50 results about "Lithium iodide" patented technology

The invention provides a modified sulfide solid electrolyte and a preparation method and application thereof.The modified sulfide solid electrolyte comprises lithium thioborate crystals, composite grain boundaries are contained between the lithium thioborate crystals, and lithium iodide is contained in the composite grain boundaries. The structures of crystal lattices and composite crystal boundaries in the modified sulfide solid electrolyte are stable, so that the lithium ion migration capability of the modified sulfide solid electrolyte can be improved, and the ionic conductivity of the modified sulfide solid electrolyte is obviously improved.

The present invention belongs to the technical field of battery materials, and discloses a silicon negative electrode material, a preparation method thereof, and a solid-state battery. The silicon negative electrode material includes silicon and a lithium iodide layer coated on the surface of the silicon, and the particle size D of the silicon 50 is less than 100 μm. For the silicon negative electrode material of the present invention, lithium iodide is used as a coating material to coat the surface of silicon materials with a specific particle size, which can significantly improve the conductivity of the silicon negative electrode, reduce polarization, improve the rate performance, and the lithium iodide shell can also inhibit the volume expansion of silicon to a certain extent, reduce the damage to the contact between the silicon material and the sulfide solid electrolyte during the lithiation and delithiation processes of the silicon material, and improve the cycle stability and rate performance of the material.

The application provides a preparation method of anhydrous lithium iodide, and belongs to the field of new energy solid-state batteries. The method comprises the following steps in sequence: mixing a lithium source and an iodine source, obtaining a mixed solution after reaction, removing impurities by filtration to obtain a filtrate; the filtrate is subjected to frozen impurity separation, and after filtration, the liquid is a frozen clear solution, and the solid is a sodium salt or a potassium salt; the frozen clear solution is heated and evaporated to concentrate, when the solid content is 50%-70%, heating is stopped, lithium iodide concentrated slurry is obtained, the lithium iodide concentrated slurry is cooled to room temperature under stirring to obtain lithium iodide one-evaporation crystal slurry, after centrifugation, one-evaporation wet product and primary mother liquor are obtained; the one-evaporation wet product is dissolved in water and filtered, and then the heating and evaporation concentration process of step c is repeated to obtain two-evaporation wet product and secondary mother liquor; the two-evaporation wet product is heated and self-dissolved, and after spray drying, anhydrous lithium iodide is obtained. The anhydrous lithium iodide prepared by the method has a purity greater than or equal to 99.9%, and can be applied to the field of solid-state batteries.

This invention relates to a method for iodine-induced lithium intercalation and exfoliation of two-dimensional materials, comprising the following steps: uniformly mixing a target bulk layered material with an inorganic salt to obtain mixture A; the inorganic salt contains lithium iodide; heating mixture A to 280–400°C under a vacuum environment or protective atmosphere, while simultaneously applying ultraviolet light irradiation, and obtaining mixture B through solid-state lithiation treatment; dispersing mixture B in deionized water, and obtaining the two-dimensional material through hydrolysis exfoliation, separation, washing, and drying. This invention uses an inorganic salt containing lithium iodide as the intercalation medium, and through the synergistic excitation of a light field and a thermal field, induces the oxidative decomposition of halide ions and the release of electrons, driving alkali metal ions to intercalate into the interlayer gaps of the bulk layered material to achieve in-situ solid-state intercalation. Then, through hydrolysis exfoliation, an ultrathin two-dimensional material with a large lateral dimension is obtained. The process is safe, has high intercalation efficiency, and good versatility.

The application discloses a method for preparing a disulfide at low temperature, which comprises the following steps: coupling reaction of m-dihalobenzene and a mercapto compound in the presence of sodium hydride and lithium iodide to prepare the disulfide. At present, the existing methods for synthesizing a disulfide have some problems to a greater or lesser extent. Either noble metal catalysis is needed, the cost is high, and there is a risk of heavy metal residue in the product; or the reaction operation is complex and complicated, and the reaction condition is harsh. The application develops a new method, which can start from cheap and readily available raw materials, use cheap initiators, and simply and effectively synthesize a disulfide under mild reaction conditions, so as to meet the needs of research and development and actual production.

