Electrolyte for lithium oxygen battery and autocatalytic lithium oxygen battery

Abstract

The invention provides an electrolyte for a lithium-oxygen battery and an autocatalytic lithium-oxygen battery. The electrolyte for the lithium-oxygen battery comprises the following components: an aprotic solvent, a lithium salt with a solute of 0.5-2 mol / L and manganese acetylacetonate with a solute of 0.01-0.1 mol / L, the aprotic solvent comprises at least 60 vol% of dimethyl sulfoxide. According to the invention, manganese acetylacetonate is used as a positive electrode electrolyte additive in the Li-O2 battery and is matched with the DMSO solvent, so that the reaction kinetics of the lithium-oxygen battery can be remarkably enhanced, low overpotential and excellent long-cycle life are realized, and the lithium-oxygen battery has very high practical value; the metal-oxygen or metal-air battery positive electrode additive can be a cheap and efficient metal-oxygen or metal-air battery positive electrode additive, and is used for constructing a high-performance battery system.

Description

Technical Field

[0001] The present invention belongs to the technical field, and in particular relates to an electrolyte for a lithium oxygen battery and an autocatalytic lithium oxygen battery. Background Art

[0002] Since its approximately 3500 Wh kg -1 Lithium-oxygen batteries (Li-O2 batteries) are considered promising candidates for advanced energy conversion and storage devices due to their high specific capacity. However, Li-O2 batteries face significant challenges associated with slow kinetics, stemming from the insulating nature of discharge products, changes in the complex gas-solid-liquid three-phase interface, and various side reactions. These slow kinetics lead to high overpotentials and limited cycling capabilities of Li-O2 batteries. To address these issues, three main strategies have been explored over the past decade: the incorporation of cathode electrocatalysts, the use of redox mediators, and the development of modified Li2O2.

[0003] The structure of modified Li2O2 has the expected structure of enhanced ionic and electronic conductivity, while promoting the formation and decomposition process, which can introduce a novel discharge-charge mechanism for the battery. In previous work, our group developed a Li-O2 battery system with an autocatalytic mechanism, which provided an innovative approach for the structural design of electrocatalyst active sites and discharge products in Li-O2 batteries. Transition metal-doped Li2O2 (M-Li2O2) was synthesized by in-situ doping of transition metal elements into the discharge product Li2O2. 2-x O2), whose conductivity is higher than that of pure Li2O2. MO x The site acts as an autocatalytic active center, promoting Li 2-x The decomposition of O2 minimizes the introduction of multiphase interfaces and effectively enhances the reaction process. The self-catalytic Li-O2 battery can enhance the battery performance through structural regulation and show a capacity of about 35000 mAh g -1 The high specific capacity and low overpotential of 0.76 V and 3000 mA g -1 However, it has limited effect on the stability of highly active interphases such as superoxide in Li-O2 batteries, which poses a major challenge to improving the cycling stability of autocatalytic Li-O2 batteries.

[0004] As a liquid phase catalyst, redox mediator plays an important role in improving battery energy efficiency and cycle stability by capturing intermediate phases, promoting electron transfer and promoting structural transformation. Redox mediator acts as a charge carrier between discharge products and electrodes, which can alleviate polarization, promote the decomposition of discharge products, and reduce overpotential during OER. Prior art discloses some reports on redox mediators as electrolyte additives for lithium-oxygen batteries.

[0005] Patent CN113258137A discloses an electrolyte additive for improving the electrochemical performance of lithium oxygen batteries, the chemical structure of which is However, its performance improvement on lithium-oxygen batteries is not obvious enough, and its preparation process is relatively complicated.

[0006] CN106785036A discloses an electrolyte additive for lithium-air batteries, including one or more of iodobenzophenone, iodobenzophenone, and iodobenzene, which can contact with the discharge product to reduce the charge overpotential, and can interact with the discharge intermediate product lithium superoxide and the discharge product lithium peroxide to stabilize the two substances and inhibit the occurrence of side reactions. Therefore, the charging polarization and cycle performance are improved. However, its structural stability is poor, and the charging capacity is significantly attenuated after less than 130 cycles, and there is no original optimization of the positive electrode reaction process of the lithium-oxygen battery.

