A free manganese (II) inhibited anion-rich aqueous electrochemical system

Abstract

The application relates to a free manganese (II) inhibited anion-rich aqueous electrochemical system, comprising a manganese positive electrode active material, a metal-based negative electrode and an aqueous electrolyte; the metal-based negative electrode comprises an active material and a kinetic auxiliary component, and the active material comprises at least one of metal zinc and a zinc alloy. The application has the beneficial effect that: by innovatively using an organic functional anion-rich aqueous electrolyte, reasonably matching the types and concentrations of anions and cations, the addition of Mn (II) and organic solvents in the electrolyte is avoided, the stability of the positive electrode material and the corrosion and safety of the electrolyte are greatly improved, the electrolyte does not contain additional manganese (II) cations, the active material with inhibited manganese dissolution is matched, the interface passivation type deposition path of Mn (II) to Mn (IV) is blocked from the root, the disproportionation of Mn (III) intermediates and the disorderly deposition of low-conductivity Mn (IV) caused by the disproportionation are simultaneously relieved, and the dissolution inhibition of the manganese-containing positive electrode active material is effectively realized.

Description

Technical Field

[0001] This invention belongs to the field of energy storage materials technology, and particularly relates to a free manganese(II)-suppressed anion-rich aqueous electrochemical system. Background Technology

[0002] Among various energy storage methods, aqueous electrochemical energy storage technology has significant advantages such as flexible site selection, high energy efficiency, simple maintenance, no precision moving parts, and relative safety. Currently, aqueous electrochemical systems, represented by aqueous zinc-ion batteries, primarily focus on solving the scientific problems of metal / alloy-based anodes, including parasitic reactions and dendrite growth at the anode interface. Methods typically include adjusting cation solvation at the anode interface, constructing the anode ion / electron conduction network, and using interface-modifying coatings. However, due to thermodynamic corrosion, the capacity deployment of the anode active material is usually in a state of significant excess compared to the cathode; therefore, addressing the anode interface problem in isolation can only alleviate the short-circuit issue caused by parasitic reactions / dendrite growth, and cannot fundamentally solve the problem of capacity decay with cycling in energy storage devices.

[0003] To ultimately develop mature and stable aqueous electrochemical energy storage products, in-depth research is needed on cathode components that limit electrochemical capacity. Among candidate cathode materials, manganese-based cathodes are among the most promising due to their low cost, low toxicity, high redox activity, and high potential. Failures in aqueous electrochemical energy storage devices based on manganese-containing cathode materials primarily stem from the structural collapse and irreversible dissolution of the cathode active material. Conventional stabilization designs for cathode active powders are also a one-sided and isolated optimization approach, offering limited improvement to battery stability in aqueous solutions. On the other hand, solutions based on electrolyte regulation mainly fall into two categories: the auxiliary addition of Mn(II) cations and the use of high-concentration organic solvents. Both can improve cycle stability to some extent, but the former is more of an ion compensation method rather than fundamentally solving cathode dissolution; while the latter's dependence on organic solvents not only inhibits ion diffusion kinetics but also significantly reduces the high-temperature safety of the electrolyte.

[0004] Therefore, a new aqueous electrochemical system is urgently needed to solve the problem caused by the irreversible dissolution of manganese-containing active materials from the positive electrode into the aqueous electrolyte in aqueous electrochemical energy storage devices. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a free manganese(II)-rich anion-rich aqueous electrochemical system.

[0006] This free manganese(II)-inhibited anion-rich aqueous electrochemical system includes a manganese positive electrode active material, a metal-based negative electrode, and an aqueous electrolyte; the metal-based negative electrode includes an active material and a kinetic auxiliary component, and the active material includes at least one of metallic zinc and zinc alloys;

[0007] The solvent for the aqueous electrolyte is pure water, which accounts for 40-80% of the electrolyte mass. There are no more than 3 types of anions, and the molar concentration of anions in the aqueous electrolyte is at least 3 times that of the positive electrode active cations.