The preparation method comprises the following steps: mixing a lithium source material, water, a first solvent and quaternary amine alkali, reacting the quaternary amine alkali with carbon dioxide in a reaction atmosphere containing carbon dioxide to generate HCO3 <->, reacting the HCO3 <-> with lithium ions in the lithium source material to generate lithium bicarbonate, and collecting a water phase after the reaction; decomposing lithium bicarbonate in the water phase to generate lithium carbonate, collecting a solid phase, and decomposing lithium carbonate in the solid phase to generate lithium oxide to obtain an intermediate; dissolving quaternary ammonium iodide in a second solvent, adding the intermediate, converting the lithium oxide into lithium hydroxide, carrying out ion exchange on the lithium hydroxide and the quaternary ammonium iodide to generate lithium iodide, and collecting a liquid phase; and collecting the lithium iodide in the liquid phase. According to the present invention, based on the characteristics of the specific quaternary ammonium base and the quaternary ammonium iodide salt, the Li in the lithium source material is selectively reinforced, carbonized and leached, the anion impurities in the lithium source material are removed, the anion exchange in the organic phase is achieved, and the high-purity anhydrous lithium iodide is prepared.

A fiber-reinforced lithium borohydride-based all-solid-state electrolyte for suppressing dendrite formation, its preparation method, and its application are disclosed. The method employs a reverse micelle precipitation method to prepare a precursor solution by dissolving lithium borohydride and lithium iodide in an ether solvent solution. Aluminum oxalate and vapor-grown carbon fibers are then added, followed by dropwise addition to an isopentane solution containing a surfactant. After reverse micelles form, the solution is allowed to settle and react completely, and the solvent is thoroughly removed. The product from the settled reaction is dried and then subjected to partial hydrogen release treatment. The partially hydrogen-released product is dispersed in a benzene solution containing polymethyl methacrylate, freeze-dried, and then melt-reacted in situ in a universal mold. This process is simple and highly controllable, significantly improving the mechanical stability and dendrite resistance of the lithium borohydride-based all-solid-state electrolyte, and enabling long lifespan of all-solid-state lithium batteries under fast-charging conditions, thus facilitating commercial applications.

The invention discloses a method for recovering elemental iodine, which comprises the following steps of: performing adsorption-elution treatment on waste gas or waste oil generated in the preparation process of anhydrous lithium iodide, and recovering the elemental iodine from eluent. According to the method, the iodine simple substance escaped by evaporation in the preparation process of lithium iodide trihydrate and the iodine simple substance dissolved in the vacuum pump oil after the lithium iodide trihydrate is subjected to gradient vacuum drying can be efficiently recovered, so that the defects of serious volatilization loss, serious pollution and high occupational risk of the iodine simple substance in the existing preparation process of anhydrous lithium iodide are overcome; the efficient recovery of iodine resources is realized, the production cost is reduced, and meanwhile, the pollution to the environment and the harm to people are reduced.

The present application belongs to the technical field of lithium-sulfur full solid electrolyte, and discloses a preparation method of a PEO-based solid-state lithium-sulfur battery without a negative electrode. Lithium iodide is in-situ coated on LLZTO, and the same is dissolved with Li2S6 and PEO in anhydrous acetonitrile to form a solid-state electrolyte; a sulfur positive electrode sheet is obtained by mixing carboxymethyl cellulose lithium / styrene-butadiene rubber adhesive with sulfur and ketchen black molten sulfur. The electrolyte and the positive electrode sheet prepared above can be assembled into a full solid-state lithium-sulfur battery without a negative electrode, thereby improving safety, reducing cost, increasing the energy density of the battery, inhibiting the dissolution of long-chain lithium polysulfide in the PEO-based full solid-state lithium-sulfur battery, increasing the utilization rate of active substances in the battery, improving the cycle life and stability of the battery, and realizing high sulfur loading of the PEO-based full solid-state lithium-sulfur battery.

The application discloses a modified bismuth oxyiodide-based composite solid-state polymer electrolyte and a lithium battery construction method thereof, and the method comprises the following steps: preparing a metal bismuth oxyiodide compound or a bismuth oxyiodide compound with defects, and preparing the bismuth oxyiodide-based composite solid-state polymer electrolyte by taking the compound as a filler. The electrolyte has the characteristics of high ionic conductivity and high mechanical strength, the bismuth oxyiodide can react in situ with a lithium negative electrode to form an SEI with lithium iodide, and the growth of dendrites is inhibited; through modification of the bismuth oxyiodide, the interface contact between a polymer and inorganic fillers can be improved, and the ionic conductivity of the composite electrolyte is improved. The composite electrolyte can match a lithium iron phosphate, NCM811 and sulfur positive electrode, and a high-conductivity and high-stability solid-state battery is realized.

