Low-temperature-resistant aqueous zinc ion battery and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant aqueous zinc ion battery and a preparation method thereof, the low-temperature-resistant aqueous zinc ion battery mainly comprises a positive electrode, a negative electrode, an electrolyte and a diaphragm, the positive electrode material is ammonium vanadate (NH4V4O10), the negative electrode is zinc metal (Zn), the electrolyte is a zinc perchlorate aqueous solution (Zn (ClO4) 2), and the diaphragm is a glass fiber membrane. Compared with the prior art, the low-temperature-resistant aqueous zinc ion battery provided by the invention adopts the low-concentration aqueous solution without adding an anti-freezing agent as the low-temperature-resistant electrolyte, can effectively resist a low-temperature environment, solves the problem that the aqueous zinc ion battery cannot normally operate in the low-temperature environment, and has the advantages that the combination mode of the low-temperature-resistant aqueous zinc ion battery is NH4V4O10 / / Zn (ClO4) 2 / / Zn; according to the present invention, the cost is substantially reduced, the charge-discharge cycles at the low temperature of-30 DEG C and-50 DEG C can achieve 2000 charge-discharge cycles, the coulombic efficiency of 99% can be maintained, and the good application prospect is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of aqueous zinc ion batteries, and in particular relates to a low-temperature resistant aqueous zinc ion battery and a preparation method thereof. Background Art

[0002] Aqueous zinc-ion batteries have attracted widespread attention in recent years due to their advantages such as being green, environmentally friendly, safe, reliable, and inexpensive. They have good application prospects in low-speed two-wheeled vehicles and large-scale energy storage. However, aqueous electrolytes are prone to freezing at low temperatures, causing a sharp drop in electrolyte ion conductivity and a sharp deterioration in battery performance. This limits the application of aqueous zinc-ion batteries in cold regions. Therefore, it is necessary to improve the low-temperature performance of aqueous zinc-ion batteries.

[0003] At present, the common methods for improving the low-temperature performance of aqueous zinc-ion batteries mainly include "salt-in-water" electrolytes and adding organic co-solvents to the electrolyte. For the former method, high-concentration electrolytes can significantly reduce the activity of free water molecules, thereby reducing the freezing point of aqueous electrolytes, enabling aqueous zinc-ion batteries to operate below zero degrees. However, high-concentration electrolytes also bring problems such as high cost, high viscosity, and salt precipitation as the temperature decreases. For the latter technical path, organic solvents are used as electrolyte solvents, and there are flammable and explosive safety risks during use, or increase production processes and manufacturing costs. In addition, organic solvents will replicate the zinc metal negative electrode, resulting in a serious reduction in the capacity retention rate and cycle stability of the battery. So far, in addition to the above two methods, the successful preparation of low-concentration and antifreeze-freezing aqueous electrolytes has not been reported.

[0004] Based on the above, in the current low-temperature aqueous zinc ion battery, the use of high-concentration salt electrolyte can reduce the solution freezing point and maintain good electrochemical performance, but the cost of high-concentration salt is too high and is not suitable for commercialization. Even if other methods can reduce the freezing point to a relatively low temperature, the capacity retention rate and cycle performance are not ideal. Therefore, the present invention provides an aqueous zinc ion battery that can operate stably at low temperatures and a preparation method thereof. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a low-temperature zinc ion battery and a preparation method thereof. The low-temperature zinc ion battery provided by the present invention adopts a low-concentration aqueous solution without adding an antifreeze agent as a low-temperature resistant electrolyte, has excellent low-temperature performance, and is relatively low in cost.

[0006] The present invention provides a low-temperature resistant aqueous zinc ion battery, comprising: a cathode, an anode, a diaphragm and an electrolyte, wherein the cathode is made of ammonium vanadate (NH4V4O 10 ) is an active substance;

[0007] The anode is a high-purity zinc foil;

[0008] The diaphragm is a glass fiber membrane;

[0009] The electrolyte is an aqueous solution of zinc perchlorate (Zn(ClO4)2);

[0010] Preferably, the NH4V4O 10 The preparation method is specifically as follows:

[0011] Dissolve ammonium metavanadate, cyclodextrin and anhydrous oxalic acid in water respectively, perform hydrothermal reaction, filter and dry in turn, and finally obtain NH4V4O 10 .

[0012] Preferably, the temperature of the hydrothermal reaction is 110-160° C., and the time is 10-24 h; the temperature of the drying is 70-90° C., and the time is 12-24 h.

