196 results about "Ionic diffusion" patented technology

The invention belongs to the technical field of design and preparation of solid electrolyte materials, and particularly relates to a LiBH4-based composite solid electrolyte material and a preparation method thereof.The LiBH4-based composite solid electrolyte material is obtained by performing high-energy ball milling on a mixture of LiBH4 and one or two metal halides MX2 in a certain molar ratio in an argon atmosphere; m is Mg, Zn, Ni or Bi; x is F, Cl, Br or I. According to the LiBH4 composite solid electrolyte prepared by the preparation method disclosed by the invention, the ionic conductivity at room temperature is improved to 10 <-4 > S cm <-1 > or above, and the ion diffusion activation energy is only 0.16 eV; the process is simple, the preparation time is short, the repeatability is high, no pollution is caused to the environment, and the industrial production requirement is met, so that the all-solid-state lithium ion battery electrolyte is expected to realize commercialized application.

The invention provides an intrinsic solid-state ion diffusion coefficient test method and device based on optical imaging, and relates to the technical field of solid-state ion test.The method comprises the steps that a test sample is pretreated; carrying out a photoelectric test on the test sample; placing the electrochemical cell in an optical imaging system, connecting the electrochemical cell with an electrical testing system, applying a constant voltage deviating from a steady state to the monodisperse electrode plate, collecting the real-time change condition of the material under the modulation of the constant voltage in real time through an industrial camera, and outputting relational data of optical intensity and time; analyzing the diffusion path through in-situ characterization equipment, and obtaining an ion diffusion path corresponding to the to-be-detected ion battery electrode material particles in combination with dynamic information provided by an optical imaging system; and determining the characteristic time according to the relational data of the optical intensity and the time, and determining the intrinsic solid ion diffusion coefficient corresponding to the test sample by combining the characteristic time and the ion diffusion path corresponding to the to-be-tested ion battery electrode material particles.

The invention discloses light self-repairing concrete and a preparation method thereof, and relates to the technical field of concrete. The method comprises the following steps: firstly, efficiently packaging a calcium nitrate solution in hollow glass beads by utilizing a negative pressure impregnation technology; then growing a porous zeolite crystal coating on the surface of the microbead in situ by adopting a sol-gel method to form a self-repairing filler with a core-shell-hole gradient structure; when the concrete cracks to cause the cracking of the microbeads, the Ca < 2 + > in the cavity is quickly released, and the Ca < 2 + > adsorbed in the zeolite layer is gradually dissociated along with water permeation, so that the new microcracks are continuously repaired. Then, uniformly coating the surface and pores of the carboxymethyl cellulose hydrogel network with polydopamine in an in-situ oxidative polymerization manner to form composite hydrogel with photo-thermal responsiveness; lighting and heating to trigger dynamic coordination bond dissociation; meanwhile, heat drives rapid directional crystallization of a repair product by promoting the ion diffusion rate, and a compact mineralization layer is formed. The concrete prepared by the invention has the effects of light weight and self-repairing.

The invention discloses a composite isolating membrane based on synergistic modification of a porous material and an ionic conductor material and a preparation method of the composite isolating membrane. The composite isolating membrane comprises a base membrane and a coating which is coated on the surface of the base membrane and comprises a porous material and an ion conductor material. The composite isolating membrane has multiple ion transmission paths including ion diffusion or migration transmission, lattice diffusion transmission and ion seepage transmission, the ion transmission efficiency is synergistically enhanced, and the problem that the ion transmission mechanism is single is solved. In addition, the composite separation membrane has accessory functionality, and migration of transition metal can be inhibited. The composite isolating membrane disclosed by the invention is suitable for a high-capacity-density and high-rate battery system, and meets the requirements of battery development.

