Alkaline iron-manganese battery

Abstract

The present invention relates to an alkaline iron-manganese battery, which uses iron-containing layered double hydroxide as the battery negative electrode active material; uses manganese-containing oxide or layered double hydroxide as the battery positive electrode active material; and uses an aqueous neutral or weakly alkaline buffer solution as the electrolyte. Compared with the prior art, the battery of the present invention has the advantages of low cost, high number of charge and discharge cycles, long service life, wide operating temperature range, etc.

Description

Technical Field

[0001] The invention relates to the field of electrochemical energy storage, and in particular to an alkaline iron-manganese storage battery technology which is low in price, stable in performance and can be flexibly used. Background Art

[0002] With the development of new energy technologies, large-scale energy storage technology has become one of the bottleneck technologies in the development of new energy technologies due to the volatility of new energy power generation technologies such as photovoltaics and wind power. At present, electrochemical energy storage is still one of the priority development directions of large-scale energy storage technology.

[0003] For lithium batteries, although the cost of lithium iron phosphate batteries has been greatly reduced compared to lithium cobalt oxide batteries or nickel-cobalt-aluminum ternary lithium batteries, they are still too expensive for large-scale energy storage purposes and have not been widely used. In addition, due to the limited production of minerals such as lithium, nickel, and cobalt, it is difficult to significantly increase production capacity.

[0004] At present, traditional lead-acid batteries are still in use. Not only do they cause heavy metal pollution during use and recycling, but the low number of charge and discharge cycles, short service life and frequent scrapping also exacerbate the pollution risk.

[0005] Analysis of lead-acid batteries shows that during the charge and discharge process, the active material lead dioxide in the positive electrode shrinks and expands, causing the binding force to be destroyed and easy to fall off, affecting the electrode performance. The negative electrode lead metal is also easily corroded and hydrogen is released, resulting in a low number of charge and discharge cycles, making it difficult to be widely used as a new energy large-scale energy storage technology. Summary of the invention

[0006] The purpose of the present invention is to provide an alkaline iron-manganese storage battery in order to overcome the defects of the above-mentioned prior art, overcome the utilization efficiency problem of the electrodes and electrolyte of the lead-acid battery, and can overcome the problems of low charge and discharge cycles of the lead-acid battery, hydrogen evolution corrosion, etc.; and there is no heavy metal pollution, and there is no need to use a large amount of metal elements such as nickel, cobalt, lithium, etc. whose production is limited and the price is relatively high.

[0007] The object of the present invention can be achieved by the following technical scheme: an alkaline iron-manganese storage battery, comprising:

[0008] (1) Using iron-containing layered double hydroxide (denoted as (Fe-LDH)) as the negative electrode active material of the battery;

[0009] (2) Using manganese-containing oxide (denoted as MnO z ) or layered double hydroxide (denoted as Mn-LDH) as the positive electrode active material of the battery;

[0010] (3) Aqueous neutral or weakly alkaline buffer solution is used as the electrolyte.

[0011] The storage battery of the present invention has the advantages of low cost, high charge-discharge cycle times, long service life, wide operating temperature range, etc. The pH of the electrolyte remains between 7 and 13 during the charge and discharge process of the battery; the electrochemical reaction equation during the charging process of the battery is:

[0012] Negative electrode: Fe(III)-LDH + e => Fe(II)-LDH;

[0013] Positive electrode: Mn(III)-LDH - e => Mn(IV)-LDH or MnO(OH) + OH - -e => MnO2 + H2O The electrochemical reaction equation during the discharging process of the battery is:

[0014] Negative electrode: Fe(II)-LDH - e => Fe(III)-LDH;

[0015] Positive electrode: Mn(IV)-LDH + e => Mn(III)-LDH or MnO2 + H2O + e => MnO(OH) + OH - Furthermore, the cations of the iron-containing layered double hydroxide are:

[0016] Fe(II)-LDH: Mg x FeAl y (OH) 2(1+x+y) y+ , where 0.1 < x ≤ 8, 0 ≤ y ≤ 3,

[0017] Or Fe(III)-LDH: Mg x FeAl y (OH) 2(1+x+y) (1+y)+ , where 0.1 < x ≤ 8, 0 ≤ y ≤ 3,

[0018] The corresponding anions are one or a mixture of sulfate, nitrate, and chloride ions.

