A modified electrolyte for zinc ion battery containing cola beverage and its preparation method and application

Abstract

The present invention relates to a modified electrolyte for zinc ion batteries containing cola drinks, and a preparation method and application thereof, wherein the pretreated cola drinks are mixed with aqueous zinc ion battery electrolytes in a certain proportion to obtain a modified electrolyte, which significantly improves the low temperature stability of the electrolyte, so that the electrolyte can still be used normally in a low temperature environment of minus 30° C. In addition, the growth of zinc dendrites is effectively inhibited, thereby extending the life of the battery, and when expired or discarded cola drinks are used as electrolytes, waste can be reduced and resources can be saved.

Description

Technical Field

[0001] The invention relates to the application field of zinc ion batteries, and in particular to a modified electrolyte for zinc ion batteries containing cola beverage, and a preparation method and application thereof. Background Art

[0002] With the rapid development of various electronic devices and energy storage systems, people have higher expectations for energy storage technology. In recent years, aqueous zinc-ion batteries have attracted much attention from researchers due to their advantages such as high capacity, high safety, low cost, and simple assembly operation. As a substance that transmits ions in batteries, electrolytes have a crucial impact on battery performance. In particular, some special equipment needs to be used in low-temperature environments, but in this case the water molecules in the electrolyte will solidify, making it difficult for zinc ions to migrate between the positive and negative electrodes, the reaction kinetics become slow, and the battery's capacity, rate and other performance drop sharply. Therefore, it is of great significance to develop the low-temperature performance of electrolytes. Summary of the invention

[0003] The primary purpose of the present invention is to provide a modified electrolyte for zinc ion batteries containing cola drinks, and a preparation method and application thereof. The zinc ion battery assembled with the modified electrolyte has low temperature stability and long life performance. Pretreated cola drinks are added, and in the preferred embodiment of the present invention, waste cola drinks are selected. Due to the presence of phosphoric acid and sugars, the solvation sheath of zinc ions in the water environment is changed, the original water molecule network is broken, and H2O and Zn 2+ The solvation of Zn is weakened, which reduces the freezing point of the electrolyte, so that the modified electrolyte can still be used normally in a low temperature environment of minus 30°C. 2+ Uniform deposition reduces the growth of zinc negative electrode dendrites in the battery, and can still function in a low temperature environment of minus 30°C, thereby extending the battery life. In addition, the present invention preferably uses waste cola drinks as additives, which improves the low temperature performance of zinc ion batteries, reduces waste, and saves resources. The present invention provides a method for preparing a modified electrolyte for zinc ion batteries containing cola drinks, comprising the following steps:

[0004] Taking a certain amount of cola beverage for pretreatment to remove carbonic acid in the cola beverage;

[0005] Then, the pretreated cola beverage is mixed with an aqueous zinc ion battery electrolyte in a certain proportion to obtain the modified electrolyte for the zinc ion battery.

[0006] Furthermore, the cola beverage is selected from expired or discarded cola beverages;

[0007] The pretreatment includes firstly rapidly stirring the cola beverage and then heating it at a certain temperature for a certain period of time.

[0008] Furthermore, the rapid stirring speed is 600 r / min, and the stirring time is 3 to 5 hours.

[0009] Furthermore, the heating temperature is 40-60° C., and the heating time is 36-48 hours.

[0010] Furthermore, the aqueous zinc ion battery electrolyte is one of zinc sulfate solution, zinc trifluoromethanesulfonate solution, zinc perchlorate solution or zinc chloride solution, and the concentration of the solute in the aqueous zinc ion battery electrolyte is 2 to 3M.

[0011] Furthermore, the volume ratio of the cola drink to the aqueous zinc ion battery electrolyte is 0.5-1.

[0012] The invention provides a modified electrolyte for zinc ion batteries containing cola beverage, and the modified electrolyte is obtained by adopting the above-mentioned preparation method.

[0013] Furthermore, the working environment temperature of the modified electrolyte is not lower than minus 30°C.

[0014] The present invention also provides a zinc ion battery, which comprises the modified electrolyte.

[0015] In one embodiment, the zinc ion battery is a full battery or a symmetrical battery, the negative electrode or symmetrical electrode of the battery is one or more of zinc foil, zinc plate, zinc powder or zinc foam, and the positive electrode of the battery is vanadium oxide or manganese oxide.

[0016] Furthermore, the working environment temperature of the zinc ion battery is not lower than minus 30°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the preparation process of an embodiment of the present invention.

[0018] Figure 2 This is a digital image of the modified electrolyte obtained in Example 1 of the present invention being inverted after being stored at low temperature.

