Aqueous alkaline zinc-iodine battery and preparation method thereof

Abstract

The invention relates to an aqueous alkaline zinc-iodine battery and a preparation method thereof, and belongs to the technical field of aqueous zinc-iodine batteries. The battery includes: a positive electrode; a negative electrode; and an aqueous alkaline electrolyte; wherein the positive electrode comprises a current collector, a positive electrode active material, a conductive agent and an adhesive, and the positive electrode active material is iodide; the aqueous alkaline electrolyte comprises a chlorine-containing additive, a zinc salt electrolyte, an alkaline inorganic salt and water. The aqueous alkaline zinc-iodine battery provided by the invention is low in cost and simple to manufacture. According to the aqueous alkaline zinc-iodine battery provided by the invention, the iodide is adopted as the positive electrode active material, so that instability and potential safety hazards caused by taking an iodine elementary substance as the positive electrode at present are avoided. The battery disclosed by the invention releases a high-potential discharge platform at 1.65-1.68 V, the discharge capacity reaches 372-385 mAh.g <-1 >, and the battery shows rapid oxidation-reduction kinetics and excellent long-acting cycle stability.

Description

Technical Field

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

[0002] Aqueous energy storage technology has re-emerged due to the expansion of the application range of electronic devices and the increase in safety requirements. In particular, zinc-based batteries have attracted much attention due to their abundant resource reserves, natural safety, high capacity and low redox potential. Compared with their "rocking chair" counterparts, conversion cathodes achieve electron transfer through direct chemical reactions and therefore have a stable discharge voltage platform.

[0003] Iodine and bromine naturally have rich valence states, so it is expected that a higher output voltage can be obtained by activating a new redox reaction. - / X 0 (X: iodine or bromine) The reversible conversion between redox pairs is achieved with the transfer of a single electron. It is worth noting that the elemental bromine electrode is based on a liquid-liquid conversion mode, which is considered to be far inferior to the elemental iodine electrode in terms of stability. The intrinsic liquid properties and severe corrosiveness of elemental bromine make it difficult to apply to portable energy storage devices, and it is usually used in liquid flow energy storage equipment. In acidic or neutral electrolytes, the conversion of iodine usually follows a single electron transfer mechanism accompanied by slower ion-element conversion kinetics, resulting in a theoretical capacity of the iodine positive electrode of less than 211 mAh g -1 , and the voltage output platform is less than 1.38V.

[0004] Given the multivalent nature of iodine, it is necessary to explore new chemical reaction pathways to further unlock its electrochemical performance. Recent studies have shown that in neutral / acidic electrolytes, the use of a dual electron transfer mode can achieve charge storage capacity nearly twice that of conventional reactions. However, the new high-voltage platform (from I 0 / I + The redox couple only contributes half of the total capacity, so the average discharge plateau voltage is about 1.5 V. In alkaline electrolytes, the zinc anode undergoes Zn(OH)4 2+ / Zn reversible conversion, with a lower redox potential (-1.25V vs. SHE). In order to increase the output voltage of the full cell, a composite ion exchange membrane with an acid-base electrolyte is usually required. However, the single electron transfer mode on the iodine electrode side has not changed, which still limits the discharge capacity.

[0005] According to the theory of previous studies, in an alkaline environment, I- / IO - (I - / I +) The redox pair involves a two-electron transfer mode, which can double the battery discharge capacity. And the battery output voltage platform can reach 1.74V. Compared with the standard two-step reaction mechanism, this single-step two-electron conversion chemical reaction is more conducive to achieving continuous output of the high-voltage platform. However, I - / IO - The conversion reaction is thermodynamically unstable and has poor reversibility because the product IO - will undergo self-differentiation and transform into I - and io3 - On the other hand, even at room temperature and pressure, iodine undergoes spontaneous disproportionation in alkaline electrolytes. Therefore, it is necessary to develop electrochemically active iodine sources with alkaline resistance to promote advanced alkaline iodine chemistry. Summary of the invention

[0006] In view of the above problems, the present invention provides an aqueous alkaline zinc-iodine battery and a preparation method thereof.

[0007] The first object of the present invention is to provide an aqueous alkaline zinc-iodine battery, the battery comprising: a positive electrode; a negative electrode; and an aqueous alkaline electrolyte;

[0008] The positive electrode comprises a current collector, a positive electrode active material, a conductive agent and a binder, and the positive electrode active material is an iodide; the aqueous alkaline electrolyte comprises a chlorine-containing additive, a zinc salt electrolyte, an alkaline inorganic salt and water.

