854 results about "Pore diameter" patented technology

The invention relates to the technical field of electrochemical energy storage devices, in particular to a silicon-carbon negative electrode material, a negative electrode plate, an electrochemical device and an electronic device, and mainly comprises a core material and a coating material, the core material comprises silicon particles, the coating material comprises a porous carbon material doped with indium particles, and the coating material comprises a porous carbon material doped with indium particles. The average pore size of the coating material ranges from 10 nm to 20 nm, and the porosity of the coating material ranges from 35% to 45%. According to the silicon-carbon negative electrode material provided by the invention, the coating material has the effects of buffering and inhibiting silicon volume expansion, so that pulverization of the silicon-carbon negative electrode material is inhibited, and the problem of volume expansion of a battery is solved.

The invention discloses a positive plate with gradient pores, a preparation method of the positive plate, a lithium ion battery and an electric device. The positive plate comprises a plurality of coatings which are symmetrically coated on the two sides of a positive current collector, the porosity in the plurality of coatings is increased layer by layer from the coating close to the side of the current collector, and the average pore size of pores is increased layer by layer. The preparation method comprises the following steps: adding a self-sacrifice pore-forming agent into positive electrode slurry, uniformly mixing, coating a carbon-coated aluminum foil with the slurry, drying and rolling, enabling the self-sacrifice pore-forming agent to occupy a certain space, heating a positive electrode plate at a certain temperature, enabling the self-sacrifice pore-forming agent in the positive electrode plate to be decomposed into CO2 and H2O, forming corresponding pores, and forming the positive electrode plate with the pores. According to the invention, gradient gaps are designed on the electrode plate by utilizing the self-sacrifice pore-forming agent, so that the concentration polarization of the thick electrode is relieved, the reaction uniformity and the material utilization rate are improved, the ion transmission performance of the thick electrode is effectively improved, and the dynamic performance of the battery is further greatly improved.

The invention relates to the technical field of porous carbon materials, and discloses a preparation method of phenolic resin-based porous carbon based on synergistic activation of water vapor and carbon dioxide. The key point of the method is to construct a multi-dimensional process of'ZIF-8 (at) Ni-MOF derived bifunctional material pore forming-nitrogen / nickel co-doping + dynamic pressure-double-gas synergistic etching + Ti < 3 > C < 2 > T < x > MXene gradient modification '. The MOF derivative material provides regular initial pore channels and active sites, and precise customization of the pore diameter of 0.7-50 nm is realized by combining dual-gas characteristic complementation and dynamic pressure regulation and control; and MXene modification synchronously improves the conductivity and the interface bonding force. The micropore rate is greater than or equal to 88%, the specific surface area is greater than or equal to 2200m < 2 > / g, the total pore volume is greater than or equal to 1.3 cm < 3 > / g, and the process is free of chemical waste liquid pollution. When the material is applied to a lithium battery silicon-carbon negative electrode, the capacity retention rate after 500 cycles is greater than or equal to 85%, and the industrialization value is high.

The invention discloses a shallow shale gas self-sealing reservoir formation identification method, which comprises the following steps: firstly, carrying out dual-energy CT scanning on a shale full-diameter core sample to obtain DEI values, and the difference of the DEI values embodies different lithologic (physical property) longitudinal change rules, i.e., different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, and different shale lithologic grain interlayer interlayers; the development of the top and bottom plates of the high-quality shale reservoir enables the shale gas to have a self-sealing reservoir forming characteristic; then simulating the adsorbability of the shale gas through laboratory thermal cracking to obtain a shale gas adsorbability rule, and identifying whether the shale gas has a self-sealing reservoir forming characteristic or not. And finally, measuring the distribution rule of the microscopic porosity and the pore diameter through a scanning electron microscope, judging whether the shale layer is a non-or ultra-low permeability layer under the formation temperature and pressure condition or not, and identifying whether the shale gas has the self-sealing reservoir forming characteristic or not. According to the method, the self-sealing reservoir forming of the shale gas is identified in multiple aspects, and the method provides effective technical support for evaluating the favorable layer section of the shale and is of great significance in improving the exploration and development effect of the shale gas.

