Zinc-nickel battery

Abstract

The invention discloses a zinc-nickel battery. The zinc-nickel battery comprises an alkaline electrolyte containing an additive, a positive electrode and a negative electrode, the additive is selected from substances with a structure shown in a formula I: # imgabs0 #, R is selected from methyl and / or-NH-methyl, and at least one R in the formula I is methyl; in the alkaline electrolyte containing the additive, the mass content of the additive is 1-10 wt%.

Description

Technical Field

[0001] The present application relates to a zinc-nickel battery, belonging to the field of zinc-nickel batteries. Background Art

[0002] As the world faces an unprecedented environmental and energy crisis, clean and renewable energy sources have become important. This surge in demand for green electricity has driven the development of grid-scale energy storage systems. Currently, non-aqueous lithium-ion batteries dominate the market for grid-scale electrochemical energy storage devices, but they have problems such as low power density, flammable, environmentally unfriendly organic electrolytes, and high cost. In contrast, aqueous rechargeable batteries have received widespread attention in the field of energy storage due to their high safety and low cost. Among many aqueous rechargeable batteries, zinc-nickel batteries have the advantages of high output voltage (≈1.8V), high energy density, and good safety. These characteristics make it possible to develop high-energy, safe, and cheap energy storage devices. However, during the charge and discharge process, the discharge product zinc oxide is highly soluble in alkaline electrolytes, resulting in changes in the surface shape of the zinc negative electrode. At the same time, zinc is thermodynamically unstable in aqueous media, and the occurrence of hydrogen evolution side reactions consumes electrolytes and reduces battery performance. Therefore, the preparation of highly stable electrolyte additives and negative electrode materials is the only way to promote the commercialization of zinc-nickel batteries, and it is also of great significance for the efficient use of clean energy and the construction of a new energy society. Summary of the invention

[0003] The purpose of the present invention is to solve the problem of low cycle performance of existing aqueous zinc-nickel battery systems, and provide a method for preparing an electrolyte additive and a negative electrode material for a zinc-nickel battery with high cycle stability. By adding the additive to the electrolyte and preparing an electrode sheet by the method of the present application, the occurrence of hydrogen evolution side reaction is reduced and the change of the zinc anode shape is alleviated, thereby realizing a zinc-nickel battery with high stability.

[0004] According to one aspect of the present application, a zinc-nickel battery is provided, the zinc-nickel battery comprising an alkaline electrolyte containing an additive, a positive electrode and a negative electrode;

[0005] The additive is selected from substances having the structure of formula I:

[0006]

[0007] wherein R is selected from methyl and / or -NH-methyl, and at least one R in Formula I is methyl;

[0008] In the alkaline electrolyte containing additives, the mass content of the additives is 1 to 10 wt %.

[0009] The negative electrode is obtained by grinding the negative electrode material, adding ethanol during the grinding process, rolling it into a thin sheet, and cutting it.

[0010] The negative electrode material contains zinc oxide, a conductive agent and a binder.

[0011] The conductive agent is selected from at least one of acetylene black and Kogen black;

[0012] The binder is selected from polytetrafluoroethylene.

[0013] In the negative electrode material, the mass content of zinc oxide is 70-80wt%;

[0014] In the negative electrode material, the mass content of the conductive agent is 8-10wt%.

[0015] The negative electrode material contains zinc powder;

[0016] In the negative electrode material, the mass content of the zinc powder is 4-6wt%.

[0017] The negative electrode material contains auxiliary metal oxide;

[0018] The auxiliary metal oxide is selected from at least one of aluminum oxide, bismuth oxide, yttrium oxide and indium oxide;

[0019] In the electrode material, the mass content of the other metal oxides is 0.1-1 wt %.

[0020] Specifically, the negative electrode is obtained by the following steps:

[0021] Take the mass ratio of ZnO, Zn, Bi2O3, Al2O3, acetylene black and PTFE as 70:5:6:1:10:8 as an example.

[0022] (1) Weigh a total of 200 mg. Mix 140 mg of ZnO, 10 mg of Zn, 12 mg of Bi2O3, 2 mg of Al2O3, and 20 mg of acetylene black together and grind for 20 min.