[0008] Preferably, the manganese-containing positive electrode active material includes at least one of manganese oxide, lithium manganese oxide, sodium manganese oxide, potassium manganese oxide, manganese ferrocyanide, and manganese ferrosulfuric cyanide.

[0009] Preferably, in the metal-based anode, the kinetic auxiliary component includes at least one of lithium vanadate, sodium vanadate, potassium vanadate, lithium titanium phosphate, sodium titanium phosphate, lithium titanium silicate, and sodium titanium silicate, and the mass ratio of the kinetic auxiliary component to the metal-based active material is 1:50 to 1:2.

[0010] Preferably, in the aqueous electrolyte, the oxyacid corresponding to the anion has a functionalized organic graft structure R, and the oxyacid molecule contains R(O). y X[(OH)] z The characteristic structure of , where R(O) y X represents R - [X = O] y The composite structural unit, X=O, has the number of double bonds equal to the value of parameter y; X[(OH)] z Represents X-[(OH)] z The single-bonded structural unit has the number of single bonds equal to the value of parameter z; the central atom X is selected from any one of boron, carbon, phosphorus and sulfur atoms; y∈{0,1,2}; z∈{1,2}; (y+z)∈{2,3}.

[0011] Preferably, the anionic characteristic structure includes at least one of RB[(OH)]2, R(O)C[(OH)], R(O)P[(OH)]2 and R(O)2S[(OH)], the total concentration of the anion relative to the aqueous solvent is 0.5 to 4.0 mol / kg, and the pH of the aqueous electrolyte is 4.0 to 7.0.

[0012] Preferably, the functionalized organic graft structure R includes at least one polar functional group, which includes at least one of the following: aromatic group, aryl group, thiol group, hydroxyl group, carbonyl group, amino group, amide group, thioamide group, ether group, and fluorine substituent; the corresponding oxyacid of the anion includes at least one of the following: aminomethylboronic acid, aminoacrylic acid, tyrosine, glutamic acid, lysine, aspartic acid, glutamine, cysteine, gluconic acid, ethylenediaminetetraacetic acid, tartaric acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, triethylenetetraaminehexamethylenephosphonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, phenolsulfonic acid, acrylamide-alkyl sulfonic acid, and derivatives of the above-mentioned oxyacids.

[0013] Preferably, the active cation in the aqueous electrolyte includes at least one of lithium, sodium and potassium ions, and the active cation also includes at least one of zinc, magnesium, aluminum, ammonium and multi-level ammonium ions.

[0014] The beneficial effects of this invention are:

[0015] 1) The aqueous electrolyte used in this invention has a simple composition and mild properties. Compared with traditional electrolytes, it innovatively uses an anion-rich aqueous electrolyte with organic functionalization and rationally adjusts the types and concentrations of anions and cations, avoiding the addition of Mn(II) and organic solvents in the electrolyte. This greatly improves the stability of the cathode material and the corrosiveness and safety of the electrolyte. The electrolyte does not contain any additional manganese(II) cations. Combined with active materials whose manganese dissolution is inhibited, it fundamentally blocks the Mn(II)→Mn(IV) interfacial passivation deposition path. It can simultaneously alleviate the disproportionation of Mn(III) intermediates and the disordered deposition of low-conductivity Mn(IV) caused by it. This not only improves the kinetic performance but also reduces the corrosiveness and flammability of organic solvents, effectively achieving the dissolution inhibition of manganese-containing cathode active materials.

[0016] 3) This invention designs a metal-based negative electrode containing kinetic auxiliary components, extending the solution for stabilizing the electrochemical system to the negative electrode, achieving uniformity and compatibility, and is suitable for industrial product development. Through the synergistic effect of the electrolyte and the inhibition of the negative electrode components, the competitive reaction of phase change and dissolution of the positive electrode active material can be suppressed, forming an aqueous electrochemical energy storage system in which active cations are fully and stably inserted and extracted on the positive electrode side. The negative electrode formulation is flexible and the preparation process is simple, with high feasibility for mass production, and can effectively improve the cycle stability of aqueous electrochemical energy storage devices. Attached Figure Description

[0017] Figure 1 This is a comparison of the battery cycle stability of Example 3 and Comparative Examples 1 and 2.

