Mixed positive electrode material based on lunar soil mineral components, preparation method of mixed positive electrode material and application of mixed positive electrode material in magnesium ion battery

Abstract

The invention discloses a mixed positive electrode material based on lunar soil mineral components and a preparation method thereof, the positive electrode material comprises a pyroxene simulant CaMgSi2O6, an olivine simulant Mg2SiO4, pyrite FeS2 and an additive graphite, and raw material powder is subjected to solid-phase mixing, low-temperature activation and compression molding to obtain the positive electrode material. The magnesium ion battery comprises an annealed magnesium sheet negative electrode, a glass fiber diaphragm, the positive electrode material and trace APC electrolyte which are sequentially stacked. The magnesium ion battery suitable for the lunar environment is prepared through in-situ utilization of lunar soil mineral resources and the method adaptive to the lunar in-situ low-energy-consumption scene, the problem that resources and energy of the lunar environment are deficient is solved, complex equipment such as smelting and electrolysis is not needed, and the magnesium ion battery has the advantage of extremely high cost.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical energy storage materials technology, and particularly relates to a hybrid cathode material based on lunar soil mineral composition, its preparation method, and its application in magnesium-ion batteries. Background Technology

[0002] With the continuous depletion of Earth's resources and increasing environmental pressure, the exploration and development of new living spaces for human use is attracting growing attention from various countries. The Moon, due to its unique geological structure and environmental conditions, has become the preferred candidate for developing extraterrestrial living spaces. To achieve long-term habitation on the Moon, efficient energy storage devices will be an essential key factor. However, bringing Earth's most advanced lithium-ion batteries to the Moon would incur substantial financial costs, and lithium-ion batteries are unlikely to meet the long-term, effective energy supply requirements for lunar survival.

[0003] The lunar regolith contains abundant resources, with pyroxene (containing Mg₂Si₂O₆), olivine (containing Mg₂SiO₄), and pyrite (containing FeS₂) comprising over 40% of the total composition. Among these lunar regolith mineral components, Mg… 2+ ion migration activity and Fe 2+ The high redox activity of lunar regolith provides a natural material basis for developing energy storage technologies based on in-situ resources and adapted to the extreme lunar environment. Therefore, in-situ resource utilization by directly converting lunar regolith minerals into functional materials is a crucial breakthrough for solving new energy storage technologies in the lunar environment. Current research on lunar regolith largely focuses on the synthesis and analysis of lunar regolith analogs, with very little research on using lunar regolith analogs to prepare energy storage devices. Therefore, in order to fully utilize the abundant resources in lunar regolith and achieve in-situ utilization of extraterrestrial resources, it is urgent to propose a hybrid cathode material based on lunar regolith mineral composition and its preparation method. This would allow for the manufacture of magnesium-ion batteries capable of extraterrestrial energy storage using in-situ lunar mineral resources and processes adapted to the low-energy consumption scenarios of the moon. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a hybrid cathode material based on lunar soil mineral composition and its preparation method. Through a simple preparation process, multiple minerals are utilized synergistically, thereby obtaining a magnesium-ion battery that balances electrochemical performance with adaptability to the lunar environment.

[0005] In a first aspect, the present invention discloses a mixed cathode material based on lunar regolith mineral composition, wherein the cathode material is a composition comprising pyroxene analog CaMgSi2O6, olivine analog Mg2SiO4, pyrite FeS2, and additive graphite, wherein the mass percentage of each component in the composition is as follows: Pyroxene simulant CaMgSi2O6 30~40%, 20-30% olivine simulant Mg2SiO4 Pyrite FeS2 30~40%, Additive: 5-10% graphite.

