37 results about "Sodium manganate" patented technology

The invention aims to provide a composite carbon negative electrode material prepared from dextrin-asphalt and a sodium ion total battery in order to further improve the electrochemical performance of an asphalt-based carbon material. According to the composite carbon negative electrode material prepared from dextrin-asphalt, dextrin and asphalt are used as reaction raw materials, reactants are mixed, and the carbon negative electrode material is obtained through the processes of high-pressure heat treatment and high-temperature carbonization in sequence. The sodium ion total battery provided by the invention is a sodium ion total battery Na-PDTCNFM composed of a Na-PDTC negative electrode, a nickel iron sodium manganate NFM positive electrode, an electrolyte and a diaphragm. The composite carbon negative electrode material PDTC is low in raw material cost and simple in preparation method, has rich oxygen-containing functional groups and good stability and conductivity, and is matched with a conventional positive electrode material sodium nickel iron manganese oxide NFM to obtain high-energy and long-cycle-life SIBs.

The invention discloses a preparation method of a metal-doped manganese dioxide aqueous zinc ion battery positive electrode material, which comprises the following steps of: preparing a solution from any one of potassium permanganate, potassium manganate, sodium permanganate and sodium manganate, and recording the solution as a solution A; preparing a solution from any one of oxalic acid, citric acid, formic acid, acetic acid, sodium hydrogen sulfite and phosphorous acid, and recording the solution as a solution B; 2-10 ml of the solution B and aluminum salt are weighed and added into the solution A, ultrasonic dispersion is carried out, stirring is carried out for 20-120 min, and a mixed solution is obtained; and transferring the mixed solution into a polytetrafluoroethylene high-pressure reaction kettle, putting the polytetrafluoroethylene high-pressure reaction kettle into a drying oven at 120-180 DEG C, carrying out heating reaction for 10-24 hours, naturally cooling to room temperature, washing the reactant with water and ethanol, centrifuging, and carrying out vacuum drying to obtain the aluminum-doped delta-MnO2 positive electrode material. The positive electrode material is applied to the field of aqueous zinc ion batteries, the specific capacity of the battery positive electrode is extremely high, the battery positive electrode has very excellent cycling stability and high-rate charge-discharge characteristics, and raw materials used for synthesis are non-toxic and low in price.

The present invention provides a preparation method of a structure-modified sodium ion battery positive electrode material, comprising the following steps: S1, mixing a sodium source, an iron source, a phosphorus source, a first carbon source, a structure modifier, and deionized water, adding the mixture to a high-gravity reactor rotating at 25,000 to 35,000 rpm, reacting at a temperature of 80 to 100° C. for 1 to 2 h, drying, and then calcining at 400 to 650° C. for 8 to 12 h in an inert gas atmosphere to obtain a precursor, wherein the structure modifier is at least one of sodium vanadate, sodium titanate, sodium manganate, sodium cobaltate, sodium chromate, metatitanic acid, magnesium oxide, copper oxide, zinc oxide, and yttrium oxide; S2, mixing the precursor, a second carbon source, and a chelate solution, adjusting the pH to 2.5 to 4.0, grinding the mixture at a temperature of 60 to 90° C. until the D50 is less than 0.95 μm, spray drying, and calcining at 400 to 650° C. for 8 to 12 h in an inert gas atmosphere. h obtain the structure-modified sodium ion battery positive electrode material.

The invention belongs to the field of electrochemical energy storage, and particularly relates to a sodium ion battery. Based on the problem of low energy density of the sodium ion battery, the invention combines the advantages of low cost of the sodium ion battery and high energy density of the lithium ion battery, and designs and realizes the sodium-lithium mixed ion battery with high energy density and low cost. The battery is composed of a positive plate, a negative plate, an electrolyte and a diaphragm, a positive active material simultaneously contains sodium manganate and lithium cobalt oxide, and a negative active material simultaneously contains hard carbon (or soft carbon) and yttrium lithium titanate, so that sodium ions and a small amount of lithium ions can be simultaneously transmitted in the charging and discharging processes of the battery, and the energy density is improved compared with that of a sodium ion battery; compared with a traditional lithium ion battery, the cost is reduced, and the long cycle life is achieved.