[0019] Furthermore, acetylene black and graphite are also added to the negative electrode active material of the storage battery. Among them, the mass ratio of the iron-containing layered double hydroxide to acetylene black and graphite is: 1: 0 to 0.2: 0 to 0.2.

[0020] Furthermore, the cations of the manganese-containing layered double hydroxide are:

[0021] Mn(III)-LDH: Mg p MnM q (OH) 2(1+p+q) (1+q)+ , where 0.1 < p ≤ 8, 0 ≤ q ≤ 3, M = Al or Fe,

[0022] Or Mn(IV)-LDH: Mg p MnM q (OH) 2(1+p+q) (2+q)+ , where 0.1 < p ≤ 8, 0 ≤ q ≤ 3, M = Al or Fe,

[0023] The corresponding anion is one or a mixture of sulfate, nitrate, and chloride.

[0024] Furthermore, acetylene black and graphite can be added to the positive electrode active material of the storage battery to enhance its conductivity. Among them, the mass ratio of the manganese-containing layered double hydroxide to acetylene black and graphite is: 1: 0 to 0.2: 0 to 0.2.

[0025] Furthermore, the manganese-containing oxide is one or several of MnO2, MnO2·H2O, Mn2O3, MnO(OH), and Mn3O4.

[0026] Furthermore, Mg(OH)2, acetylene black, and graphite can be added to the positive electrode active material of the storage battery. Among them, the mass ratio of the manganese-containing oxide to Mg(OH)2, acetylene black, and graphite is 1: 0 to 2: 0 to 0.2: 0 to 0.2.

[0027] Furthermore, the electrolyte contains a soluble magnesium salt; the concentration of the magnesium salt is 0.01 to 5 mol / L; the corresponding anion is Cl - 、NO3 - 、SO4 2- or a mixture of several of them.

[0028] Furthermore, a conductive substance is added to the electrolyte, and the addition concentration is 0 to 10 mol / L;

[0029] The cations of the conductive substance include: sodium ions or potassium ions, and the corresponding anions include: Cl - 、NO3 - 、SO4 2- or a mixture of several of them.

[0030] Furthermore, the alkaline iron-manganese storage battery includes a corrosion-resistant inner cavity, which is divided into a positive electrode cavity and a negative electrode cavity by a diaphragm; after the negative electrode active material and the positive electrode active material of the storage battery are uniformly mixed with the electrolyte, they are respectively injected into the negative electrode cavity and the positive electrode cavity and contact with the graphite carbon electrode, and the graphite carbon electrode is selected from one or a combination of conductive graphite plates, graphite felts, conductive graphite meshes, carbon cloths, and activated carbons.

[0031] The diaphragm is one or a composite of several of porous polymer membrane, filter paper, glass paper and non-woven fabric.

[0032] The corrosion-resistant inner cavity of the alkaline iron-manganese storage battery is connected with the positive / negative electrode lead-out wires, the liquid injection port, the safety valve and the inspection valve, and is wrapped in the battery shell.

[0033] Considering that zinc-manganese batteries use manganese compounds as positive electrodes and nickel-iron batteries use iron elements as negative electrodes, and the raw materials are abundant and inexpensive, using manganese compounds as positive electrodes and iron elements as negative electrodes has certain cost advantages.

[0034] The present invention draws on the advantages of zinc-manganese battery positive electrode and nickel-iron battery negative electrode, overcomes the corresponding shortcomings, and develops an alkaline iron-manganese storage battery; the alkaline iron-manganese storage battery has the advantages of low cost, high number of charge and discharge cycles, long service life, wide operating temperature range, etc.