[0006] Secondly, this invention also discloses a method for preparing a mixed cathode material based on lunar regolith mineral composition, wherein the cathode material is the mixed cathode material based on lunar regolith mineral composition according to the first aspect of this invention, and the preparation method includes the following steps: S1. Raw material pretreatment Pyroxene and olivine analogs were ball-milled into powder, pyrite was crushed and ground into powder, and graphite was dried to remove water. S2. Solid-phase mixing Weigh the pretreated pyroxene, olivine, pyrite and graphite raw material powders according to the proportions and mix them thoroughly until they are evenly mixed. S3. Low-temperature activation The raw material powder after solid-phase mixing is placed in a vacuum drying oven for drying treatment to desorb the solvent, water vapor and trace impurities adsorbed on the surface of the raw material, while avoiding thermal decomposition of the raw material. S4. Electrode preparation The activated mixed raw materials and binder are added to N-methylpyrrolidone, stirred into a slurry, coated onto a titanium foil current collector, dried under vacuum, and then pressed into a positive electrode sheet.

[0007] Furthermore, the pyroxene and olivine analogs are ball-milled to a particle size of 5-10 μm.

[0008] Furthermore, the pyrite is crushed and ground into powder that passes through a 200-mesh sieve.

[0009] Furthermore, the graphite is dried to a moisture content of less than 0.5%.

[0010] Furthermore, the drying conditions for the low-temperature activation in step S3 are as follows: heat treatment at 100~140℃ for 2~4 hours.

[0011] Furthermore, the binder used in the preparation of the electrode sheet in step S4 is polyvinylidene fluoride, and the mass ratio of the mixed raw materials to the binder is 9:1.

[0012] Furthermore, the thickness of the positive electrode sheet is 50~80μm.

[0013] Thirdly, the present invention also discloses a magnesium-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte; the positive electrode is a mixed positive electrode material based on lunar soil mineral composition according to the first aspect of the present invention or a positive electrode material obtained by the method for preparing a mixed positive electrode material based on lunar soil mineral composition according to the second aspect of the present invention; the negative electrode is a magnesium sheet; the separator is a glass fiber membrane; and the electrolyte is tetrahydrofuran with a concentration of (MgPhCl)2-AlCl3 of 0.4 mol / L.

[0014] Furthermore, the negative electrode undergoes vacuum annealing to eliminate surface stress. The vacuum annealing process includes the following steps: heating the magnesium sheet to 130°C in a vacuum environment at a rate of 5°C / min, holding it at that temperature for 2 hours, and then cooling it to room temperature in the furnace.

[0015] This invention provides a hybrid cathode material based on lunar soil mineral composition, its preparation method, and its application in magnesium-ion batteries. Compared with the prior art, this invention has at least the following advantages: (1) This invention is the first to propose the preparation of magnesium-ion battery cathode materials by combining pyroxene, olivine, and pyrite in lunar soil proportions. By utilizing lunar soil mineral resources in situ, it not only solves the problem of raw material scarcity in the preparation of energy storage materials in the lunar environment, but also activates Mg 2+ with Fe 2+ / Fe 3+ The synergistic electrochemical activity enables a discharge specific capacity of >120 mAh / g (1 A / g current density), and the capacity retention rate after 50 cycles at both 1 A / g and 2 A / g current densities is ≥60%.

[0016] (2) This invention not only utilizes lunar soil to simulate minerals in the raw material components of the cathode material, but also takes into account the distribution of natural resources on the moon to the greatest extent in the selection of cathode current collector materials and separator materials, effectively improving the resource simulation utilization rate of magnesium ion batteries.

[0017] (3) The preparation process of the positive electrode material and the processing process of the negative electrode of the present invention adopt room temperature mixing and low temperature activation (≤150℃) and slow heating and low temperature heating throughout the process. There is no need for complex equipment such as smelting and electrolysis. Compared with the traditional high temperature process, the energy consumption required for preparation is greatly reduced. The preparation process is restored as much as possible to the real environment of the moon. It is not only suitable for the low energy consumption scenario in the moon, but can also be quickly implemented in the Earth laboratory or small and medium-sized production scenario.