The invention relates to the technical field of sodium ion battery positive electrode materials, in particular to a boron-modified O3-phase sodium ferro-nickel manganate layered oxide positive electrode material and a preparation method and application thereof. The chemical general formula of the boron-modified O3-phase sodium ferronickel manganate layered oxide positive electrode material is NaNi1 / 3Mn1 / 3Fe1 / 3BxO2, x is greater than 0 and less than or equal to 0.2, and the boron-modified O3-phase sodium ferronickel manganate layered oxide positive electrode material is prepared by taking Na2B4O7. 10H2O as a boron source and co-sintering the boron source, Ni1 / 3Mn1 / 3Fe1 / 3 (OH) 2 precursor and Na2CO3 at high temperature, so that a composite structure of boron element doping and a NaBO2 surface coating layer is formed. Through a strategy of combining element doping and compound surface modification, a series of problems faced by the sodium ion positive electrode material are effectively solved, the electrochemical performance of the material is remarkably improved, and particularly, the performance is excellent in the aspects of cycling stability and capacity retention rate.

The preparation method comprises the following steps: mixing a sodium source, a manganese source, a metal ion source and a carbon source according to a chemical molar ratio of Na < 0.44 > M < x > Mn < 1-x > O < 2 > / C (x is greater than or equal to 0.1 and greater than or equal to 0.3), then mixing the mixture with binder powder at a high speed, and granulating the mixed material to obtain the metal ion doped sodium manganate and carbon composite aqueous sodium ion battery positive electrode material. The preparation method comprises the following steps: preparing a small spherical sodium manganate positive electrode material precursor for a water-based sodium-ion battery, tabletting, calcining at high temperature, and crushing to prepare the metal ion doped sodium manganate and carbon composite water-based sodium-ion battery positive electrode material. The battery is a button battery assembled by a sodium sheet and a sodium manganate and carbon composite aqueous sodium ion battery positive electrode material doped with metal ions and an aqueous sodium ion total battery assembled by an active carbon pole piece, and has relatively good cycle stability.

The invention discloses a sodium manganate positive electrode material with an interlayer stacking structure as well as a preparation method and application of the sodium manganate positive electrode material. The sodium manganate positive electrode material has an ABB 'C' ABB 'C' type oxygen layer stacking sequence, Mg < 2 + > ions specifically occupy twisted triangular prism sites in an alkali metal sodium layer, and P type and O type NaO6 coordination polyhedrons exist in a crystal structure of the material at the same time. Through a composite three-step synthesis process of'sol-gel-solvothermal-solid phase method ', the thermodynamic tendency that conventional magnesium ions occupy a transition metal layer is effectively broken, and synergistic distortion of prismatic interstitial sites is realized, so that a brand new symmetric structure different from a traditional P phase and a traditional O phase is constructed. According to the positive electrode material disclosed by the invention, unfavorable phase transformation in the charging and discharging process is remarkably relieved through a special lattice stacking structure, the positive electrode material has high capacity and long cycle life, and a new thought is provided for the design of a high-energy-density sodium or potassium ion battery.

The invention provides a multiphase composite sodium manganate-based material as well as a preparation method and application thereof. The multiphase composite sodium manganate-based material comprises a P2 phase, an alpha-NaMnO2 phase and a beta-NaMnO2 phase, wherein the mass fraction of the P2 phase is more than 55 wt%. On one hand, the alpha-NaMnO2 phase and the beta-NaMnO2 phase can play a role of a sodium supplementing agent, and the defect that the P2 phase is low in capacity is overcome; and on the other hand, the P2 phase, the alpha-NaMnO2 phase and the beta-NaMnO2 phase coexist in the same crystal lattice, so that the entropy value of the positive electrode material can be improved, and more phase changes of a sodium manganate system can be fully inhibited, thereby realizing higher multiplying power and cycle performance. The sodium ion battery prepared by taking the multi-phase composite sodium manganate-based material as a positive electrode active material has excellent capacity, rate capability and cycle performance.

