Aqueous manganese ion battery and preparation process

Abstract

The present invention provides an aqueous manganese ion battery and its preparation process, which relates to the field of chemical batteries. The aqueous manganese ion battery comprises a positive electrode, a negative electrode and an electrolyte. The positive electrode is a carbon-based conductive substrate, the active material of the negative electrode is an organic compound or organic polymer containing a carbonyl functional group, and the electrolyte is a Mn-containing 2+ aqueous solution; during the charging process, Mn in the electrolyte 2+ Lose electrons and be oxidized to MnO2 and deposited on the positive electrode. The carbonyl functional group in the active material of the negative electrode obtains electrons to generate enolate anion, which reacts with Mn in the electrolyte. 2+ Combined into a stable complex. The aqueous manganese ion battery of the embodiment of the present application is Mn 2+ As the only energy-carrying ion, by combining the deposition / stripping reaction of MnO2 and Mn 2+ The complexation / decomplexation process achieves a high average discharge voltage, excellent energy density and cycle stability.

Description

Technical Field

[0001] The present application relates to the field of chemical batteries, and more specifically, to an aqueous manganese ion battery and a preparation process thereof. Background Art

[0002] Aqueous batteries not only have higher ionic conductivity than organic batteries, but are also environmentally friendly and low-cost. More importantly, because they eliminate the use of flammable organic electrolytes, aqueous batteries significantly improve their safety and hold great promise for applications in large-scale energy storage and wearable electronics. In recent years, aqueous ion batteries have flourished, particularly those containing high-valent metal ions such as zinc, aluminum, and calcium, which have further increased the battery's energy storage density and greatly expanded the design possibilities of aqueous batteries.

[0003] Manganese is the second most abundant transition metal on Earth. It has a high theoretical capacity, especially divalent manganese ions (Mn 2+ ) has a wide stable voltage window, so the design is based on Mn 2+ The new aqueous manganese ion battery with energy-carrying ions has important theoretical and application value. 2+ The redox process of MnO2 / MnO2 has a theoretical potential of 1.23V, and the reversibility and cyclability of the MnO2 deposition / stripping reaction are much higher than the solid-phase conversion process of traditional manganese-based positive electrode materials, so it has been widely favored by researchers. Based on this, researchers have constructed a series of aqueous ion batteries including MnO2-Zn, MnO2-Cu, MnO2-H2, MnO2-PTO, etc. using the MnO2 deposition / stripping process as the positive electrode reaction. However, due to the limitation of Mn 2+ Larger ionization radius and slow negative electrode Mn 2+ Reaction kinetics, there is still a lack of suitable negative electrode active materials to match the deposition / stripping reaction of MnO2, and the construction of Mn 2+ It is the only high-efficiency aqueous manganese ion battery that carries energy ions.

[0004] Therefore, developing excellent negative electrode material systems and designing new battery reaction models are of great practical significance for promoting the development of aqueous manganese ion batteries. Summary of the Invention

[0005] The purpose of the present invention is to provide an aqueous manganese ion battery and a preparation process thereof. 2+ As the only energy-carrying ion, the open pore structure and highly active functional groups of organic molecular crystals / organic polymers are used to promote the 2+ The diffusion and reaction kinetics of MnO2 are combined with the deposition / stripping reaction of Mn 2+By utilizing the coordination / decomposition process, an aqueous manganese ion battery with high average discharge voltage, excellent energy density and cycle stability was constructed.

[0006] In the first aspect, the present invention provides an aqueous manganese ion battery comprising a positive electrode, a negative electrode and an electrolyte, wherein the positive electrode is a carbon-based conductive substrate, the active material of the negative electrode is an organic compound or organic polymer containing a carbonyl functional group, and the electrolyte is a Mn-containing 2+ aqueous solution;

[0007] During the charging process, Mn in the electrolyte 2+ Lose electrons and be oxidized to MnO2 and deposited on the positive electrode. The carbonyl functional group in the active material of the negative electrode obtains electrons to generate enolate anion, which reacts with Mn in the electrolyte. 2+ Combine into a complex;

[0008] During the discharge process, MnO2 on the positive electrode is reduced to Mn 2+ Dissolved back into the electrolyte, the enolate anions in the active material of the negative electrode lose electrons and are oxidized to organic compounds or organic polymers containing carbonyl groups, while releasing Mn 2+ Dissolve back into the electrolyte.