[0035] Taking both cost and energy efficiency factors into consideration, the present invention mainly utilizes the property of anion migration in the layered structure of double metal hydroxide (LDH) to develop a new type of efficient and inexpensive alkaline iron-manganese battery, which has achieved an energy density close to that of lead-acid batteries; but the number of charge and discharge cycles is more than 10 times that of lead-acid batteries; and compared with liquid flow batteries used in large-scale energy storage, it has the advantages of simple structure, low cost, and easy industrial mass production, which promotes the development of large-scale power energy storage industry.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The present invention utilizes the variable valence characteristics of iron and manganese elements and adopts water-insoluble layered double hydroxides (LDH) or oxides as battery electrode active materials; there is no need to use a proton exchange membrane and circulation system similar to redox flow batteries; compared with flow batteries, it has the advantages of simple structure and easy maintenance.

[0038] (ii) The present invention uses an aqueous electrolyte instead of an organic electrolyte, which not only reduces the production cost but also eliminates the fire risk caused by the organic electrolyte.

[0039] (III) The present invention adopts an aqueous electrolyte and utilizes the shuttling of anions in the solution between the molecular layers of double hydroxide (LDH), thereby avoiding significant volume changes of the electrode material and maintaining the stability of the electrolyte composition. Compared with lead-acid batteries and sodium-ion batteries, it has the advantages of stable performance and high number of cycles.

[0040] (iv) The present invention uses a neutral or weakly alkaline aqueous electrolyte with a pH value of 7 to 13. The electrode potentials of the positive and negative electrode materials are both within the electrochemical window of water, and the stability of the active material is enhanced by the double hydroxide (LDH) structure, thereby avoiding the occurrence of hydrogen evolution (HER) / oxygen evolution (OER) reactions.

[0041] (V) The iron, manganese, magnesium and aluminum elements used in the present invention are all metal elements that are mined on a large scale, and can make full use of the existing industrial chain foundation, with a simple manufacturing process, a large output of raw materials and low production costs.

[0042] Compared with lithium-ion batteries, lead-acid batteries, and liquid flow batteries, the alkaline iron-manganese storage battery of the present invention has significant advantages in the field of large-scale power energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the pH-potential diagram of iron and manganese (alkaline aqueous solution);

[0044] Figure 2 This is a test chart of the battery in Test 1 in the Example Table, which is a test chart of the number of cycles in which the battery capacity decays to 80% of the rated capacity when the battery is charged and discharged at a rate of 0.2C;

[0045] Figure 3 It is a side view of the battery of Test 6 in the Example Table, which is subjected to a charge and discharge test at a rate of 0.2C and the number of cycles at which the battery capacity decays to 80% of the rated capacity. DETAILED DESCRIPTION

[0046] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Relevant statistical reports show that currently in the field of new power storage, most still use lithium batteries, despite the high mining cost of lithium, limited production capacity, and certain fire risks; however, lithium batteries have the advantages of simple maintenance and long cycle times (compared to lead-acid batteries, etc.), the essential reason being that lithium ions have a small ionic radius and are easy to shuttle back and forth between electrode materials and electrolytes, with little impact on electrode materials and electrolytes; in contrast, the electrode materials and electrolytes of lead-acid batteries change greatly in their properties during the charge and discharge process, and thus have poor cycle stability; and the sodium-ion batteries, which are currently receiving much attention, have a much larger performance gap with lithium-ion batteries because the sodium ions they use have an ionic radius significantly larger than lithium ions.

[0048] Although the redox flow battery, which is highly valued in the field of new power energy storage, has the advantages of high safety and long service life due to the use of aqueous electrolytes, vanadium flow batteries are subject to the production capacity and cost limitations of vanadium, and iron-chromium flow batteries still have factors such as negative electrode hydrogen evolution reaction and cross-linking of active substances in the electrolyte, which greatly restricts further development. The maturity of other new energy storage technologies needs to be further improved, and the cost needs to be further reduced.