[0009] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the iodide is a mixture of methylammonium iodide, trimethylammonium iodide, tetrabutylammonium iodide, and tetrabutylammonium triiodide in any ratio. The iodide used in the present invention can provide active iodine and has thermal stability, and can replace traditional iodine.

[0010] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the mass proportion of the positive electrode active material in the positive electrode is in the range of 1-99wt%, the mass proportion of the conductive agent is in the range of 0.1-90wt%, and the mass proportion of the binder is in the range of 0.01-20wt%.

[0011] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the binder includes one or more types.

[0012] The present invention does not make any specific requirements on the specific materials of the conductive agent and the adhesive, and they can be reasonably selected according to actual operation needs.

[0013] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the conductive agent is conductive particles.

[0014] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the current collector is one of carbon cloth, carbon paper, aluminum foil, and nickel foam. In some embodiments of the present invention, the carbon paper may be, for example, carbon nanotube paper.

[0015] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the concentration of the chlorine-containing additive is 0.01-40 mol / L.

[0016] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the chlorine-containing additive is a mixture of any proportion of LiCl, NH4Cl, CaCl2, CsCl, FeCl2, MgCl2, KCl, NaCl, AgCl, and ZnCl2.

[0017] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the concentration of the zinc salt electrolyte is 0.01-30 mol / L.

[0018] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the zinc salt electrolyte is one of zinc sulfate, zinc chloride, zinc acetate, zinc nitrate, zinc perchlorate, zinc tetrafluoroborate, zinc trifluoromethanesulfonate, and zinc bistrifluoromethanesulfonate imide.

[0019] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the concentration of the alkaline inorganic salt is 0.01-30 mol / L.

[0020] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above in the present invention, the alkaline inorganic salt is any one of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, and aluminum hydroxide.

[0021] As a specific embodiment of the aqueous alkaline zinc-iodine battery described above, the zinc metal negative electrode includes zinc foil or zinc powder.

[0022] The second object of the present invention is to provide a method for preparing an aqueous alkaline zinc-iodine battery. The aqueous alkaline zinc-iodine battery, such as the above-mentioned battery, comprises:

[0023] The iodide positive electrode active material, the conductive agent and the binder are uniformly mixed in an organic solvent to obtain a slurry, and then the slurry is applied to a current collector and dried to obtain a positive electrode;

[0024] The positive electrode, the negative electrode and the aqueous alkaline electrolyte are assembled to obtain an aqueous alkaline zinc-iodine battery.

[0025] The third object of the present invention is to provide the application of the aqueous alkaline zinc-iodine battery in automobiles, computers or robots.

[0026] Beneficial effects of the present invention:

[0027] (1) The aqueous alkaline zinc-iodine battery provided by the present invention has low cost and is easy to manufacture.

[0028] (2) The aqueous alkaline zinc-iodine battery provided by the present invention uses iodide as the positive electrode active material, avoiding the instability and safety hazards existing in the current use of iodine as the positive electrode.

[0029] (3) The aqueous alkaline zinc-iodine battery provided by the present invention uses an aqueous alkaline solvent containing a chlorine-containing additive as an electrolyte, and provides excellent electrochemical performance through a double electron conversion mode. Compared with traditional aqueous zinc-iodine batteries, it has higher capacity, energy density and higher output voltage. Specifically, in the embodiment of the present invention, a safe and stable halide (tetrabutylammonium triiodide) is developed as an electrochemically active iodine source to replace elemental iodine, thereby achieving chemical adsorption of iodine by the host rather than just physical adsorption. At the same time, the introduction of chloride ions (0.1M) as an additive in the aqueous alkaline electrolyte can fully activate and stabilize the reversible I of the halide (tetrabutylammonium triiodide) positive electrode. - / I + Redox reaction. Therefore, the tetrabutylammonium triiodide positive electrode paired with the zinc metal negative electrode releases a high potential discharge platform at 1.65-1.68V. Based on the new two-electron transfer mechanism, the discharge capacity of the aqueous alkaline zinc-iodine battery reaches 372-385mAh·g -1 , showing fast redox kinetics and excellent long-term cycling stability. More importantly, its energy density can be increased to an astonishing 553-577Wh·kg -1 , reaching 260% of the traditional lithium-iodine battery based on the single-electron conversion reaction mechanism, which is better than all the aqueous zinc-iodine batteries reported so far. In addition, the high-voltage discharge platform region also significantly improves the effective energy output of the high-voltage region.

