A phenol electrolyte for electrolytic aqueous zinc-manganese battery, its preparation method, and soft-pack battery application

Abstract

The present invention relates to the technical field of secondary batteries and provides a phenol-based organic additive electrolyte for aqueous zinc-manganese batteries that is easy to produce, reasonably priced, and non-toxic. The electrolyte comprises a mixed aqueous solution of manganese acetate, zinc acetate, potassium chloride, and phenol-based organics. The phenol-based organic additive acts as a redox medium and participates in the electrochemical reaction process at the positive electrode, thereby promoting the dissolution of manganese dioxide during discharge, achieving high reversibility of the positive electrode reaction, and improving the long-cycle performance of the aqueous zinc-manganese battery. The invention also proposes a device-based structural design for a soft-pack battery based on the dissolution and deposition mechanism of manganese dioxide, thereby promoting the energy storage application process of aqueous zinc-manganese batteries based on the dissolution and deposition mechanism of manganese dioxide.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary batteries, in particular to the technical field of electrolytic aqueous zinc-manganese secondary batteries, and particularly designs a phenol electrolyte for electrolytic aqueous zinc-manganese batteries, a preparation method thereof, and soft-pack battery applications. Background Art

[0002] In order to cope with the increasingly serious problems of energy shortage and environmental pollution, the development of renewable energy and its related large-scale energy storage technology is one of the key tasks to be solved worldwide. Among them, secondary batteries, as a high-efficiency electrochemical energy storage technology, have received widespread attention from the scientific and industrial communities. Although non-aqueous lithium-ion batteries dominate the fields of portable electronic devices and electric vehicles, flammable organic electrolytes make them face serious safety issues. Aqueous zinc-manganese batteries have more outstanding advantages than other energy storage technologies due to their low cost, environmental protection, high safety, simple preparation, and high conversion efficiency. The development of green and safe secondary batteries is the key to developing new electrochemical energy storage systems and optimizing the energy supply structure.

[0003] Among them, aqueous zinc-manganese batteries have attracted much attention due to their low cost, high voltage, and large theoretical capacity. + / Zn 2+ The intercalation mechanism of manganese dioxide (MnO2) cathode has been reported and studied intensively, however, the lower Mn 3+ / Mn 4+ The conversion reaction kinetics and the capacity decay caused by the structural collapse of the manganese dioxide positive electrode active material during the cycle in a weak acid electrolyte environment limit the large-scale application of secondary zinc-manganese batteries. In recent years, aqueous zinc-manganese batteries based on the MnO2 deposition / dissolution reaction mechanism of double electron transfer have begun to attract attention. Compared with the single electron reaction of conventional neutral zinc-manganese batteries, zinc-manganese batteries based on the MnO2 deposition / dissolution mechanism have a high theoretical capacity (616 mAh g) due to the double electron transfer of the positive electrode reaction. -1 ). In addition, water Mn 2+ The reversible solid / liquid conversion reaction mechanism in / MnO2 batteries can release the pressure of structural collapse and achieve long-term high-efficiency cycle stability. 2+ / MnO2-based aqueous zinc-manganese battery has a simple assembly process and is one of the aqueous batteries with great potential for large-scale energy storage.

[0004] However, Mn 2+ / The practical application of MnO2-based aqueous zinc-manganese batteries still faces huge challenges. The most fundamental reason is that the Mn 2+ Mn / MnO2 conversion process 3+The poor reaction kinetics caused by disproportionation makes it extremely challenging to achieve a reversible and efficient cathode reaction. 2+ / MnO2 conversion reaction of aqueous zinc-manganese flow batteries rely on expensive ion exchange membranes to maintain the normal operation of the battery, which will greatly increase the manufacturing cost of the battery. Therefore, the design also meets the requirements of high positive electrode Mn 2+ The electrolyte engineering of reversible Zn / MnO2 conversion and high zinc anode compatibility is the key challenge to achieve high specific energy, long life and low cost aqueous ampere-hour zinc-manganese battery.