[0018] (4) The magnesium-ion battery preparation process of the present invention is short and the equipment investment is low. The unit cost can be further reduced when it is mass-produced. It can not only support the scientific research and verification of lunar in-situ energy storage technology, but also has strong cost competitiveness in practical application scenarios such as low-power energy storage on Earth, such as microgrids in remote areas and emergency power supply equipment. Its cost advantage is extremely significant. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The image shows the SEM image of the cathode material prepared in Example 1.

[0021] Figure 2 The EDS spectrum of the cathode material prepared in Example 1 is shown.

[0022] Figure 3 The image shows the AC impedance spectroscopy (EIS) curve of the magnesium-ion battery in Example 1.

[0023] Figure 4 This is the first discharge curve of the magnesium-ion battery in Example 1 at a current density of 1 A / g.

[0024] Figure 5 This is the first discharge curve of the magnesium-ion battery in Example 1 at a current density of 2 A / g.

[0025] Figure 6 This is a cyclic voltammetry (CV) curve of the magnesium-ion battery in Example 1. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] Unless otherwise specified, all temperatures mentioned herein are in degrees Celsius, and the preferred embodiments can be freely combined as needed. Those skilled in the art will understand that the data and parameters described in the examples are merely exemplary and do not constitute a limitation of the invention. All components used in the following examples and comparative examples are compounds known in the art, and all equipment used is equipment publicly known in the art. All components and equipment used in this invention can be obtained commercially or prepared using known techniques.

[0028] This invention provides a hybrid cathode material based on lunar soil mineral composition. The cathode material is a composition comprising pyroxene mimic CaMgSi2O6, olivine mimic Mg2SiO4, pyrite FeS2, and graphite as an additive. The pyroxene mimic CaMgSi2O6 and olivine mimic Mg2SiO4 can serve as the Mg content of the cathode in magnesium-ion batteries. 2+ The cathode material provides a substrate and enhances the ion conductivity of the electrode. The pyrite phase FeS2 provides electrochemical active sites for the positive electrode reaction, and the additive graphite, as a carbon powder mimic extracted from lunar soil, helps improve the conductivity of the positive electrode material. In this invention, the components of the positive electrode material composition are compounded according to the proportion of lunar soil, and the preferred mass ratio of each component is: Pyroxene simulant CaMgSi2O6 30~40%, 20-30% olivine simulant Mg2SiO4 Pyrite FeS2 30~40%, Additive: 5-10% graphite.

[0029] This invention also provides a method for preparing a mixed cathode material based on lunar regolith mineral composition, wherein the cathode material is the mixed cathode material based on lunar regolith mineral composition of this invention, and the preparation method includes the following steps: S1. Raw material pretreatment Pyroxene and olivine analogs were ball-milled into powder, pyrite was crushed and ground into powder, and graphite was dried to remove water. The pyroxene and olivine analogs are ball-milled to a particle size of 5-10 μm. The ball-milling conditions are related to the amount of pyroxene and olivine analogs used, and usually ball-milling at 300 r / min for 2 hours is sufficient.

[0030] In this invention, pyrite is preferably crushed and ground into powder that can pass through a 200-mesh sieve to ensure that the pyrite powder particle size is ≤75μm. The graphite in this invention is preferably dried to a moisture content of <0.5 wt%.

[0031] S2. Solid-phase mixing Weigh the pretreated raw material powder according to the proportions of pyroxene, olivine, pyrite, and graphite, and add it to a polytetrafluoroethylene beaker. Stir thoroughly until the mixture is homogeneous. To simulate the mechanical mixing scenario under low gravity on the moon, a planetary mixer can be used for stirring. The preferred stirring conditions are 200 r / min for 30 min, with manual scraping of the wall every 10 min to ensure homogeneous mixing.