A gas separation membrane for separating carbon dioxide includes: a separation layer formed of a polymer material and having a function of selecting and separating carbon dioxide; and a porous substrate including a first porous layer and a second porous layer. The gas separation membrane has a layer thickness T1 of 0.1 μm or more and 10.0 μm or less, an average pore diameter d1 of 10 nm or more and 10,000 nm or less, an aperture ratio A1 of 40% or more and 80% or less, a maximum height roughness R1 of 1 nm or more and 200 nm or less, a layer thickness T2 of 10 μm or more and 1,000 μm or less, a ratio d2 / d1 of an average pore diameter d2 to the average pore diameter d1 of 1.1 or more and 10,000 or less, and a ratio A2 / A1 of an aperture ratio A2 to the aperture ratio A1 of 1.1 or more and 2.0 or less.

The invention relates to a road snow melting device as well as a preparation method and application thereof. The road snow melting device comprises a stable base layer and a thermal resistor, the stable base layer comprises an energy storage body, and the energy storage body can play a structure supporting role; the energy storage body is connected with external electric energy and the thermal resistor through wires. The preparation method of the energy storage body comprises the following steps: preparing cement-based printing slurry; filling the cement-based printing slurry into a 3D printing device, and stacking layer by layer to form a printing body; curing, maintaining, trimming and drying the printing body, and immersing the printing body into a soluble alkali / salt solution to obtain a cement-based electrolyte; a soluble alkali / salt solution is dropwise added to the surface of the electrode, then the electrode and the cement-based electrolyte are stacked and assembled, and an assembly is obtained; sealing and packaging the assembly body to obtain an energy storage body; a printing interlayer interface of the cement-based electrolyte has a directionally arranged pore structure, the pore diameter is 0.5-20 microns, and the porosity is 10-50%; and the hole orientation of the hole structure is consistent with the ion migration direction between the electrodes.

The invention discloses environment-friendly degradable forming paper with self-cleaning and oil-proof functions for cigarettes and a preparation method of the environment-friendly degradable forming paper. The forming paper is composed of bamboo pulp base paper, a composite oil adsorption resisting layer and a biological source super-hydrophobic coating. In the middle layer, polylactic acid emulsion is matched with diatomite and activated carbon to form a microporous network, and the pore diameter peak value is 50-150 nm to inhibit oil seepage; the outer layer is formed by compounding vegetable wax, AKD, chitosan and double-particle-size SiO (10-20 nm and 120-280 nm), and surface layer particle enrichment and a thickness-direction asymmetric structure are achieved through wet stacking and wet continuous coating and double-section flash evaporation drying. The structure has the advantages of low surface energy, high hydrocarbon contact angle and good wear-resistant adhesion while keeping degradability and air permeability, and is suitable for the antifouling and cleaning requirements of cigarette appearances.

Herein is described a composite material, the composite material comprising composite 5 particles comprising particles of a mesoporous carbon support material having dispersed on their surfaces noble metal nanoparticles and / or noble metal-M alloy nanoparticles and optionally particles of the elemental metal M or metal oxide MOy, wherein y is >0 to a stoichiometric value of the metal oxide, wherein M is a less noble metal than the noble metal, wherein the composite particles have a BJH average pore diameter of from 2 to 0 50 nm and a particle size D90, as measured by laser diffraction and volume distribution, of 10 µm or less.

The invention relates to the technical field of data processing, and discloses a method for accurately predicting the concrete dosage of a cast-in-place pile in foundation pit engineering. The method comprises the following steps: collecting the pore-forming arrival time of each depth section of an initial calibration pile group, the soil layer type, the slurry density and the actual concrete dosage to establish a database, calculating the exposure duration of a hole wall, and establishing a pore diameter expansion coefficient time sequence evolution relationship of soil layer classification through power function fitting; and obtaining the soil layer type of each depth section of the to-be-predicted pile and the estimated exposure duration, substituting into the evolution relationship, and accumulating to obtain the total predicted concrete dosage. According to the method, the soil layer classification time sequence evolution relation of the hole diameter expansion coefficient along with the hole wall exposure duration is established, and the mud density correction term and the dynamic parameter updating mechanism are introduced; the technical problems that an existing cast-in-place pile concrete dosage prediction method cannot accurately reflect the hole wall state time-varying characteristic, ignores the soil layer differential response rule and lacks the construction process self-adaptive calibration capacity are solved.