The invention discloses a P2-phase sodium ion positive electrode material with a superlattice ordered structure and a preparation method of the P2-phase sodium ion positive electrode material. The chemical formula of the P2-phase sodium ion positive electrode material is Na < x > M < 1-a-b > A B O < 2 >, wherein M is a transition metal element Mn or / and Ni; a doping sites are transition metal vacancies, and / or doped metal elements Mg and / or doped metal elements Li; the doping site of B is doped with a transition metal element Fe or doped with a transition metal element Cu or doped with a transition metal element Zn; 0.8 < = x < = 0.9, 0.25 < = a, 0.04 < = b < = 0.09. According to the P2 type material with the superlattice ordered structure, the layered structure stability and the sodium ion transmission efficiency of the material can be remarkably improved, so that the problems of poor structure stability and low ion diffusion rate of a traditional sodium ion positive electrode material are effectively solved; the P2 type material with the superlattice ordered structure can be suitable for preparing a sodium ion battery system with high energy density.

The invention discloses a silicon-carbon composite material and a preparation method thereof. The composite material is composed of porous hard carbon, inorganic lithium salt doped with the porous hard carbon and a porous metal frame as a matrix, nano silicon deposited in pores of the matrix, and an amorphous carbon composite material coated on the surface. The preparation method comprises the following steps: uniformly mixing resin, inorganic lithium salt and a porous metal framework, and carrying out hydrothermal reaction, activation and secondary carbonization to obtain a porous carbon complex; and depositing nano silicon and coating the nano silicon with an organic lithium salt through a vapor deposition method to obtain the silicon-carbon composite material. According to the obtained material, expansion is reduced through large-aperture deposited nanometer silicon of the metal frame structure, the defects are reduced through the inorganic lithium salt of the inner core and the organic lithium salt of the outer shell, the ion diffusion rate is increased, and the first efficiency and the rate performance are improved.

The invention discloses a binder system with an electron and ion conduction function and application thereof. The binder system comprises 1) a cross-linking agent containing an ethyoxyl unit and 2) a polymer with electron conduction or electron and ion conduction functions, and the cross-linking agent and the polymer respectively have groups which are cross-linked under light and / or heat conditions; when in use, light and / or heat are utilized to initiate a cross-linking reaction, so that the polymer is cross-linked in situ by the cross-linking agent, and a three-dimensional binder network structure for ion and electron transmission is formed. According to the binder system disclosed by the invention, the polymer is subjected to in-situ crosslinking by utilizing the cross-linking agent to form a three-dimensional binder network structure, the polymer is used as a conjugated main chain for providing electron transmission, and the cross-linking agent is used as a flexible cross-linking chain segment beneficial to ion diffusion, so that the mechanical property of the binder is improved to the greatest extent while the high adhesive force of the binder is ensured; enough mechanical properties are provided for a battery pole piece to maintain the integrity of an electrode, so that the cycling stability of the high-specific-capacity negative electrode material is improved.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a modified sodium ferric sulfate positive electrode material as well as a preparation method and application thereof. The chemical structural formula of the modified sodium ferric sulfate positive electrode material is Na < 2 + 2x > (Fe < 1-a-b > MaMb < 2-x > (SO4) z (PO4) < 3-z, a is more than 0 and less than 1, b is more than 0 and less than 3, z is more than 0 and less than 3, Ma and Mb are transition metal elements, and Ma is Ni; and Mb is Zn. The transition metal element is introduced and the doping proportion is controlled, so that fine regulation and control on the material performance can be realized, the conductivity and the ion diffusion rate of the positive electrode material are improved, and the structural stability and the air stability of the material are enhanced; the problems of slow Na < + > diffusion kinetics, poor crystallinity and poor material air stability of the sodium ferric sulfate positive electrode material are solved, and a new possibility is provided for the development of a sodium ion battery technology.

The invention provides a high-strength cement-based hydrogel electrolyte, a rechargeable pool-based battery and a preparation method of the rechargeable pool-based battery, and belongs to the technical field of energy storage. The invention provides a high-strength cement-based hydrogel electrolyte and a preparation method thereof. The invention also provides a high-strength rechargeable pool-based battery and a preparation method thereof. According to the invention, cement is constructed into a layered structure, the basic strength of a cement skeleton is maintained, pores between adjacent cement sheet layers are filled with the PVA-CuSO4 hydrogel, and the adhesion force of the PVA hydrogel enhances the adhesion capacity between a cement material and an electrode, so that the construction of a continuous ion diffusion channel is facilitated, the contact resistance is reduced, and the layered structure can buffer deflection, so that the service life of the electrode is prolonged, and the service life of the electrode is prolonged. The strength and the toughness of the cement are improved, and ions are expected to be quickly transferred through interlayer channels, so that the ionic conductivity is remarkably improved.