[0032] S3. Low-temperature activation The raw material powder after solid-phase mixing is placed in a vacuum drying oven and activated at low temperature to simulate the high vacuum-sunlight temperature characteristics of the lunar surface. The vacuum degree is controlled to be ≤10Pa to match the high vacuum environment of the lunar surface. The temperature is kept at 100~140℃ for 2~4h. This temperature range is close to the actual temperature of the lunar daytime sunlight area and is much lower than the thermal decomposition temperature of pyroxene CaMgSi2O6, olivine Mg2SiO4 and pyrite FeS2, thereby desorbing the solvent, water vapor and trace impurities adsorbed on the surface of the raw material.

[0033] S4. Electrode preparation The activated mixed raw materials and binder are added to N-methylpyrrolidone, stirred into a slurry, coated onto a titanium foil current collector, dried under vacuum, and pressed into a positive electrode sheet; In this invention, polyvinylidene fluoride (PVDF) is preferably used as the binder, and the mass ratio of the mixed raw materials to the binder is 9:1. Titanium foil current collectors are selected to simulate Ti-based materials extracted in situ from the moon. The vacuum drying process is preferably performed at 80°C for 8 hours. The pressing pressure is preferably 5 MPa, ultimately pressing the material into a positive electrode sheet with a thickness of 50-80 μm.

[0034] This invention also provides a magnesium-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte; the positive electrode is a mixed positive electrode material based on lunar soil mineral composition according to this invention, or a positive electrode material obtained by the method for preparing a mixed positive electrode material based on lunar soil mineral composition according to this invention. The negative electrode of this invention is preferably a magnesium sheet. The separator of this invention is preferably a glass fiber membrane, the main component of which can be derived from SiO2-based materials found in lunar soil.

[0035] The electrolyte of this invention uses APC electrolyte, namely tetrahydrofuran (100 vol%) with a (MgPhCl)2-AlCl3 concentration of 0.4 mol / L. This invention uses a very small amount of electrolyte; only tens of microliters are needed for a single assembly to meet basic electrochemical performance requirements. Compared to traditional batteries, this significantly reduces the amount of electrolyte used, thereby significantly reducing the cost of transporting the electrolyte from Earth and further adapting it to the practical needs of in-situ extraterrestrial applications.

[0036] The Mg anode of this invention preferably undergoes vacuum annealing to eliminate surface stress, and this treatment is carried out in a vacuum tube furnace. This vacuum annealing aims to simulate stress elimination under the in-situ vacuum conditions of the moon. During the lunar day, the temperature can reach 100~140℃ through solar heating. This natural temperature provides natural conditions for the low-temperature stress relaxation of the Mg sheet. The vacuum degree is set to ≤10Pa to match the vacuum environment on the lunar surface.

[0037] The vacuum annealing process of this invention includes the following steps: (1) Heating process Magnesium sheets were placed in an environment with a vacuum degree of ≤10Pa and heated to 130℃ at a rate of 5℃ / min to simulate the slow heating process of solar energy during lunar day. This temperature range can prevent the crystal structure of magnesium sheets from being damaged by high temperature. (2) Insulation stage By holding the temperature at 130℃ for 2 hours, the residual stress on the surface generated by the etching of magnesium sheet can be eliminated by physical means, and the original oxide layer (MgO) on the surface of magnesium sheet can be reconstructed into a dense thin layer (thickness ≤5nm), thereby inhibiting the oxidation reaction in the subsequent vacuum environment. (3) Cooling process After the heat preservation is completed, the magnesium sheet is naturally cooled to room temperature in the furnace to simulate the slow cooling process at night on the moon, so as to avoid excessive temperature difference that may cause grain boundary cracking. No new phase is generated on the surface of the magnesium sheet after annealing.