[0009] In the above technical solution, the reversible deposition / stripping process of MnO2 on the positive electrode and the reversible Mn in the carbonyl-containing organic compound or organic polymer are used to generate the MnO2. 2+ The coordination / decomplexation reaction realizes the 2+ It is the only rechargeable aqueous battery architecture that carries energy ions.

[0010] The embodiment of the present application adopts the MnO2 deposition-stripping process as the positive electrode, which effectively avoids the Mn 2+ The poor cycle stability and low energy density caused by the slow insertion-extraction kinetics in the embedded positive electrode can be solved, thereby significantly improving the cycle stability and energy density of aqueous manganese ion batteries. In the embodiment of the present application, organic molecular crystals or organic covalent polymers are used as the active material of the negative electrode, and their open structure and adjustable active functional groups are used to provide Mn 2+ It provides an ideal place and channel for the diffusion and reaction of manganese ions, ensuring the excellent energy density and cycle stability of aqueous manganese ion batteries.

[0011] In addition, the electrochemical reactions of the positive and negative electrodes in the embodiments of the present application only involve the reversible conversion of manganese-containing compounds and do not require the participation of other metal ions; no additional acid needs to be added to the electrolyte, which can greatly reduce corrosion to the equipment and is environmentally friendly; because the electrolyte is mild, the positive electrode in the embodiments of the present application does not require additional deposition of MnO2 in advance, and the energy storage effect can be achieved directly using a carbon-based conductive substrate with no active substances.

[0012] In one possible implementation, the active material of the negative electrode is at least one of a ketone organic compound, an amide organic compound, a microporous polymer, and a three-dimensional organic covalent polymer;

[0013] And / or, the active material of the negative electrode includes but is not limited to at least one of pentacenetetraketone, 3,4,9,10-perylenetetracarboxamide diimide, melamine-1,4,5,8-naphthalenetetracarboxylic anhydride oligomer and melamine-1,4,5,8-naphthalenetetracarboxylic anhydride polymer.

[0014] In the above technical solution, the negative electrode active material of the embodiment of the present application can ensure high coulombic efficiency of battery operation. In particular, compared with the manganese metal negative electrode, the organic negative electrode active material can better suppress the generation of hydrogen evolution side reaction and achieve higher coulombic efficiency under low current charging and discharging conditions.

[0015] In one possible implementation, the negative electrode is composed of a negative electrode pole piece, which is a negative electrode current collector and a negative electrode material layer attached to the surface of the negative electrode current collector and containing a negative electrode active material; optionally, the negative electrode current collector is carbon cloth, and the negative electrode material layer also contains Ketjen black, single-walled carbon nanotubes and polytetrafluoroethylene.

[0016] In the above technical solution, the negative electrode material layer is formed by organic negative electrode active material, conductive agent Ketjen black and binder polytetrafluoroethylene, and the addition of single-arm carbon nanotubes can effectively increase the interfacial charge transfer of the active material and promote electron transmission in the negative electrode material layer.

[0017] In a possible implementation, the thickness of the negative electrode plate is 0.1 to 2.0 mm.

[0018] In one possible implementation, the positive electrode is composed of a positive electrode plate, which is a carbon-based conductive substrate. The positive electrode plate includes but is not limited to at least one of carbon felt, carbon paper, carbon fiber paper, and carbon fiber cloth.

[0019] In the above technical solution, no active substances need to be added to the positive electrode, and a commercial carbon-based conductive substrate can achieve an efficient electrochemical energy storage process.

[0020] In a possible implementation, the thickness of the positive electrode plate is 0.1 to 5.0 mm.

[0021] In a possible implementation, it further includes a separator for separating the positive electrode and the negative electrode; optionally, the separator is a glass fiber separator, and the thickness of the glass fiber separator is 0.05 to 2.0 mm.

[0022] In one possible implementation, the electrolyte contains Mn 2+A manganese salt aqueous solution, the electrolyte includes but is not limited to at least one of a MnSO4 aqueous solution, a MnCl2 aqueous solution, a Mn(NO3)2 aqueous solution and a Mn(CH3COO)2 aqueous solution;

[0023] and / or, Mn in the electrolyte 2+ The concentration is 0.5~2.0mol / L;

[0024] And / or, the pH value of the electrolyte is 2.0 to 6.0.