The invention discloses a synthesis method of gamma-type manganese dioxide with high specific surface area, and belongs to the field of chemical synthesis, the gamma-type manganese dioxide is synthesized through mild liquid phase reaction, has unique microspherical morphology, average pore size of 8.49 nm and specific surface area up to 168.70 m / g, and obviously improves charge storage capacity, catalytic efficiency and ion diffusion rate. The synthesis method disclosed by the invention is simple in process and low in cost, and the obtained material has high specific surface area, a mesoporous structure and excellent surface activity.

The invention relates to the technical field of supercapacitors, and particularly discloses a spherical hollow multi-layer high-entropy metal oxide and a preparation method and application thereof. The spherical hollow multi-layer high-entropy metal oxide is prepared by the following steps: cross-linking metal cation nitrate comprising iron nitrate nonahydrate, zinc nitrate hexahydrate, copper nitrate hexahydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate with dextrose monohydrate to generate spherical high-entropy metal hydroxide FeZnCuCoNi-HO with a solid core structure, and annealing to induce the metal hydroxide. And the spherical hollow multi-layer high-entropy metal oxide is formed. Compared with the prior art, the high-entropy metal oxide is prepared through a low-energy-consumption and simple synthesis method, the problem of volume change of the high-entropy metal oxide serving as an electrode material in the circulation process is solved, more reaction active sites are provided, an ion diffusion path is improved, and the specific capacitance of the composite material is improved while the specific capacitance of the composite material is improved. And the stability of the material is maintained, so that the energy storage performance of the supercapacitor is improved.

The invention discloses a method for preparing an adsorption material for simultaneously extracting rubidium and cesium by using soft / hard template co-assembly and application, and belongs to the technical field of adsorption material preparation. The invention aims to solve the problems that a traditional adsorbent is poor in selectivity to similar alkali metal ions, slow in mass transfer rate, insufficient in acid environment stability and lack of an adsorption material for specific recognition of rubidium and cesium ions. The method comprises the following steps: 1, preparing cesium-imprinted hierarchical-pore mesoporous silica; 2, Cs / Rb-HMS is prepared; according to the invention, a macroporous-mesoporous channel is constructed; wherein a large hole (PS template) provides a rapid mass transmission channel, and an ion diffusion path is remarkably shortened, so that target ions can rapidly reach adsorption sites in the material; mesopores (Pluronic F127 template) provide a huge specific surface area and load a large number of Cs < + > imprinting sites and Rb < + > imprinting polymer layers, so that high adsorption capacity to Cs < + > and Rb < + > is ensured.

The invention relates to a controllable electrochemical etching strategy based on solubility product difference, in particular to a preparation method of a barium sulfate modified NiCo-LDH aqueous alkaline zinc battery positive electrode material, which comprises the following steps: firstly, dissolving 1, 4-phthalic acid and sodium hydroxide in a molar ratio of 1: 2 in water to obtain a solution A; dissolving barium nitrate pentahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and ammonium fluoride in water according to a molar ratio of (0-1.5): 1: 4: 10 to obtain a solution B; the preparation method comprises the following steps: fully mixing the solutions, transferring the mixed solution into an autoclave containing foamed nickel (NF), and carrying out solvothermal reaction to obtain a tri-metal Co / Ni / Ba-MOF precursor (CNBx-BDC); cNBx-BDC is used as a working electrode, a platinum wire is used as a counter electrode, Hg / HgO is used as a reference electrode, 5-6M potassium hydroxide and 0.05-0.06 M sodium sulfate are used as electrolyte, a three-electrode system and a cyclic voltammetry method are adopted, electrochemical etching is carried out at the scanning rate of 20-30mV s <-1 > under the voltage range of 0-0.5 V, and the barium sulfate nanodot functionalized Co / Ni / Ba-LDH electrode (BS (at) CN-LDH) is obtained after six times of circulation. The unique porous structure can provide more electrochemical active sites and enhance electrolyte infiltration capacity, and the constructed heterostructure forms a strong built-in electric field, accelerates charge transfer, reduces ion diffusion energy barriers and improves energy utilization efficiency.