The invention discloses a lightweight heat-insulation cement-based composite material, and relates to the technical field of cement-based composite materials, the lightweight heat-insulation cement-based composite material comprises the following material components by weight: 40-60 parts of a cement matrix, 20-35 parts of a lightweight aggregate, 5-12 parts of a polymer modifier, and 0.5-0.3 part of a functional additive, the cement matrix is sulphoaluminate cement or Portland cement, and the functional additive is a water-based composite material. The lightweight aggregate comprises hollow glass beads with the particle size of 0.1-0.5 mm, expanded perlite with the particle size of 0.5-2 mm and surface modified aerogel particles, the aerogel particles are silicon dioxide aerogel or silicon carbide aerogel, the surface area of the aerogel particles is 700-600 m / g, the pore diameter of the aerogel particles is 40-50 nm, the polymer modifier is acrylate-styrene copolymer emulsion, and the particle size of the polymer modifier is 1-10 m / g. The solid content of the acrylate-styrene copolymer emulsion is 50-45%, the glass transition temperature of the acrylate-styrene copolymer emulsion is-10 DEG C to 15 DEG C, and the functional additive comprises a cellulose ether thickener, a polycarboxylate superplasticizer and a nano aluminum oxide dispersion liquid.

The invention relates to the technical field of fiber reinforced resin-based composite materials, in particular to a two-component sweating type fiber reinforced phenolic aerogel composite material and a preparation method thereof. The method comprises the following steps: (1) modifying phenolic resin; (2) preparing a phenolic resin pregel solution; (3) impregnating the fiber reinforcement; (4) gel curing; (5) drying; (6) filling with an inorganic phase change agent; and (7) filling with an organic phase change agent. The phenolic aerogel is prepared by taking the phenolic resin modified by hot acid treatment as a raw material, so that the curing crosslinking degree of the phenolic resin can be effectively improved, and the skeleton and pore diameter of the aerogel can be refined. According to the invention, the inorganic phase change agent and the organic phase change agent with high phase change enthalpy values are sequentially introduced into pores of the phenolic aerogel, and the hierarchically distributed binary phase change agent can be subjected to solid-liquid-gas phase change in sequence from outside to inside in a high-temperature environment, so that the composite material has comprehensive properties such as ultrahigh temperature resistance, long-term efficient heat insulation and high mechanical strength.

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 invention provides a high-internal-phase emulsion foam material as well as a preparation method and application thereof, and the preparation method comprises the following steps: under a certain pressure, starting microwaves at intervals for multiple times to enable a high-internal-phase emulsion to be subjected to a curing reaction, so as to obtain the high-internal-phase emulsion foam material. According to the method, the curing efficiency can be improved and the curing reaction can be stably carried out by utilizing intermittent microwaves under a certain pressure, the uniformity and consistency of the curing degree are relatively excellent, and the pore diameter uniformity of the obtained high-internal-phase emulsion foam material is relatively high.

This separator is used in a zinc secondary battery. The separator comprises an inorganic compound in which pores are formed. The average pore diameter of the inorganic compound is at least 0.3 nm and at most 10 nm. When a liquid tank in which two tubes each having an inner diameter of 6 mm protrude upward, which is partitioned into two chambers by a separator having a diameter of 26 mm, and which is filled with a 6M KOH aqueous solution is used as a measurement device, the liquid permeation amount measured 168 hours after the liquid level difference of the tubes is set to 70 cm is at least 0.05 mL and at most 5 mL.

The embodiment of the invention provides a preparation method of a high-load electrode with a vertical pore channel structure and a battery, which comprises the following steps: grinding and premixing carbon fluoride and a conductive carbon material in proportion, adding a binder, carrying out high-speed ball milling to obtain fiberized powder, and rolling to prepare an electrode material, thereby obtaining the high-load electrode with the vertical pore channel structure. Compounding the carbon fluoride with a current collector through hot rolling to obtain a positive pole piece; and finally, carrying out laser pore-forming treatment on the positive pole piece to obtain the high-load carbon fluoride electrode with a vertical pore channel structure. The pore diameter of the pore channel structure is 10-100 [mu] m, the pore pitch is 1-10 times of the thickness of the electrode material, the pore depth is 50-100% of the thickness of the electrode material, the ion tortuosity of the electrode is effectively reduced and the ion transmission efficiency is improved by constructing a vertical pore channel, meanwhile, high-energy laser induces an in-situ defluorination reaction on the pore wall to generate a high-conductivity sp2 carbon phase, and the conductivity of the electrode is improved. And the limitation of sacrifice conductivity of a mechanical pore-forming technology is broken through.