[0025] In a second aspect, an embodiment of the present application provides a preparation process for an aqueous manganese ion battery, which mainly involves arranging the positive electrode and the negative electrode at intervals and adding an electrolyte.

[0026] In one possible implementation, the negative electrode sheet, the glass fiber separator and the positive electrode sheet are stacked in sequence to form a battery cell, and the electrolyte is added. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of the operation of an aqueous manganese ion battery provided in an embodiment of the present application;

[0029] Figure 2 1 is a performance diagram of the rechargeable aqueous manganese ion battery of Example 1;

[0030] Figure 3 This is a performance diagram of the rechargeable aqueous manganese ion battery of Example 2;

[0031] Figure 4 This is a performance diagram of the rechargeable aqueous manganese ion battery of Example 3;

[0032] Figure 5 This is a performance diagram of the rechargeable aqueous manganese ion battery of Example 4. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions and advantages of the examples of the present application clearer, the technical solutions in the examples of the present application will be described clearly and completely below. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0034] The aqueous manganese ion battery and its preparation process according to the embodiment of the present application are described in detail below.

[0035] The present invention provides an aqueous manganese ion battery, which includes a positive electrode, a negative electrode, a separator for separating the positive electrode and the negative electrode, and an electrolyte. The positive electrode is a carbon-based conductive substrate, the negative electrode active material is an organic compound containing a carbonyl group or an organic polymer containing a carbonyl group, and the electrolyte is a Mn-containing 2+ of aqueous solution.

[0036] like Figure 1 As shown, the aqueous manganese ion battery is a rechargeable battery. The charge and discharge behavior of the battery comes from the reversible conversion of manganese active components on the positive and negative electrodes. 2+ It is the only known energy-carrying ion in this battery system, which is specifically reflected in the deposition / stripping process of MnO2 on the positive electrode and the Mn 2+ The coordination / decoordination process. The reaction formula is as follows:

[0037] positive electrode:

[0038] negative electrode:

[0039] Overall reaction:

[0040] During the charging process, Mn in the electrolyte 2+ The carbonyl functional group in the negative electrode active material (N) obtains electrons to generate an enolate anion (N 2- ) and with Mn in the electrolyte 2+ Combined into a stable complex (Mn 2+ …N 2- );

[0041] During the discharge process, MnO2 on the surface of the carbon-based conductive substrate of the positive electrode is reduced to Mn by electrons. 2+ Dissolved back into the electrolyte, the complex in the negative electrode active material is oxidized to a carbonyl-containing organic compound or organic polymer (N) due to the loss of electrons by the enolate anion, and Mn is released at the same time. 2+ Dissolve back into the electrolyte.

[0042] Among them, the negative electrode active material includes but is not limited to at least one of a ketone organic compound represented by pentacenetetraketone PT, an amide organic compound represented by 3,4,9,10-perylenetetracarboxylic diimide PTCDI, a microporous polymer represented by melamine-1,4,5,8-naphthalenetetracarboxylic anhydride oligomer NM-CMP, and a three-dimensional organic covalent polymer represented by melamine-1,4,5,8-naphthalenetetracarboxylic anhydride polymer NM-COF.

[0043] The positive electrode is designed as a carbon-based conductive substrate without any active material. Even without any active material, the positive electrode can still achieve excellent battery performance. The carbon-based conductive substrate can also have a three-dimensional structure, which can further enhance battery performance by increasing the specific surface area of the positive electrode.

[0044] As an implementation method, the negative electrode exists in the form of a pole piece, and the positive electrode also exists in the form of a pole piece.

[0045] Specifically, the negative electrode is composed of several (at least one) negative electrode sheets, which are a negative electrode current collector and a negative electrode material layer attached to the surface of the negative electrode current collector (substrate). The negative electrode current collector can be carbon cloth, and the negative electrode material layer contains negative electrode active material, Ketjen black, single-walled carbon nanotubes and binder polytetrafluoroethylene (PTFE); the thickness of the negative electrode sheet is usually 0.1 to 2.0 mm.