[0005] The Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences proposed an electrolytic zinc-manganese aqueous battery in CN 118198527 A, which includes a positive electrode, a zinc metal negative electrode and an electrolyte; the electrolyte includes a manganese salt, a zinc salt, water, an acid and an electrolyte additive; the electrolyte additive is hydroxymethyl (sub)dimethyl phosphite. The present invention uses the synergistic effect of the hydroxyl group and the phosphate group in hydroxymethyl (sub)dimethyl phosphite to induce the electrolytic effect. Since the phosphorus-oxygen double bond (PO) in the phosphate group can open the complex electrolyte metal manganese and zinc cations, they can quickly migrate to the electrode electrolyte interface under the guidance of the hydroxyl group to carry out electrochemical redox reaction, thereby facilitating the deposition and dissolution chemistry of manganese dioxide and zinc cations and catalyzing the electrolytic reaction kinetics. A solution is proposed for the problem of poor electrochemical dissolution kinetics of manganese dioxide during the discharge process of electrolytic aqueous zinc-manganese batteries, but the battery still has a large loss in discharge capacity relative to charging capacity at high areal capacity density (11.95mAh cm -2 The discharge capacity is compared with 15 mAh cm -2 of charging capacity).

[0006] The University of Science and Technology of China proposed an aqueous composite mechanism zinc-manganese battery in CN 116525973 A, including: a positive electrode, a negative electrode and an electrolyte system. The positive electrode includes an electrode material loaded with manganese dioxide, wherein the first part of manganese dioxide as an active material undergoes insertion / deintercalation reaction with hydrogen ions and zinc ions, and the second part of manganese dioxide undergoes deposition and dissolution reaction. The negative electrode includes a conductive current collector material to achieve the redox reaction of zinc ions and zinc elements. The electrolyte system includes a mixed solution of zinc salt, manganese salt and pH regulating solution. Among them, the charging and discharging conditions of the battery include: the charging cut-off voltage range includes 1.99~2.2V, so as to meet the simultaneous insertion and deintercalation reaction and deposition and dissolution reaction. During the composite process, the MnO2 deposited and dissolved at the positive electrode not only directly contributes to the battery capacity, but also can participate in the Zn 2+ and H + The insertion / extraction reaction contributes additional capacity through single electron transfer, which not only increases the capacity of the battery but also ensures the working stability of the battery.

[0007] In CN 118099557 A, Central South University proposed a colloidal electrolyte for aqueous zinc-manganese dioxide batteries. The electrolyte comprises a solvent and an electrolyte, wherein the solvent is water. The electrolyte includes a zinc salt, a manganese salt, an additive, and an organic / inorganic acid that provides additional protons when MnO2 dissolves. The additives include a gelling agent and ferrous sulfate, with the gelling agent comprising 5-12.5% ​​of the electrolyte mass. The molar concentration of ferrous sulfate is 0.005-0.02 mol / L. This patent utilizes the colloidal electrolyte as a promoter for the deposition of manganese dioxide during charging, and the ferrous sulfate as a dissolution promoter during the discharge of manganese dioxide, both participating in the electrode reaction. Ferrous ions can corrode the negative electrode, and the added sulfuric acid also causes severe corrosion. This patent, however, utilizes a phenolic compound that is more compatible with the zinc negative electrode. Therefore, this patent is suitable for use in closed-system electrolytic zinc-manganese dioxide soft-pack batteries.

[0008] The University of Science and Technology of China disclosed an aqueous electrolyte and an aqueous electrolytic MnO2-Zn battery in CN 113054264 B. The aqueous electrolytic MnO2-Zn battery comprises: an electrolyte comprising a zinc salt, a manganese salt and a liquid redox medium, wherein the electrolyte is an acidic electrolyte; a positive electrode for reacting with the electrolyte to form a MnO2 / Mn 2+ The negative electrode is used to react with the electrolyte to produce Zn 2+ The patent uses iodine salts, bromide salts, and vanadium salts as redox mediator additives. These additives cause corrosion of the zinc anode and are unsuitable for soft-pack battery systems. They also have poor kinetics, which affects battery cycling performance. This patent, however, uses phenolic compounds, which have better compatibility with the zinc anode and faster electrode reaction kinetics. Therefore, this patent is suitable for use in closed-system zinc-manganese soft-pack batteries.