The present application relates to a modified solid-state electrolyte material, a preparation method thereof and a full solid-state lithium ion battery, and belongs to the technical field of full solid-state lithium ion batteries.The modified solid-state electrolyte material comprises solid-state electrolyte particles and a lithium iodide and ethyllithium complex coating layer coated on the surface of the solid-state electrolyte particles.The preparation method comprises coating LiI on the surface of the solid-state electrolyte particles to obtain LiI-coated solid-state electrolyte particles;mixing the LiI-coated solid-state electrolyte particles with C2H5Li, and then complexing by heating to form a lithium iodide and ethyllithium complex coating layer on the surface of the solid-state electrolyte particles, thereby obtaining the modified solid-state electrolyte material.The modified solid-state electrolyte material can significantly improve the compatibility of the solid-state electrolyte and the pole piece, and has low cost.

The present invention relates to a method for producing a lithium halide compound, capable of industrially advantageously producing a lithium halide compound having a low water content, particularly lithium bromide and lithium iodide, at a high reaction efficiency without accompanying a step of directly removing water, and the method including mixing lithium sulfide, a halogen molecule of at least one of bromine and iodine, and a first solvent; and removing the first solvent, wherein the first solvent is a solvent that dissolves a lithium halide containing the same halogen element as the halogen molecule.

The invention discloses a pyrite-based composite positive electrode material, a preparation method thereof and an application of the pyrite-based composite positive electrode material in an all-solid-state battery, the preparation method of the pyrite-based composite positive electrode material comprises the following steps: (1) carrying out oscillation ball milling treatment on pyrite square crystals to obtain iron sulfide fine powder; (2) mixing lithium sulfide and lithium iodide, and then carrying out high-energy ball milling treatment to obtain a lithium-iodine-sulfur amorphous mixture; and (3) mixing the iron sulfide fine powder and the lithium-iodine-sulfur amorphous mixture, and then carrying out high-energy ball milling treatment to obtain the pyrite-based composite positive electrode material. The pyrite-based composite positive electrode material is combined with a solid electrolyte membrane and a lithium-indium negative electrode, so that a high-capacity and low-attenuation pyrite composite positive electrode sulfide all-solid-state battery can be prepared, and high specific capacity and long circulation performance are shown.

The application relates to a self-bleaching electrochromic device based on titanium dioxide and lithium iodide, and belongs to the technical field of electrochromic devices. The application discloses a self-bleaching electrochromic device based on titanium dioxide and lithium iodide, which comprises a non-polar self-bleaching electrochromic device or a polar self-bleaching electrochromic device. The application has the following advantages: (1) the cycle life of the electrochromic device is improved, and the color change contrast of the electrode in the 300nm-800nm visible light band is less than 5% after at least 4000 coloring-bleaching on-off cycle operations; (2) the electrode is self-bleached, that is, the electrode can be completely restored to the state before color change within 60s under the condition of no additional voltage; and (3) the device is non-polar, that is, both electrodes can be used as cathodes or anodes, and can normally work under the condition of an additional positive or negative voltage, and the same color change performance index is achieved.

This invention belongs to the technical field of comprehensive recycling of waste lithium-ion power batteries, specifically relating to a method for recovering battery-grade lithium carbonate from the cathode material of waste lithium iron phosphate batteries. In the recycling process of this invention, lithium iodide is added as a precipitant for impurity metal ions. This not only utilizes the extremely low solubility of Cu, Al, and Mg iodides in anhydrous ethanol, while LiI is highly soluble in ethanol, but also ensures complete precipitation of impurity ions such as Cu, Al, and Mg in the lithium-rich solution, thus achieving impurity removal. Furthermore, in the subsequent lithium precipitation process to prepare lithium carbonate, the added lithium iodide can be converted into lithium carbonate, realizing the secondary utilization of the input material. That is, lithium iodide is used as both an impurity precipitant and a raw material, saving costs and generating revenue.