The present invention discloses an electrode material with excellent anti-swelling performance, its preparation method and application, and the present invention belongs to the field of energy storage technology. The electrode material is an H2V3O8 / MXene / VO2 heterojunction material, and the lattice change rules of the two materials H2V3O8 and VO2 are opposite during the charge and discharge process. The present invention successfully synthesizes the H2V3O8 / MXene / VO2 heterojunction material through a one-step high-temperature mixed hydrothermal method, and the H2V3O8 / MXene / VO2 heterojunction material can slow down the volume expansion during the charge and discharge process. At the same time, the successful construction of the heterojunction material enables the redistribution of charges at the interface, and the formation of the built-in electric field accelerates the ion diffusion kinetics and induces more active sites. This material has a high reversible specific capacity, excellent rate performance, good cycle stability and anti-swelling performance when used as a cathode material for zinc-ion batteries.

A composite positive electrode material precursor, a preparation method therefor, and the use thereof. The composite positive electrode material precursor comprises an N element-doped ferric phosphate core and an M element-doped ferric phosphate coating layer which coats the surface of the ferric phosphate core, the N element including at least one of Mn, Ni, Co, Cr, V, Mg, Sr, Nb, La, Nd, Ce and Y, and the M element including at least one of Al, Ti and Zr. The doping elements N and M are respectively introduced into the core and the coating layer of the positive electrode material precursor, so that the crystal structure of ferric phosphate can be regulated, thereby improving the conductivity and the ion diffusion rate thereof. Secondly, the doping elements N and M form a synergistic effect in the composite positive electrode material precursor, which optimizes the crystal nucleus structure, enhances the stability of the coating layer, regulates the electron structure and the like, thus comprehensively improving the structural stability, the cycle life, the ion transmission rate and electrochemical properties of positive electrode materials.

The invention discloses a graphite material and a preparation method and application thereof, and belongs to the technical field of carbon materials and energy storage. The graphite material provided by the invention comprises a first pore region and a second pore region, the second hole area is located outside the first hole area; the aperture of the first hole region is less than or equal to 15nm; the aperture of the second hole area is larger than 15 nm and smaller than or equal to 50 nm. The graphite material has the gradient pore structure of the first pore region and the second pore region, and the pore structure is reasonable, so that the graphite material has relatively high crystal orientation degree, the ion diffusion energy barrier is effectively reduced, and the fast charging performance of the graphite material under high magnification is greatly improved.

The present invention provides a super junction device and a forming method therefor. The super junction device comprises: a substrate, the substrate comprising a first surface; a deep trench located in the substrate from the first surface; an insulating layer located on the sidewall surface of the deep trench; a doped pillar located in the deep trench, the doped pillar having first dopant ions therein, wherein in the direction perpendicular to the surface of the substrate, the concentration of the first dopant ions in the doped pillar and the width of the deep trench have a self-adaptive matching relationship, and wherein the doped pillar comprises: a first polysilicon layer located on the surface of the insulating layer and the bottom surface of the deep trench, the first polysilicon layer having the first dopant ions therein; and a second polysilicon layer located on the surface of the first polysilicon layer, wherein a portion of the first dopant ions in the first polysilicon layer diffuses into the second polysilicon layer. The super junction device effectively increases the breakdown voltage, provides the possibility for further reduction of the device size, and has a wide range of applications.

