, the volume of C2H6O2 in the alkaline electrolyte is 40 mL, and the electrolyte becomes viscous at -25℃.

[0069] Figure 1 A schematic diagram of a novel matched integrated low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery device provided in an embodiment of the present invention is shown.

[0070] from Figure 1 As can be seen, the battery includes an acidic cathode chamber, an alkaline anode chamber, an air cathode, a zinc anode, an ion conduction isolation component, and an independent electrolyte circulation channel. The cathode side uses an acidic electrolyte of H3PO4+C2H6O2, while the anode side uses an alkaline electrolyte of ZnCl2+NiCl2+C2H6O2+KOH. The two electrolytes are located in different chambers and ion conduction and charge balance are achieved through an ion conduction membrane, which can prevent the acidic and alkaline electrolytes from mixing directly.

[0071] Figure 2 The illustration shows an actual working drawing of the novel matched integrated low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery device provided in an embodiment of the present invention.

[0072] from Figure 2 It is evident that the device can connect the battery body, the liquid circulation assembly including the cathode storage unit, the anode storage unit, the circulation pump, and the circulation pipeline. The acidic electrolyte and the alkaline electrolyte circulate in their respective flow paths, indicating that the dual-chamber liquid flow structure provided by the present invention has practical assembly and operational feasibility.

[0073] Figure 3The actual appearance and color of the acidic and alkaline electrolytes provided in the embodiments of the present invention are shown. The acidic electrolyte is obtained by mixing 20 mL of H3PO4, 30 mL of C2H6O2, and 67 mL of H2O, with the volume fraction of C2H6O2 being approximately 25.6%.

[0074] from Figure 3 It is evident that both the acidic and alkaline electrolytes are in a homogeneous liquid phase without significant stratification, indicating that the two electrolytes can exist stably in their respective chambers.

[0075] Figure 4 The cycling curves of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at 25°C and -25°C are shown.

[0076] from Figure 4 As can be seen, Example 1 can operate stably at both 25°C and -25°C. At 25°C, the battery can cycle stably for approximately 100 hours. At -25°C, it can still maintain stable charge-discharge cycle operation for 180 hours, indicating that the acid-base decoupled electrolyte system provided by this invention can improve the operational stability of the zinc-air flow battery under low-temperature conditions.

[0077] Figure 5 The discharge polarization curves and discharge power density curves of the zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0078] from Figure 5 As can be seen, compared with Comparative Example 1 and Comparative Example 2, Example 1 has a higher discharge voltage and power density, indicating that the H3PO4+C2H6O2 acidic cathode electrolyte, ZnCl2+NiCl2+C2H6O2+KOH alkaline anode electrolyte and dual-chamber structure can jointly reduce battery discharge polarization and improve battery output performance.

[0079] Figure 6 The discharge step diagrams of the zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 at 25°C are shown.

[0080] from Figure 6 As can be seen, Example 1 has a relatively stable discharge platform under different current densities, and the voltage can maintain good recovery ability after the current density changes, indicating that the battery has good discharge stability at 25°C.

[0081] Figure 7 The cycling curves of Example 1 under rapid charging for 2 h and slow discharging for 6 h at 25°C and -25°C are shown.

[0082] from Figure 7As can be seen, under simulated industrial fast charging and slow discharging conditions, Example 1 can first achieve a charging speed of 20 mA cm⁻¹. -2 Under these conditions, fast charge for 2 hours, then at 5 mA cm -2 Under these conditions, slow discharge lasted for 6 hours. At 25°C, this operating condition allowed for stable cycle operation for approximately 60 hours. At -25°C, the fast charging voltage remained at approximately 3.0 V, and a high discharge plateau of approximately 1.50 V was maintained during slow discharge, demonstrating that the zinc-air flow battery provided by this invention is suitable for the operational requirements of backup power in low-temperature environments.

[0083] Figure 8 The discharge step diagrams of the zinc-air flow batteries prepared in Example 1, Comparative Example 1, and Comparative Example 2 at -25°C are shown.

[0084] from Figure 8 It can be seen that Example 1 still has a relatively stable discharge platform at -25°C, at 5 mA cm⁻¹ -2 Under certain conditions, it can maintain a discharge voltage of approximately 1.40–1.50 V.