[0009] Therefore, how to improve the discharge capacity of aqueous zinc-manganese batteries and maintain their cycle stability has become a hot topic of current research. Summary of the Invention

[0010] In order to address the deficiencies and shortcomings of the above-mentioned prior art, the present invention aims to propose an aqueous zinc-manganese battery based on a phenol additive electrolyte, which realizes the manganese dioxide dissolution and deposition mechanism process of stable double electron transfer in the battery by designing and regulating the electrolyte ratio, and improves technical problems such as low positive capacity and unstable cycle of aqueous zinc-manganese batteries.

[0011] A phenolic electrolyte for an electrolytic aqueous zinc-manganese battery, wherein the electrolyte comprises a mixed aqueous solution of zinc acetate, manganese acetate, potassium chloride and a phenolic organic matter, wherein the concentrations of the components are: 0.5-3 mol / L manganese acetate, 0.5-2 mol / L zinc acetate, 1-3 mol / L potassium chloride, and 0.0005-0.01 mol / L phenolic organic matter, respectively. The phenolic organic matter is one or more of hydroquinone, 2-methylhydroquinone, 2,6-dimethylhydroquinone, 2,3,5-trimethylhydroquinone, tert-butylhydroquinone, 2-methoxyhydroquinone and 2,5-dihydroxybiphenyl.

[0012] Preferably, the concentrations of the components are: 1 mol / L zinc acetate, 1.5 mol / L manganese acetate, 2 mol / L potassium chloride and 0.002 mol / L phenolic organic matter.

[0013] A method for preparing the above-mentioned phenol electrolyte for electrolytic aqueous zinc-manganese battery is characterized by comprising the following steps:

[0014] 1) adding deionized water to a mixture of manganese acetate, zinc acetate, and potassium chloride to obtain solution A;

[0015] 2) adding deionized water to the phenol compound powder to obtain solution B;

[0016] 3) Ultrasonic dispersion of solution A and solution B to obtain a clear solution;

[0017] 4) A certain amount of solution B is added to solution A, and the mixture is mixed and dispersed uniformly to obtain solution C; solution C is the phenol electrolyte for electrolytic aqueous zinc-manganese battery.

[0018] The application of the above-mentioned phenol electrolyte for electrolytic aqueous zinc-manganese battery in soft-pack batteries.

[0019] As an advantage, the method comprises the following steps:

[0020] 1) preparing a positive electrode sheet;

[0021] 2) Preparation of zinc negative electrode sheet:

[0022] 3) Preparation of soft-pack batteries: A phenol-based electrolyte for an electrolytic aqueous zinc-manganese battery is added to a glass fiber separator to obtain an electrolyte-added separator, and the separator is paired with a negative electrode sheet, a positive electrode sheet, a titanium foil, a heat shrinkable film, and an aluminum-plastic film. The assembly and stacking order is negative electrode sheet, electrolyte-added separator, positive electrode sheet, titanium foil, positive electrode sheet, electrolyte-added separator, and negative electrode sheet to obtain a single cell of a zinc-manganese soft-pack battery. The cell is then encapsulated with an aluminum-plastic film to prepare a soft-pack battery.

[0023] Preferably, the positive electrode sheet is prepared by: preparing a dispersion A of conductive carbon and polyvinylidene fluoride binder in N-methylpyrrolidone; wherein the mass ratio of the conductive carbon and the polyvinylidene fluoride binder is (1-20):1, and the mass ratio of the solute to the solvent in the dispersion A is 1 / 50 to 1 / 70; adding the dispersion A dropwise to the positive electrode carbon material until saturated, and drying until the dispersion solvent N-methylpyrrolidone is completely removed to obtain a positive electrode;

[0024] The conductive carbon includes one or more of activated carbon, carbon micron, nanofiber, carbon nanotube, carbon sphere, Ketjen black and conductive carbon black;

[0025] The positive electrode carbon material is one or more of carbon felt, graphite felt, graphite, graphene, carbon cloth, and carbon paper.

[0026] Preferably, the zinc negative electrode sheet is prepared by cutting commercial foil to obtain a zinc metal negative electrode sheet.

[0027] The soft-pack battery is obtained by applying the phenol electrolyte for the electrolytic aqueous zinc-manganese battery to the soft-pack battery.

[0028] Compared with the prior art, the beneficial effect is

[0029] (1) The present invention provides an electrolyte additive that is easy to produce and has a suitable price. The phenol compound is reacted with Mn 2+ The positive electrode reaction of / MnO2 promotes the dissolution stage of MnO2 during discharge, achieving a highly reversible positive electrode reaction and improving the long-cycle performance of aqueous zinc-manganese batteries. The optimal embodiment can achieve a capacity retention rate of 95% after 240 cycles (capacity retention rate = 230th cycle capacity / maximum capacity within 230 cycles).