[0007] CN109193030A discloses a lithium oxygen battery electrolyte with molybdenum pentachloride as a redox medium, including a soluble lithium salt as a solute, a proton-free solvent and an additive molybdenum pentachloride; wherein the solute concentration in the electrolyte is 0.1~1 mol / L; the concentration of molybdenum pentachloride in the electrolyte is 0.01~0.1 mol / L. However, the molybdenum ions contained in the electrolyte are unstable to the lithium negative electrode, and molybdenum is an oxygen-philic element, so the battery system also shows extremely poor cycle stability, only 45 cycles, and high overpotential and severe polarization; during the charge and discharge process, the action form of molybdenum ions is mainly to transfer electrons through the redox of molybdenum, and does not produce an effective regulatory effect on the insulating lithium peroxide itself, and the main function is very single; in this oxygen-rich condition, it is easy to be attacked by oxygen ions, superoxide ions, etc. and inactivated.

[0008] CN116780051A discloses an electrolyte additive for lithium oxygen battery, which is a crown ether compound. + It has strong adsorption capacity, increases the amount of lithium peroxide, effectively alleviates the passivation of the positive electrode, and alleviates the blockage problem. In addition, the generated complex adsorbs O2 through electrostatic attraction. -Active ions can avoid side reactions. However, there is no essential optimization of the insulating properties of the products in lithium-oxygen batteries. It only plays a role in stabilizing the oxygen-rich intermediates, but does not contribute much to the kinetics of the entire battery reaction.

[0009] Although the above patent has partially optimized the reaction path of lithium-oxygen batteries, the stability and catalytic activity of the battery have been improved to a certain extent. However, due to the lack of changes in the intrinsic physical and chemical properties of the structure of the positive electrode insulating product, the important problem of slow kinetics has not been fundamentally solved. The new additive disclosed in the present invention, through layer-by-layer screening, comprehensively considers the liquid phase reaction mechanism and the characteristics of the positive electrode solid phase product, and utilizes the molecular-ion coexistence Mn(acac)3 additive system to obtain multiple effects of stable molecular intermediates and self-catalytic properties of solid phase products. In particular, it solves the shortcoming of lithium peroxide itself in electronic insulation from the intrinsic characteristics, giving it excellent electrochemical activity, greatly improving the reaction kinetics and cycle stability of lithium-oxygen batteries, and obtaining ultra-low overpotential and ultra-long life.

[0010] Ma et al. introduced vanadium acetylacetonate (V(acac)3) into Li-O2 batteries. During discharge, V(acac)3 binds and stabilizes superoxide intermediates, thereby accelerating ORR kinetics. During charge, V(acac)3 acts as a redox mediator, enabling Li2O2 to oxidize at a lower voltage. Batteries using V(acac)3 exhibit high rate performance, low overpotential, and long cycle life. -1 Zhou et al. introduced Ir(acac)3 into Li-O2 batteries. This compound can react with O2 to form an intermediate complex (Ir(acac)3-O2 - ), regulates the ORR pathway and stabilizes superoxide radical species. During the charging process, Ir(acac)3 acts as a redox mediator, promoting the decomposition of Li2O2 by reacting with superoxide intermediates. The battery using Ir(acac)3 exhibits lower overpotential, higher discharge capacity (17446 mAhg -1 ) and improved cycling performance (at 100 mA g -1 However, the presence of the above-mentioned V(acac)3 or Ir(acac)3 redox mediators can lead to the appearance of ring-shaped discharge products in Li-O2 batteries, which are difficult to completely decompose during the charging process, resulting in high overpotentials, which is not conducive to the enhancement of rate performance and fast charging characteristics. Therefore, the simultaneous coupling of autocatalysis and redox regulation in the same battery system is expected to further promote the development of high-performance Li-O2 battery systems. Summary of the invention