[0013] Preferably, the preparation method of the cathode is specifically as follows:

[0014] The active substance NH4V4O 10 The conductive agent Super P and the binder PVDF are mixed in a mass ratio of (7-8): (1-2): 1 to prepare a slurry; the slurry is then coated on a stainless steel mesh and dried at 70-90° C. for 12-24 hours to obtain a cathode.

[0015] Preferably, the zinc foil has a thickness of 0.01 to 1 mm.

[0016] Preferably, the glass fiber membrane has a thickness of 0.26-0.42 mm.

[0017] Preferably, the concentration of the Zn(ClO4)2 aqueous solution is 1 to 5 mol L -1 .

[0018] The present invention also provides a method for preparing the low-temperature resistant aqueous zinc ion battery described in the above technical solution, comprising the following steps:

[0019] Using water as solvent, Zn(ClO4)2 is dissolved in water to obtain an electrolyte, which is then assembled with a cathode and an anode to obtain a low-temperature resistant aqueous zinc ion battery; the cathode is made of NH4V4O 10 For active substances.

[0020] The present invention provides a low-temperature resistant aqueous zinc ion battery, comprising: a cathode, an anode, a diaphragm and an electrolyte, wherein the cathode is NH4V4O 10The active material is the cathode, the cathode is zinc foil, the separator is a glass fiber membrane, and the electrolyte is a Zn(ClO4)2 aqueous solution. Compared with the prior art, the low-temperature zinc ion battery provided by the present invention uses a low-concentration aqueous solution without adding antifreeze as a low-temperature resistant electrolyte, which can effectively resist the low-temperature environment and solve the problem that the aqueous zinc ion battery cannot work normally in a low-temperature environment; the combination of the low-temperature zinc ion battery is NH4V4O 10 / / Zn(ClO4)2 / / Zn combination can significantly reduce costs and has good cycle stability and high coulombic efficiency at low temperatures. In addition, the preparation method provided by the present invention has a simple process, mild conditions, easy control, and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of a low-temperature resistant aqueous zinc ion battery in an embodiment of the present invention;

[0022] Figure 2 is the X-ray diffraction pattern of ammonium vanadate in the present invention;

[0023] Figure 3 is a scanning electron microscope image of ammonium vanadate in the present invention;

[0024] Figure 4 This is a cycle test diagram of the aqueous zinc ion battery in Example 1 of the present invention at a low temperature of -30°C;

[0025] Figure 5 This is a cycle test diagram of the aqueous zinc ion battery in Example 2 of the present invention at a low temperature of -50°C; DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention provides a low temperature resistant aqueous zinc ion battery. Figure 1 , Figure 1 The structure diagram of the low temperature resistant aqueous zinc ion battery in the embodiment of the present invention is shown in FIG. It mainly comprises a cathode, an anode, a diaphragm and an electrolyte. The active material of the cathode is ammonium vanadate (NH4V4O 10 ), the anode is zinc foil, the diaphragm is glass fiber membrane, and the electrolyte is Zn(ClO4)2 aqueous solution.

[0028] In the present invention, the NH4V4O 10 The preparation method is specifically as follows:

[0029] (a) Dissolve 3 g of ammonium metavanadate in deionized water and stir in a 60 °C water bath for 30 min;

[0030] Then, 2 mmol of cyclodextrin was added and the stirring was continued for 30 min. Finally, 25 mmol of anhydrous oxalic acid was added and the stirring was continued for 30 min to form a green mixed solution.

[0031] (b) placing the green mixed solution in a hydrothermal reactor, heating it to 120° C. and keeping it at that temperature for 6 hours, and cooling it to room temperature after the hydrothermal reaction is completed;

[0032] (c) The sample after the hydrothermal reaction was washed alternately with deionized water and ethanol for 6 times, and then dried in a vacuum drying oven at 80° C. for 12 h to obtain the ammonium vanadate material.

[0033] Figure 2 The X-ray diffraction spectrum of the ammonium vanadate sample in the embodiment of the present invention, the shape, position and relative intensity of the diffraction peak correspond to the standard card of ammonium vanadate (JCPDS: 31-0075), indicating that the prepared ammonium vanadate has a high pure phase and does not contain impurities. In addition, the prepared ammonium vanadate has a large diffraction peak intensity and a sharp peak shape, indicating good crystallinity.