[0030] (2) The present invention provides a soft-pack battery structure of an electrolytic aqueous zinc-manganese battery based on the dissolution and deposition reaction of manganese dioxide. Compared with other electrolytic aqueous zinc-manganese batteries, this soft-pack battery structure has the advantages of low preparation cost, short preparation process, and easy preparation process, which is conducive to promoting the application of electrolytic aqueous zinc-manganese batteries.

[0031] (3) Compared with existing battery systems, the electrolytic aqueous zinc-manganese battery electrolyte provided by the present invention has the advantages of low-cost raw materials, simple preparation, and no use of toxic heavy metal elements such as lead, cadmium, and vanadium. It has the advantages of environmental protection and safety.

[0032] (4) Compared with the existing battery system, the aqueous zinc-manganese battery electrolyte provided by the present invention does not require additional acid additives (sulfuric acid, acetic acid, phosphoric acid, etc.), and compared with the existing electrolyte additives such as Fe that promote the dissolution of manganese dioxide during the discharge process of electrolytic aqueous zinc-manganese batteries, the electrolyte provided by the present invention does not require additional acid additives (sulfuric acid, acetic acid, phosphoric acid, etc.). 2+ Cr 3+, I - Br - Phenol compounds have better compatibility with zinc metal negative electrodes, which prevents the corrosion of zinc metal negative electrodes by additives and prolongs battery life.

[0033] According to the embodiments of the present invention, a large number of experiments were conducted to verify the feasibility of phenolic compounds promoting the dissolution of manganese dioxide during the discharge stage, and it was concluded that by adding phenolic compounds to the electrolyte, the battery system can be regulated to perform highly reversible Mn 2+ / MnO2 double electron transfer, that is, manganese dioxide itself undergoes a double electron transfer deposition / dissolution reaction and is applied to soft-pack batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 Schematic diagram of the voltage curve and positive electrode reaction of the battery system using phenol electrolyte of the present invention;

[0036] Figure 2 This is a schematic diagram of the assembly of a soft-pack battery using a phenolic additive electrolyte according to the present invention;

[0037] Figure 3 Graph showing Fourier transform infrared test results of the electrolyte in Example 1 of the present invention before and after adding manganese dioxide powder;

[0038] Figure 4 1 is a comparison chart of the cycle performance of Example 1, Example 2 and Comparative Example 1 in the present invention;

[0039] Figure 5 1 is a comparison chart of the cycle performance of Example 3, Example 4 and Example 5 of the present invention;

[0040] Figure 6 1 is a comparison chart of the cycle performance of Example 6, Example 7 and Example 8 of the present invention;

[0041] Figure 7 This is a cycle performance diagram of Example 9 of the present invention;

[0042] Figure 8 This is a voltage-capacity diagram of Example 9 of the present invention;

[0043] Figure 9 This is a cycle performance diagram of Example 10 of the present invention;

[0044] Figure 10 This is a voltage-capacity diagram of Example 10 of the present invention; DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation methods of the present invention are further described below.

[0046] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0047] The battery positive electrode reaction mechanism diagram provided by the present invention is as follows Figure 1 As shown:

[0048] Charging process:

[0049] Mn 2+ +2H2O=MnO2+4H + +2e -

[0050] Discharge process 1:

[0051] MnO2+4H + +2e - =Mn 2+ +2H2O

[0052] Discharge process 2:

[0053] C6H4O2+2H + +2e - =C6H6O2

[0054] C6H6O2+MnO2+2H + =Mn 2+ +C6H4O2+H2O

[0055] Example 1

[0056] 1) Preparation of Example 1 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L hydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain Solution A containing 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride. 20 mL of deionized water was added to 0.11 g of hydroquinone powder to obtain Solution B. 2 mL of Solution B was added to Solution A to obtain a hydroquinone-additive electrolyte.