[0018] Figure 2This is a comparison of the battery cycle stability of Example 4 and Comparative Example 3;

[0019] Figure 3 This is a comparison of the Mn element content in the battery electrolyte after cycles of Example 3, Comparative Example 4, and Comparative Examples 1 to 3. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0021] Example 1

[0022] As an example, in this first embodiment, addressing the shortcomings of existing technologies, the present invention designs an anion-rich aqueous electrochemical system with free manganese(II) suppression. Through the synergistic design of the electrolyte and negative electrode components, the stability of the manganese-containing positive electrode material is improved, thereby enhancing the overall cycle stability of the aqueous electrochemical energy storage device. Specifically, it includes:

[0023] Manganese-containing positive electrode active material with active cation insertion and extraction as the target energy storage mechanism; metal-based negative electrode containing kinetic auxiliary components; and organically functionalized anion-rich aqueous electrolyte.

[0024] The solvent in the aqueous electrolyte is pure water, and the water solvent accounts for 40-80% of the electrolyte mass fraction. By using a formula without organic solvents, the corrosiveness of the electrolyte is reduced and its thermal safety is improved.

[0025] Regarding the electrolyte, an anion-rich aqueous electrolyte with organic functionalization is used, and the types and concentrations of anions and cations are rationally adjusted to avoid the addition of Mn(II) and organic solvents in the electrolyte.

[0026] Regarding the negative electrode, a metal-based negative electrode containing a kinetic auxiliary component was designed, and its kinetic performance and thermodynamic stability were optimized. This effectively enables a fully and stably intercalated and deintercalated aqueous electrochemical system with active cations on the positive electrode side. The metal-based negative electrode comprises: at least one of zinc metal and its alloys as the negative electrode active material; and a compound for intercalation and deintercalation of active cations as the kinetic auxiliary component. Preferably, the kinetic auxiliary component comprises at least one of lithium vanadate, sodium vanadate, potassium vanadate, lithium titanium phosphate, sodium titanium phosphate, lithium titanate, and sodium titanate. The mass ratio of the kinetic auxiliary component to the metal-based active material is 1:50 to 1:2.

[0027] By adding kinetic auxiliary components, the kinetic characteristics and thermodynamic stability of the negative electrode are regulated: In terms of kinetics, by introducing auxiliary components that allow active cations to intercalate and deintercalate, the electrochemical reaction kinetics of the positive electrode are matched, avoiding battery failure caused by interfacial charge accumulation; in terms of thermodynamic stability, the introduction of auxiliary components slows down the (e)chemical corrosion of the metal-based negative electrode active material, promoting the overall stabilization of the electrochemical system.

[0028] In the above electrochemical system, the manganese-containing positive electrode active material includes at least one of the following: manganese oxide, lithium manganese oxide, sodium manganese oxide, potassium manganese oxide, manganese ferrocyanide, and manganese ferrosulfuric cyanide. The energy storage mechanism of the manganese-containing positive electrode active material involves the insertion and extraction of active cations, as well as a competitive reaction involving proton insertion leading to phase transition and dissolution.

[0029] Example 2

[0030] As another embodiment, this second embodiment, based on the first embodiment, proposes a more specific free manganese(II)-suppressed anion-rich aqueous electrochemical system, wherein the composition and concentration of the electrolyte are specifically as follows:

[0031] The electrolyte uses pure water as its solvent, which accounts for 40-80% of the electrolyte's mass fraction. This water serves to disperse and dilute the electrolyte, while also preventing the corrosiveness and thermal stability of the electrolyte from the influence of organic solvents. The electrolyte contains no more than three types of anions, with a total anion concentration relative to the water solvent of 0.5-4.0 mol / kg, and a pH of 4.0-7.0.