[0046] The positive electrode is composed of several (at least one) positive electrode sheets, which are carbon-based conductive substrates, including but not limited to at least one of carbon felt, carbon paper, carbon fiber paper and carbon fiber cloth; the thickness of the positive electrode sheet is usually 0.1 to 5.0 mm.

[0047] The diaphragm may be a glass fiber diaphragm, and the thickness of the glass fiber diaphragm is usually 0.05 to 2.0 mm.

[0048] Exemplarily, the positive electrode sheet, the glass fiber separator, and the negative electrode sheet are stacked together in sequence, that is, the positive electrode sheet and the negative electrode sheet are stacked alternately in sequence and the adjacent positive electrode sheet and negative electrode sheet are separated by the glass fiber separator. The whole is stacked together in the order of positive electrode sheet, glass fiber separator, negative electrode sheet, glass fiber separator, positive electrode sheet...

[0049] In other embodiments, the positive electrode and the negative electrode can also exist in other forms, not limited to the electrode form, and the battery as a whole can be in the form of a Swagelok battery, a button battery or other battery forms; the diaphragm can also be made of other materials, not limited to glass fiber diaphragms, and the negative electrode current collector is not limited to carbon cloth. The conductive agent used in the negative electrode is not limited to single-arm carbon nanotubes and Ketjen black, and the proportion of each material in the negative electrode material layer is not limited to the addition ratio in the embodiment of the present application.

[0050] In the embodiment of the present application, the electrolyte is a Mn-containing 2+ Aqueous solution of manganese salt, including but not limited to at least one of MnSO4 aqueous solution, MnCl2 aqueous solution, Mn(NO3)2 aqueous solution and Mn(CH3COO)2 aqueous solution; Mn in the electrolyte 2+ The concentration is 0.5-2.0 mol / L; the pH value of the electrolyte is 2.0-6.0.

[0051] The aqueous manganese-ion batteries of the present invention have the advantages of high safety, high energy density, high average output voltage, and good cycle stability, and can be applied to various types of electronic devices. In addition, the substrates of both the positive and negative electrodes can be made of flexible and bendable materials. Aqueous manganese-ion batteries based on flexible substrates are expected to be used as energy supply elements in flexible wearable electronic devices.

[0052] The embodiment of the present application also provides a preparation process for an aqueous manganese ion battery, which mainly arranges the positive electrode and the negative electrode at intervals and adds electrolyte. In the case where both the positive electrode and the negative electrode are in the form of pole pieces, the negative pole piece, the glass fiber separator and the positive pole piece are stacked in sequence and in close contact with each other to form a battery core, and the electrolyte is added. The negative pole pieces together constitute the negative electrode, and the positive pole pieces together constitute the positive electrode. As an embodiment, the preparation process of the negative pole piece is: the negative electrode active material, Ketjen black, single-walled carbon nanotubes and binder PTFE are uniformly mixed, and the solvent N-methylpyrrolidone NMP is added to grind to form a slurry; then the prepared slurry is evenly coated on the surface of the negative electrode current collector, and vacuum dried to form a negative pole piece.

[0053] The aqueous manganese ion battery of the embodiment of the present application has low production cost, and the required raw materials are environmentally friendly, and is expected to be widely used in energy storage systems.

[0054] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0055] Example 1

[0056] This embodiment provides a rechargeable aqueous manganese ion battery, which is assembled using an organic covalent polymer NM-COF with a three-dimensional regular pore structure as the negative electrode active material, carbon fiber cloth as the conductive substrate of the positive electrode, carbon cloth as the inactive conductive negative electrode current collector, a glass fiber membrane as the separator, and a 2.0 mol / L MnSO4 aqueous solution as the supporting electrolyte. The specific assembly process is as follows:

[0057] Preparation of negative electrode: (1) Clean the surface of carbon cloth with anhydrous ethanol and treat the surface of carbon cloth with 30% by volume of hydrogen peroxide to obtain a hydrophilic carbon cloth current collector. (2) Evenly mix NM-COF powder, Ketjen black, single-walled carbon nanotubes and binder PTFE in a mass ratio of 6:2:1:1, then add N-methylpyrrolidone (NMP) and grind and stir thoroughly to obtain a slurry for use. (3) Evenly coat the prepared slurry on the surface of the hydrophilic carbon cloth current collector and place it on a hot plate at 60°C to slowly evaporate the NMP solvent; then transfer it to a vacuum oven for drying at a baking temperature of 100°C for 24 hours to obtain a negative electrode.