[0057] 2) Preparation of positive electrode: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​25 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0058] 3) Preparation of zinc negative electrode sheet: Cut the commercial zinc foil into an area of ​​27cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0059] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (25cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 27cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2 The assembly is to stack the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order, then put them into heat shrink film and heat them to make the heat shrink film fit tightly to the battery cell, and then seal them in aluminum plastic film to obtain a soft pack battery. The soft pack battery structure diagram is shown in the figure. Figure 2 shown.

[0060] 5) Study on the reaction mechanism of electrolyte phenol compounds: Fourier transform infrared spectroscopy was performed on the electrolyte solution A in Example 1 and the electrolyte dispersion B in Example 1 with added manganese dioxide powder. The results are as follows: Figure 3 The results show that manganese dioxide reacts with phenolic compounds and converts phenolic compounds into benzoquinone compounds.

[0061] 5) Soft pack battery test: Using the Xinwei battery test system, at 4mA / cm 2 The soft pack battery was tested at a current density of Figure 4 As shown in Example 1.

[0062] Example 2

[0063] 1) Preparation of Example 2 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L tert-butylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.166 g of tert-butylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a tert-butylhydroquinone additive electrolyte.

[0064] 2) Preparation of positive electrode: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​25 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0065] 3) Preparation of zinc negative electrode sheet: Cut the commercial zinc foil into an area of ​​27cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0066] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (25cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 27cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2 The battery is assembled by stacking the zinc negative electrode, separator (electrolyte has been added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (electrolyte has been added), and zinc negative electrode in this order, placing them in a heat shrinkable film and heating them so that the heat shrinkable film can fit the battery cell tightly and fix it, and then sealing it in an aluminum-plastic film to obtain a soft-pack battery.

[0067] 5) Soft pack battery test: Using the Xinwei battery test system, at 4mA / cm 2 The soft pack battery was tested at a current density of Figure 4 As shown in Example 2, after 240 cycles, a capacity retention rate of 95% can be achieved, where capacity retention rate = (capacity at the 240th cycle / maximum capacity within 240 cycles). This demonstrates the promoting effect of the tert-butyl additive electrolyte on the cycling performance of aqueous zinc-manganese batteries.

[0068] Example 3

[0069] 1) Preparation of Example 3 electrolyte (concentrations of 1 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 12.2 g of manganese acetate, and 7.45 g of potassium chloride to obtain 1 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.138 g of 2,6-dimethylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a 2,6-dimethylhydroquinone additive electrolyte.

[0070] 2) Preparation of positive electrode sheet: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​80 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0071] 3) Preparation of zinc negative electrode sheet: Commercial zinc foil was cut into 84cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0072] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (80cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 84cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2 The battery is assembled by stacking the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order, then placing them in heat shrink film and heating them so that the heat shrink film tightly adheres to the battery cell to obtain a single-layer battery cell. The single battery cells are stacked and placed in aluminum-plastic film to obtain a soft-pack battery.

[0073] 5) Testing of soft pack batteries: Using the Xinwei battery testing system, the soft pack batteries were tested at a charging current of 0.6C and a discharge current density of 0.2C. The test results are as follows: Figure 5 As shown in Example 3.

[0074] Example 4

[0075] 1) Preparation of Example 4 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.138 g of 2,6-dimethylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a 2,6-dimethylhydroquinone additive electrolyte.

[0076] 2) Preparation of positive electrode sheet: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​80 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0077] 3) Preparation of zinc negative electrode sheet: Commercial zinc foil was cut into 84cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0078] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (80cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 84cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2 The battery is assembled by stacking the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order, then placing them in heat shrink film and heating them to tightly adhere to the heat shrink film and fix them to form a single-layer battery cell. The stacked single cells are then encapsulated in aluminum-plastic film to form a soft-pack battery.

[0079] 5) Testing of soft pack batteries: Using the Xinwei battery testing system, the soft pack batteries were tested at a charging current of 0.6C and a discharge current density of 0.2C. Figure 5 As shown in Example 4. Compared with Example 3 and Example 5, Example 4 has the longest cycle life, indicating that the optimal concentration of manganese ions in the electrolyte is 1.5 mol / L.

[0080] Example 5

[0081] 1) Preparation of Example 5 electrolyte (concentrations: 2 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 24.4 g of manganese acetate, and 7.45 g of potassium chloride to obtain 2 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.138 g of 2,6-dimethylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a 2,6-dimethylhydroquinone additive electrolyte.