The application relates to the technical field of sodium ion batteries, in particular to a sodium ion positive electrode material, a preparation method thereof and a sodium ion positive electrode sheet, wherein the sodium ion positive electrode material comprises a sodium nickel-iron-manganese acid base and an organic conductive coating, the organic conductive coating is coated on the sodium nickel-iron-manganese acid base, and the organic conductive coating comprises polyacrylonitrile and a conductive agent. The sodium ion positive electrode material of the application is coated with an organic conductive coating on the surface of the sodium nickel-iron-manganese acid material, the organic conductive coating comprises polyacrylonitrile and a conductive agent, the polyacrylonitrile can effectively prevent chemical reaction between the positive electrode material and an aluminum foil, the conductive agent connects the positive electrode material and the aluminum foil, and the resistance of the positive electrode sheet is reduced. Compared with the positive electrode material coated with aluminum oxide, the compaction density of the sodium ion positive electrode sheet prepared from the sodium ion positive electrode material of the application is increased by 0.1 g / cm 3 -0.2 g / cm 3 , the capacity of the prepared sodium ion battery is increased by 14%-25%, and the cycle life is increased by 40%-80%.

This invention discloses a photothermal synergistic phase change composite thin film based on a heterostructure and its preparation method, belonging to the technical field of nanomaterials and composite phase change materials. The composite thin film includes a heterostructured photothermal carrier film and a phase change material confined and loaded thereon. The heterostructured photothermal carrier film uses manganese oxide coated with a carbon layer as a framework, with heterostructured functional units composed of metal particles constructed in situ on its surface. Sodium manganate, as a precursor film for the heterostructure construction, is modified with a metal-organic coordination structure and derivatized in an inert atmosphere to form a heterostructure interface on its surface where the carbon layer and metal particles are coupled in situ, further confining and loading the phase change material. The carbon layer and metal particles form a tightly contacted interface structure on the manganese oxide surface, which enhances light absorption and regulates heat conduction behavior under illumination, thereby achieving efficient conversion of light energy into heat energy and synergistically completing the storage and release of heat energy with the phase change material. This invention effectively improves the photothermal conversion efficiency and thermal energy utilization performance of composite films by constructing a heterogeneous structure interface coupling carbon layers and metal particles. The resulting composite film has rapid heating, stable heat storage and good cycle stability, and has good application prospects in the fields of solar thermal storage and thermal management.

The present invention discloses a coated lithium manganese oxide cathode material and a preparation method thereof, belonging to the technical field of lithium ion batteries. The preparation method first obtains a primary sintered material by using a lithium compound, a manganese compound and a doping compound containing a doping element, wherein the molar ratio of lithium, manganese and the doping element is a: 2 - b: b, 1 ≤ a ≤ 1.2, 0 < b ≤ 0.1; then the primary sintered material is subjected to surface coating treatment with a sodium compound to obtain a coated product, wherein the ratio of the sodium compound to the primary sintered material makes the molar ratio of sodium to manganese be c: 2 - b - c, 0 < c ≤ 0.1; and then the coated product is sintered and post-treated in sequence to obtain the coated lithium manganese oxide cathode material, and its particle surface has a sodium manganate coating layer. By forming a sodium manganate Na2MnO3 coating layer on the surface of the lithium manganese oxide cathode material particles, the present invention can significantly improve the conductivity and structural stability of the lithium manganese oxide structure, and further improve the rate performance and cycle performance of the cathode material.

A titanium-cobalt co-doped sodium manganate-based cathode material, its preparation method, and its application, relating to the field of sodium-ion battery technology, wherein the general structural formula of the titanium-cobalt co-doped sodium manganate-based cathode material is Na. 0.44 Mn 0.95 Co x Ti 0.05‑x O2, wherein titanium and cobalt are both doped at manganese sites and the sum of the molar fractions of titanium and cobalt is 0.05, and x is the molar fraction of cobalt doped at manganese sites, 0 < x ≤ 0.03. This invention constructs a stable doping system by synergistically introducing titanium and cobalt elements into the transition metal sites of sodium manganate cathode material without disrupting the main crystal lattice structure, inducing the formation of a sodium vacancy environment conducive to sodium ion migration, thereby improving the overall structural stability of the material.