[0058] The NM-COF powder was prepared in-house. The specific preparation route was as follows: 0.60 g of 1,4,5,8-naphthalenetetracarboxylic anhydride and 0.21 g of melamine were added to a mixed solution of 15.0 mL of N,N-dimethylformamide and 15.0 mL of ethylene glycol. After sufficient ultrasonication for 2 hours, the above precursor solution was transferred to a reactor and heated in an oven at 180°C for 70 hours. After the solution cooled to room temperature, the precipitate in the reactor was collected and washed alternately with ethanol and water for 6 times, and then dried at 60°C to obtain NM-COF powder.

[0059] Battery assembly: Add a certain amount of MnSO4 to deionized water, then stir and dissolve it thoroughly to obtain a 2.0 mol / L MnSO4 aqueous solution, i.e., the electrolyte; submerge the negative electrode and carbon fiber cloth in the electrolyte, and use the vacuum exhaust method to remove the adsorbed gas on the electrode and carbon fiber cloth; stack the 0.5 mm thick negative electrode, 0.68 mm thick glass fiber separator, and 0.4 mm thick carbon fiber cloth in sequence to assemble the battery, and perform performance testing after filling the electrolyte. The test results are as follows: Figure 2 shown.

[0060] from Figure 2 It can be seen that the rechargeable aqueous manganese ion battery exhibits excellent electrochemical energy storage properties, with an energy density of 135 mAh / g at a current density of 0.2 A / g and an average discharge voltage platform of 1.3 V.

[0061] At 2 mA / cm 2 At a low current of 2 mA / cm, the charge and discharge coulomb efficiency of the rechargeable aqueous manganese ion battery can reach more than 98.5%; at a low current of 2 mA / cm 2 After 100 cycles at a charge and discharge current of , the battery's capacity retention rate can still be maintained at above 91%.

[0062] Example 2

[0063] This embodiment provides a rechargeable aqueous manganese ion battery, which is assembled using a microporous polymer NM-CMP with a relatively low degree of polymerization as the negative electrode active material, a carbon fiber cloth as the carbon-based conductive substrate of the positive electrode, a carbon cloth as the inactive conductive negative electrode current collector, a glass fiber membrane as the separator, and a 2.0 mol / L MnSO4 aqueous solution as the supporting electrolyte. The specific assembly process is as follows:

[0064] Preparation of negative electrode: (1) Clean the surface of carbon cloth with anhydrous ethanol and treat the surface of carbon cloth with 30% by volume of hydrogen peroxide to obtain a hydrophilic carbon cloth current collector. (2) Evenly mix NM-CMP powder, Ketjen black, single-walled carbon nanotubes and binder PTFE in a mass ratio of 6:2:1:1, then add N-methylpyrrolidone (NMP) and grind and stir thoroughly to obtain a slurry for use. (3) Evenly coat the prepared slurry on the surface of the hydrophilic carbon cloth current collector and place it on a hot plate at 60°C to slowly volatilize NMP; then transfer it to a vacuum oven for drying at a temperature of 100°C for 24 hours to obtain a negative electrode.

[0065] The NM-CMP was prepared in-house. The specific preparation route was as follows: 4.0 g of 1,4,5,8-naphthalenetetracarboxylic anhydride and 1.26 g of melamine were added to a mixed solution of 7.0 mL of N,N-dimethylformamide and 7.0 mL of ethylene glycol. After sufficient ultrasonication for 2 hours, the above precursor solution was transferred to a reactor and heated in an oven at 180°C for 70 hours. After the solution cooled to room temperature, the precipitate in the reactor was collected and washed alternately with ethanol and water for 6 times, and then dried at 60°C to obtain NM-CMP powder.