[0011] In order to overcome the problem that the performance of lithium-oxygen battery electrolytes in the prior art needs to be further improved, the present invention uses manganese acetylacetonate as a cathode additive in Li-O2 batteries. On the one hand, transition metal acetylacetonate acts as a weak electrolyte, allowing partial cation dissociation, and then integrating into the discharge product through doping during the discharge process, thereby acting as an autocatalytic active site. On the other hand, the undissociated acetylacetonate molecules act as liquid-phase redox mediators, capturing and stabilizing the intermediate phase. The results show that the electrolyte of the present invention uses manganese acetylacetonate and DMSO solvent to significantly enhance the reaction kinetics of lithium-oxygen batteries, achieving a low overpotential of 0.43 V, and at 1A g -1 Furthermore, when combined with an optimized reaction environment and preloaded solid-phase electrocatalysts, the system exhibited excellent stability at 1 A g -1 The present invention has an excellent lifespan of 3850 cycles and has a very high practical value. It can be used as a cheap and efficient metal oxygen or metal air battery cathode additive to construct a high-performance battery system. Specifically, the present invention achieves the above-mentioned purpose through the following technical solutions: An electrolyte for a lithium-oxygen battery comprises the following components: an aprotic solvent, a solute of 0.5-2 mol / L of a lithium salt, and 0.01-0.1 mol / L of manganese acetylacetonate; the aprotic solvent comprises at least 50 vol% of dimethyl sulfoxide.

[0012] Preferably, the aprotic solvent comprises at least 60 vol % of dimethyl sulfoxide; more preferably, the aprotic solvent comprises at least 66 vol % of dimethyl sulfoxide.

[0013] Preferably, the electrolyte for the lithium-oxygen battery is a cathode electrolyte.

[0014] Furthermore, the aprotic solvent is dimethyl sulfoxide or a mixed solvent of dimethyl sulfoxide and an organic solvent A, and the organic solvent A is selected from at least one of 1,3-dioxolane, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene carbonate, ethylene carbonate, N,N-dimethylacetamide, dimethylformamide, and ethyl methyl sulfone.

[0015] Preferably, the aprotic solvent is a mixed solvent of dimethyl sulfoxide and organic solvent A in a volume ratio of 1-4:1; more preferably, the aprotic solvent is a mixed solvent of dimethyl sulfoxide and 1,3-dioxolane in a volume ratio of 2-4:1. The solvent compounded according to the above ratio can better play the role of the compounded solvent. The inventors found that the compounding of DOL and DMSO can complement the advantages of both and reduce their respective disadvantages. As electrolyte components, DOL and DMSO each have their own unique properties and advantages and disadvantages. DOL (1,3-dioxolane) has a lower freezing point and viscosity, and is suitable for use in low temperature environments, but it is prone to polymerization. DMSO (dimethyl sulfoxide) has a higher dielectric constant and donor number, which can promote the generation of trisulfide free radicals, but the cycle efficiency is higher in the first 10 weeks and may decrease thereafter. The compounding of DOL and DMSO can complement the advantages of both and reduce their respective disadvantages. Through compounding, the excellent kinetics of DOL at low temperatures can be utilized, while the cycle efficiency and stability of the battery can be improved by DMSO.

[0016] Furthermore, the lithium salt is selected from at least one of lithium trifluoromethanesulfonate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium nitrate.

[0017] The present invention also provides a lithium-oxygen battery, comprising a lithium negative electrode, a positive electrode, a separator, and the above electrolyte. It is clear to those skilled in the art that the lithium-oxygen battery also includes a lithium-air battery.

[0018] Furthermore, the positive electrode is carbon paper coated with KB and platinum carbon, and the separator is a glass fiber separator.

[0019] The present invention also protects the use of manganese acetylacetonate as an additive for a positive electrode electrolyte of a lithium-oxygen battery; the positive electrode electrolyte of the lithium-oxygen battery comprises 0.01-0.1 mol / L manganese acetylacetonate, 0.5-2 mol / L lithium salt, and an aprotic solvent, wherein the aprotic solvent comprises at least 50 vol% of dimethyl sulfoxide; preferably, the aprotic solvent comprises at least 60 vol% of dimethyl sulfoxide.

[0020] Furthermore, the aprotic solvent is dimethyl sulfoxide or a mixed solvent of dimethyl sulfoxide and an organic solvent A, and the organic solvent A is selected from at least one of 1,3-dioxolane, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene carbonate, ethylene carbonate, N,N-dimethylacetamide, dimethylformamide, and ethyl methyl sulfone.