[0049] Therefore, the present invention proceeds from the first principles:

[0050] First, the performance of the number of charge and discharge cycles should be similar to that of lithium-ion batteries, maintaining the stable long-term cycle of the electrode materials and avoiding significant changes in the volume of the electrode materials and the composition of the electrolyte;

[0051] Furthermore, the cost should be reduced as much as possible, and the elements that have been mined on a large scale should be used as active materials, and their cost should be as low as possible;

[0052] Furthermore, aqueous electrolytes are used to ensure safety;

[0053] Finally, the energy efficiency performance reaches a level similar to that of lithium-ion batteries. When using aqueous electrolytes, the potentials of the positive and negative electrode electrochemical reactions are controlled within the electrochemical window of water, avoiding the occurrence of hydrogen evolution (HER) / oxygen evolution (OER) reactions.

[0054] The present invention selects iron and manganese double hydroxide (LDH) as the negative electrode / positive electrode active material, and develops the aqueous alkaline iron-manganese storage battery, and the battery open circuit voltage under alkaline conditions (pH=7-13) is 0.7V. Specifically, magnesium iron aluminum double hydroxide (MgFeAl-LDH) is mainly used as the negative electrode of the battery, and magnesium manganese aluminum double hydroxide (MgMnAl-LDH) or magnesium manganese iron double hydroxide (MgMnFe-LDH) is used as the positive electrode. It is also possible to consider replacing magnesium with calcium, mainly considering that Mg(OH)2 has a low solubility in aqueous solution, which can reduce the dissolution loss of active materials, while Ca(OH)2 has a high solubility, and the dissolution-precipitation equilibrium of the active material may cause damage to the structure of the active material.

[0055] The present invention provides a novel alkaline iron-manganese storage battery, which solves the following problems:

[0056] Solve the charging and discharging stability problem of positive electrode materials to increase the number of charging and discharging cycles of the battery;

[0057] Solve the charge and discharge stability problem of negative electrode materials to increase the number of charge and discharge cycles of the battery;

[0058] Solve the problem of hydrogen evolution at the iron negative electrode and oxygen evolution at the positive electrode, maintain the stability of the electrolyte, and improve the energy efficiency of the battery;

[0059] Solve the problem of conductivity of electrode materials.

[0060] Figure 1 This is the pH-potential diagram of iron and manganese (alkaline aqueous solution). It can be seen from the figure:

[0061] (1) In the pH range of 7.5 to 13, the electrode potential of the manganese electrode Mn(IV) / Mn(III) is lower than that of oxygen, thus avoiding the oxygen evolution reaction (OER) during the positive electrode charge and discharge process.

[0062] (2) In the pH range of 7.5 to 13, the electrode potential of the iron electrode Fe(III) / Fe(II) is higher than that of hydrogen, thus avoiding the occurrence of hydrogen evolution reaction (HER) during the negative electrode charge and discharge process.

[0063] (3) In the pH range of 7.5 to 13, the manganese electrode Mn(IV) / Mn(III) and the iron electrode Fe(III) / Fe(II) have the same trend in changing with pH, ​​so the battery voltage can be kept stable and is not affected by pH changes in this range.

[0064] Furthermore, since the manganese electrode Mn(IV) / Mn(III) and the iron electrode Fe(III) / Fe(II) of the battery of the present invention are both located within the electrochemical window of water, the material purity requirements in the manufacturing process are reduced. Compared with the zinc negative electrode of the zinc-manganese battery, since the electrode potential of zinc is lower than that of hydrogen, if the purity of the zinc negative electrode is not up to standard, hydrogen evolution reaction is very likely to occur at the negative electrode, and the present invention can avoid this situation.

[0065] The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0066] Example 1

[0067] The negative electrode material A for alkaline iron-manganese battery is prepared by coprecipitation method:

[0068] Prepare 1L of solution containing the following ingredients:

[0069] Containing 1.0mol / L MgSO4, 1.4mol / L FeSO4, and 0.3mol / L Fe2(SO4)3; 30g acetylene black and 30g graphite powder were added under sufficient stirring to form a suspension, and then 1L of a solution containing 6mol / L NaOH was added under sufficient stirring. The suspension was filtered under stirring, and the wet precipitate was separated as the negative electrode material A for testing.