The invention discloses low-water-content anhydrous lithium iodide as well as a preparation method and application thereof, and relates to the technical field of lithium iodide production. The ceramic grinding balls are added into the lithium iodide trihydrate concentrated solution for vacuum heating and drying, so that autolysis of lithium iodide in the drying process can be effectively avoided, water in the lithium iodide trihydrate concentrated solution can be removed in a targeted manner, and meanwhile, due to the fact that the ceramic grinding balls are added for vacuum heating and drying, the drying efficiency of the lithium iodide trihydrate concentrated solution is improved. After drying is finished, ball milling can be directly carried out, operation steps are saved, and after ball milling is finished, open drying is carried out, so that moisture generated in the transferring process of the anhydrous lithium iodide coarse material can be quickly, simply and conveniently removed. The preparation method can obtain the anhydrous lithium iodide with low water content, has the advantages of simple operation, mild reaction conditions and low operation cost, and is beneficial to large-scale production of the anhydrous lithium iodide with low water content.

The invention relates to the technical field of lithium iodide material synthesis, in particular to a method for preparing anhydrous lithium iodide powder. Aiming at the defects that the traditional anhydrous lithium iodide preparation process is complicated, high in cost, difficult to purify, serious in pollution and the like, the invention discloses a method for respectively generating anhydrous lithium iodide microspheres and anhydrous lithium iodide powder by reacting lithium nitride and iodine under a heating condition or reacting lithium nitride and iodine under a ball milling condition. The anhydrous lithium iodide is generated in situ by using lithium nitride and iodine under the condition of heating or ball milling, so that one-step in-situ preparation of the anhydrous lithium iodide is realized, and the preparation process is greatly simplified. The method does not involve complex preparation and purification processes, the preparation process is simple and easy to control, green and environment-friendly, the cost is low, and industrial production is easy to realize. An electrochemical test result shows that a trace amount of anhydrous lithium iodide is added into the electrolyte, so that the discharge capacity of the lithium sulfide positive electrode can be effectively improved, and the first activation voltage potential barrier of the lithium sulfide positive electrode is reduced.

The utility model belongs to the technical field of lithium batteries, and particularly relates to a device for synthesizing anhydrous lithium iodide. Comprising a tubular reactor, a material processing tank and a vacuum dryer, one end of the tubular reactor is provided with a feed port, and the other end is provided with a discharge port; the material treatment tank is connected with the discharge port through a material flowing pipe, a filter membrane is detachably mounted in the material treatment tank, the top of the material treatment tank is connected with a feeder through a feeding pipe, and a first valve is arranged on the feeding pipe; and the vacuum dryer is connected to the bottom of the material treatment tank through a material outlet pipe. By adopting the tubular reactor, the reaction efficiency is effectively improved, and the tubular reactor has the characteristic of small backmixing, so that the volume efficiency (unit volume production capacity) is high, the reaction efficiency of lithium hydroxide and hydrogen iodide is accelerated, the problem of non-uniform concentration of a reaction system in the industrial production process of lithium iodide is avoided, and the product quality is improved. And meanwhile, the production efficiency of anhydrous lithium iodide is improved.

The application provides a solid-state electrolyte and application thereof, and the solid-state electrolyte at least comprises: a core body comprising a sulfide electrolyte; and a shell layer wrapped on the surface of the core body, and the shell layer comprises lithium iodide and lithium fluoride. Through the solid-state electrolyte and application thereof, the stability of the solid-state electrolyte to air and positive and negative electrodes can be improved, so that the cycle life and stability of the battery are improved.

A preparation method of lithium iodide and a solid-state battery, the preparation method comprising mixing a lithium source material, water, a first solvent and a quaternary amine base, reacting the quaternary amine base with carbon dioxide under a reaction atmosphere containing carbon dioxide to generate HCO3 ‑ , HCO3 ‑ reacting with lithium ions in the lithium source material to generate lithium bicarbonate, collecting an aqueous phase after the reaction; decomposing the lithium bicarbonate in the aqueous phase to generate lithium carbonate, collecting a solid phase, decomposing the lithium carbonate in the solid phase to generate lithium oxide to obtain an intermediate; dissolving a quaternary ammonium iodide salt in a second solvent and adding the intermediate, converting the lithium oxide into lithium hydroxide, and performing ion exchange between the lithium hydroxide and the quaternary ammonium iodide salt to generate lithium iodide, collecting a liquid phase; and collecting the lithium iodide in the liquid phase. Based on the characteristics of the specific quaternary amine base and the quaternary ammonium iodide salt, the application selectively enhances carbonization leaching of Li in the lithium source material, removes anion impurities in the lithium source material, and also realizes anion exchange in an organic phase and preparation of high-purity anhydrous lithium iodide.