The invention discloses a method and a device for determining a gas reservoir water plugging and pore plugging radius boundary based on a capillary tube bundle, and the method is characterized in that the method comprises the following steps: collecting physical property data of a tight gas reservoir, and obtaining a capillary tube bundle pore diameter sample set; according to the capillary tube bundle pore diameter sample set, single-tube gas-water two-phase flow is calculated one by one; accumulating the single-tube gas-water two-phase flow to obtain the total flow of a capillary tube bundle under different water saturations, and obtaining a simulated water-gas ratio according to the total flow of the capillary tube bundle; according to the simulated water-gas ratio, obtaining a global optimal solution of the maximum permissible plugging pore radius; and obtaining a field recommendation scheme according to the global optimal solution of the maximum allowable plugging radius. According to the method, the critical plugging aperture under different reservoir conditions can be accurately identified, and the gas production capacity and the water control effect are effectively considered.

A foam sheet, relating to the field of foam manufacturing, comprises: a cross-linked resin layer, an independent pore layer, and an open-cell layer; the independent pore layer has closed and non-communicating pores; the open-cell layer has cavities communicating with the outside of the foam sheet; the open-cell layer is located on at least one of the upper and lower surfaces of the foam sheet distributed along its thickness direction; the average number of pores T / R of the foam sheet parallel to the thickness direction satisfies: 1.5 ≤ T / R ≤ 10; the average pore diameter of the independent pore layer parallel to the thickness direction is 100 μm to 500 μm. The foam sheet of this application embodiment has excellent shock absorption and cushioning performance.

The utility model discloses a smashing device for fishery feed processing. The smashing device comprises a U-shaped support, a shell is fixedly connected to the U-shaped support, a feeding port is formed in the shell, a smashing assembly is arranged in the shell, and a discharging port used for outputting materials is formed in the shell. According to the feed crushing device, the shell and the crushing assembly are arranged and matched with each other, so that feed raw materials can be crushed, and crushed feed can be output outwards through the screens during crushing through the screen drum and the screens with different pore diameters arranged on the screen drum, so that the particle size of the crushed feed can be accurately controlled, and the crushing efficiency is improved. Through the cooperative arrangement of the circular track and the limiting assembly, the use state of the screen drum can be flexibly adjusted according to requirements, and different production requirements can be fully met by replacing and using the screens of different specifications, so that feed of different particle sizes is produced, the ingestion efficiency is improved, digestion and absorption are promoted, and the nutritional requirements of different fishes are met.

When a conventional porous membrane is used for a contaminative liquid to be filtered, the surface of the membrane is blocked due to turbid matter separated by filtration and, as a result, membrane clogging occurs, so that the permeation performance tends to deteriorate. Provided is a porous membrane that has high water permeability and excellent contamination resistance, and is capable of maintaining high filtrate permeability for a contaminative liquid to be filtered. The porous membrane contains a polyvinylidene fluoride resin, in which, given that one surface is a surface A and another surface is a surface B, a ratio (ratio of Hα / Hβ) between an α-type crystal (Hα) and a β-type crystal (Hβ) in a crystalline portion of the polyvinylidene fluoride resin measured by an attenuated total reflection (ATR) method at the surface A is 0 or more and 0.5 or less, a pure water permeability is 0.25 to 1.2 m3 / m2 / h / 50 kPa, and an average value of a surface pore diameter of a surface pore of the surface A of the porous membrane is 5.0 nm or more and 12.0 nm or less.

This utility model discloses a vacuum clamping device for honeycomb materials, relating to the field of honeycomb material processing technology. It includes a base and a baffle. The base has an internal pore cleaning mechanism, which includes a cylinder. A lifting plate is located at the top of the cylinder. This utility model, through the pore cleaning mechanism, can clean impurities stuck in the pores of a square-hole plate. During use, the cylinder is activated to insert a top block into the corresponding pore, pushing out the impurities. Then, a fan is activated to blow away the impurities. This avoids the situation where some pores in the square-hole plate are blocked by impurities due to difficulty in cleaning them, resulting in uneven force during clamping and a poor clamping effect. It also avoids the difficulty of manual cleaning due to the small pore diameter, thus ensuring the working effect of the vacuum clamping device.