[0066] Battery assembly: Add a certain amount of MnSO4 to deionized water, then stir and dissolve it thoroughly to obtain a 2.0 mol / L MnSO4 aqueous solution, i.e., the electrolyte; submerge the negative electrode sheet and carbon fiber cloth in the electrolyte, and use the vacuum exhaust method to remove the gas adsorbed on the negative electrode sheet and carbon fiber cloth; stack the negative electrode sheet with a thickness of 0.6 mm, the glass fiber separator with a thickness of 0.68 mm, and the carbon fiber cloth with a thickness of 0.4 mm in sequence to assemble the battery, and perform a performance test after filling the electrolyte. The test results are as follows: Figure 3 shown.

[0067] Example 3

[0068] This embodiment provides a rechargeable aqueous manganese ion battery, which is assembled using amide organic molecular crystal 3,4,9,10-perylenetetracarboxylic diimide PTCDI as the negative electrode active material, carbon fiber cloth as the carbon-based conductive substrate of the positive electrode, carbon cloth as the inactive conductive negative electrode current collector, glass fiber membrane as the separator, and a 2.0 mol / L MnSO4 aqueous solution as the supporting electrolyte. The specific assembly process is as follows:

[0069] Preparation of negative electrode sheet: (1) Clean the surface of carbon cloth with anhydrous ethanol and treat its surface with 30% by volume of hydrogen peroxide to obtain a hydrophilic carbon cloth current collector. (2) Evenly mix commercial PTCDI powder, Ketjen black, single-walled carbon nanotubes and binder PTFE in a mass ratio of 6:2:1:1, then add solvent N-methylpyrrolidone NMP and grind and stir thoroughly to obtain a slurry for use. (3) Evenly coat the prepared slurry on the surface of the hydrophilic carbon cloth current collector and place it on a hot plate at 60°C to slowly evaporate the solvent NMP; then transfer it to a vacuum oven for drying at a baking temperature of 100°C for 24 hours to obtain a negative electrode sheet.

[0070] Battery assembly: Add a certain amount of MnSO4 to deionized water, then stir and dissolve it thoroughly to obtain a 2.0 mol / L MnSO4 aqueous solution, i.e., the electrolyte; submerge the negative electrode sheet and carbon fiber cloth in the electrolyte, and use the vacuum exhaust method to remove the gas adsorbed on the negative electrode sheet and carbon fiber cloth; stack the negative electrode sheet with a thickness of 0.6 mm, the glass fiber separator with a thickness of 1.36 mm, and the carbon fiber cloth with a thickness of 0.4 mm in sequence to assemble the battery, and perform performance testing after filling the electrolyte. The test results are as follows: Figure 4 shown.

[0071] Example 4

[0072] This embodiment provides a rechargeable aqueous manganese ion battery, which is assembled using a ketone-containing organic molecular crystal pentacenetetraketone (PT) as the negative electrode active material, a carbon fiber cloth as the carbon-based conductive substrate of the positive electrode, a carbon cloth as the inactive conductive negative electrode current collector, a glass fiber membrane as the separator, and a 2.0 mol / L MnSO4 aqueous solution as the supporting electrolyte. The specific assembly process is as follows:

[0073] Preparation of negative electrode sheet: (1) Clean the surface of carbon cloth with anhydrous ethanol and treat its surface with 30% by volume of hydrogen peroxide to obtain a hydrophilic carbon cloth current collector. (2) Evenly mix commercial PT powder, Ketjen black, single-walled carbon nanotubes and binder PTFE in a mass ratio of 6:2:1:1, then add solvent N-methylpyrrolidone NMP and grind and stir thoroughly to obtain a slurry for use. (3) Evenly coat the prepared slurry on the surface of the hydrophilic carbon cloth current collector and place it on a hot plate at 60°C to slowly evaporate the solvent NMP; then transfer it to a vacuum oven for drying at a baking temperature of 100°C for 24 hours to obtain a negative electrode sheet.

[0074] Battery assembly: Add a certain amount of manganese sulfate MnSO4 into deionized water, then stir and dissolve it thoroughly to obtain a MnSO4 aqueous solution with a concentration of 2.0 mol / L, i.e., the electrolyte; submerge the negative electrode sheet and carbon fiber cloth in the electrolyte, and use the vacuum exhaust method to remove the gas adsorbed on the negative electrode sheet and carbon fiber cloth to improve the contact between the solution and the electrode surface; stack a layer of negative electrode sheet with a thickness of 0.7 mm, a glass fiber separator with a thickness of 1.36 mm, and a carbon fiber cloth with a thickness of 0.4 mm in each layer in sequence to assemble a battery, and perform performance testing after filling with electrolyte. The test results are as follows: Figure 5 shown.