[0082] 2) Preparation of positive electrode sheet: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​80 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0083] 3) Preparation of zinc negative electrode sheet: Commercial zinc foil was cut into 84cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0084] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (80 cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 84cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2 The battery is assembled by stacking the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order, then placing them in heat shrink film and heating them to tightly adhere to the heat shrink film and fix them to form a single-layer battery cell. The stacked single cells are then encapsulated in aluminum-plastic film to form a soft-pack battery.

[0085] 5) Testing of soft pack batteries: Using the Xinwei battery testing system, the soft pack batteries were tested at a charging current of 0.6C and a discharge current density of 0.2C. The results are as follows: Figure 5 As shown in Example 5.

[0086] Example 6

[0087] 1) Preparation of Example 6 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.001 mol / L 2,6-dimethylhydroquinone): 49 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain Solution A containing 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride. 20 mL of deionized water was added to 0.110 g of hydroquinone powder to obtain Solution B. 1 mL of Solution B was added to Solution A to obtain a hydroquinone-additive electrolyte.

[0088] 2) Preparation of positive electrode: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on the active area of ​​1cm -2 , on 6mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0089] 3) Preparation of zinc negative electrode: Cut the commercial zinc foil into an active area of ​​1cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0090] 4) Preparation of a static electrolytic cell: The electrolyte prepared in Example 6 was added to an electrolytic cell. The positive electrode and the zinc negative electrode were mounted on platinum metal electrode holders. This resulted in a static electrolytic cell.

[0091] 5) Static electrolytic cell battery test: Using the Xinwei battery test system, at 10mA / cm 2 , 10mAh / cm 2 The static electrolyzer battery was tested under the charge and discharge regime of Figure 6 As shown in Example 6.

[0092] Example 7

[0093] 1) Preparation of Example 7 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain Solution A containing 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride. 20 mL of deionized water was added to 0.110 g of hydroquinone powder to obtain Solution B. 2 mL of Solution B was added to Solution A to obtain a hydroquinone-additive electrolyte.

[0094] 2) Preparation of positive electrode: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on the active area of ​​1cm -2 , on 6mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0095] 3) Preparation of zinc negative electrode: Cut the commercial zinc foil into an active area of ​​1cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0096] 4) Preparation of a static electrolytic cell: The electrolyte prepared in Example 7 was added to an electrolytic cell. The positive electrode and the zinc negative electrode were mounted on platinum metal electrode holders. This resulted in a static electrolytic cell.

[0097] 5) Static electrolytic cell battery test: Using the Xinwei battery test system, at 10mA / cm 2 , 10mAh / cm 2 The static electrolyzer battery was tested under the charge and discharge regime of Figure 6 As shown in Example 7.

[0098] Example 8

[0099] 1) Preparation of the electrolyte from Example 8 (concentrations of 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 47 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain Solution A containing 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride. 20 mL of deionized water was added to 0.110 g of hydroquinone powder to obtain Solution B. 3 mL of Solution B was added to Solution A to obtain a hydroquinone-additive electrolyte.

[0100] 2) Preparation of positive electrode: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on the active area of ​​1cm -2 , on 6mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0101] 3) Preparation of zinc negative electrode: Cut the commercial zinc foil into an active area of ​​1cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0102] 4) Preparation of a static electrolytic cell: The electrolyte prepared in Example 8 was added to an electrolytic cell. The positive electrode and the zinc negative electrode were mounted on platinum metal electrode holders. This resulted in a static electrolytic cell.

[0103] 5) Static electrolytic cell battery test: Using the Xinwei battery test system, at 10mA / cm 2 , 10mAh / cm 2 The static electrolyzer battery was tested under the charge and discharge regime of Figure 6 As shown in Example 8. Figure 6 The results showed that the optimal addition concentration of phenolic organic matter was 0.002 mol / L.

[0104] Example 9

[0105] 1) Preparation of Example 9 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.138 g of 2,6-dimethylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a 2,6-dimethylhydroquinone additive electrolyte.

[0106] 2) Preparation of positive electrode sheet: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​80 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0107] 3) Preparation of zinc negative electrode sheet: Commercial zinc foil was cut into 84cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0108] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (80 cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 84cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2The battery is assembled by stacking the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order, then placing them in heat shrink film and heating them to tightly adhere to the heat shrink film and fix them to form a single-layer battery cell. Two battery cells are stacked and placed in aluminum-plastic film to form a soft-pack battery.