[0070] The wet precipitate contains 1 mol MgFe(II) 1.4 Fe(III) 0.6 (OH)6(SO4) 0.3 ingredients.

[0071] 0.1 mol Mg(NO3)2 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte A1 for testing.

[0072] Example 2

[0073] The negative electrode material B for alkaline iron-manganese battery is prepared by coprecipitation method:

[0074] Prepare 1L of solution containing the following ingredients:

[0075] Containing 1.0mol / L Mg(NO3)2, 1.0mol / L Fe(NO3)2, and 0.4mol / L Al(NO3)3; 20g acetylene black and 20g graphite powder were added under sufficient stirring to form a suspension, and then 1L of a solution containing 5.2mol / L NaOH was added under sufficient stirring. The suspension was filtered while stirring, and the wet precipitate was separated as the negative electrode material B for testing.

[0076] The precipitate contains 1 mol MgFeAl 0.4 (OH) 4.8 (NO3) 0.4 ingredients.

[0077] 0.1 mol Mg(NO3)2 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte B1 for testing.

[0078] Example 3

[0079] The negative electrode material C for alkaline iron-manganese battery is prepared by coprecipitation method:

[0080] Prepare 1L of solution containing the following ingredients:

[0081] Contains 0.6mol / L MgCl2, 1.4mol / L FeCl2, and 0.4mol / L AlCl3; 10g acetylene black and 10g graphite powder are added under sufficient stirring to form a suspension, and then 1L of a solution containing 5.2mol / L NaOH is added under sufficient stirring. The suspension is filtered under stirring, and the wet precipitate is separated as the negative electrode material C for testing.

[0082] The precipitate contains MgFeAl 0.4 (OH) 4.8 Cl 0.4 ingredients.

[0083] 0.1 mol MgCl2 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte C1 for testing.

[0084] Example 4

[0085] The positive electrode material A for alkaline iron-manganese battery is prepared by co-precipitation oxidation method:

[0086] Prepare 1L of solution containing the following ingredients:

[0087] Contains 2.0mol / L MgSO4 and 1.0mol / L MnSO4; 30g acetylene black and 30g graphite powder are added under sufficient stirring to form a suspension, and then 1L of a solution containing 6mol / L NaOH is added under sufficient stirring, and then oxygen is introduced and stirred for more than 3 hours, and then the suspension is filtered under stirring to separate the wet precipitate as the positive electrode material A for testing.

[0088] The precipitate contained a component of 1 mol of Mg2Mn(OH)6SO4.

[0089] 0.1 mol MgSO4 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte A2 for testing.

[0090] Example 5

[0091] The positive electrode material B for alkaline iron-manganese battery is prepared by co-precipitation oxidation method:

[0092] Prepare 1L of solution containing the following ingredients:

[0093] Contains 2.0mol / L Mg(NO3)2, 1.0mol / L Mn(NO3)2, and 0.2mol / L Fe(NO3)3; 20g acetylene black and 20g graphite powder are added under sufficient stirring to form a suspension, and then 1L of a solution containing 6.4mol / L KOH is added under sufficient stirring, and oxygen is introduced and stirred for more than 3 hours. The suspension is then filtered under stirring to separate the wet precipitate as the positive electrode material B for testing.

[0094] The precipitate contains Mg2MnFe 0.2 (OH) 6.4 (NO3) 2.2 ingredients.

[0095] 0.1 mol Mg(NO3)2 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte B2 for testing.

[0096] Example 6

[0097] The positive electrode material C for alkaline iron-manganese battery is prepared by co-precipitation oxidation method:

[0098] Prepare 1L of solution containing the following ingredients:

[0099] Containing 2.0mol / L MgCl2, 1mol / L MnCl2, and 0.2mol / L AlCl3; 15g acetylene black and 15g graphite powder were added under sufficient stirring to form a suspension, and then 1L of a solution containing 6.4mol / L KOH was added under sufficient stirring. The suspension was filtered under stirring, and the wet precipitate was separated as the positive electrode material C for testing.