[0038] The assembly process of the magnesium-ion battery of this invention includes: simulating the inert environment of the moon, stacking the magnesium anode, glass fiber membrane separator, and positive electrode in the order of "annealed magnesium anode → glass fiber membrane separator → positive electrode" in an argon-filled glove box, adding 30-50 μL of electrolyte with a pipette, and then encapsulating to obtain the magnesium-ion battery. The battery encapsulation process does not require laser welding or chemical sealing.

[0039] The present invention will now be described in more detail with reference to exemplary embodiments. The following embodiments or experimental data are intended to illustrate the present invention by way of example, and those skilled in the art should understand that the present invention is not limited to these embodiments or experimental data.

[0040] Preparation of hybrid cathode materials based on lunar soil mineral composition Example 1 of cathode material preparation The preparation of a hybrid cathode material based on lunar soil mineral composition includes the following steps: S1. Raw material pretreatment Pyroxene analog CaMgSi2O6 and olivine analog Mg2SiO4 were ball-milled in an agate ball mill jar at 300 r / min for 2 h to obtain powders with a particle size of 5-10 μm. Pyrite FeS2 was crushed and ground into powder that could pass through a 200-mesh sieve. Graphite was dried to a moisture content of 0.4 wt%. S2. Solid-phase mixing Weigh out the raw material powders as follows: 35g of pyroxene analog, 24g of olivine analog, 34g of pyrite, and 7g of carbon powder. Add them to a polytetrafluoroethylene beaker and stir using a planetary mixer at 200r / min for 30min. During this period, manually scrape the wall once every 10min to ensure uniform mixing. S3. Low-temperature activation The raw material powder after solid-phase mixing was placed in a vacuum drying oven with a vacuum degree ≤10Pa for drying, and the drying conditions were 140℃ for 2 hours. S4. Electrode preparation 90g of activated mixed raw material powder and 10g of polyvinylidene fluoride binder were added to N-methylpyrrolidone, stirred into a slurry, and then coated onto a titanium foil current collector. After vacuum drying at 80℃ for 8h, the positive electrode sheet with a thickness of 70μm was obtained by pressing at 5MPa.

[0041] Figure 1 The image shown is an SEM image of the cathode material prepared in this example. It can be seen that the cathode material of the present invention has a regular particle morphology, uniform size distribution, and exhibits a dense and continuous overall structure. This uniform structure helps to improve the continuity of electron / ion transport inside the material, providing a stable microscopic basis for subsequent electrochemical performance. Figure 2 The image shows the elemental distribution spectrum of the cathode material prepared in this example, obtained by EDS, demonstrating the high uniformity of the material composition. Spatial distribution analysis of key elements such as Fe and Mg shows that the signals of each element exhibit a continuous, uniform, and highly consistent distribution throughout the entire particle region, with no obvious enrichment or depletion areas observed.

[0042] Example 2 of cathode material preparation The preparation of a hybrid cathode material based on lunar soil mineral composition includes the following steps: S1. Raw material pretreatment Pyroxene analog CaMgSi2O6 and olivine analog Mg2SiO4 were ball-milled in an agate ball mill jar at 300 r / min for 2 h to obtain powders with a particle size of 5-10 μm. Pyrite FeS2 was crushed and ground into powder that could pass through a 200-mesh sieve. Graphite was dried to a moisture content of 0.4 wt%. S2. Solid-phase mixing Weigh out 30g of pyroxene analog, 30g of olivine analog, 30g of pyrite, and 10g of carbon powder, add them to a polytetrafluoroethylene beaker, and stir using a planetary mixer at 200r / min for 30min. During this period, manually scrape the wall once every 10min to ensure uniform mixing. S3. Low-temperature activation The raw material powder after solid-phase mixing was placed in a vacuum drying oven with a vacuum degree ≤10Pa for drying, and the drying conditions were 130℃ for 2 hours. S4. Electrode preparation 99g of activated mixed raw material powder and 11g of polyvinylidene fluoride binder were added to N-methylpyrrolidone, stirred into a slurry, and then coated onto a titanium foil current collector. After vacuum drying at 80℃ for 8h, the positive electrode sheet with a thickness of 75μm was obtained by pressing at 5MPa.