[0085] Figure 9 The discharge curve of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at 25°C is shown.

[0086] from Figure 9 As can be seen, Example 1 was performed at 25°C and 5 mA cm⁻¹. -2 Under the given conditions, the battery can stably and continuously discharge for approximately 105 hours, with a stable discharge voltage of approximately 1.50 V, indicating that the battery provided by this invention has a high room temperature discharge platform and good continuous discharge capability.

[0087] Figure 10 The discharge curve of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery prepared in Example 1 at -25°C is shown.

[0088] from Figure 10 As can be seen, Example 1 was performed at -25°C and 5 mA cm⁻¹. -2 Under these conditions, it can operate stably for approximately 180 hours, with a stable discharge voltage of approximately 1.40–1.50 V. Compared to the discharge voltage of approximately 1.50 V at 25°C, the low-temperature discharge voltage difference is approximately 0.13 V, indicating that the battery provided by this invention still exhibits a high discharge voltage and excellent low-temperature operational stability at -25°C.

[0089] Figure 11 SEM images of zinc anodes after immersion at 25°C and -25°C are shown for Example 1, Comparative Example 1, and Comparative Example 2.

[0090] from Figure 11As can be seen, compared with the comparative example, the zinc anode surface in Example 1 is smoother, without severe corrosion, cracks, or irregular deposition, indicating that the alkaline electrolyte ZnCl2 + NiCl2 + C2H6O2 + KOH can improve the stability of the zinc anode interface. This is because C2H6O2 is used to reduce the risk of low-temperature freezing of both acidic and alkaline electrolytes, allowing the electrolyte to maintain a liquid-phase flow state at low temperatures. NiCl2 forms nickel-containing interface species on the zinc anode side, thereby reducing passivation and uneven deposition on the zinc anode surface.

[0091] Figure 12 Symmetric cell tests of Example 1, Comparative Example 1, and Comparative Example 2 under alkaline electrolyte conditions at 25°C are shown.

[0092] from Figure 12 As can be seen, Example 1 has a more stable zinc deposition / stripping voltage plateau, indicating that the alkaline electrolyte provided by the present invention can improve the deposition / dissolution reversibility of the zinc anode under 25°C conditions and reduce the polarization of the zinc anode interface.

[0093] Figure 13 Symmetric cell tests of Example 1, Comparative Example 1, and Comparative Example 2 under alkaline electrolyte conditions at -25°C are shown.

[0094] from Figure 13 As can be seen, Example 1 was able to maintain a relatively stable deposition / stripping process at -25℃, indicating that the ZnCl2+NiCl2+C2H6O2+KOH alkaline electrolyte can improve the interfacial reaction stability of the zinc anode under low temperature conditions.

[0095] Figure 14 The HER tests of Example 1 and Comparative Example 2 under alkaline electrolyte conditions are shown.

[0096] from Figure 14 As can be seen, compared with Comparative Example 2, the hydrogen evolution reaction in Example 1 was suppressed, indicating that the ZnCl2+NiCl2+C2H6O2+KOH alkaline electrolyte provided by the present invention can reduce the hydrogen evolution side reaction on the zinc anode side. The reduction of the hydrogen evolution side reaction is beneficial for reducing active zinc loss, improving zinc anode utilization, and enhancing the cycle stability of the zinc-air flow battery.

[0097] As can be seen from the above, this invention regulates the reaction environment on the air cathode side using an acidic electrolyte (H3PO4+C2H6O2), regulates the zinc anode side deposition / dissolution process using an alkaline electrolyte (ZnCl2+NiCl2+C2H6O2+KOH), and achieves acid-base electrolyte decoupling through a dual-chamber structure. Example 1 was conducted at 25°C and 5 mA cm⁻¹. -2 It can stably discharge for approximately 105 hours at -25°C with a discharge voltage of 1.60 V; at 5 mA cm⁻¹... -2It can operate stably for approximately 180 hours, with a discharge voltage of approximately 1.40–1.50 V. It reacts with 6 mol / L KOH and 0.2 mol / L C4H₂O. 10 Compared with the traditional alkaline electrolyte system O6Zn, the zinc-air flow battery provided by this invention has better low-temperature discharge stability, zinc anode interface stability and cycle operation capability.

