12 results about "Membrane porosity" patented technology

The present application relates to the technical field of powder membrane filter element, and particularly relates to a numerical modeling method and system of sintered metal porous membrane filter material, which comprises obtaining powder membrane porosity and particle size distribution; initializing geometric space; generating particle sphere center coordinates and particle size; judging whether newly generated particle spheres overlap with original particle spheres; calculating theoretical total volume; judging the adjacent overlapping relationship between particle spheres, and using an array to record all original particle spheres overlapping with the generated particle spheres; calculating the overlapping volume between the newly generated particle spheres and all original particle spheres; calculating the actual total volume of the total particle spheres and the total porosity; and continuously iterating until the total particle spheres are less than the porosity of the powder membrane, and then stopping iteration. The present application provides a numerical model construction method of real physical microstructure characteristics of the powder membrane, generates an accurate model conforming to the entity structure characteristics of the porous membrane filter material, and is used for simulating the filtering characteristics of the porous material.

The application relates to a preparation method of a high-porosity high-flux asymmetric membrane, and belongs to the field of membrane separation technology. The preparation method of the high-porosity high-flux asymmetric membrane comprises the following steps: uniformly dissolving a polymer and a hydrophilic additive in an organic solvent to prepare a homogeneous casting solution; preparing a nascent membrane from the casting solution; then, performing atomization pretreatment on the nascent membrane; rapidly cooling the nascent membrane after the pretreatment; then, immersing the nascent membrane in a gel bath to form an asymmetric membrane; and performing multiple flushing and soaking on the asymmetric membrane in normal-temperature deionized water to obtain the high-porosity high-flux asymmetric membrane. The asymmetric membrane adopts a non-solvent atomization technology combined with cooling-induced crystallization, the non-solvent atomization is introduced into the surface of the nascent membrane, the solution is rapidly saturated by accurate temperature control, the crystal formation is triggered, the macroporous pores are formed, and the membrane porosity and flux are improved. The obtained asymmetric membrane has a macroporous network on the surface layer and a finger-shaped pore on the support layer, the porosity is 75% to 85%, the pure water flux is greatly improved, and the high-efficiency separation requirement is met.

The invention belongs to the technical field of biomass materials and green chemical engineering, and discloses a green preparation method and system of a high-porosity cellulose porous membrane based on solvent replacement. The invention aims to solve the problems that the pore structure is easy to dry and collapse, the solvent cost is high and the environment is not protected when the cellulose porous membrane is prepared in the prior art. The core of the method is that cellulose is dissolved in a lithium bromide aqueous solution, and a cellulose hydrogel network is formed through cooling solidification and washing regeneration; then, completely replacing the hydrogel by using a low-surface-tension alcohol or ketone solvent (such as tertiary butanol) so as to eliminate destructive capillary force in the drying process and maintain a porous structure; and finally, drying at normal pressure to obtain the high-porosity cellulose membrane. The core of the system is that a three-loop recycling system of lithium bromide and alcohol or ketone solvents is integrally designed, and near-zero emission and cyclic utilization of the solvents are achieved. The prepared cellulose porous membrane is high in porosity (50-80%) and controllable in structure, and the whole process is green, economical and suitable for large-scale production.

This utility model discloses a lithium battery sheet metal box, including a top cover with a venting structure. The venting structure connects the interior and exterior of the lithium battery sheet metal box to allow gas generated inside the battery to escape. The venting structure includes a venting component and a waterproof and breathable membrane. The venting component includes a large-hole section and a small-hole section, which are connected by a stepped surface. The large-hole section is detachably connected to a fixing component. The waterproof and breathable membrane is clamped and fixed between the stepped surface and the fixing component, thus preventing the membrane from easily falling off. The fixing component has a through hole connecting the waterproof and breathable membrane to the interior of the sheet metal box. Furthermore, during the airtightness test of the lithium battery, the yield rate of the lithium battery sheet metal box can be ensured by replacing the waterproof and breathable membrane between the venting component and the fixing component. Alternatively, the membrane can be replaced when the membrane porosity increases and / or the waterproof and breathable membrane is damaged, causing a decrease in waterproof performance, to ensure the safety of the lithium battery sheet metal box during use.