[0075] Comparative Example 1

[0076] This comparative example provides a manganese ion battery, which is different from Example 1 in that: Comparative Example 1 is based on Mn 0.18 V2O5·nH2O or chloranil is the positive electrode active material, metal Mn is the negative electrode active material, MnSO4 or Mn(CF3SO3)2 is the electrolyte, and its positive and negative electrode reactions and battery model are not similar to those of Example 1.

[0077] In addition, the Mn in this comparative example 2+ The energy storage mechanism is the intercalation-deintercalation mechanism, and in Example 1, Mn 2+ The redox and coordination mechanisms of the cathode are completely different, and the inherent energy storage principle is also completely different; the loading amount of the negative electrode manganese metal in the comparative example needs to be >30mg / cm 2 , and through the new positive and negative electrode reaction design, the new manganese ion battery in Example 1 can still achieve an average discharge voltage and energy density similar to those of the comparative example without using excessive manganese metal, which is conducive to further improving the utilization efficiency of active materials; in addition, the positive electrode of Example 1 does not require active materials, and a commercial carbon fiber substrate can achieve an energy storage effect. In terms of electrode processing technology and scale prospects, it is far superior to the positive electrode design in the comparative example.

[0078] Comparative Example 2

[0079] This comparative example provides a Mn 2+ The aqueous zinc ion battery is designed with / MnO2 as the positive electrode and Zn metal as the negative electrode, and its electrolyte conditions are a mixed solution of 0.1mol / L H2SO4, 1.0mol / L ZnSO4 and 1.0mol / L MnSO4.

[0080] This comparative example belongs to a zinc ion battery. 2+ The energy storage mechanism of manganese ion batteries, which are the only energy-carrying ions, is not similar to the battery reaction principle; in addition, no additional acid needs to be added to the electrolyte of the embodiment, and the mild electrolyte conditions can greatly reduce corrosion to the equipment and are more environmentally friendly.

[0081] Comparative Example 3

[0082] This comparative example provides a Mn 2+ A hydrogen ion battery with MnO2 as the positive electrode and organic PTO as the negative electrode, and the electrolyte is a mixed solution of 2.0 mol / L H2SO4 and 2.0 mol / L MnSO4. To compensate for the dissolution loss of the positive electrode MnO2 in the acidic solution, a large amount of additional MnO2 was deposited on the positive electrode of this comparative example before the reaction.

[0083] In this comparative example, hydrogen ions are used as energy-carrying ions, and the negative electrode reaction mechanism is the reversible conversion of enol and keto structures, which is different from the embodiment in which Mn 2+ The coordination reaction and energy storage mechanism of the negative electrode of the manganese ion battery, which is the sole energy-carrying ion, are not similar. No acid is required to be added to the electrolyte of the manganese ion battery in the embodiment, so the positive electrode of the embodiment does not require a large amount of MnO2 to be deposited in advance. The mild electrolyte conditions in the embodiment can also significantly reduce the corrosion of the electrolyte on the equipment and are more environmentally friendly. Compared with the hydrogen ion battery in this comparative example, the manganese ion battery in the embodiment also exhibits a higher average output voltage (approximately 1.3V), which is more valuable for large-scale utilization.

[0084] Comparative Example 4

[0085] This comparative example provides a manganese ion battery, which uses MnO2 as the positive electrode, metal Mn as the negative electrode, the diaphragm is an AGM diaphragm, and the electrolyte is Mn. 2+ The concentration is 1.2 mol / L. This comparative example only provides 30 mA / cm 2 Coulombic efficiency under high current charge and discharge conditions.