[0021] Preferably, the aprotic solvent is a mixed solvent of dimethyl sulfoxide and organic solvent A in a volume ratio of 1-4:1; more preferably, the aprotic solvent is a mixed solvent of dimethyl sulfoxide and 1,3-dioxolane in a volume ratio of 1-4:1.

[0022] The present invention uses manganese acetylacetonate as an additive, dissolves it in a basic electrolyte to configure a functional electrolyte, and assembles a lithium oxygen battery. Through the operation of battery charge and discharge, positive electrode materials with self-catalytic active sites, i.e., discharge products, can be repeatedly generated and decomposed on the positive electrode, and the catalytic active sites can be implanted in the discharge products for catalytic action; at the same time, the metal sites doped into the discharge products have good regulatory properties for the electronic structure of the discharge products themselves, making them change from insulators to semiconductors or conductors, showing certain metallic properties, and essentially accelerating the positive electrode reaction kinetics; in addition, acetylacetonate in molecular form can directly interact with superoxide, enhance its stability, and make it easier to disproportionately transform and generate lithium peroxide, reducing the occurrence of side reactions. The application of the new additive in the present invention enables the electrolyte solution to have good electrochemical properties, which plays a fundamental role in improving the performance of metal oxygen batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the UV spectra of the functional electrolyte with and without KO2 added in step 2 of Example 1; Figure 2 This is the XPS spectrum of the positive electrode of the lithium-oxygen battery in the fully discharged state of Example 1; Figure 3 The limited capacity cycle charge-discharge curve (a) and the corresponding overpotential and energy efficiency (b) in Li-O2 battery; Figure 4 This is an electron microscope photograph of the discharge product after the battery of Example 1 is operated, and it can be seen that it has a film-like morphology; Figure 5 This is an electron microscope photograph of the discharge product after the battery of Comparative Example 3 is operated; Figure 6 This is an electron microscope photograph of the discharge product after the battery of Example 4 was operated. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments.

[0025] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0026] Example 1 1. The porous carbon material and commercial platinum carbon material are mixed with (1%) polyvinylidene fluoride solution or Nafion solution in an appropriate mass ratio (45%:45%:10%), and an appropriate amount of pyrrolidone solvent is added and ultrasonicated until well dispersed and evenly coated on the substrate, and then baked at 100 degrees Celsius for 12 hours to prepare an air electrode.

[0027] 2. Prepare the electrolyte: dissolve the additive manganese acetylacetonate (0.1 M) and lithium salt LiCF3SO3 (1 M) in solvent DMSO as a functional electrolyte; dissolve the lithium salt LiCF3SO3 (1 M) in solvent DMSO as a basic electrolyte.

[0028] 3. Use the air electrode prepared as above as the positive electrode, metallic lithium as the negative electrode, the basic electrolyte as the negative electrode electrolyte, and the functional electrolyte as the positive electrode electrolyte to assemble a self-catalytic metal oxygen battery.

[0029] Figure 1 The UV spectra of the functional electrolyte with and without KO2 added in step 2 of Example 1 are shown in Figure 1. It can be seen that potassium superoxide (KO2) generates O2 in DMSO. - , which was then introduced into a 1 M LiCF3SO3 / DMSO electrolyte containing Mn(acac)3 ( Figure 1 ). The saturated KO2 / DMSO solution was injected into the Li + After the electrolyte is added, the peak intensity at 292 nm increases rapidly and broadens to longer wavelengths, indicating a strong interaction with superoxide. Therefore, Mn(acac)3 can directly interact with the discharge product intermediates superoxide and lithium superoxide, thereby stabilizing them and avoiding attacking the electrolyte solution or carbon materials, causing a large number of side reactions. Currently, this effect requires the presence of DMSO in the solvent to be achieved.

[0030] Figure 2 This is the XPS spectrum of the positive electrode of the lithium oxygen battery in Example 1 under full discharge. The contents of different elements on the electrode were studied by XPS. The atomic ratio of Mn to Li in the discharge product was about 2:98, indicating that Mn 2+ Doped into the discharge product Li2O2, and during the reaction, Mn 2+ The doping amount is significantly lower than that of Li + .