[0030] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A comparison diagram of electron transfer modes in an alkaline electrolyte according to an embodiment of the present invention and in a conventional acidic electrolyte is shown. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0034] Figure 1 A comparison diagram of electron transfer modes in an alkaline electrolyte according to an embodiment of the present invention and in a conventional acidic electrolyte is shown, Figure 1 Redox potential is redox potential, Acidic / neutral is acidic / neutral, Alkaline is alkaline, Single-electron is single electron transfer, Two-electrons is two electron transfer, Figure 1 It can be seen that in traditional acidic electrolytes or neutral electrolytes, iodine conversion chemistry is based on a single electron transfer mode, while in alkaline electrolytes it is based on a two-electron transfer mode. The theoretical discharge capacity is twice that of the single electron transfer mode and the conversion voltage is higher.

[0035] Example 1

[0036] This embodiment provides an aqueous alkaline zinc-iodine battery, which is manufactured according to a manufacturing method comprising the following specific steps:

[0037] Production of positive electrode:

[0038] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 8:1:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 3 mg cm -2 ;

[0039] Preparation of aqueous alkaline electrolyte:

[0040] Dissolve 0.1M KOH, 0.1M ZnAc and 0.1M KCl in 1M deionized water and mix them to obtain an aqueous alkaline electrolyte;

[0041] Assembly of aqueous alkaline zinc-iodine battery:

[0042] A CR-2032 button-type aqueous alkaline zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 300 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared alkaline aqueous solution containing KCl as the electrolyte.

[0043] The assembled CR-2032 button-type full cell obtained in Example 1 was used for electrochemical property testing, in which polished zinc metal was used as the negative electrode and a commercial cellulose / polymer composite porous film was used as the separator. Constant current charge and discharge tests were performed using a LAND CT2001A battery cycler (Wuhan, China). Cyclic voltammetry (CV) curves and electrochemical impedance spectroscopy (EIS) data were studied using a CHI-760 electrochemical workstation. All electrochemical properties, including capacity and energy density, were calculated based on the absolute weight of iodine in the positive electrode.

[0044] Cyclic voltammetry (CV) test data show that the aqueous alkaline zinc-iodine battery obtained in Example 1 exhibits a single discharge platform at 1.68V;

[0045] The constant current charge and discharge test data show that the discharge capacity of the aqueous alkaline zinc-iodine battery obtained in Example 1 reaches 385 mAh·g -1 , showing fast redox kinetics and excellent long-term cycling stability, with an energy density of 577Wh·kg -1 .

[0046] Example 2

[0047] This embodiment provides an aqueous alkaline zinc-iodine battery, which is manufactured according to a manufacturing method comprising the following specific steps:

[0048] Production of positive electrode:

[0049] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 7:2:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 20 mg cm -2;

[0050] Preparation of aqueous alkaline electrolyte:

[0051] 15M KOH, 0.1M ZnAc and 0.01M LiCl were dissolved in 1M deionized water and mixed to obtain an aqueous alkaline electrolyte;

[0052] Assembly of aqueous alkaline zinc-iodine battery:

[0053] A CR-2032 button-type aqueous alkaline zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 300 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared alkaline aqueous solution containing LiCl as the electrolyte.

[0054] The assembled CR-2032 button-type full battery obtained in Example 2 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0055] Cyclic voltammetry (CV) test data show that the aqueous alkaline zinc-iodine battery obtained in Example 2 exhibits a single discharge platform at 1.65V;

[0056] The constant current charge and discharge test data show that the discharge capacity of the aqueous alkaline zinc-iodine battery obtained in Example 2 reaches 372 mAh·g -1 , showing fast redox kinetics and excellent long-term cycling stability, with an energy density of 552Wh·kg -1 .

[0057] Example 3

[0058] This embodiment provides an aqueous alkaline zinc-iodine battery, which is manufactured according to a manufacturing method comprising the following specific steps:

[0059] Production of positive electrode:

[0060] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 5:4:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 30 mg cm -2 ;

[0061] Preparation of aqueous alkaline electrolyte:

[0062] 6M NaOH, 0.1M ZnAc and 1M NH4Cl were dissolved in 1M deionized water and mixed to obtain an aqueous alkaline electrolyte;

[0063] Assembly of aqueous alkaline zinc-iodine battery:

[0064] A CR-2032 button-type aqueous alkaline zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 600 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared alkaline aqueous solution containing NH4Cl as the electrolyte.