[0100] The precipitate contains Mg2MnAl 0.2 (OH) 6.4 Cl 2.2 ingredients.

[0101] 0.1 mol MgCl2 was added to the separated filtrate to dissolve it, and the resulting solution was used as electrolyte C2 for testing.

[0102] Example 7

[0103] Mixed method to prepare positive electrode material D for alkaline iron-manganese battery:

[0104] 1 mol MnO2 and 2 mol Mg(OH)2 powders were added to 45 g acetylene black and 45 g graphite powder, stirred and mixed thoroughly, and ball milled for more than 1 hour. The mixture was positive electrode material D, which was mixed with the electrolyte and injected into the positive electrode cavity of the battery for testing.

[0105] Comparative Example 1

[0106] Commercially available lithium batteries

[0107] Manufacturer: Huizhou Yiwei Lithium Energy Co., Ltd.

[0108] Model: LF280K

[0109] Nominal voltage: 3.280V-3.305V, nominal capacity: ≥280Ah

[0110] Cycle times: 6000 times

[0111] Combination: Single cell, Battery type: Square lithium iron phosphate battery,

[0112] Weight: 5.42±0.3Kg.

[0113] Comparative Example 2

[0114] Commercially available lead-acid batteries

[0115] Manufacturer: Yangzhou Dongtai Power Supply Co., Ltd.

[0116] Specification model: 6-CNJ-150

[0117] Weight: 40kg

[0118] Nominal voltage: 12V, nominal capacity: 150Ah, rated power: 800W

[0119] Discharge time: 20h

[0120] Number of cycles: 500.

[0121] Performance Testing

[0122] According to the above-mentioned Examples 1-7, multiple portions of positive and negative electrode materials and electrolytes were prepared, and different electrode materials and diaphragms were used to assemble alkaline iron-manganese batteries and tested, wherein the positive electrode material and the negative electrode material were respectively added to the electrolyte and mixed evenly, and respectively injected into the positive electrode cavity and the negative electrode cavity of the corrosion-resistant inner cavity of the battery, and contacted with the graphite carbon electrode, and the graphite carbon electrode was led out through the lead wire; wherein, the amount of electrolyte used is generally 30-200% of the weight of the positive electrode material or the negative electrode material, and the amount of electrolyte used in the following test samples is 50% of the weight of the positive electrode material or the negative electrode material, and the corrosion-resistant inner cavity of the alkaline iron-manganese battery is also provided with a safety valve and a maintenance valve, and wrapped in the battery shell.

[0123] The test conditions and methods are as follows:

[0124] The above assembled battery was subjected to charge and discharge tests at a rate of 0.2C to test energy density and cycle life, and the active material cost of each test case was estimated based on the prices of commercially available bulk chemicals.

[0125] Record the battery voltage and the number of cycles for the battery capacity to decay to 80% of the rated capacity as shown in the following table:

[0126] The results are as follows:

[0127]

[0128] From the above data, it can be concluded that the test 1 scheme uses the aforementioned negative electrode material A, positive electrode material A, electrolyte A1, and uses conductive graphite plate electrodes and porous polymer membranes as separators. The number of cycles of the alkaline iron-manganese storage battery can reach more than 10,000 times. The test graph of the number of cycles when the battery capacity decays to 80% of the rated capacity in the battery test 1 and test 6 at a rate of 0.2C is shown in FIG. Figure 2-3, and the cost of active materials is low. Considering that the battery uses an aqueous electrolyte, the structure is relatively simple, and the cost of large-scale industrial production of battery cells is low. The number of cycles of the alkaline iron-manganese battery of the present invention can be higher than that of the lithium iron phosphate battery (Comparative Example 1), and the cost can be lower than that of the lithium iron phosphate battery. Although the number of cycles of the lithium iron phosphate battery is higher than that of some test batteries, its cost is indeed 2-3 times that of the test battery. Compared with the lithium iron phosphate battery, the shortcomings of the alkaline iron-manganese battery of the present invention are lower battery voltage and lower energy density, but this is still acceptable for large-scale power storage fields such as balanced wind energy and photovoltaic power generation. As for the lead-acid battery, although its energy density is higher than that of the present invention, the number of cycles is much lower than that of the iron-manganese battery of the present invention, and the cost is higher than the product of the present invention.