[0109] 5) Soft pack battery test: Using the Xinwei battery test system, at 8.3mA / cm 2 The soft pack battery was tested at a current density of Figure 7 As shown in Example 9, after 50 cycles, the capacity retention rate can reach 99%, and the capacity retention rate = (capacity at the 50th cycle / maximum capacity within 50 cycles). The voltage capacity of the soft pack battery in Example 9 is as follows: Figure 8 As shown, it has a stable discharge platform, which illustrates the promoting effect of 2,6-dimethylhydroquinone additive electrolyte on the cycle performance of aqueous zinc-manganese battery.

[0110] Example 10

[0111] 1) Preparation of Example 10 electrolyte (concentrations: 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, 2 mol / L potassium chloride, and 0.002 mol / L 2,6-dimethylhydroquinone): 48 mL of deionized water was added to a mixture of 10.8 g of zinc acetate, 18.3 g of manganese acetate, and 7.45 g of potassium chloride to obtain 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride solution A. 20 mL of deionized water was added to 0.138 g of 2,6-dimethylhydroquinone powder to obtain solution B. 2 mL of solution B was added to solution A to obtain a 2,6-dimethylhydroquinone additive electrolyte.

[0112] 2) Preparation of positive electrode sheet: Superconducting carbon black (super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​80 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0113] 3) Preparation of zinc negative electrode sheet: Commercial zinc foil was cut into 84cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0114] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (80cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 84cm 2), heat shrink film, aluminum plastic film for attachment Figure 2 The battery is assembled by stacking the zinc negative electrode, separator (with electrolyte added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (with electrolyte added), and zinc negative electrode in this order. The battery is then placed in heat shrink film and heated to ensure that the heat shrink film adheres tightly to the battery cell, resulting in a single-layer battery cell. The three stacked cells are then encapsulated in aluminum-plastic film to form a soft-pack battery.

[0115] 5) Soft pack battery test: Using the Xinwei battery test system, at 9.3mA / cm 2 The soft pack battery was tested at a current density of Figure 9 As shown in Example 4. After 30 cycles, the capacity retention rate can reach 95%, and the capacity retention rate = (30th cycle capacity / maximum capacity within 30 cycles). The voltage-capacity curve of Example 10 is shown in Figure 10 As shown, it has a stable discharge platform, which further illustrates the promoting effect of 2,6-dimethylhydroquinone on ampere-hour-level aqueous zinc-manganese soft-pack batteries.

[0116] Comparative Example 1

[0117] 1) Preparation of the electrolyte of Comparative Example 1 (concentrations of 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride): 50 ml of deionized water was added to a mixture of 10.8 g zinc acetate, 18.3 g manganese acetate, and 7.45 g potassium chloride to obtain an electrolyte of 1.5 mol / L manganese acetate, 1 mol / L zinc acetate, and 2 mol / L potassium chloride.

[0118] 2) Preparation of positive electrode sheet: Superconducting carbon black (Super P) and PVDF binder were mixed and ground evenly in a ratio of 10:1, and a certain amount of NMP dispersion was added and evenly dripped on an area of ​​25 cm -2 , on 1mm thick graphite felt, the conductive carbon loading is 7mg / cm -2 , and then taken out after drying at 70 degrees Celsius for 24 hours to obtain the positive electrode sheet.

[0119] 3) Preparation of zinc negative electrode sheet: Cut the commercial zinc foil into an area of ​​27cm 2 , zinc metal negative electrode sheet with a thickness of 0.6mm.

[0120] 4) Preparation of soft pack battery: The electrolyte, positive electrode sheet and titanium foil (25cm 2 , 20μm) zinc negative electrode sheet, Whatman GF / A glass fiber separator (area 27cm 2 ), heat shrink film, aluminum plastic film for attachment Figure 2The battery is assembled by stacking the zinc negative electrode, separator (electrolyte has been added), carbon felt positive electrode, titanium foil, carbon felt positive electrode, separator (electrolyte has been added), and zinc negative electrode in this order, placing them in a heat shrinkable film and heating them so that the heat shrinkable film fits tightly to the battery cell and then sealing them in an aluminum-plastic film to obtain a soft-pack battery.