The invention discloses a sodium ion battery capable of improving rapid charging performance, performance breakthrough is realized through common optimization design of multiple components of positive and negative electrode materials, a diaphragm and electrolyte, and the positive electrode material is composed of sodium nickel iron manganese oxide, polyvinylidene fluoride, conductive carbon black and carbon nanotubes; a negative electrode material adopts a hard carbon material matched with a conductive agent and a composite binder, and the binder comprises sodium carboxymethyl cellulose, 3-(5-(2-nitrophenyl)-2-furan) acrylic acid and 4-(hydroxymethyl) phenylboronic acid pinacol ester; the diaphragm is a ceramic coating polyvinyl base membrane, the electrolyte takes sodium hexafluorophosphate as an electrolyte and is matched with an electrolyte additive and a composite solvent, and the electrolyte additive comprises three to five of sodium bis (fluorosulfonyl) imide, sodium difluorophosphate, sodium difluoro (oxalato) borate, ethylene sulfate, fluoroethylene carbonate and ethylene sulfite. The composite solvent comprises methyl ethyl carbonate, propylene carbonate and diethyl carbonate.

The invention relates to a sodium-ion battery layered transition metal oxide positive electrode material and a preparation method and application thereof, and belongs to the technical field of battery materials. The method comprises the following steps: mixing and grinding an NFM hydroxide precursor and a sodium source according to a mass ratio of greater than 1.5 to form slurry; evaporating and crystallizing the slurry at 60 DEG C or above to obtain a precursor; pre-sintering the precursor for more than 1 hour at the temperature of more than 450 DEG C, then calcining for more than 10 hours at the temperature of more than 800 DEG C, and naturally cooling to obtain a black positive electrode material; crushing the material into small particles with the maximum particle diameter of not more than 10mm; and finally, carrying out jet milling and grinding to obtain the micron-sized sodium ferro-nickel manganate positive electrode material with the maximum particle diameter of not more than 10 [mu] m. The preparation of the high-performance layered transition metal oxide positive electrode material of the sodium-ion battery is realized through a multi-step accurately controlled preparation process, and the material has excellent electrochemical performance and is suitable for the field of sodium-ion batteries.

The invention discloses a Ca / Mg co-doped sodium nickel manganese oxide positive electrode material, a preparation method thereof, a pole piece and a battery, and belongs to the field of batteries. According to the Ca / Mg co-doped sodium nickel manganese oxide positive electrode material, three different metal cations of nickel, manganese and magnesium are contained in a transition metal layer, two different metal cations of sodium and calcium are contained in a sodium layer, and the chemical formula of the Ca / Mg co-doped sodium nickel manganese oxide positive electrode material is Na < 0.61 > Ca < 0.03 > Ni < 0.23 > Mg < 0.10 > Mn < 0.67 > O2; the Ca / Mg co-doped sodium nickel manganese oxide positive electrode material is of a P2 type; the problem that an existing P2 type Na < 0.67 > Ni < 0.33 > Mn < 0.67 > O < 2 > positive electrode material is poor in cycling stability and structural reversibility in a high-voltage interval is solved.