The invention relates to the technical field of lithium ion batteries, in particular to a composite diaphragm for in-situ gelation of an electrolyte, a battery cell, application and a method. The composite diaphragm comprises a base membrane with the porosity of 40-50%, a ceramic coating arranged on at least one side of the base membrane, and an oxide solid electrolyte coating arranged on the outer side of the ceramic coating and / or the other side of the base membrane, wherein the thickness ratio of the ceramic coating to the oxide solid electrolyte coating is (1-5): 1. The permeability and structural stability of a gel monomer in the in-situ curing process are ensured by controlling the porosity of the base membrane, the ceramic layer provides thermal support and mechanical stability, and the oxide solid electrolyte coating and a gel system form a chemically compatible transition interface. Through collaborative design of interlayer thickness ratios, dense and continuous generation of a gel network is realized, and the bonding stability of a diaphragm and a gel interface is improved, so that the cycle consistency and high-temperature safety performance of a battery cell are improved.

The application discloses a cellulose diaphragm, a preparation method thereof and a lithium battery, and relates to the technical field of battery diaphragms. In the process of forming a film by using a cellulose dispersion liquid, calcium carbonate is introduced, and the porosity and pore size are adjusted by a calcium carbonate pore forming method; acid liquid containing chitosan is used for reaction, chitosan is introduced while the calcium carbonate is removed, the strength of the diaphragm can be increased, the migration of anions can be inhibited, and the electrochemical performance of the diaphragm is improved. The prepared lithium ion battery diaphragm has a porosity of 60-70%, a tensile strength greater than 45 MPa, an ion conductivity greater than 1.7 mS cm ‑1 , and a lithium ion migration number greater than 0.5.

The invention relates to a polished wear-resistant granite ceramic tile and a preparation method thereof, and a high-simulation multilayer granite ceramic tile and a preparation method thereof. The polished wear-resistant granite ceramic tile comprises a green body layer, a colored glaze spot-spraying glaze layer, a transparent dry particle layer and a curing agent layer which are sequentially stacked from bottom to top, the colored glaze spraying spot glaze layer is formed by a multi-station dynamic glaze spraying system, the diameter range of glaze spots is 0.5-8 mm, the fluctuation height of the glaze layer is 0.3-0.6 mm, and the colored glaze spraying spot glaze layer has granite-imitated three-dimensional textures; the transparent dry particle layer is formed by transparent dry particles of 80-250 meshes through a slicking process, the thickness of the compaction layer is 0.8-1.2 mm, and the surface flatness is smaller than or equal to 0.05 mm; the filling module is used for filling and striking off peaks and valleys of the colored glaze spot glaze layer; the curing agent layer is formed by spraying a curing agent and permeates into gaps of dry particles to form a semi-cured film, the porosity is smaller than or equal to 1%, and the residual carbon content after sintering is smaller than or equal to 0.05%; the surface glossiness of the ceramic tile is 20 degrees, 45 degrees or larger than or equal to 95 degrees, the wear-resistant grade is larger than or equal to 4 grades, the anti-fouling grade is larger than or equal to 5 grades, and the color difference delta E is smaller than or equal to 1.5.

The invention relates to the technical field of reverse osmosis membrane modification, and particularly discloses a method for modifying a high-pressure industrial reverse osmosis membrane into a household low-pressure reverse osmosis membrane. The separation layer structure of the original industrial reverse osmosis membrane is precisely regulated and controlled under the mild room temperature condition, and dual optimization of the porosity and hydrophilicity of the membrane is realized. The flux of the modified membrane is increased to 45.12 LMH or above from 15.74 LMH of an original industrial membrane under the 65psi household low-pressure working condition, the NaCl retention rate is stably maintained to be 96.5% or above, meanwhile, the membrane has the advantages that the process is simple, raw materials are easy to obtain, the modification cost is low, and the membrane is high in compatibility with existing household reverse osmosis equipment, conversion from the industrial membrane to the household membrane is efficiently achieved, and the membrane is suitable for large-scale popularization and application. The industrial problems of insufficient flux and high preparation cost of the household reverse osmosis membrane are solved, secondary utilization of industrial membrane resources is realized, and the method has large-scale production and popularization values.