The invention belongs to the related field of battery materials, and discloses a lithium-rich manganese-based positive electrode material and a preparation method and application thereof, the lithium-rich manganese-based positive electrode material comprises a core, a transition layer and a coating layer, the transition layer at least coats part of the surface of the core, and the coating layer at least coats part of the surface of particles formed by the core and the transition layer. The transition layer and the coating layer not only can isolate electrolyte and improve the interface stability, but also can promote the transmission of lithium ions through the formed heterojunction structure; the transition layer is a lithium-rich material doped with an element M and an element N and is used for connecting the coating layer and the core and reducing the possibility of interface defects between the coating layer and the core, and lithium ions can be promoted to be transferred into the doped lithium-rich layer from the outer layer by doping the element M and the element N, so that the conductivity and the ion diffusion rate of the positive electrode material are improved; the inner layer is made of a pure-phase lithium-rich material and is homologous with the middle layer, and lithium ions can still be quickly embedded into the inner layer from the middle layer while high capacity is kept.

This invention belongs to the field of hydraulic structure analysis technology, specifically disclosing a gravity dam coupling analysis method, system, electronic equipment, and storage medium, including: models describing water flow in concrete, the relationship between water pressure and stress, the dissolution reaction process, and the coupling of ion diffusion with water flow. By acquiring influencing variables, parameters of each model are correlated, and a solubility function considering performance parameters is established and dynamically updated. The solubility function is iteratively trained using experimental data to construct a finite element model, and simulations are performed based on the trained function. Early warnings are generated based on the simulation results to predict the concrete deterioration process and optimize maintenance decisions. It has the following advantages: by coupling multiple models such as water flow, chemical dissolution, and hydraulic fracturing, the long-term deterioration process of concrete under the action of water flow and dissolution is accurately simulated. The introduction of a solubility function and dynamic updating of material parameters, considering time-varying deterioration effects, comprehensively improves the accuracy of deterioration prediction and simulation results.

The invention relates to the technical field of oxide preparation, and discloses a three-dimensional porous high-entropy oxide preparation method, which comprises: dissolving a plurality of metal salts in deionized water according to an equal molar ratio; dropwise adding ammonia water into the metal salt mixed solution, and regulating the pH value of the solution to 4.8-8.2; carrying out homogenization treatment on the solution of which the pH value is regulated and controlled in a water bath of 50-60 DEG C; drying the stable precursor solution to obtain a precursor; calcining the precursor powder in an air atmosphere to form a three-dimensional porous structure; and grinding, cleaning and drying the high-entropy oxide material. The hydrolysis-polycondensation behavior of the precursor is accurately regulated and controlled through the pH value, a three-dimensional through pore channel structure is directly constructed without sacrificing a template, the process is simplified and environmentally friendly, systematic regulation and control of parameters such as pore channel morphology and specific surface area are achieved, and the prepared spinel type high-entropy oxide material has excellent ion diffusion efficiency and electrochemical performance and is suitable for industrial production. Higher specific capacity and cycling stability are shown in the field of lithium ion battery negative electrode materials.

The invention discloses a device and a method for testing a steam oxidation mass transfer mechanism of a metal material. The device comprises a reaction chamber, and a sample holder is arranged in the reaction chamber; the gas inlet end of the reaction chamber is simultaneously connected with an 18O2 storage piece, an inert gas storage piece, an H216O storage piece and a D218O storage piece; a first heating assembly is arranged outside the reaction chamber, a second heating assembly is arranged outside the H216O storage part, and a third heating assembly is arranged outside the D218O storage part. According to the method disclosed by the invention, an invisible ion diffusion path is converted into a detectable signal gradient through isotope labeling, and experimental verification of an oxygen ion / metal cation diffusion dominant mechanism, visual proving of a hydroxyl participation oxidation process and quantitative analysis of a dissolved oxygen effect are realized for the first time; and a direct experimental criterion is provided for optimization of the oxidation resistance of the metal material.

The application relates to a high-capacity porous niobium pentoxide material and a preparation method and application thereof, relates to niobium pentoxide and preparation and application thereof, and aims to solve the technical problems of low conductivity and slow ion diffusion of existing orthogonal phase niobium pentoxide materials. The material is formed by interconnection of 100-300 nm niobium pentoxide matrix nanoparticles, growth of 10-30 nm secondary nanoparticles on the surface, and a 'raspberry-like' multi-level assembly morphology; the material has a pore diameter of 2-20 nm, a specific surface area of 15-45 m 2 / g; and has an orthogonal phase niobium pentoxide structure and carbon doping characteristics. The material is prepared by using a surfactant containing a quaternary ammonium cation as a soft template, utilizing electrostatic-coordination synergistic action to drive niobium salt and organic quaternary ammonium cation assembly, and high-temperature sintering in an inert atmosphere. When used as a negative electrode of a lithium ion battery, the material reaches a capacity of 350 mAh / g at a current density of 0.1 A / g, and can be used in the field of fast-charging type alkali metal ion batteries.