[0098] Obviously, the above embodiments are merely examples to clearly illustrate the technical solution of the present invention and are not intended to limit the implementation of the present invention. For those skilled in the art, without departing from the concept and scope of protection of the present invention, various adjustments, substitutions, or modifications can be made to the electrolyte composition, chamber structure, ion-conducting membrane type, electrode material, liquid circulation method, and testing conditions according to actual application needs. All equivalent or obvious modifications made based on the technical solution of the present invention should fall within the scope of protection of the present invention.

Claims

1. A low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery, characterized in that, This low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery is equipped with an acidic cathode chamber and an alkaline anode chamber. The cathode acidic chamber is provided with an acidic electrolyte, which includes H3PO4 and C2H6O2; The anode alkaline chamber is equipped with an alkaline electrolyte, which includes ZnCl2, NiCl2, C2H6O2 and KOH.

2. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1, characterized in that, The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery includes: a battery body, an ion conduction isolation component, an air cathode, a zinc anode, and a flow circulation component; The battery body is divided into an acidic cathode chamber and an alkaline anode chamber by an ion conduction isolation group. The air cathode is disposed on one side of the cathode acid chamber, and the zinc anode is disposed on one side of the anode alkaline chamber; The liquid circulation assembly is connected to the acidic cathode chamber and the alkaline anode chamber respectively, and is used to drive the independent circulation of acidic electrolyte and alkaline electrolyte.

3. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1 or 2, characterized in that, The acidic electrolyte also includes H2O; by volume ratio, C2H6O2:H2O=(1~5):(4~8); in the acidic electrolyte, the molar concentration of H3PO4 is 1~3 mol / L.

4. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1 or 2, characterized in that, The alkaline electrolyte also includes H2O; by volume ratio, C2H6O2:H2O=(1~4):(4~7); in the alkaline electrolyte, the molar concentration of ZnCl2 is 0.1mol / L, the molar concentration of NiCl2 is 0.01mol / L, and the molar concentration of KOH is 6mol / L.

5. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1, characterized in that, The NiCl2 is used to form nickel-containing interface species on the zinc anode side, and the nickel-containing interface species include at least one of metallic nickel, nickel hydroxide, and nickel hydroxyl oxide.

6. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 2, characterized in that, The ion conduction isolation component is one of a bipolar membrane, a cation exchange membrane, an anion exchange membrane, or a composite ion exchange membrane. The air cathode includes a gas diffusion layer, a catalyst layer, and a current collection layer, with the catalyst layer in contact with the acidic electrolyte.

7. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 2, characterized in that, The liquid circulation assembly includes a cathode storage unit, an anode storage unit, a circulation pump, and a circulation pipeline. The cathode storage unit is connected to the cathode acid chamber, and the anode storage unit is connected to the anode alkaline chamber.

8. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1, characterized in that, At room temperature, the current density is 5 mA / cm². -2 Under these conditions, it can operate stably for 105 hours with a stable discharge voltage of approximately 1.50 V, and can also operate stably in cycles for 100 hours. Simulating actual industrial backup power applications under ambient temperature conditions, firstly at 20 mAcm... -2 Under these conditions, after fast charging for 2 hours and retaining power for 8 hours, at 5mAcm -2 Under certain conditions, it can be slowly discharged at 1.50 V for 6 hours and then run stably for 60 hours. Under low temperature conditions of -25°C, simulating actual industrial backup power applications, the first step was to test at 20 mAcm. -2 Under these conditions, after 2 hours of fast charging, the charging voltage can be maintained at 2.5V, and at 5mA / cm. -2 Under these conditions, maintain a high voltage of 1.50 V for slow discharge for 6 hours; At -25℃, the current density is 5 mA / cm². -2 Under stable cyclic operation for 180 hours, the discharge voltage remained stable at approximately 1.40~1.50 V, which is only slightly different from the stable discharge voltage ΔE=~0.13V under normal temperature cyclic operation.

9. The low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to claim 1, characterized in that, The aforementioned low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery has a discharge voltage of 1.4V~1.6V.

10. The application of the low-temperature resistant dual-chamber acid-base decoupled zinc-air flow battery according to any one of claims 1-9 in low-temperature energy storage, backup power supply or emergency power supply devices.

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