[0019] Figure 3 This is a performance test diagram of the button-type symmetrical Zn / / Zn battery obtained in Example 1 of the present invention.

[0020] Figure 4 This is a performance test diagram of the button-type Zn / / V2O5 battery obtained in Example 1 of the present invention.

[0021] Figure 5 It is a performance test diagram of button-type symmetrical Zn / / Zn batteries obtained at room temperature in Example 1 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, other embodiments obtained by ordinary technicians in this field without creative work all belong to the scope of protection of the present invention. The experimental methods described in the following embodiments are all conventional methods unless otherwise specified; the reagents and materials are all available from public commercial channels unless otherwise specified. In the following embodiments, zinc trifluoromethanesulfonate solution is used as the electrolyte for aqueous zinc ion batteries. The cola of the present invention is one or more of any brand of cola on the market. The following is combined with Figure 1 Examples of the present invention are given.

[0023] Example 1

[0024] Measure more than 50 mL of waste cola, stir at a speed of 600 r / min for 5 hours, and then heat at 50°C for 48 hours to remove the carbonic acid in the cola. Weigh 2.1812 g of zinc trifluoromethanesulfonate and dissolve it in 2 mL of deionized water to prepare a zinc trifluoromethanesulfonate solution. Then, measure 2 mL of the above cola and the above zinc trifluoromethanesulfonate solution cooled to room temperature and mix them evenly to prepare the electrolyte used.

[0025] Using zinc foil as the positive and negative electrodes and glass fiber as the separator, 180 μL of the above electrolyte was added to assemble a button-type symmetrical battery, and the cycle life of the symmetrical battery was tested at -20°C.

[0026] With V2O5 as the positive electrode, zinc foil as the negative electrode, and glass fiber as the separator, 180 μL of the above electrolyte was added to assemble a button cell, and its cycle performance was tested at -20°C.

[0027] Example 2

[0028] Take more than 50 mL of waste cola, stir at 600 r / min for 5 hours, and then heat at 50°C for 48 hours to remove the carbonic acid in the cola. Weigh 2.1812 g of zinc trifluoromethanesulfonate and dissolve it in 2 mL of deionized water to prepare a zinc trifluoromethanesulfonate solution. Take 1 mL of the above cola and 2 mL of the above zinc trifluoromethanesulfonate solution after cooling to room temperature and mix them evenly to prepare the electrolyte used.

[0029] Using zinc foil as the positive and negative electrodes and glass fiber as the separator, 180 μL of the above electrolyte was added, and the battery was assembled. The cycle life of the symmetrical battery was tested at -20°C.

[0030] With V2O5 as the positive electrode, zinc foil as the negative electrode, and glass fiber as the separator, 180 μL of the above electrolyte was added, the battery was assembled, and its cycle performance was tested at -20°C.

[0031] Example 3

[0032] Measure more than 50 mL of waste cola, stir at a speed of 600 r / min for 5 hours, and then heat at 50°C for 36 hours to remove carbonic acid in the cola. Weigh 2.1812 g of zinc trifluoromethanesulfonate and dissolve it in 2 mL of deionized water to prepare a zinc trifluoromethanesulfonate solution. Then, measure 2 mL of the above cola and the above zinc trifluoromethanesulfonate solution cooled to room temperature and mix them evenly to prepare the electrolyte used.

[0033] Using zinc foil as the positive and negative electrodes and glass fiber as the separator, 180 μL of the above electrolyte was added, and the battery was assembled. The cycle life of the symmetrical battery was tested at -20°C.

[0034] With V2O5 as the positive electrode, zinc foil as the negative electrode, and glass fiber as the separator, 180 μL of the above electrolyte was added, the battery was assembled, and its cycle performance was tested at -20°C.

[0035] Example 4

[0036] Measure more than 50 mL of waste cola, stir at a speed of 600 r / min for 5 hours, and then heat at 50°C for 36 hours to remove the carbonic acid in the cola. Weigh 2.1812 g of zinc trifluoromethanesulfonate and dissolve it in 2 mL of deionized water to prepare a zinc trifluoromethanesulfonate solution. Then, measure 1.5 mL of the above cola and 2 mL of the above zinc trifluoromethanesulfonate solution after cooling to room temperature and mix them evenly to prepare the electrolyte used.

[0037] Using zinc foil as the positive and negative electrodes and glass fiber as the separator, 180 μL of the above electrolyte was added, and the battery was assembled. The cycle life of the symmetrical battery was tested at -20°C.

[0038] With V2O5 as the positive electrode, zinc foil as the negative electrode, and glass fiber as the separator, 180 μL of the above electrolyte was added, the battery was assembled, and its cycle performance was tested at -20°C.