The invention belongs to the field of polymer batteries, and relates to a polymer solid-state battery, a use method of an electrolyte membrane of the polymer solid-state battery, a polymer solid-state battery electrolyte and a solid-state lithium battery electrolyte. The polymer solid-state battery electrolyte comprises one or more groups selected from an alcohol group, a hydroxyl group, an amine group, a halogenated group, a sulfonic acid group, an acyl group, a dilute hydrocarbon material and a carboxyl group, a film has high thermal stability, and the average coulombic efficiency of a battery of the polymer electrolyte is higher than 99%. The polymer solid-state battery electrolyte has high cycling stability, the membrane of the polymer solid-state battery electrolyte has good ionic conductivity, exchange and transmission of lithium ions are promoted, the high ionic conductivity of the membrane reflects good ion diffusion and migration ability of the membrane, and the membrane has a high electrochemical window; the membrane of the polymer solid-state battery electrolyte improves the contact or compatibility effect of an electrode and a solid-state electrolyte interface, and the membrane of the polymer solid-state battery electrolyte has profound significance in solid-state batteries and electrolytes.

The invention provides a device for detecting pesticide in water based on nano-composite hydrogel and a preparation method. The device comprises first hydrogel and second hydrogel which are attached to each other, first ITO conductive glass is attached to the side, away from the second hydrogel, of the first hydrogel, second ITO conductive glass is attached to the side, away from the first hydrogel, of the second hydrogel, and the first ITO conductive glass and the second ITO conductive glass are covered with ITO films; the ITO film is connected with a voltage detection unit through a wire, and the voltage detection unit is connected with a display; the wall surface of the porous structure in the first hydrogel is positively charged and has anion selectivity; the wall surface of the porous structure in the second hydrogel is negatively charged and has cation selectivity. According to the invention, the information of the pesticide in water can be judged by detecting the voltage signal by utilizing an ion diffusion migration mechanism, and the method has the advantages of high detection speed, portability, easiness in operation and the like.

The present invention relates to the technical field of precious metal powders, and provides a method for preparing smooth spherical gold powder with a narrow particle size distribution and a low organic residue rate. The present invention uses a water-n-propanol mixed solvent system to prepare gold powder, which can appropriately increase the solution viscosity, reduce the ion diffusion rate, slow down the reaction rate, and promote the uniform growth of the formed gold crystal nuclei, resulting in gold powder with a relatively uniform particle size distribution. At the same time, the present invention disperses the gold-containing precipitate obtained by the reduction reaction in a treatment liquid with strong oxidizing properties, and removes the organic matter remaining on the surface of the gold powder particles through ultrasonic treatment. The gold powder prepared by the present invention has a low organic residue rate, a smooth surface without attachments, a uniform and controllable particle size, high dispersibility, and high sphericity. It can be used to prepare gold conductor pastes, and the preparation process is simple, the batch repetition stability is high, and large-scale production can be carried out.

A composite cathode material precursor, its preparation method, and its application are disclosed. The composite cathode material precursor comprises an N-doped iron phosphate core and an M-doped iron phosphate coating layer covering the surface of the iron phosphate core. The N element includes at least one selected from Mn, Ni, Co, Cr, V, Mg, Sr, Nb, La, Nd, Ce, and Y, and the M element includes at least one selected from Al, Ti, and Zr. By introducing doping elements N and M into the core and coating layer of the cathode material precursor, respectively, the crystal structure of iron phosphate can be adjusted, improving its conductivity and ion diffusion rate. Furthermore, the doping elements N and M form a synergistic effect in the composite cathode material precursor, comprehensively improving the structural stability, cycle life, ion transport rate, and electrochemical performance of the cathode material by optimizing the crystal nucleus structure, enhancing the stability of the coating layer, and regulating the electronic structure.