[0032] Regarding the solute, specifically, the number of anions is limited to no more than three, and it does not contain any additional manganese(II) cations, which can suppress Mn(III) disproportionation and disordered Mn(IV) deposition. By setting the aqueous electrolyte to be rich in anions, it can simultaneously suppress the dissolution of manganese-containing active cathode materials, suppress the disproportionation of Mn(III) intermediates, and suppress the disordered deposition of Mn(IV). Although the electrolyte does not contain any additional introduced manganese(II) cations and loses the function of simple ion compensation, it also greatly avoids the passivation-type deposition of Mn(II)→Mn(IV) and avoids the formation of a poorly conductive deposition layer covering the cathode surface. At the same time, the design of this electrolyte further suppresses the generation and disproportionation of Mn(III), avoids the generation of free Mn(II), and further avoids the disproportionation-type deposition of Mn(III)→Mn(IV). Simultaneously, the inhibitory effects of the electrolyte and the negative electrode components work synergistically to suppress the competitive reactions of phase transition and dissolution of the positive electrode active material, including inhibiting adverse reactions such as the disproportionation of Mn(III), the dissolution of Mn(II) ions, and the passivation of the positive electrode interface caused by the disordered deposition of Mn(IV). Based on this, the target energy storage mechanism of intercalation and deintercalation of manganese-containing positive electrode active materials can be achieved.

[0033] The aforementioned preferred electrolyte has a simple formulation, with all solutes containing no more than three types of anions. Specifically, the oxyacid corresponding to the anion has a functionalized organic grafted structure R, and a characteristic structure associated with R: R(O). y X[(OH)] z Where R(O) y X represents the complex structural unit R-[X=O]y, where the number of X=O double bonds is equal to the value of parameter y; X[(OH)] z The single-bonded structural unit representing X-[(OH)]z has the number of single bonds equal to the value of parameter z.

[0034] Preferably, the central atom X is selected from any one of boron, carbon, phosphorus, and sulfur atoms. Parameters y and z simultaneously satisfy the following conditions: 1) Parameter y can be any value from 0, 1, or 2; 2) Parameter z can be any value from 1 or 2; 3) The sum of parameters y and z can be any value from 2 or 3. Based on the above restrictive conditions, the aforementioned anionic characteristic structure R(O) is... y X[(OH)] z Preferably, it is at least one of RB[(OH)]2, R(O)C[(OH)], R(O)P[(OH)]2, and R(O)2S[(OH)], and at most no more than three.

[0035] Based on the above overview of preferred conditions, it should be specifically noted that the solute in the electrolyte does not contain traditional sulfates and halides. The former, as a typical inorganic oxyacid salt, suffers from limited solubility, a small pH range for stabilization, and a tendency to passivate the positive electrode. The latter, although possessing high solubility, is associated with strong acidity, strong hydrolysis, strong corrosiveness, and high cost, making it difficult to manufacture electrochemical energy storage devices with industrial value.

[0036] Therefore, the disclosed solution of this invention is an organically functionalized anion-rich solute and combinations thereof. Preferably, the functionalized organic graft structure R contains at least one polar functional group and optionally links one or more of the aforementioned characteristic structures. Preferably, R is selected from at least one of aromatic, aryl, thiol, hydroxyl, carbonyl, amino, amide, thioamide, ether, and fluorine substituents. Preferably, it contains R(O). y X[(OH)] z The oxyacid corresponding to the anion of the characteristic structure can be selected from at least one of the following: aminomethylboronic acid, aminoacrylic acid, tyrosine, glutamic acid, lysine, aspartic acid, glutamine, cysteine, gluconic acid, ethylenediaminetetraacetic acid, tartaric acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, triethylenetetraaminehexamethylenephosphonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, phenolsulfonic acid, acrylamide-alkyl sulfonic acid, and their derivatives.