[0065] The assembled CR-2032 button-type full battery obtained in Example 3 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0066] Cyclic voltammetry (CV) test data show that the aqueous alkaline zinc-iodine battery obtained in Example 3 exhibits a single discharge platform at 1.67V;

[0067] The constant current charge and discharge test data show that the discharge capacity of the aqueous alkaline zinc-iodine battery obtained in Example 3 reaches 376 mAh·g -1 , showing fast redox kinetics and excellent long-term cycling stability, with an energy density of 575Wh·kg -1 .

[0068] Comparative Example 1

[0069] This comparative example provides an aqueous acid zinc-iodine battery, which is prepared according to a preparation method comprising the following specific steps:

[0070] Production of positive electrode:

[0071] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 8:1:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 3 mg cm -2 ;

[0072] Aqueous acid zinc-iodine battery:

[0073] Dissolve 2M ZnSO4 in 1M deionized water and mix to obtain an aqueous acidic electrolyte;

[0074] Assembly of aqueous acid zinc-iodine battery:

[0075] A CR-2032 button-type aqueous acidic zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 300 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared acidic aqueous solution as the electrolyte.

[0076] The assembled CR-2032 button-type full battery obtained in Comparative Example 1 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0077] Cyclic voltammetry (CV) test data show that the aqueous acid zinc-iodine battery obtained in Comparative Example 1 exhibits a single discharge platform at 1.24V;

[0078] The constant current charge and discharge test data show that the discharge capacity of the aqueous acid zinc-iodine battery obtained in Comparative Example 1 reaches 205 mAh g -1 , its energy density is 246Wh·kg -1 .

[0079] Comparative Example 2

[0080] This comparative example provides an aqueous acid zinc-iodine battery, which is prepared according to a preparation method comprising the following specific steps:

[0081] Production of positive electrode:

[0082] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 8:1:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 3 mg cm -2 ;

[0083] Aqueous acid zinc-iodine battery:

[0084] Dissolve 1M Zn(Ac)2 in 1M deionized water and mix to obtain an aqueous acidic electrolyte;

[0085] Assembly of aqueous acid zinc-iodine battery:

[0086] A CR-2032 button-type aqueous acidic zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 300 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared acidic aqueous solution as the electrolyte.

[0087] The assembled CR-2032 button-type full battery obtained in Comparative Example 2 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0088] The cyclic voltammetry (CV) test data showed that the aqueous acid zinc-iodine battery obtained in Comparative Example 2 exhibited a single discharge platform at 1.15V;

[0089] The constant current charge and discharge test data show that the discharge capacity of the aqueous acid zinc-iodine battery obtained in Comparative Example 2 reaches 185 mAh g -1 , its energy density is 204Wh·kg -1 .

[0090] Comparative Example 3

[0091] This comparative example provides an aqueous acid zinc-iodine battery, which is prepared according to a preparation method comprising the following specific steps:

[0092] Production of positive electrode:

[0093] The TBAI3 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 8:1:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 °C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 3 mg cm -2 ;

[0094] Aqueous acid zinc-iodine battery:

[0095] Dissolve 0.1M Zn(ClO4)2 in 1M deionized water and mix to obtain an aqueous acidic electrolyte;

[0096] Assembly of aqueous acid zinc-iodine battery:

[0097] A CR2032 button-type aqueous acidic zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 300 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared acidic aqueous solution as the electrolyte.

[0098] The assembled CR-2032 button-type full battery obtained in Comparative Example 3 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0099] Cyclic voltammetry (CV) test data show that the aqueous acid zinc-iodine battery obtained in Comparative Example 3 exhibits a single discharge platform at 1.32V;

[0100] The constant current charge and discharge test data show that the discharge capacity of the aqueous acid zinc-iodine battery obtained in Comparative Example 3 reaches 207 mAh·g -1 , its energy density is 275Wh·kg -1 .