[0031] In order to evaluate the battery performance of the system, it was assembled into button cells and tested in a high-purity oxygen (Li-O2 evaluation system) atmosphere. All current densities and specific capacities are calculated based on the mass of the loaded material. The test system pressure is 0.1 MPa atmospheric pressure, the test system temperature is room temperature, the test system is a Newwell tester, and the constant current charge and discharge voltage range is 2.0-4.5 V. Among them, the cycle test is at 1000 mA g -1 carried out at a current density of . Figure 3 The limited capacity cycle charge and discharge curve (a) and the corresponding overpotential and energy efficiency (b) of Li-O2 battery. It can be seen that at 1000 mA g -1 At a high current density of 1.5 Å, the Mn(acac)3-added self-catalytic Li-O2 battery system can run for more than 3850 cycles, and its charge and discharge capacities can still reach 500 mAh g during the cycle. -1 , achieving the maximum lifespan reported. In the discharge-charge curve ( Figure 3 a) and the corresponding parameters in the bar graph ( Figure 3 b), the median discharge voltage remained above 2.7V in 2000 cycles; the median charge voltage gradually increased in the first 200 cycles, reached a steady state at 500 cycles, and remained consistent in the first 2000 cycles. The energy efficiency of the battery dropped from the initial 75.2% to 62.5%. In the system without Mn(acac)3 additive, the battery can run up to 30 cycles. From the above analysis, it can be seen that the introduction of Mn(acac)3 has greatly improved the cycle stability of Li-O2 batteries, and fully demonstrates that Li-O2 batteries have practical use value and significance.

[0032] Example 2 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO is replaced by a mixed solvent of DMSO:DOL in a volume ratio of 2:1.

[0033] Example 3 The other conditions were the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO was replaced with a mixed solvent of DMSO:DOL in a volume ratio of 4:1.

[0034] Example 4 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO is replaced by a mixed solvent of DMSO:ethylene glycol dimethyl ether in a volume ratio of 2:1.

[0035] Example 5 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO is replaced by a mixed solvent of DMSO:ethylene carbonate in a volume ratio of 2:1.

[0036] Example 6 The other conditions were the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO was replaced by a mixture of DMSO and DOL in a volume ratio of 1:1.

[0037] Comparative Example 1 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, manganese acetylacetonate is replaced by iron acetylacetonate of an equimolar concentration.

[0038] Comparative Example 2 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, manganese acetylacetonate is replaced by nickel acetylacetonate of equimolar concentration.

[0039] Comparative Example 3 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, manganese acetylacetonate is replaced by vanadium acetylacetonate of an equimolar concentration.

[0040] Comparative Example 4 The other conditions are the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, manganese acetylacetonate is replaced by iridium acetylacetonate of equimolar concentration.

[0041] Comparative Example 5 The other conditions were the same as those in Example 1, except that in step 2, in the preparation of the functional electrolyte, the solvent DMSO was replaced by DOL.

[0042] Figure 4 This is an electron microscope photograph of the discharge product of the battery in Example 1 after operation, and it can be seen that it has a film-like morphology. Figure 5 This is an electron microscope photo of the discharge product after the battery in comparative example 3 is operated. Figure 6 This is an electron microscope photograph of the discharge product after the battery of Example 4 was operated. Figure 5 , Figure 6It can be seen that when V(acac)3 or Ir(acac)3 is used as an additive to the positive electrode electrolyte of a lithium-oxygen battery, its discharge product has a ring-shaped morphology. Normally, as the discharge capacity increases, the electrode is covered with annular Li2O2 through a solution-mediated pathway. This ring-shaped product morphology is difficult to completely decompose during the charging process, resulting in a high overpotential. In the invention, during the discharge process, the introduction of Mn(acac)3 promotes the adsorption and growth of reaction intermediates LiO2 and Li2O2 molecules on the KB electrode. This is a surface-mediated pathway, and the discharge product presents a film-like structure and / or a sheet-like structure, which is easier to form and decompose during the charge and discharge process, thereby giving the lithium-oxygen battery a low overpotential and high cycle performance. The electrochemical performance data of the lithium-oxygen batteries of the above-mentioned embodiments and comparative examples are listed in Table 1 below.