[0023] (2) Add 16 mg of 60 wt% PTFE emulsion to the mixed powder of (1), and continuously crush with a medicine spoon until the mixed powder sticks together.

[0024] (3) Add ethanol to the mixture in (2), and after continuous rolling with a large glass rod, cut out a raw sheet with a diameter of 10 mm.

[0025] (4) Soak the copper mesh in the tinning solution for 2 minutes to obtain a copper mesh with a uniform tinning surface, and cut out a tinned copper sheet with a diameter of 12 mm.

[0026] (5) The electrode sheet in (3) is pressed onto the tinned copper mesh obtained in (4) using a tablet press to obtain a finished negative electrode sheet.

[0027] The alkaline electrolyte containing additives contains an alkaline substance.

[0028] The alkaline substance is selected from at least one of sodium hydroxide and potassium hydroxide.

[0029] The concentration of the alkaline substance in the alkaline electrolyte containing the additive is 1-6M.

[0030] The beneficial effects of this application include:

[0031] 1) The additive provided in the present application has the function of regulating the solvation structure of zinc.

[0032] 2) The additive provided in this application has the effect of reducing negative electrode corrosion and HER.

[0033] 3) The negative electrode preparation method provided in the present application has the function of adjusting the loading capacity and preparing high-loading electrodes.

[0034] 4) The additive provided in the present application has the effect of inhibiting the dissolution of zinc oxide and HER. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 1 is a discharge specific capacity-cycle diagram of Example 1 and Comparative Example 1 of the present application.

[0036] Figure 2 Graph showing the discharge specific capacity and charge-discharge efficiency of Example 2 and Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0037] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0038] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0039] Example 1

[0040] Add 5 wt% SO2(CH3)2 into 6M potassium hydroxide solution and stir for 30 min to obtain an electrolyte.

[0041] For the negative electrode material, the nano zinc oxide powder was soaked in a 1 mol / L InCl3 solution and stirred for 5 hours. The resulting solution was centrifuged and precipitated, washed with deionized water three times, and dried at 60°C for 24 hours. The obtained nano zinc oxide, zinc powder, bismuth trioxide, aluminum trioxide, acetylene black and polytetrafluoroethylene were ground in a ratio of 70:5:6:1:10:8 for 30 minutes, and ethanol was continuously added to the powder to roll it into a mud. The mud was rolled into thin sheets and cut into pole pieces with a diameter of 10 mm.

[0042] Aqueous zinc-nickel battery assembly:

[0043] The synthesized negative electrode was used as the negative electrode of the battery, GF-D was used as the separator, 6M potassium hydroxide containing 5wt% SO2(CH3)2 was used as the electrolyte, and Chaowei positive electrode material was used as the positive electrode. It was assembled into a button cell at a pressure of 1.2T, and constant current charge and discharge tests were carried out using the Land battery testing system.

[0044] Example 2

[0045] SO2NH(CH3)2 with a mass ratio of 5 wt% was added to 6 M potassium hydroxide solution and stirred for 30 min to obtain an electrolyte.

[0046] For the negative electrode material, the nano zinc oxide powder was immersed in a 1 mol / L InCl3 solution and stirred for 5 h. The resulting solution was centrifuged and the precipitate was washed with deionized water three times and dried at 60 °C for 24 h. The obtained nano zinc oxide, zinc powder, bismuth trioxide, aluminum trioxide, acetylene black and polytetrafluoroethylene were ground in a ratio of 70:5:6:1:10:8 for 30 min, and ethanol was continuously added to the powder to make it into a mud.

[0047] Aqueous zinc-nickel cylindrical battery assembly:

[0048] The synthesized negative electrode was used as the negative electrode sheet of the battery, PP was used as the separator, 6M potassium hydroxide containing 5wt% SO2NH(CH3)2 was used as the electrolyte, and commercial Chaowei positive electrode material was used as the positive electrode of the battery. They were assembled into alkaline cylindrical batteries and constant current charge and discharge tests were carried out using the Land battery test system.

[0049] Comparative Example 1

[0050] Compared with Example 1, a solution containing only 6M potassium hydroxide was prepared and stirred for 30 minutes as an electrolyte.