[0121] 5) Soft pack battery test: Using the Xinwei battery test system, at 4mA / cm 2 The soft pack battery was tested at a current density of Figure 4 As shown in Comparative Example 1.

[0122] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A phenol electrolyte for an electrolytic aqueous zinc-manganese battery, characterized in that: The electrolyte is composed of a mixed aqueous solution of zinc acetate, manganese acetate, potassium chloride and phenolic organic matter, and the concentrations of each component are: 0.5-3 mol / L of manganese acetate, 0.5-2 mol / L of zinc acetate, 1-3 mol / L of potassium chloride, and 0.0005-0.01 mol / L of phenolic organic matter. The phenolic organic matter is one or more of hydroquinone, 2-methylhydroquinone, 2,6-dimethylhydroquinone, 2,3,5-trimethylhydroquinone, tert-butylhydroquinone, 2-methoxyhydroquinone and 2,5-dihydroxybiphenyl.

2. The phenol electrolyte for electrolytic aqueous zinc-manganese battery according to claim 1, characterized in that: The concentrations of each component are: zinc acetate 1 mol / L, manganese acetate 1.5 mol / L, potassium chloride 2 mol / L and phenolic organic matter 0.002 mol / L.

3. A method for preparing the phenol electrolyte for electrolytic aqueous zinc-manganese battery according to claim 1 or 2, characterized in that: The steps include: 1) Deionized water was added to a mixture of manganese acetate, zinc acetate, and potassium chloride to obtain solution A; 2) adding deionized water to the phenol compound powder to obtain solution B; 3) Ultrasonic dispersion of solution A and solution B to obtain a clear solution; 4) A certain amount of solution B is added to solution A, and the mixture is mixed and dispersed uniformly to obtain solution C; solution C is the phenol electrolyte for electrolytic aqueous zinc-manganese battery.

4. Use of the phenol electrolyte for electrolytic aqueous zinc-manganese battery according to claim 1 or 2 in soft-pack batteries.

5. The use of a phenol electrolyte for an electrolytic aqueous zinc-manganese battery in a soft-pack battery according to claim 4, characterized in that: The steps include: 1) Preparation of positive electrode sheet; 2) Preparation of zinc negative electrode sheet: 3) Preparation of soft-pack batteries: Add a phenol-based electrolyte for an electrolytic aqueous zinc-manganese battery into a glass fiber separator to obtain an electrolyte-added separator, and then match it with a negative electrode sheet, a positive electrode sheet, titanium foil, a heat shrink film, and an aluminum-plastic film. The assembly and stacking order is negative electrode sheet, electrolyte-added separator, positive electrode sheet, titanium foil, positive electrode sheet, electrolyte-added separator, and negative electrode sheet to obtain a zinc-manganese soft-pack battery cell. The cell is then encapsulated with an aluminum-plastic film to prepare a soft-pack battery.

6. The use of a phenol electrolyte for an electrolytic aqueous zinc-manganese battery in a soft-pack battery according to claim 5, characterized in that: The positive electrode sheet is prepared by preparing a dispersion A of conductive carbon and a polyvinylidene fluoride binder in N-methylpyrrolidone, wherein the mass ratio of the conductive carbon to the polyvinylidene fluoride binder is (1-20):1, and the mass ratio of the solute to the solvent in the dispersion A is 1 / 50 to 1 / 70; the dispersion A is added dropwise to the positive electrode carbon material until saturated, and dried until the dispersion solvent N-methylpyrrolidone is completely removed, thereby obtaining a positive electrode; The conductive carbon includes one or more of activated carbon, carbon microns, nanofibers, carbon nanotubes, carbon balls and conductive carbon black; The positive electrode carbon material is one or more of carbon felt, graphite felt, graphite, graphene, carbon cloth, and carbon paper.

7. The use of a phenol electrolyte for an electrolytic aqueous zinc-manganese battery in a soft-pack battery according to claim 5, characterized in that: The zinc negative electrode sheet is prepared by cutting commercial zinc foil to obtain a zinc metal negative electrode sheet.

8. A soft-pack battery obtained by applying the phenol electrolyte for electrolytic aqueous zinc-manganese battery according to any one of claims 4 to 7 to a soft-pack battery.

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