[0043] Table 1 Electrochemical performance data of lithium-oxygen batteries .

[0044] The present invention prepares a positive electrode electrolyte for a lithium oxygen battery by dissolving manganese acetylacetonate in a basic electrolyte, and uses the basic electrolyte as a negative electrode electrolyte to assemble a lithium oxygen battery. Through the operation of battery charge and discharge, a positive electrode material with self-catalytic active sites, i.e., a discharge product, can be repeatedly generated and decomposed on the positive electrode, and the catalytic active sites can be implanted in the discharge product for catalytic action; at the same time, the metal site doped into the discharge product has good control characteristics for the electronic structure of the discharge product itself, so that it changes from an insulator to a semiconductor or conductor, showing a certain metallic property, and essentially accelerates the positive electrode reaction kinetics; in addition, manganese acetylacetonate in molecular form can directly interact with superoxide, enhance its stability, and make it easier to disproportionately transform and generate lithium peroxide, reducing the occurrence of side reactions. The application of the additive in the present invention makes the electrolyte solution have good electrochemical properties, which plays a fundamental role in improving the performance of lithium oxygen batteries. The new method of the present invention is based on common commercial raw materials, optimizes the operating mechanism of the battery system through normal battery reactions, and the method is simple and easy to implement, the raw materials are cheap and easy to obtain, the performance is excellent, and it has good practical value and economic prospects.

Claims

1. An electrolyte for a lithium oxygen battery, characterized in that: The invention comprises the following components: an aprotic solvent, a solute of 0.5-2 mol / L lithium salt and 0.01-0.1 mol / L manganese acetylacetonate; the aprotic solvent comprises at least 50 vol% of dimethyl sulfoxide.

2. The electrolyte for lithium oxygen battery according to claim 1, characterized in that: The aprotic solvent is dimethyl sulfoxide or a mixed solvent of dimethyl sulfoxide and an organic solvent A, wherein the organic solvent A is selected from at least one of 1,3-dioxolane, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene carbonate, ethylene carbonate, N,N-dimethylacetamide, dimethylformamide, and ethyl methyl sulfone.

3. The electrolyte for lithium oxygen battery according to claim 2, characterized in that: The aprotic solvent is a mixed solvent of dimethyl sulfoxide and an organic solvent A in a volume ratio of 1-4:

1.

4. The electrolyte for lithium oxygen battery according to claim 1, characterized in that: The aprotic solvent is a mixed solvent of dimethyl sulfoxide and 1,3-dioxolane in a volume ratio of 2-4:

1.

5. The electrolyte for lithium oxygen battery according to claim 1, characterized in that: The lithium salt is selected from at least one of lithium trifluoromethanesulfonate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium nitrate.

6. An autocatalytic lithium oxygen battery, characterized in that: The invention comprises a lithium negative electrode, a positive electrode, a separator, and an electrolyte for a lithium-oxygen battery according to any one of claims 1 to 5.

7. The autocatalytic lithium oxygen battery according to claim 6, characterized in that: The positive electrode is carbon paper coated with KB and platinum carbon, and the separator is a glass fiber separator.

8. Use of manganese acetylacetonate as an additive for positive electrode electrolyte of an autocatalytic lithium oxygen battery, characterized in that: The lithium-oxygen battery positive electrode electrolyte contains 0.01-0.1 mol / L of manganese acetylacetonate, 0.5-2 mol / L of lithium salt, and an aprotic solvent, wherein the aprotic solvent contains at least 50 vol% of dimethyl sulfoxide.

9. The use according to claim 8, characterized in that The aprotic solvent is dimethyl sulfoxide or a mixed solvent of dimethyl sulfoxide and an organic solvent A, wherein the organic solvent A is selected from at least one of 1,3-dioxolane, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene carbonate, ethylene carbonate, N,N-dimethylacetamide, dimethylformamide, and ethyl methyl sulfone.

10. The use according to claim 8, characterized in that The aprotic solvent is a mixed solvent of dimethyl sulfoxide and 1,3-dioxolane in a volume ratio of 1-4:1.

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