[0051] For the negative electrode material, the nano zinc oxide powder was soaked in a 1 mol / L InCl3 solution and stirred for 5 hours. The resulting solution was centrifuged and precipitated, washed with deionized water three times, and dried at 60°C for 24 hours. The obtained nano zinc oxide, zinc powder, bismuth trioxide, aluminum trioxide, acetylene black and polytetrafluoroethylene were ground in a ratio of 70:5:6:1:10:8 for 30 minutes, and ethanol was continuously added to the powder to roll it into a mud. The mud was rolled into thin sheets and cut into pole pieces with a diameter of 10 mm.

[0052] Figure 1 1 is a discharge specific capacity-cycle diagram of Example 1 and Comparative Example 1 of the present application.

[0053] from Figure 1It can be seen that after adding SO2(CH3)2, the specific capacity of the battery increased significantly and the life was significantly extended. This is attributed to the high polarity of SO2(CH3)2, which allows the oxygen to be added to the solvation structure of zincate ions, thereby reducing the dissolution of the negative electrode and the occurrence of HER side reactions.

[0054] Comparative Example 2

[0055] Compared with Example 2, an electrolyte containing Chaowei commercial zinc-nickel alkaline batteries is used.

[0056] For the negative electrode material, the nano zinc oxide powder was immersed in a 1 mol / L InCl3 solution and stirred for 5 h. The resulting solution was centrifuged and the precipitate was washed with deionized water three times and dried at 60 °C for 24 h. The obtained nano zinc oxide, zinc powder, bismuth trioxide, aluminum trioxide, acetylene black and polytetrafluoroethylene were ground in a ratio of 70:5:6:1:10:8 for 30 min, and ethanol was continuously added to the powder to make it into a mud.

[0057] Figure 2 Graph showing the discharge specific capacity and charge-discharge efficiency of Example 2 and Comparative Example 2 of the present application.

[0058] from Figure 2 It can be seen that after adding SO2NH(CH3)2, the battery life can be significantly extended and the coulombic efficiency is significantly increased. This is attributed to the high polarity of SO2NH(CH3)2, which allows the oxygen to be added to the solvation structure of zincate ions, thereby reducing the dissolution of the negative electrode and the occurrence of HER side reactions.

[0059] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A zinc-nickel battery, characterized in that: The zinc-nickel battery comprises an alkaline electrolyte containing an additive, a positive electrode and a negative electrode; The additive is selected from substances having the structure of formula I: wherein R is selected from methyl and / or -NH-methyl, and at least one R in Formula I is methyl; In the alkaline electrolyte containing additives, the mass content of the additives is 1 to 10 wt %.

2. The zinc-nickel battery according to claim 1, characterized in that: The negative electrode is obtained by grinding the negative electrode material, adding ethanol during the grinding process, rolling it into a thin sheet, and cutting it.

3. The zinc-nickel battery according to claim 2, characterized in that: The negative electrode material contains zinc oxide, a conductive agent and a binder.

4. The zinc-nickel battery according to claim 3, characterized in that: The conductive agent is selected from at least one of acetylene black and Kogen black; The binder is selected from polytetrafluoroethylene.

5. The zinc-nickel battery according to claim 4, characterized in that: In the negative electrode material, the mass content of zinc oxide is 70-80wt%; In the negative electrode material, the mass content of the conductive agent is 8-10wt%.

6. The zinc-nickel battery according to claim 4, characterized in that: The negative electrode material contains zinc powder; In the negative electrode material, the mass content of the zinc powder is 4-6wt%.

7. The zinc-nickel battery according to claim 4, characterized in that: The negative electrode material contains auxiliary metal oxide; The auxiliary metal oxide is selected from at least one of aluminum oxide, bismuth oxide, yttrium oxide and indium oxide; In the electrode material, the mass content of the other metal oxides is 0.1-1 wt %.

8. The zinc-nickel battery according to claim 1, characterized in that: The alkaline electrolyte containing additives contains an alkaline substance.

9. The zinc-nickel battery according to claim 8, characterized in that: The alkaline substance is selected from at least one of sodium hydroxide and potassium hydroxide.

10. The zinc-nickel battery according to claim 8, characterized in that: The concentration of the alkaline substance in the alkaline electrolyte containing the additive is 1-6M.

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