The present invention provides a composite interfacial layer material and its application in the preparation of all-solid-state lithium batteries. The composite interfacial layer material is obtained by mixing and grinding soft carbon, lithium difluorooxalate borate, and Li6PS5Cl sulfide solid electrolyte. In the present invention, lithium difluorooxalate borate is embedded in the SC matrix, and a LiF nanolayer with high interfacial energy can be in-situ generated during the cycling process. LiF forms a fast ion diffusion network between soft carbon particles. Combining with the high ionic conductivity of LiDFOB itself, the overall ion transport efficiency of the interfacial layer is significantly improved. At the same time, the electron conduction of SC and the ionic conduction of LiDFOB / LiF act synergistically to promote the homogenization of Li+ flux and reduce the local current density, thereby inhibiting the growth of lithium dendrites. This multi-scale synergistic regulation strategy provides a new solution for the interfacial engineering of high-performance solid-state lithium batteries.

The present invention provides a method for preparing a Sn4P3 nanoparticle / carbon nanotube composite material, including steps such as a directed template method, polydopamine coating, carbonization, and phosphidation. The structure of the obtained composite material includes Sn4P3 nanoparticles encapsulated in carbon nanotubes. The outer diameter of the carbon nanotubes is 100 - 200 nm, the wall thickness is 1 - 25 nm, and the particle size distribution of Sn4P3 is in the range of 2 - 10 nm. The present invention has a reasonable design, a simple preparation method, and low cost. The obtained composite material is suitable for preparing the negative electrode material of a secondary battery. Among them, the carbon nanotube network can provide high electrical conductivity and buffer volume expansion. Monodisperse Sn4P3 nanoparticles can shorten the ion diffusion path. Nitrogen-doped carbon sites help improve electron conductivity, and porous hard carbon materials can maintain mechanical stability. The secondary battery prepared from the composite material has excellent energy storage performance and long cycle stability, which is conducive to future commercial applications.

The invention discloses a method for preparing a bulk phase-surface layer gradient doped niobium titanium oxygen negative electrode material by adopting a fused salt electrochemical method and application, and belongs to the field of negative electrode material preparation. The method comprises the following specific steps: preparing a niobium-titanium-oxygen sheet as a cathode; the method comprises the following steps: by taking a LiCl-KCl eutectic mixture as basic fused salt, sequentially adding a first group of dopants and a second group of dopants; in an inert atmosphere, electrolysis is firstly carried out at a relatively low voltage to reduce the first group of elements and diffuse to a bulk phase; electrolysis is carried out under high voltage, so that the second group of elements are reduced and enriched on the surface layer; and washing, drying and grinding the product to obtain the negative electrode material with component and functional gradients from a bulk phase to a surface layer. A continuous gradient structure with a bulk phase rich in high-conductivity elements and a surface layer rich in fast ion elements is constructed in a single particle. According to the structure, the intrinsic electron conductivity, the bulk phase ion diffusion rate and the interface ion migration kinetics of the material are synergistically improved, and the low-temperature fast charging performance, the rate capability and the cycling stability of the material serving as the negative electrode of the lithium ion battery are remarkably enhanced.

The application discloses a method for determining a silicate cement hydration performance index, comprising the following steps: 1) respectively establishing mathematical relational expressions of mineral phase dissolution, hydration product deposition, ion adsorption reaction rate and ion concentration; 2) establishing chemical field control equations of mineral phase dissolution, product deposition, ion diffusion and ion adsorption reaction coupling in the hydration process, and potential field and temperature field control equations; combining corresponding boundary and initial conditions, solving the three groups of control equations, and outputting the results of ion concentration, potential and temperature changes with time and spatial distribution in the whole hydration process; and 3) establishing a hydration heat calculation formula of the whole hydration process of the silicate cement. The application further discloses an analysis device. The method is more in line with the real situation of the silicate cement hydration, more accurately describes the cement hydration process from the essential mechanism, can completely, accurately and truly reflect the silicate cement hydration process, and has important research and popularization significance.