This invention discloses a method for preparing a bio-based aramid-coated lithium battery separator for ternary lithium batteries, belonging to the field of battery separator processing technology. This invention addresses the technical problem in existing technologies where aramid itself has low conductivity and porosity, and coating an aramid solution onto a base membrane reduces the porosity and electrical performance of the base membrane. The method for preparing a bio-based aramid-coated lithium battery separator for ternary lithium batteries includes the following steps: washing the surface of seaweed with clean water, draining it, and cutting it into small segments to obtain seaweed segments; subjecting the seaweed segments to heat treatment and modification treatment sequentially to obtain modified biocarbon; adding 4,4'-diacyl chloride diphenyl ether, 2,5-bis(allyloxy)terephthaloyl chloride, and N-methylpyrrolidone to a three-necked flask and stirring, while lowering the temperature of the three-necked flask to -20±2℃. This invention, by coating the exterior of the PE separator, not only effectively improves the porosity and mechanical properties of the separator but also enhances its electrical performance.

This invention provides an MXene / polyamide dual-selective layer ceramic-based composite nanofiltration membrane, its preparation method, and its application, relating to the field of composite nanofiltration membrane technology. The composite nanofiltration membrane of this invention comprises, from the inside out, an α-Al₂O₃ ceramic support, an MXene selective layer, and an ultrathin gradient PA functional layer; the α-Al₂O₃ ceramic support is a single-channel tubular α-Al₂O₃ membrane with an average pore size of 400-700 nm and a porosity of 40%-55%; the MXene selective layer is composed of Ti₃C₂T₂... x The MXene nanosheets are stacked in an ordered manner, with a thickness of 100-400 nm and interlayer channels with a pore size of 1-5 nm. The ultrathin gradient PA functional layer has a thickness of 50-200 nm and exhibits a gradient cross-linking structure, with a high degree of cross-linking and a pore size of 0.3-0.8 nm on the side closer to the MXene selective layer, and a low degree of cross-linking and a pore size of 0.8-1.2 nm on the membrane surface side. This invention fundamentally solves the problems of poor stability and difficulty in balancing flux, selectivity, and stability of MXene membranes by constructing a sandwich composite structure of "ceramic support-MXene sieve layer-ultrathin gradient PA functional layer," thereby achieving efficient separation and resource utilization of dyes and salts.

The invention discloses a cellulose diaphragm, a preparation method thereof and a lithium battery, and relates to the technical field of battery diaphragms. Calcium carbonate is introduced in the process of forming a film by utilizing cellulose dispersion liquid, and the porosity and the pore size are adjusted by a calcium carbonate pore-forming method; the acid liquor containing chitosan is used for reaction, chitosan is introduced while calcium carbonate is removed, the strength of the diaphragm can be improved, anion migration can be inhibited, and the electrochemical performance of the diaphragm is improved. The porosity of the prepared lithium ion battery diaphragm is 60-70%, the tensile strength is greater than 45 MPa, the ionic conductivity is greater than 1.7 mS cm <-1 >, and the lithium ion transference number is greater than 0.5.

The utility model relates to a lithium battery diaphragm porosity testing device which comprises a frame body, a testing assembly is arranged on the frame body and comprises a first pressing block, a second pressing block, a liquid storage pipe and a liquid storage tank, a first air hole is formed in the first pressing block, a second air hole is formed in the second pressing block, and a groove used for containing a diaphragm is formed in the second pressing block; a sealing ring is arranged on the surface, facing the second pressing block, of the first pressing block, and a sealing groove matched with the sealing ring is formed in the second pressing block. The method has the effect of improving the accuracy of porosity measurement.