[0101] Comparative Example 4

[0102] This embodiment provides an aqueous alkaline zinc-iodine battery, which is manufactured according to a manufacturing method comprising the following specific steps:

[0103] Production of positive electrode:

[0104] The iodine element I2 powder, Ketjen black and PVDF were mixed in N-methylpyrrolidone solvent at a mass ratio of 5:4:1, and then vigorously stirred for 0.5 h. The resulting slurry was then coated on a flexible carbon cloth (380 μm thick) and dried in a vacuum oven at 70 ° C for 24 h to obtain a flexible positive electrode, wherein the area mass loading of the positive electrode was controlled to be about 30 mg cm -2 ;

[0105] Preparation of aqueous alkaline electrolyte:

[0106] 6M NaOH, 0.1M ZnAc and 1M NH4Cl were dissolved in 1M deionized water and mixed to obtain an aqueous alkaline electrolyte;

[0107] Assembly of aqueous alkaline zinc-iodine battery:

[0108] A CR-2032 button-type aqueous alkaline zinc-iodine battery was assembled using a zinc metal sheet (zinc foil) with a thickness of 600 μm as the negative electrode, the above-prepared flexible positive electrode (a disc with a diameter of about 12 mm) as the positive electrode, a commercial cellulose / polymer composite porous film with a thickness of 18 μm as the separator, and the above-prepared alkaline aqueous solution containing NH4Cl as the electrolyte.

[0109] The assembled CR-2032 button-type full battery obtained in Comparative Example 4 was used to test the electrochemical properties, and the specific method was the same as that in Example 1.

[0110] The cyclic voltammetry (CV) test data showed that the aqueous alkaline zinc-iodine battery obtained in Comparative Example 4 did not show an obvious discharge platform;

[0111] The constant current charge and discharge test data show that the discharge capacity of the aqueous alkaline zinc-iodine battery obtained in Comparative Example 4 is 112 mAh·g -1 , showing extremely low coulombic efficiency, with an energy density of 92Wh·kg -1 .

[0112] From the electrical performance test data of the aqueous acid zinc-iodine batteries obtained in Examples 1-3 and Comparative Examples 1-4, it can be seen that the aqueous acid zinc-iodine batteries obtained in Examples 1-3 exhibit better reduction kinetics and superior long-term cycle stability, and also have a higher energy density.

[0113] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aqueous alkaline zinc-iodine battery, characterized in that: include: A positive electrode; a negative electrode; and an aqueous alkaline electrolyte; The positive electrode comprises a current collector, a positive electrode active material, a conductive agent and a binder, and the positive electrode active material is an iodide; the aqueous alkaline electrolyte comprises a chlorine-containing additive, a zinc salt electrolyte, an alkaline inorganic salt and water.

2. An aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The iodide is a mixture of methylammonium iodide, trimethylammonium iodide, tetrabutylammonium iodide and tetrabutylammonium triiodide in any ratio.

3. An aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The mass proportion of the positive electrode active material in the positive electrode is in the range of 1-99wt%, the mass proportion of the conductive agent is in the range of 0.1-90wt%, and the mass proportion of the binder is in the range of 0.01-20wt%.

4. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The current collector is one of carbon cloth, carbon paper, aluminum foil and nickel foam.

5. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The concentration of the chlorine-containing additive is 0.01-40 mol / L.

6. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The chlorine-containing additive is a mixture of any proportion of LiCl, NH4Cl, CaCl2, CsCl, FeCl2, MgCl2, KCl, NaCl, AgCl, and ZnCl2.

7. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The concentration of the zinc salt electrolyte is 0.01-30 mol / L.

8. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The zinc salt electrolyte is one of zinc sulfate, zinc chloride, zinc acetate, zinc nitrate, zinc perchlorate, zinc tetrafluoroborate, zinc trifluoromethanesulfonate, and zinc bistrifluoromethanesulfonate imide.

9. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The concentration of the alkaline inorganic salt is 0.01-30 mol / L.

10. The aqueous alkaline zinc-iodine battery according to claim 1, characterized in that: The alkaline inorganic salt is any one of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide and aluminum hydroxide.

11. An aqueous alkaline zinc-iodine battery according to any one of claims 1 to 10, characterized in that: The zinc metal negative electrode includes zinc foil or zinc powder.

12. A method for preparing an aqueous alkaline zinc-iodine battery, characterized in that: The aqueous alkaline zinc-iodine battery is a battery as claimed in any one of claims 1 to 11, comprising: The iodide positive electrode active material, the conductive agent and the binder are uniformly mixed in a solvent to obtain a slurry, and then the slurry is applied to a current collector and dried to obtain a positive electrode; The positive electrode, the negative electrode and the aqueous alkaline electrolyte are assembled to obtain an aqueous alkaline zinc-iodine battery.

13. Use of the aqueous alkaline zinc-iodine battery according to any one of claims 1 to 11 in automobiles, computers or robots.

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