[0037] Furthermore, considering the compatibility and synergistic effect of salts, the present invention proposes an anion-rich structure. The active cation is at least one of lithium, sodium, and potassium ions; other cations added to ensure charge neutrality are at least one of zinc, magnesium, aluminum, ammonium, and multi-level ammonium ions. Preferably, the molar concentration of total anions is at least three times that of the positive electrode active cation. For aqueous electrochemical systems, using homogeneous solute components, especially single active cation components, presents a contradiction regarding optimal concentrations: at low concentrations, not only is there insufficient ion concentration to ensure high conductivity, but the number of functionalized anions is also relatively lacking, leading to large polarization and poor stability in the aqueous electrochemical system; at high concentrations, ion crowding and micro-clusters are easily formed, which also limits the conductivity of the solution and tends to affect the uniformity of interfacial reactions. Therefore, the optimization scheme proposed in this invention is to control the type and concentration distribution of cations at a moderate functionalized anion concentration to balance the physicochemical properties and kinetic characteristics of the electrolyte. Compared to the concentration of active cations, the above-mentioned preferred electrolyte has a concentration of organically functionalized anions several times higher, and is therefore an anion-rich aqueous electrolyte system.

[0038] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0039] Example 3

[0040] As another embodiment, this third embodiment, based on embodiments one and two, proposes a specific free manganese(II)-suppressed anion-rich aqueous electrochemical system:

[0041] In this embodiment, the manganese-containing positive electrode active material is a manganese oxide rich in ion insertion and extraction pathways; the negative electrode active material is metallic zinc and sodium vanadate, with a molar ratio of sodium vanadate to metallic zinc of 1:20. The solvent for the aqueous electrolyte is pure water.

[0042] The aqueous electrolyte is prepared as follows: Take 10 kg of deionized water, and add 2.29 kg of sodium acrylamide methanepropanesulfonate, 2.28 kg of zinc gluconate, 2.07 kg of magnesium gluconate, and 1.67 kg of ammonium trifluoromethanesulfonate sequentially. Stir continuously for 1 hour until fully dissolved. Finally, adjust the pH to 4.5 using gluconic acid or sodium hydroxide. During the above preparation process, heating within the range of 50–70°C is performed to promote solute dissolution, or filtration is used to remove small amounts of impurities. The active cation in the above electrolyte is sodium ion, with a molar ratio of sodium ion to total anions of 1:4; for sodium ions, this electrolyte is an anion-rich type.

[0043] Example 4

[0044] As another embodiment, this fourth embodiment, based on the third embodiment, proposes another free manganese(II)-suppressed anion-rich aqueous electrochemical system prepared using the same method:

[0045] In this embodiment, the preparation method of the free manganese(II)-inhibited anion-rich aqueous electrochemical system is the same as in Example 3, but the components used are different. Specifically, the negative electrode active material is changed to zinc metal and lithium titanium phosphate, with a molar ratio of lithium titanium phosphate to zinc of 1:3. When preparing the aqueous electrolyte, the solutes used are changed to: 1.52 kg of dilithium ethylenediaminetetraacetate, 3.27 kg of sodium gluconate, and 1.19 kg of sodium trifluoromethanesulfonate are added sequentially, and each is stirred continuously for 1 hour until fully dissolved. Finally, the pH is finely adjusted to 7.0 using ethylenediaminetetraacetic acid or sodium hydroxide. The active cation in the above electrolyte is lithium ion, with a molar ratio of lithium ion to total anion of 1:3; for lithium ions, this electrolyte belongs to the anion-rich type.

[0046] In this embodiment, the components and preparation methods for the parts not mentioned are the same as in Example 3.

[0047] Comparative Example 1

[0048] As a comparative example, this Comparative Example 1 presents an electrochemical system prepared from a conventional sulfate electrolyte that does not possess the characteristics of inhibiting free manganese(II) cations, Mn(III) intermediates, and Mn(IV) deposition products:

[0049] In this comparative example, the positive and negative electrode materials are the same as in Example 3, namely: the manganese-containing positive electrode active material is a manganese oxide rich in ion insertion and extraction pathways; the negative electrode active material is metallic zinc and sodium vanadate, with a molar ratio of sodium vanadate to metallic zinc of 1:20. The solvent for the aqueous electrolyte is pure water.

[0050] The aqueous electrolyte is prepared as follows: Take 10 kg of deionized water, and add 1.42 kg of sodium sulfate, 0.81 kg of zinc sulfate, 0.60 kg of magnesium sulfate, and 1.32 kg of ammonium sulfate sequentially. Stir continuously for 1 hour until fully dissolved. Finally, adjust the pH to 4.5 using sulfuric acid or sodium hydroxide. Heating within the range of 50–70°C is also performed to promote solute dissolution, or filtration can be used to remove small amounts of impurities.