The invention discloses a manganese sulfate solution-based sodium permanganate in-situ reaction deep adsorption molybdenum removal process, which comprises the following steps of: taking a manganese sulfate solution, and pouring the manganese sulfate solution into a container; the PH value of the solution in the container is adjusted to 3.0-3.5, and the temperature in the container is increased to 60 DEG C or above; sodium permanganate is added into the manganese sulfate solution, manganese sulfate is oxidized by permanganate radicals in the sodium permanganate, chemical manganese dioxide is directly generated in the container, and molybdenum in the container is adsorbed by the chemical manganese dioxide. The method has the beneficial effects that potassium ions are not remained in the solution after the oxidant is added, the problem of overhigh concentration of the potassium ions in the solution can be directly avoided, and when the concentration of the potassium ions in the electrolytic manganese dioxide for preparing the alkaline zinc-manganese battery is overhigh, the corrosion of a zinc negative electrode in the alkaline zinc-manganese battery can be reduced, and the service life of the alkaline zinc-manganese battery is prolonged. The molybdenum removal process has the advantage that the concentration of the residual potassium ions in the manganese sulfate solution is relatively low.

The invention discloses a W (VI)-doped sodium manganate single-crystal positive electrode material and a preparation method and application thereof in a sodium ion battery, the W (VI)-doped sodium manganate single-crystal positive electrode material has a P2-type layered structure and is in a single-crystal form, the chemical general formula of the W (VI)-doped sodium manganate single-crystal positive electrode material is NaxWyMn1-yOz, 0.6 < = x < = 0.85, 0.005 < = y < = 0.02, 2.0 < = z < = 2.1, and the W (VI)-doped sodium manganate single-crystal positive electrode material is a W (VI)-doped sodium manganate single-crystal positive electrode material and a W (VI)-doped sodium manganate single-crystal positive electrode material. The invention also specifically discloses a preparation method of the W (VI)-doped sodium manganate single-crystal positive electrode material and an application of the W (VI)-doped sodium manganate single-crystal positive electrode material in a sodium ion battery. The W (VI)-doped sodium manganate single-crystal positive electrode material prepared by the invention has the characteristic of no grain boundary, can effectively relieve mechanical stress and reduce electrolyte erosion, so that the cycle stability of a battery is remarkably improved, and the W (VI)-doped sodium manganate single-crystal positive electrode material has important application value in the fields of sodium ion battery electrode preparation and energy storage equipment research.

The application belongs to the technical field of sodium-ion battery cathode material preparation, and particularly relates to a high-sodium-content sodium manganate cathode material and a preparation method and application thereof; the high-sodium-content sodium manganate material is prepared by using a simple and feasible solid-phase method, raw materials are first subjected to ball milling and pre-sintering treatment, so that the raw materials are mixed more uniformly to obtain a sodium manganate precursor, then the precursor is pressed into a round sheet, the particles are in closer contact, and the area available for reaction is more, then the surface phase and internal uniform heating of the precursor are realized by using a microwave heating mode, so that the reaction is more consistent at the same rate, and the generation of a heterogeneous phase is avoided. The preparation process can be scaled up in industry at equal proportions, the rate performance of the two prepared materials is relatively excellent, the discharge capacity is about 110 mAh / g at 0.1C, the discharge capacity is about 100 mAh / g at 0.2C, when the rate is increased to 5C, the capacity is still about 40 mAh / g, and the material has a good application prospect in the field of sodium-ion batteries.

The invention discloses a preparation method of a Ti < 4 + >-doped sodium manganate material and application of the Ti < 4 + >-doped sodium manganate material in a sodium ion battery, and provides an improved strategy of titanium doping through a high-temperature solid-phase reaction, and the improved strategy changes the electronic structure and morphology of the material at the same time. Due to the addition of Ti < 4 + >, the interlayer spacing is increased, rapid diffusion of sodium ions is promoted, the structural evolution from a two-dimensional (2D) flat plate to a one-dimensional (1D) nanorod is also caused, and an additional sodium ion storage position is created. The electrochemical performance of the Na0. 7MnO2.05 positive electrode material is jointly improved through the synergistic effect of electronic modulation, Ti < 4 + > doping and nanostructure engineering. The preparation method is simple, raw materials are easy to obtain, and the process is simple. Tests show that a battery using the doped modified positive electrode material has a good capacity retention rate, and the sodium ion battery positive electrode material has excellent structural stability and cycle performance, so that the actual service life of the sodium ion battery is effectively prolonged.