[0043] Example 3 of cathode material preparation The preparation of a hybrid cathode material based on lunar soil mineral composition includes the following steps: S1. Raw material pretreatment Pyroxene analog CaMgSi2O6 and olivine analog Mg2SiO4 were ball-milled in an agate ball mill jar at 300 r / min for 2 h to obtain powders with a particle size of 5-10 μm. Pyrite FeS2 was crushed and ground into powder that could pass through a 200-mesh sieve. Graphite was dried to a moisture content of 0.4 wt%. S2. Solid-phase mixing Weigh out the raw material powders as follows: 40g of pyroxene analog, 20g of olivine analog, 35g of pyrite and 5g of carbon powder. Add them to a polytetrafluoroethylene beaker and stir using a planetary mixer at 200r / min for 30min. During the stirring process, manually scrape the wall every 10min to ensure uniform mixing. S3. Low-temperature activation The raw material powder after solid-phase mixing was placed in a vacuum drying oven with a vacuum degree ≤10Pa for drying, and the drying conditions were 120℃ for 3 hours. S4. Electrode preparation 81g of activated mixed raw material powder and 9g of polyvinylidene fluoride binder were added to N-methylpyrrolidone, stirred into a slurry, coated onto a titanium foil current collector, vacuum dried at 60℃ for 8h, and then pressed into a positive electrode sheet with a thickness of 65μm at 5MPa.

[0044] Example 4 of cathode material preparation The preparation of a hybrid cathode material based on lunar soil mineral composition includes the following steps: S1. Raw material pretreatment Pyroxene analog CaMgSi2O6 and olivine analog Mg2SiO4 were ball-milled in an agate ball mill jar at 300 r / min for 2 h to obtain powders with a particle size of 5-10 μm. Pyrite FeS2 was crushed and ground into powder that could pass through a 200-mesh sieve. Graphite was dried to a moisture content of 0.4 wt%. S2. Solid-phase mixing Weigh out the raw material powders as follows: 30g of pyroxene analog, 20g of olivine analog, 40g of pyrite and 10g of carbon powder. Add them to a polytetrafluoroethylene beaker and stir using a planetary mixer at 200r / min for 30min. During the stirring process, manually scrape the wall every 10min to ensure uniform mixing. S3. Low-temperature activation The raw material powder after solid-phase mixing was placed in a vacuum drying oven with a vacuum degree ≤10Pa for drying, and the drying conditions were 100℃ for 4 hours. S4. Electrode preparation 54g of activated mixed raw material powder and 6g of polyvinylidene fluoride binder were added to N-methylpyrrolidone, stirred into a slurry, coated onto a titanium foil current collector, vacuum dried at 60℃ for 8h, and then pressed into a positive electrode sheet with a thickness of 50μm at 5MPa.

[0045] Vacuum low-temperature annealing of anode materials Example 1 of anode material preparation Vacuum low-temperature annealing of the negative electrode includes the following steps: Magnesium sheets of a certain size are placed in a vacuum drying oven with a vacuum degree ≤10Pa and slowly heated to 130℃ at a rate of 5℃ / min. After reaching 130℃, the temperature is held for 2 hours and then naturally cooled to room temperature to obtain annealed magnesium sheets.

[0046] Example 2 of anode material preparation Vacuum low-temperature annealing of the negative electrode includes the following steps: Magnesium sheets of a certain size are placed in a vacuum drying oven with a vacuum degree ≤10Pa and slowly heated to 120℃ at a rate of 5℃ / min. After reaching 120℃, the temperature is held for 2 hours and then naturally cooled to room temperature to obtain annealed magnesium sheets.