The invention discloses a microwave-controlled all-solid-state lithium battery. The all-solid-state phosphorus sulfide lithium battery sequentially comprises a graphene positive electrode thin film, a first layer of phosphorus sulfide powder containing lithium iodide, a first layer of lithium silicide ceramic powder, a first layer of graphene thin film,..., a graphene negative electrode thin film from inside to top. The phosphorus sulfide solid electrolyte containing lithium iodide is an all-solid-state phosphorus sulfide lithium battery positive electrode material, and the lithium silicide ceramic powder is an all-solid-state phosphorus sulfide lithium battery negative electrode material. The all-solid-state sulfur phosphorus sulfide lithium battery is arranged in an automobile chassis metal container. Cooling water is filled in an interlayer at the bottom of the automobile chassis metal container, a quartz glass interlayer is arranged below the top of the automobile chassis metal container, and blades of an electric microwave stirrer are arranged in the quartz glass interlayer arranged below the top of the automobile chassis metal container. Before charging and discharging, microwaves are introduced into an automobile chassis metal container filled with the all-solid-state sulfur phosphorus sulfide lithium battery to control the chemical reaction in the all-solid-state sulfur phosphorus sulfide lithium battery and the temperature in the all-solid-state sulfur phosphorus sulfide lithium battery.

The application belongs to the technical field of lithium metal batteries and photoelectrochemical energy storage, and discloses a starch-polyiodide composite solid electrolyte film and a preparation method thereof. The electrolyte film takes a polymer as a matrix, lithium bisfluorosulfonylimide and the like as a lithium salt, and a mixture of soluble branched starch, lithium iodide and iodine as a redox composite filler. Through the synergistic effect of the soft support effect of starch and the iodine-based redox pair, a uniform mixed conductive network is constructed, which can effectively reduce the interface impedance, inhibit the polymer crystallization, and significantly improve the ionic conductivity, lithium ion transference number and mechanical flexibility. The application further provides an integrated flexible photoelectrochemical energy storage battery device. The positive electrode-electrolyte integration is realized through an in-situ coating process, so that the device can still work stably under repeated bending and folding, and has high-efficiency light charging function, thereby providing a high-performance and high-safety solid electrolyte solution for the flexible light charging lithium metal battery.

The application discloses a glassy sulfide solid electrolyte with high lithium iodide content, a preparation method thereof and application of the glassy sulfide solid electrolyte in a full solid-state lithium metal battery. A synthesis procedure of the glassy sulfide solid electrolyte comprises a manual pre-grinding raw material procedure and a mechanical ball milling procedure. A general formula of the prepared glassy sulfide solid electrolyte is (0.65-x)((0.75+0.5y)Li2S-(0.25-0.5y)P2S5-yMS2)-(0.35+x)LiI, wherein x>=0, wherein y>0, and wherein M is a metal or a non-metal element in the fourth main group. The novel glassy sulfide solid electrolyte with high lithium iodide content has high ionic conductivity and good stability to metal lithium. The full solid-state lithium metal battery assembled by using the novel glassy sulfide solid electrolyte with high lithium iodide content has the characteristics of excellent cycle performance, high charge-discharge specific capacity and high safety.

The invention relates to the technical field of batteries, in particular to a polymer-based solid electrolyte membrane based on lithium iodide as well as a preparation method and application of the polymer-based solid electrolyte membrane. The polymer-based solid electrolyte membrane based on lithium iodide comprises the following components: lithium titanium aluminum phosphate, polyvinylidene fluoride hexafluoropropylene and lithium iodide. Through the composite synergistic effect of polyvinylidene fluoride hexafluoropropylene and lithium iodide, performance improvement is realized from three dimensions of interface compatibility, ion transmission kinetics and structural stability.