[0129] It can be seen that the alkaline iron-manganese storage battery of the present invention has good comprehensive economic performance and is easier to achieve large-scale mass production and application.

Claims

1. An alkaline iron-manganese battery, characterized in that: Using iron-containing layered double hydroxide as the negative electrode active material of the battery; using manganese-containing oxide or layered double hydroxide as the positive electrode active material of the battery; using aqueous neutral or weak alkaline buffer solution as the electrolyte; The cation of the iron-containing layered double hydroxide is: Fe(II)-LDH:Mg x FeAl y (OH) 2(1+x+y) y+ , where 0.1 <x≤8,0<y≤3, or Fe(III)-LDH:Mg x FeAl y (OH) 2(1+x+y) (1+y)+ , where 0.1 <x≤8,0≤y≤3, The corresponding anions are sulfate, nitrate, chloride, or a mixture of several; The cation of the manganese-containing layered double hydroxide is: Mn(III)-LDH: Mg p MnM q (OH) 2(1+p+q) (1+q)+ , where 0.1 < p ≤ 8, 0 ≤ q ≤ 3, M = Al or Fe, Or Mn(IV)-LDH: Mg p MnM q (OH) 2(1+p+q) (2+q)+ , where 0.1 < p ≤ 8, 0 ≤ q ≤ 3, M = Al or Fe, and the corresponding anion is one or a mixture of sulfate, nitrate, and chloride; The electrolyte contains a soluble magnesium salt; the concentration of the magnesium salt is 0.01-5 mol / L; the corresponding anion is Cl - 、NO3 - 、SO4 2- One or a mixture of several.

2. An alkaline iron-manganese storage battery according to claim 1, characterized in that: Acetylene black and graphite are also added to the negative electrode active material of the storage battery, wherein the mass ratio of the iron-containing layered double hydroxide to the acetylene black and the graphite is 1:0-0.2:0-0.

2.

3. An alkaline iron-manganese storage battery according to claim 1, characterized in that: Acetylene black and graphite are also added to the positive electrode active material of the battery, wherein the mass ratio of the manganese-containing layered double hydroxide to the acetylene black and the graphite is 1:0-0.2:0-0.

2.

4. An alkaline iron-manganese storage battery according to claim 1, characterized in that: The manganese-containing oxide is one or more of MnO2, MnO2·H2O, Mn2O3, MnO(OH), and Mn3O4.

5. An alkaline iron-manganese storage battery according to claim 1 or 4, characterized in that: Mg(OH)2, acetylene black and graphite are also added to the positive electrode active material of the battery, wherein the mass ratio of manganese-containing oxide to Mg(OH)2, acetylene black and graphite is 1:0-2:0-0.2:0-0.

2.

6. An alkaline iron-manganese storage battery according to claim 1, characterized in that: A conductive substance is also added to the electrolyte at a concentration of 0 to 10 mol / L; The cations of conductive materials include: sodium ions or potassium ions, and the corresponding anions include: Cl - 、NO3 - 、SO4 2- One or more of.

7. An alkaline iron-manganese storage battery according to claim 1, characterized in that: The alkaline iron-manganese battery comprises a corrosion-resistant inner cavity, which is divided into a positive electrode cavity and a negative electrode cavity by a diaphragm; the negative electrode active material and the positive electrode active material of the battery are respectively mixed with the electrolyte uniformly and then injected into the negative electrode cavity and the positive electrode cavity respectively.

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