[0047] Example 3 of anode material preparation Vacuum low-temperature annealing of the negative electrode includes the following steps: Magnesium sheets of a certain size are placed in a vacuum drying oven with a vacuum degree ≤10Pa and slowly heated to 140℃ at a rate of 5℃ / min. After reaching 140℃, the temperature is held for 2 hours and then naturally cooled to room temperature to obtain annealed magnesium sheets.

[0048] Magnesium-ion battery assembly and performance testing Example 1 In an argon-filled glove box, the negative electrode sheet, glass fiber membrane separator, and positive electrode sheet of Preparation Example 1 were stacked in sequence. 40 μL of APC electrolyte, which was a tetrahydrofuran (100 vol%) electrolyte with a concentration of (MgPhCl)2-AlCl3 of 0.4 mol / L, was added dropwise using a pipette. After encapsulation, a magnesium-ion battery was obtained.

[0049] Example 2 In an argon-filled glove box, the negative electrode sheet, glass fiber membrane separator, and positive electrode sheet of Preparation Example 2 were stacked in sequence. 40 μL of APC electrolyte, which was a tetrahydrofuran (100 vol%) electrolyte with a concentration of (MgPhCl)2-AlCl3 of 0.4 mol / L, was added dropwise using a pipette. After encapsulation, a magnesium-ion battery was obtained.

[0050] Example 3 In an argon-filled glove box, the negative electrode sheet, glass fiber membrane separator, and positive electrode sheet of Preparation Example 3 were stacked in sequence. 40 μL of APC electrolyte, which was a tetrahydrofuran (100 vol%) electrolyte with a concentration of (MgPhCl)2-AlCl3 of 0.4 mol / L, was added dropwise using a pipette. After encapsulation, a magnesium-ion battery was obtained.

[0051] Example 4 In an argon-filled glove box, the negative electrode sheet of Preparation Example 1, the glass fiber membrane separator, and the positive electrode sheet of Preparation Example 4 were stacked in sequence. 40 μL of APC electrolyte was added dropwise using a pipette, and the mixture was then encapsulated to obtain a magnesium-ion battery.

[0052] The specific capacity of the magnesium-ion batteries in Examples 1-4 during the first discharge was measured at current densities of 1 A / g and 2 A / g. The capacity retention rate of the magnesium-ion batteries in Examples 1-4 after 50 cycles at current densities of 1 A / g and 2 A / g was also measured. The test results are shown in Table 1.

[0053] Table 1. Test results of electrical performance of magnesium-ion batteries

[0054] Performance test results analysis As shown in Table 1, the magnesium ion batteries of Examples 1-4 of the present invention can achieve a discharge specific capacity of about 130 mAh / g at a current density of 1 A / g, and the capacity retention rate after 50 cycles at current densities of 1 A / g and 2 A / g is >60%. Figure 3 The electrochemical impedance spectroscopy (EIS) spectrum of the magnesium-ion battery in Example 1 of the present invention shows that its charge transfer impedance is low and its interface impedance is stable, indicating that the material has excellent ion transport capability and a high magnesium ion diffusion coefficient. Figure 4 and Figure 5 The figures show the first discharge curves of the magnesium-ion battery in Example 1 of this invention at current densities of 1 A / g and 2 A / g, respectively. The first discharge specific capacities reached 133.37 mAh / g and 105.28 mAh / g, respectively, demonstrating that this material still has excellent capacity retention and fast dynamic response even under high current density conditions. Figure 6 The figure shown is the cyclic voltammogram (CV) of the magnesium-ion battery in Example 1. Figure 6The redox process exhibits good repeatability, reflecting the system's reversible magnesium ion intercalation / deintercalation behavior and relatively stable electrochemical reaction kinetics. Therefore, the cathode material and preparation method of this invention are well-suited to in-situ lunar mineral resources and low-energy consumption scenarios on the moon. Although the electrochemical performance of the magnesium-ion battery prepared in this way needs further improvement, considering the significant advantages of low raw material cost and low process energy consumption, it has basically met the energy support requirements for future lunar exploration. The cathode material, its preparation method, and its application in magnesium-ion batteries are of great significance and scientific research value for exploring and utilizing extraterrestrial resources. Furthermore, this invention requires only tens of microliters of electrolyte per assembly to meet basic electrochemical performance requirements. Compared to the electrolyte usage of traditional batteries, this significantly reduces the transportation cost of electrolyte between Earth and the Moon, making the magnesium-ion battery of this invention even more suitable for in-situ extraterrestrial applications.