[0051] Comparative Example 2

[0052] As another comparative example, Comparative Example 2 proposes an electrochemical system prepared with an aqueous electrolyte that does not possess the characteristic of being rich in anions:

[0053] In this comparative example, the positive and negative electrode materials are the same as in Example 3, namely: the manganese-containing positive electrode active material is a manganese oxide rich in ion insertion and extraction pathways; the negative electrode active material is metallic zinc and sodium vanadate, with a molar ratio of sodium vanadate to metallic zinc of 1:20. The solvent for the aqueous electrolyte is pure water.

[0054] The aqueous electrolyte is prepared as follows: Take 10 kg of deionized water, and add 2.29 kg of sodium acrylamide methanepropanesulfonate, 4.36 kg of sodium gluconate, and 1.72 kg of sodium trifluoromethanesulfonate sequentially. Stir continuously for 1 hour until fully dissolved. Finally, adjust the pH to 4.5 using gluconic acid or sodium hydroxide. Optionally, heating within the range of 50–70°C can be performed to promote solute dissolution, or filtration can be used to remove small amounts of impurities. The active cation in the above electrolyte is sodium ion, with a molar ratio of 1:1 to total anions, and it does not exhibit anion-rich characteristics.

[0055] Comparative Example 3

[0056] As another comparative example, Comparative Example 3 proposes an electrochemical system prepared by a negative electrode of a pure metal-based active material without kinetic auxiliary components:

[0057] In this comparative example, the positive electrode material is the same as in Example 4, namely, lithium manganese oxide rich in ion insertion and extraction pathways. The negative electrode active material differs in this comparative example; it is a pure metal-based active material composed of metallic zinc.

[0058] The aqueous electrolyte used in this example is the same as in Example 4. The solvent is pure water. The preparation method for the aqueous electrolyte is as follows: Take 10 kg of deionized water, and add 1.52 kg of dilithium ethylenediaminetetraacetate, 3.27 kg of sodium gluconate, and 1.19 kg of sodium trifluoromethanesulfonate sequentially. Stir continuously for 1 hour until fully dissolved. Finally, adjust the pH to 7.0 using ethylenediaminetetraacetic acid or sodium hydroxide. Optionally, heating within the range of 50–70°C can promote solute dissolution, or filtration can be used to remove small amounts of impurities. The active cation in the above electrolyte is lithium ion, with a molar ratio of 1:3 to the total anions; for lithium ions, this electrolyte is an anion-rich type.

[0059] The electrochemical systems obtained in Examples 3, 4, 1, 2, and 3 were subjected to 100-cycle battery cycle stability tests, and the Mn content in the battery electrolyte after cycling was measured. Figures 1 to 3 As shown:

[0060] like Figure 1 As shown, the battery in Example 3 retained 97.3% of its capacity after 100 cycles, the battery in Comparative Example 1 retained 60.7% of its capacity after 100 cycles, and the battery in Comparative Example 2 retained 71.6% of its capacity after 100 cycles. The electrochemical system proposed in this invention, due to the use of an organically functionalized, anion-rich aqueous electrolyte, exhibits significantly higher cycle stability than Comparative Example 1 and Comparative Example 2.

[0061] like Figure 2 As shown, the battery in Example 4 retains more than 100% of its capacity after 100 cycles, while the battery in Comparative Example 3 retains only 72.9% of its capacity after 100 cycles. This demonstrates that the electrochemical system proposed in this invention, due to the addition of a non-kinetic auxiliary component, exhibits significantly higher cycle stability than Comparative Example 3.

[0062] like Figure 3As shown in the ICP elemental analysis results, the manganese content in the electrolyte after cycling in Examples 3 and 4 was less than or equal to 1 ppm, with almost no free Mn element detected. Considering the stability of manganese in various valence states, the Mn element measured in the ICP mainly exists in the form of Mn(II) cations. However, significant amounts of Mn element were present in Comparative Examples 1 to 3, with Comparative Example 1 showing the highest free manganese content at 798 ppm. This demonstrates that the electrochemical system proposed in this invention indeed possesses extremely high free manganese(II) suppression performance.