The invention relates to the technical field of lithium ion batteries, in particular to a sodium manganate-coated nickel-cobalt-manganese ternary material prepared through anhydrous cleaning and a preparation method thereof.The preparation method comprises the steps that sodium formate, manganese acetate tetrahydrate and a nickel-cobalt-manganese ternary positive electrode material with different mole percentages are used for cleaning under the stirring effect, oxalic acid is used for precipitation, and a precursor is obtained; and putting the obtained precursor into an atmosphere furnace, and carrying out high-temperature treatment at a certain temperature under the protection of oxygen to obtain the sodium manganate-coated nickel-cobalt-manganese ternary positive electrode material. The sodium manganate-coated nickel-cobalt-manganese ternary positive electrode material prepared through anhydrous cleaning has relatively high initial discharge capacity, relatively good rate capability, relatively large lithium ion diffusion coefficient and good cycle performance. The method is simple in preparation process, short in preparation period, low in cost and suitable for large-scale production.

The invention belongs to the technical field of sodium-ion batteries, and discloses a sodium-ion battery positive electrode material with a core-shell structure and a preparation method of the sodium-ion battery positive electrode material with the core-shell structure, the core of the sodium-ion battery positive electrode material with the core-shell structure is sodium ferro-nickel manganate, and the shell of the sodium-ion battery positive electrode material with the core-shell structure is sodium copper ferro manganate; and the mass percentage of the shell is 10-35 wt%. The invention provides a sodium ion battery positive electrode material with a core-shell structure, which adopts sodium ferro-nickel manganate as a core and sodium copper ferro manganate as a shell, and has the advantages of high air stability and high capacity.

The invention discloses a sodium nickel manganese oxide layered oxide material as well as a preparation method and application thereof, and relates to the technical field of preparation of sodium ion battery positive electrode materials. According to the preparation method disclosed by the invention, the P2-type sodium nickel manganese oxide layered oxide material with more {001} exposed surfaces can be obtained, the stability of a crystal structure of the material is improved, and the P2-type sodium nickel manganese oxide layered oxide material has excellent cycling stability in a high-voltage region as a sodium-ion battery positive electrode material and is suitable for being applied under high voltage.

This invention relates to the field of sodium-ion battery technology, and particularly to a sodium iron manganese oxide layered cathode material, its molten salt preparation method, and its application. The preparation method includes: weighing sodium source, manganese source, iron source, and potassium chloride molten salt according to stoichiometric ratios; adding anhydrous ethanol and ball milling to obtain a precursor; pressing the dried precursor powder and calcining it; grinding the calcined material into a fine powder; filtering and washing with deionized water and anhydrous ethanol; drying; and then annealing to obtain the sodium iron manganese oxide layered cathode material. The cathode material prepared using the molten salt method exhibits an initial discharge capacity of 214 mAh / g at 0.1C, a discharge capacity of 175 mAh / g at 1C, and a discharge capacity retention rate of 64.91% after 100 cycles. This invention has a simple preparation method, high safety, and is suitable for large-scale industrial production, and can be widely applied in the field of layered cathodes for sodium-ion batteries.

The invention belongs to the field of sodium manganate positive electrode materials, and particularly relates to a preparation method of a mixed-phase sodium manganate positive electrode material and a sodium ion battery. The method comprises the following steps: (1) mixing sodium hydroxide, manganese dioxide, citric acid and water to obtain mixed slurry; and (2) carrying out freeze drying treatment on the mixed slurry to obtain a precursor, and calcining the precursor to obtain the Na < 0.4 > MnO2 positive electrode material with both the P2 phase and the T phase. The Na0. 44MnO2 positive electrode material with the P2 phase and the T phase is prepared by using organic acid doping and combining a freeze drying technology, the high energy density of the P2 phase and the excellent cycle performance of the T phase can be integrated, and the electrochemical performance is excellent.