[0039] Comparative Example 1

[0040] 2.1812 g of zinc trifluoromethanesulfonate was weighed and dissolved in 2 mL of deionized water to prepare a zinc trifluoromethanesulfonate solution to prepare the electrolyte used.

[0041] Using zinc foil as the positive and negative electrodes and glass fiber as the separator, 180 μL of the above electrolyte was added to assemble a button-type symmetrical battery, and the cycle life of the symmetrical battery was tested at -20°C.

[0042] Figure 2Figure (a) is a digital picture of the electrolyte of Example 1 before adding waste cola, wherein the left side is the aqueous zinc trifluoromethanesulfonate electrolyte, and the right side is the aqueous zinc trifluoromethanesulfonate electrolyte after adding cola; Figure (b) is a digital picture of the electrolyte in Figure (a) after being stored at -20°C for 24 hours. It can be seen that before adding cola, the aqueous zinc trifluoromethanesulfonate electrolyte completely changes from liquid to solid after being stored at low temperature, and there is no liquid backflow even after being inverted. However, after adding cola, the electrolyte is still liquid at low temperatures. Therefore, adding cola is beneficial to lowering the freezing point of the aqueous zinc trifluoromethanesulfonate electrolyte.

[0043] Figure 3 The modified electrolyte prepared in Example 1 was assembled with zinc foil into a button-type symmetrical battery at -20°C, 0.2 mA cm -2 -0.2mAh cm -2 From the cycle life test chart below, it can be seen that the zinc ions in the battery can migrate normally in the electrolyte at low temperatures. It is worth noting that there is still no short circuit phenomenon after 2100h of cycling. Therefore, adding cola can not only show low temperature performance, but also effectively inhibit the formation of zinc dendrites.

[0044] Figure 4 The modified electrolyte prepared in Example 1 was assembled into a button cell with a metal zinc foil negative electrode and a V2O5 positive electrode at -20°C, 0.5Ag -1 Cycling performance test diagram under current density. Obviously, after 1000 cycles at this temperature, the specific capacity of the battery is ~125mAh g -1 , and there is no capacity decay.

[0045] Figure 5 Figure (b) shows the modified electrolyte prepared in Example 1 and Figure (a) shows the electrolyte prepared in Comparative Example 1. They were assembled into button-type symmetrical batteries with metal zinc foil at room temperature and 0.5 mA cm -2 -0.5mAh cm -2 From the cycle life test graph below, it can be seen that the battery using the unmodified electrolyte had a short circuit phenomenon only after 370 hours of circulation, while the battery using the modified electrolyte of Example 1 did not have a short circuit phenomenon after 1150 hours of circulation. Therefore, the addition of cola can effectively inhibit the formation of zinc dendrites at both low and normal temperatures.

[0046] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a modified electrolyte for a zinc ion battery containing a cola drink, characterized in that: The following steps are involved: Taking a certain amount of cola beverage for pretreatment to remove carbonic acid in the cola beverage; Then, the pretreated cola beverage is mixed with an aqueous zinc ion battery electrolyte in a certain proportion to obtain the modified electrolyte for the zinc ion battery.

2. The preparation method according to claim 1, characterized in that: The cola beverage is an expired or discarded cola beverage; the pretreatment includes firstly quickly stirring the cola beverage and then heating it at a certain temperature for a certain time.

3. The preparation method according to claim 2, characterized in that: The rapid stirring speed is 600 r / min, and the stirring time is 3 to 5 hours.

4. The preparation method according to claim 2 or 3, characterized in that: The heating temperature is 40-60° C., and the heating time is 36-48 hours.

5. The preparation method according to any one of claims 1 to 3, characterized in that: The aqueous zinc ion battery electrolyte is one of zinc sulfate solution, zinc trifluoromethanesulfonate solution, zinc perchlorate solution or zinc chloride solution, and the concentration of the solute in the aqueous zinc ion battery electrolyte is 2-3M.

6. The preparation method according to any one of claims 1 to 3, characterized in that: The volume ratio of the cola beverage to the aqueous zinc ion battery electrolyte is 0.5-1.

7. A modified electrolyte for zinc ion battery containing cola beverage, characterized in that: The modified electrolyte is obtained by the preparation method described in any one of claims 1 to 6 above.

8. The modified electrolyte according to claim 7, characterized in that: The working environment temperature of the modified electrolyte is not lower than minus 30°C.

9. A zinc ion battery, characterized in that It comprises the modified electrolyte of claim 8.

10. The zinc ion battery according to claim 9, characterized in that: The working environment temperature of the zinc ion battery is not lower than minus 30°C.

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