The application relates to a high-pressure-resistant PES filter membrane and a preparation process thereof, which comprises a porous main body, the porous main body comprises a mesoporous layer, a pre-filter layer and a separation layer in sequence along the thickness direction, the surface of one side of the mesoporous layer is a liquid inlet surface, the SEM average pore diameter of the pre-filter layer is larger than that of the mesoporous layer; the PMI average pore diameter of the filter membrane is 0.15-0.6 microns; a plurality of liquid inlet holes are distributed on the liquid inlet surface, the SEM average pore diameter K of the liquid inlet hole is 0.2-1.5 microns, and the hole area rate of the liquid inlet surface is 5-35%; the pore diameter of the liquid inlet hole is not less than 1.5K, which is a main liquid inlet hole, and the hole area rate of the main liquid inlet hole is 2-25%. After the mesoporous layer is introduced into the filter membrane, the mechanical property of the filter membrane is obviously improved, so that the pore structure of the porous main body on the liquid inlet surface and near the liquid inlet surface of the filter membrane does not deform too much under high pressure, so that the filter membrane still maintains a large effective flow channel area, and the high flux and high load of the filter membrane are ensured.

The invention discloses a graphite material, a preparation method thereof and a secondary battery, and belongs to the technical field of lithium ion battery materials. The graphite material comprises: secondary particles formed by graphite aggregate polymerization and bonded by an adhesive, the particle size Dv50 of the secondary particles being 8-30 [mu] m; the particle size Dv50 of the graphite aggregate is 3-15 [mu] m, and pores with the pore diameter of 10-1000 nm are distributed on the surface of the graphite aggregate. According to the invention, the problems of difficult graphite pore-forming and difficult pore-forming agent impurity removal are solved, and the defect that the particles are easy to disintegrate during circulation is improved by enhancing the structural strength of the secondary particles, so that the cycle stability of the battery is remarkably improved; in addition, the method has the advantages of low cost and easy industrialization; therefore, the material has wide application prospects in the fields of power batteries and the like.

The invention belongs to the technical field of nano materials, and particularly relates to a nitrogen doping method and application of gamma-graphdiyne. Graphdiyne oxide is prepared through a hydrothermal method, then melamine serves as a nitrogen source, graphdiyne oxide serves as a framework, in-situ doping of nitrogen elements and reduction of graphdiyne oxide are achieved at the same time through high-temperature calcination, and the gamma-graphdiyne is obtained. The method is simple and easy to implement, the processing period is short, the doping amount is easy to control, dangerous chemicals such as concentrated sulfuric acid and concentrated nitric acid are not involved, the production safety is greatly improved, and the prepared nitrogen-doped gamma-graphdiyne has the advantages of high purity, high specific surface area, nanoscale pore diameter and excellent wave absorbing performance, gas sensitivity and ferromagnetism.

Provided is a magnetic recording medium comprising a non-magnetic support and a magnetic layer containing ferromagnetic powder, and further comprising a non-magnetic layer containing non-magnetic powder between the non-magnetic support and the magnetic layer. The average pore diameter of the magnetic layer and the non-magnetic layer is 30.0 nm or less, and the standard deviation of the pore diameter distribution of the magnetic layer and the non-magnetic layer is 30.0 nm or less.

The invention discloses a powder mesh composite gas diffusion layer, which is prepared by metallurgical bonding of titanium powder and a titanium mesh framework, and has the thickness of 20-100m, the porosity of 20-50%, the average pore size of 5-35m and the tensile strength of 200-500MPa. The invention also discloses a preparation method of the powder mesh composite gas diffusion layer, which comprises the following steps: step 1, tiling the titanium mesh framework and then filling with the titanium powder; a loose composite structure is formed; and 2, carrying out vacuum pressure sintering on the loose composite structure obtained in the step 1, and carrying out furnace cooling to finally obtain the powder net composite gas diffusion layer. The powder net composite gas diffusion layer disclosed by the invention has the ultrathin characteristic, the platinum plating amount can be greatly reduced, so that the cost of hydrogen production by electrolysis of water is reduced, the titanium net framework can effectively enhance the mechanical strength of the gas diffusion layer, and the problem of deformation of the diffusion layer in the assembly operation process is avoided.