[0055] All materials used in this invention are commercially available and can be purchased from retail sources. The above description is merely a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A hybrid cathode material based on lunar soil mineral composition, characterized in that, The cathode material is a composition comprising pyroxene analog CaMgSi2O6, olivine analog Mg2SiO4, pyrite FeS2, and graphite additive, wherein the mass percentage of each component in the composition is as follows: Pyroxene simulant CaMgSi2O6 30~40%, 20-30% olivine simulant Mg2SiO4 Pyrite FeS2 30~40%, Additive: 5-10% graphite.

2. A method for preparing a mixed cathode material based on lunar soil mineral composition, characterized in that, The cathode material is the hybrid cathode material based on lunar regolith mineral composition as described in claim 1, and the preparation method includes the following steps: S1. Raw material pretreatment Pyroxene and olivine analogs were ball-milled into powder, pyrite was crushed and ground into powder, and graphite was dried to remove water. S2. Solid-phase mixing Weigh the pretreated pyroxene, olivine, pyrite and graphite raw material powders according to the proportions and mix them thoroughly until they are evenly mixed. S3. Low-temperature activation The raw material powder after solid-phase mixing is placed in a vacuum drying oven for drying treatment to desorb the solvent, water vapor and trace impurities adsorbed on the surface of the raw material, while avoiding thermal decomposition of the raw material. S4. Electrode preparation The activated mixed raw materials and binder are added to N-methylpyrrolidone, stirred into a slurry, coated onto a titanium foil current collector, dried under vacuum, and then pressed into a positive electrode sheet.

3. The method for preparing a mixed cathode material based on lunar soil mineral composition according to claim 2, characterized in that, The pyroxene and olivine analogs were ball-milled to a particle size of 5-10 μm.

4. The method for preparing a mixed cathode material based on lunar soil mineral composition according to claim 2, characterized in that, The pyrite is crushed and ground into powder that passes through a 200-mesh sieve.

5. The method for preparing a mixed cathode material based on lunar soil mineral composition according to claim 2, characterized in that, The drying conditions for the low-temperature activation in step S3 are: maintaining the temperature at 100~140℃ for 2~4 hours.

6. The method for preparing a mixed cathode material based on lunar soil mineral composition according to claim 2, characterized in that, The binder used in step S4, electrode sheet preparation, is polyvinylidene fluoride, and the mass ratio of the mixed raw materials to the binder is 9:

1.

7. The method for preparing a mixed cathode material based on lunar soil mineral composition according to claim 2, characterized in that, The thickness of the positive electrode is 50~80μm.

8. A magnesium-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte, characterized in that, The positive electrode is a mixed positive electrode material based on lunar soil mineral composition as described in claim 1 or a positive electrode material obtained by the preparation method of mixed positive electrode material based on lunar soil mineral composition as described in any one of claims 2-7; the negative electrode is a magnesium sheet; the separator is a glass fiber membrane; and the electrolyte is tetrahydrofuran with a concentration of (MgPhCl)2-AlCl3 of 0.4 mol / L.

9. The magnesium-ion battery according to claim 8, characterized in that, The negative electrode undergoes vacuum annealing to eliminate surface stress; the vacuum annealing process includes the following steps: heating the magnesium sheet to 130°C in a vacuum environment at a rate of 5°C / min, holding it at that temperature for 2 hours, and then cooling it to room temperature in the furnace.

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