[0086] The difference between this comparative example and the embodiment is that the negative electrode reaction in the comparative example is the deposition / stripping process of Mn metal, which is different from the negative electrode Mn in the embodiment. 2+ The coordination / decoordination process has an essential difference in the energy storage principle; the negative electrode in the embodiment is an organic molecular crystal or organic polymer containing a carbonyl functional group, which can effectively inhibit the hydrogen evolution side reaction caused by the manganese metal negative electrode and improve the energy storage efficiency of the battery, especially the energy storage efficiency under low current charge and discharge conditions; the manganese ion battery in the embodiment can be 2mA / cm 2 At a small current density, excellent charge and discharge coulomb efficiency and stable energy storage are achieved; in addition, the positive electrode in the embodiment is a carbon-based conductive substrate with inactive material, which has low cost, simple preparation process and potential for large-scale utilization, which is better than the positive electrode sheet preparation process in the comparative example.

[0087] In summary, the aqueous manganese ion battery of the embodiment of the present application is based on Mn 2+is the only energy-carrying ion, and is based on the deposition / stripping process of the positive electrode MnO2 and the negative electrode Mn 2+ The complexation / decomplexation reaction achieves excellent energy density, high output voltage and good cycling stability.

[0088] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An aqueous manganese ion battery, characterized in that: The invention comprises a positive electrode, a negative electrode and an electrolyte, wherein the positive electrode is a carbon-based conductive substrate, the active material of the negative electrode is an organic compound or an organic polymer containing a carbonyl functional group, the active material of the negative electrode comprises at least one of pentacene tetraketone, 3,4,9,10-perylenetetracarboxamide diimide, melamine-1,4,5,8-naphthalenetetracarboxylic anhydride oligomer and melamine-1,4,5,8-naphthalenetetracarboxylic anhydride polymer, and the electrolyte is a Mn-containing 2+ aqueous solution; During the charging process, the Mn in the electrolyte 2+ The carbonyl functional group in the active material of the negative electrode obtains electrons to generate an enolate anion, which reacts with the Mn in the electrolyte. 2+ Combine into a complex; During the discharge process, the MnO2 on the positive electrode is reduced to Mn by electrons. 2+ Dissolved back into the electrolyte, the enolate anions in the active material of the negative electrode lose electrons and are oxidized to organic compounds or organic polymers containing carbonyl groups, while releasing Mn 2+ Dissolve back into the electrolyte.

2. The aqueous manganese ion battery according to claim 1, wherein The negative electrode is composed of a negative electrode sheet, which is a negative electrode current collector and a negative electrode material layer attached to the surface of the negative electrode current collector and containing the active material of the negative electrode.

3. The aqueous manganese ion battery according to claim 2, wherein: The negative electrode current collector is carbon cloth, and the negative electrode material layer further comprises Ketjen black, single-walled carbon nanotubes and polytetrafluoroethylene.

4. The aqueous manganese ion battery according to claim 2, wherein: The thickness of the negative electrode plate is 0.1-2.0 mm.

5. The aqueous manganese ion battery according to claim 1, wherein The positive electrode is composed of a positive electrode plate, which is a carbon-based conductive substrate and contains at least one of carbon felt, carbon paper, carbon fiber paper and carbon fiber cloth.

6. The aqueous manganese ion battery according to claim 5, characterized in that The thickness of the positive electrode plate is 0.1-5.0 mm.

7. The aqueous manganese ion battery according to claim 1, wherein It also includes a separator for separating the positive electrode and the negative electrode.

8. The aqueous manganese ion battery according to claim 7, wherein: The diaphragm is a glass fiber diaphragm, and the thickness of the glass fiber diaphragm is 0.05-2.0 mm.

9. The aqueous manganese ion battery according to claim 1, wherein The electrolyte contains Mn 2+ an aqueous solution of a manganese salt, wherein the electrolyte comprises at least one of an aqueous solution of MnSO4, an aqueous solution of MnCl2, an aqueous solution of Mn(NO3)2, and an aqueous solution of Mn(CH3COO)2; And / or, Mn in the electrolyte 2+ The concentration is 0.5~2.0mol / L; And / or, the pH value of the electrolyte is 2.0-6.

0.

10. A process for preparing an aqueous manganese ion battery according to claim 1, characterized in that: It includes the following steps: The positive electrode and the negative electrode are arranged at intervals and filled with electrolyte.

11. The process for preparing an aqueous manganese ion battery according to claim 10, wherein: It includes the following steps: The negative electrode sheet, glass fiber separator and positive electrode sheet are stacked in sequence to form a battery cell, and the electrolyte is added.

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