The invention discloses a silk fibroin freeze-dried powder preparation process for improving specific surface area and porosity, and belongs to the technical field of biological materials, and the silk fibroin freeze-dried powder preparation process comprises the following steps: firstly, adding tert-butyl alcohol into a purified silk fibroin aqueous solution as a pore-foaming agent and a cosolvent to obtain a mixed solution; treating the mixed solution by adopting a multi-stage programmed freezing scheme which sequentially comprises three stages of slow precooling to construct a macroscopic ice crystal skeleton, constant-temperature annealing to realize crystal curing and rapid deep cooling to lock microcosmic ice crystals, so as to form a frozen sample with a graded ice crystal structure; and finally, removing water and tert-butyl alcohol through vacuum freeze drying to obtain a target product. The silk fibroin freeze-dried powder with a macroporous-microporous hierarchical porous structure can be controllably prepared through the synergistic effect of tert-butyl alcohol induction and programmed freezing, and compared with the prior art, the obtained product has ultrahigh porosity, remarkably increased specific surface area and uniform pore diameter.

An electrochemical apparatus includes a separator, a positive electrode plate, and an electrolyte solution, where the separator includes a porous layer, and an average pore diameter of the porous layer is 0.5 μm to 18 μm; the electrolyte solution includes propyl propionate, and based on a mass of the electrolyte solution, a mass content of propyl propionate is 25% to 55%; and the positive electrode plate includes a positive active material layer, the positive active material layer includes a conductive agent, the conductive agent includes at least one of conductive carbon black or Ketjen black, and a specific surface area of the conductive agent is 600 m2 / g to 1100 m2 / g.

The invention belongs to the technical field of quality detection, and provides a light high-reliability heat dissipation cold plate brazing forming process which comprises the steps that through multi-power testing, the surface temperature conditions of a heat dissipation cold plate finished product under different powers are obtained, a local overheating area is screened, the diameter of a welding spot air hole in the heat dissipation cold plate finished product is obtained, and a suspected welding spot defect area is obtained; carrying out coincidence analysis on the local overheating area and the suspected welding spot defect area to obtain a co-occurrence sub-area, carrying out synchronism analysis on the temperature and the pore diameter in the co-occurrence sub-area under overload power, judging whether relevance exists or not, if yes, obtaining a local temperature-welding spot defect relevance model, and if not, obtaining a local temperature-welding spot defect relevance model; and whether a high error exists in the current air hole diameter detection result of the heat dissipation cold plate finished product or not is judged based on the correlation model, if yes, correction is carried out, heat dissipation cold plate defect classification is carried out according to the air hole diameter of the heat dissipation cold plate finished product after correction, and the production quality and use reliability of the heat dissipation cold plate can be improved.

The invention discloses a battery baking method, a control device and baking equipment, and belongs to the technical field of batteries, the battery baking method comprises the following steps: determining a first target value of t and a second target value of T based on a formula, and baking the battery according to the first target value and the second target value in a vacuum environment, d1 is the target aperture of the battery diaphragm after the battery is baked, D0 is the initial aperture of the battery diaphragm, k is the diaphragm shrinkage rate, e is the Euler number, T is the baking temperature, and t is the baking duration. Therefore, the initial pore diameter D0 of the battery diaphragm, the target pore diameter D1 of the battery diaphragm after the battery is baked and the numerical value of the diaphragm shrinkage rate k can be preferably selected in advance as required, and the baking temperature T and the baking time t are correspondingly obtained, so that the diaphragm cost is reduced to a certain extent, and meanwhile, the baking reject ratio of the battery is remarkably reduced.

It suppresses the decrease in conductivity and charge / discharge efficiency. [Solution] The porous silicon material has a Si phase and a conductive phase which is a silicide phase containing Cr and V and may also contain Al, and may also have an SiO2 phase. When the total of the Si phase, conductive phase and SiO2 phase is considered to be 100% by mass, the conductive phase is contained in an amount of 12% by mass or more and 60% by mass or less, the SiO2 phase content is 12% by mass or less, the porosity determined by the mercury intrusion method is 45% by volume or more and the average pore diameter is 100 nm or less.