The present invention relates to a method for recycling lithium iron phosphate using lithium iodide, comprising the following steps: mixing waste lithium iron phosphate with a lithium source to obtain a mixture; heating the mixture in an inert atmosphere to obtain a reduced material; washing the reduced material with a cleaning solvent to obtain regenerated lithium iron phosphate powder and an eluate, collecting the eluate, and recrystallizing it to obtain regenerated lithium iodide; the lithium source is lithium iodide and lithium hydroxide in a molar ratio of 1:1 to 5, and the cleaning solvent comprises at least one of water, ethanol, and acetone. The present invention fully utilizes the eutectic system formed by lithium iodide and lithium hydroxide to reduce the reaction temperature. Simultaneously, lithium iodide acts as a reducing agent, and lithium hydroxide provides lithium ions, thereby jointly repairing the lithium iron phosphate and achieving the recycling of lithium iodide.

The present invention discloses a method for directly regenerating waste lithium iron phosphate induced by internal stress, which comprises the following steps: mixing waste lithium iron phosphate cathode material, lithium source and ion source for inducing internal stress generation according to a certain molar ratio, and grinding to obtain powder I; after wrapping powder I with carbon-based material, subjecting it to rapid Joule heating sintering to generate internal stress induction to obtain powder II; using deionized water to desalt powder II at room temperature, and drying in a vacuum drying oven to obtain regenerated lithium iron phosphate cathode material. The lithium source is one or more of lithium iodide, lithium chloride, lithium carbonate, lithium fluoride, lithium hydroxide; the ion source for inducing internal stress generation is one or more of sodium iodide, sodium chloride, sodium carbonate, sodium hydroxide. This method has short time consumption and less pollution, can quickly repair the structural defects of waste lithium iron phosphate and supplement the lacking active lithium; the obtained regenerated lithium iron phosphate has excellent electrochemical performance and can reach the commercial level.

This invention discloses a method for preparing a single-crystal lithium nickel manganese oxide cathode material with specific exposed crystal planes. The method involves adding a low eutectic point lithium salt system to alcohol for grinding, adding a nickel-manganese precursor, grinding and drying, sintering twice, centrifuging and washing, and vacuum drying to obtain the single-crystal lithium nickel manganese oxide cathode material with specific exposed crystal planes. The low eutectic point lithium salt system is a lithium salt composition capable of undergoing a eutectic reaction, including two of lithium hydroxide, lithium nitrate, lithium carbonate, lithium chloride, lithium bromide, lithium fluoride, lithium iodide, and lithium sulfate. The preparation method of this invention is applicable to preparing single-crystal lithium nickel manganese oxide cathode materials with (111), (110), and (100) planes as the main exposed crystal planes, resulting in significantly improved electrochemical cycle performance.

The invention provides a lithium ion battery, and belongs to the technical field of secondary batteries, the lithium ion battery is internally provided with a quenching device, and the quenching device comprises a container and a quenching agent. Wherein the quenching agent is packaged in the container, the quenching agent comprises a solvent and a quenching material dissolved in the solvent, the quenching material comprises lithium polysulfide and / or lithium polyiodide, the lithium polysulfide comprises Li2Sx, x is greater than or equal to 2 and less than or equal to 6, the lithium polyiodide comprises LiIy, and y is greater than or equal to 3 and less than or equal to 5. According to the lithium ion battery, the quenching device is arranged in the lithium ion battery, so that the thermal safety performance of the battery can be effectively improved on the premise of not increasing the internal resistance of the battery and not influencing the electrochemical performance of the battery.

The invention relates to a lithium metal anode (1, 10, 11) for a battery, comprising an anode active substrate (2) comprising an anode current collector (7) and a layer (8) consisting essentially of lithium metal arranged on a surface (4) of the anode current collector (7), and a first lithium metal anode protective layer (3) arranged on the layer (8) consisting essentially of lithium metal, characterized in that the first lithium metal anode protective layer (3) comprises lithium iodide (LiI) and lithium fluoride (LiF). The invention further relates to a method for manufacturing such a lithium metal anode.

The invention discloses a multi-reaction-mechanism positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of preparation of aqueous zinc ion battery positive electrode materials. The preparation method disclosed by the invention comprises the following steps: adding layered vanadium oxide into deionized water, then adding iodide, and stirring to obtain a mixed solution; sequentially centrifuging, washing, drying and grinding the mixture to obtain the multi-reaction-mechanism positive electrode material; the layered vanadium oxide comprises vanadium pentoxide; the iodide is lithium iodide, zinc iodide, ammonium iodide, calcium iodide, sodium iodide or potassium iodide. According to the method, volume expansion and structure collapse caused by repeated embedding / removing of Zn < 2 + > in the circulation process are inhibited, and the stability is improved.