The invention provides a nickel iron sodium manganate positive electrode material, a preparation method thereof and a sodium ion battery, and belongs to the technical field of sodium ion battery positive electrode material manufacturing. The nickel iron sodium manganate positive electrode material comprises a matrix and a surface layer located outside the matrix, both the matrix and the surface layer are doped with P, only the surface layer is doped with F, and the positive electrode material has relatively excellent structural stability, so that the corresponding battery has the advantage of less gas production in the cycle process.

This invention provides a nanosheet-like ternary sodium nickel iron manganese oxide cathode material, its preparation method, and its applications. The ternary sodium nickel iron manganese oxide cathode material has a nanosheet structure, and the spacing between the transition metal oxide layer and the sodium layer, as well as the valence state of Mn, are controlled by varying the contents of Fe and Ni. The molecular formula is Na. x Ni 1 / 3‑y Fe y Mn 2 / 3 O2 where 0.44≤x≤0.67, 0≤y≤1 / 3; also provides a preparation method for this material: mix and dissolve transition metal salts of nickel, iron and manganese, then add sodium salt to dissolve to obtain a mixed metal ion salt solution, add citric acid dropwise, heat and stir, dry, and sinter to obtain a ternary nickel-iron-manganese sodium cathode material.

The invention discloses a sodium cathode composite material and a preparation method thereof. The sodium cathode composite material comprises a FeF3 matrix and sodium manganate loaded thereon; the molar ratio of the sodium manganate to the FeF3 matrix is ​​(1-10):100; the molecular formula of the sodium manganate is Na x MnO2, 0.5≤x≤1. The preparation method comprises the following steps: (1) dispersing a manganese salt and graphene in a solvent to obtain a solution A; dissolving an organic ligand in a solvent to obtain a solution B; reacting solution B and solution A to obtain Mn-MOF; (2) dissolving an iron salt and a fluorine source in a solvent to obtain an iron salt solution and a fluorine source solution, respectively, and adding the fluorine source solution to the iron salt solution to react for a certain period of time to obtain a solid; (3) mixing the solid, Mn-MOF and a sodium source and sintering at a high temperature. The sodium-based positive electrode composite material of the present invention forms an interface heterogeneous structure and a built-in electric field through a unique structural design, which can improve the kinetic properties of the material; the preparation process of the present invention is simple, the process is short, the raw materials are easily available, the preparation process does not contain toxic and harmful substances, and is suitable for large-scale production.

This invention discloses a method and application for controlling the interface concentration of electrode materials. The interface concentration control is achieved by coating a protective layer onto a common electrode material. The protective layer has the chemical formula XPAN, where X is one of S, Se, Te, P, and I. XPAN is generated by reacting elemental X with polyacrylonitrile (PAN) under high-temperature conditions. The common electrode material is one of lithium iron phosphate, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide, sodium iron manganese oxide, sodium vanadium phosphate, graphite, hard carbon, or silicon-carbon composites. The electrode material is obtained by first coating the surface of a commercial electrode material with PAN, and then annealing the PAN-coated commercial electrode material with elemental X under an argon atmosphere. The reaction of X in XPAN with the high-temperature cyclized PAN produces a stable chemical structure. During charge-discharge using a commercial ester electrolyte, the interface concentration is controlled through the electrochemical reaction of XPAN, thereby enhancing the battery's cycle performance and stability.

Methods and compositions for rapid verification of cleaning performance on surfaces in cleaning-in-place (CIP) systems and in cleaning-in-place (COP) systems and in high flow areas. The solution comprises alkali metal hydroxide; one or more oxidizing compounds, wherein the one or more oxidizing compounds comprise sodium hypochlorite, potassium hypochlorite, sodium persulfate, potassium persulfate and monopersulfate; and one or more compounds selected from the group consisting of potassium permanganate, sodium permanganate, potassium dichromate, and sodium dichromate. In some examples, the solution also includes potassium tripolyphosphate, sodium tripolyphosphate, or other tripolyphosphate. The substrate is in contact with the solution, and a chromogenic reaction may occur indicating the presence of an organic substance or non-organic contaminant. The chromogenic reaction may occur within less than 30 minutes and at a temperature of 10 DEG C to 60 DEG C.