[0034] Figure 3 This is a scanning electron microscope image of the ammonium vanadate sample in the embodiment of the present invention. It can be seen from the figure that the prepared ammonium vanadate has a regular morphology and a sea urchin-like structure, and its size is about 5 microns.

[0035] Example 1

[0036] Using deionized water as solvent, Zn(ClO4)2 was added at 3 mol L -1 The concentration of is dissolved in water to prepare a zinc salt electrolyte.

[0037] The active substance NH4V4O 10 , conductive agent Super P and binder PVDF are mixed in a mass ratio of 7:2:1 to prepare a slurry, and then the slurry is evenly coated on a stainless steel mesh and dried at 80°C for 12 hours to obtain a cathode of a zinc ion battery; a zinc ion button battery is assembled using zinc foil as an anode.

[0038] Figure 4 This is a cycle test diagram of the aqueous zinc ion battery in Example 1 of the present invention at a low temperature of -30°C. The assembled aqueous zinc ion battery is tested on a Xinwei battery tester at 1Ag. -1 The current density was used for charge and discharge test, and the discharge capacity was 152mAh g at -30℃. -1 After 2000 charge and discharge cycles, the battery can still operate normally, showing good low-temperature stability.

[0039] Example 2

[0040] Using deionized water as solvent, Zn(ClO4)2 was added at 3 mol L -1 The concentration of is dissolved in water to prepare a zinc salt electrolyte.

[0041] The active substance NH4V4O 10 , conductive agent Super P and binder PVDF are mixed in a mass ratio of 7:2:1 to prepare a slurry, and then the slurry is evenly coated on a stainless steel mesh and dried at 80°C for 12 hours to obtain a cathode of a zinc ion battery; a zinc ion button battery is assembled using zinc foil as an anode.

[0042] Figure 5 This is a cycle test diagram of the aqueous zinc ion battery in Example 2 of the present invention at a low temperature of -50°C. The assembled aqueous zinc ion battery is 1Ag -1 The current density was used for charge and discharge test, and the discharge capacity was 105 mAh g at -50 °C. -1 , after cycling 2000 times at a low temperature of -50℃, the battery can still operate normally, demonstrating good low-temperature stability.

[0043] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A low-temperature resistant aqueous zinc ion battery, comprising: Cathode, anode, diaphragm and electrolyte, characterized in that the active material of the cathode is NH4V4O 10 ; The anode is zinc foil; the diaphragm is a glass fiber membrane; the electrolyte is a Zn(ClO4)2 aqueous solution.

2. The low temperature resistant aqueous zinc ion battery according to claim 1, characterized in that: The NH4V4O 10 The specific preparation method is as follows: ammonium metavanadate, cyclodextrin and anhydrous oxalic acid are dissolved in water respectively, subjected to hydrothermal reaction, filtered and dried in sequence to obtain NH4V4O 10 .

3. The low temperature resistant aqueous zinc ion battery according to claim 2, characterized in that: The temperature of the hydrothermal reaction is 110-160° C., and the time is 10-24 hours; the temperature of the drying is 70-90° C., and the time is 12-24 hours.

4. The low-temperature resistant aqueous zinc ion battery according to claim 1, characterized in that: The cathode preparation method is specifically as follows: the active material NH4V4O 10 The conductive agent Super P and the binder PVDF are mixed in a mass ratio of (7-8): (1-2): 1 to prepare a slurry; the slurry is then coated on a stainless steel mesh and dried at 70-90° C. for 12-24 hours to obtain a cathode.

5. The low temperature resistant aqueous zinc ion battery according to claim 1, characterized in that: The thickness of the zinc foil is 0.01-1 mm.

6. The low-temperature resistant aqueous zinc ion battery according to claim 1, characterized in that: The thickness of the glass fiber membrane is 0.26-0.42 mm.

7. The low-temperature resistant aqueous zinc ion battery according to claim 1, characterized in that: The concentration of the Zn(ClO4)2 aqueous solution is 1 to 5 mol L -1 .

8. A method for preparing a low-temperature resistant aqueous zinc ion battery according to any one of claims 1 to 7, comprising the following steps: Using water as solvent, Zn(ClO4)2 is dissolved in water to obtain an electrolyte, which is then assembled with a cathode and an anode to obtain a low-temperature resistant aqueous zinc ion battery; the active material of the cathode is NH4V4O 10 .

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