[0063] Based on the above results, the technical solutions disclosed in this invention, including Examples 3 and 4, demonstrate that the electrochemical system proposed in this invention can suppress the dissolution of manganese-containing materials and improve the cycle stability of the battery.

[0064] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A free divalent manganese inhibited, anion-rich aqueous electrochemical system characterized in that, The application relates to a water-based electrolyte, a manganese-containing positive electrode active material and a metal-based negative electrode. The solvent of the water-based electrolyte is pure water, the water solvent accounts for 40-80% of the mass fraction of the electrolyte, the number of anion types is less than or equal to 3, and the molar concentration of the anion in the water-based electrolyte is at least 3 times that of the positive electrode active cation. The kinetic auxiliary component includes at least one of lithium vanadate, sodium vanadate, potassium vanadate, lithium titanium phosphate, sodium titanium phosphate, lithium titanium silicate and sodium titanium silicate. The central atom X is selected from any one of boron, carbon, phosphorus and sulfur atoms; y is in the range of 0, 1 and 2; z is in the range of 1 and 2; (y+z) is in the range of 2 and 3. In the aqueous electrolyte, the anion corresponds to the functionalized organic branched structure R, the molecule of the oxygen-containing acid contains R(O) y X[(OH)] z characteristic structure, wherein R(O) y X represents a complex structure unit of R-[X=O] y , and the number of X=O double bonds is the value of parameter y; X[(OH)] z represents a single bond structure unit of X-[(OH)] z , and the number of single bonds is the value of parameter z; The manganese-containing positive electrode active material includes at least one of manganese oxide, lithium manganese oxide, sodium manganese oxide, potassium manganese oxide, manganese iron cyanide and manganese iron thiocyanide.

2. The free divalent manganese inhibited, anion-rich aqueous electrochemical system of claim 1, wherein, In the metal-based negative electrode, the mass ratio of the kinetic auxiliary component and the metal-based active material is 1:50-1:

2.

3. The free divalent manganese inhibited, anion-rich aqueous electrochemical system of claim 1, wherein, The anion characteristic structure includes at least one of RB[(OH)]2, R(O)C[(OH)], R(O)P[(OH)]2 and R(O)2S[(OH)], the total concentration of the anion relative to the water solvent is 0.5-4.0 mol / kg, and the water-based electrolyte has a pH value of 4.0-7.

0.

4. The free divalent manganese inhibited, anion-rich aqueous electrochemical system of claim 1, wherein, The functionalized organic dendritic structure R includes at least one polar functional group, and R includes at least one of an aromatic hydrocarbon group, an aromatic alcohol group, a thiol group, a hydroxyl hydrocarbon group, a carbonyl group, an amino group, an amide group, a thioamide group, an ether group and a fluorine substituent; the oxygen-containing acid corresponding to the anion includes at least one of aminomethyl boronic acid, aminoacrylic acid, tyrosine, glutamic acid, lysine, aspartic acid, glutamine, cysteine, gluconic acid, ethylenediaminetetraacetic acid, tartaric acid, ethylenediaminetetramethylene phosphonic acid, diethylene triamine penta methylene phosphonic acid, triethylene tetramine hexamethylene phosphonic acid, trifluoromethanesulfonic acid, benzene sulfonic acid, phenol sulfonic acid, acrylamide hydrocarbon sulfonic acid and derivatives of the above oxygen-containing acids.

5. The free divalent manganese inhibited, anion-rich aqueous electrochemical system of claim 1, wherein, In the water-based electrolyte, the active cation includes at least one of lithium, sodium and potassium ions, and the active cation further includes at least one of zinc, magnesium, aluminum, ammonium and multi-stage ammonium ions.

6. The free divalent manganese inhibited, anion-rich aqueous electrochemical system of claim 1, wherein, ​

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