63results about How to "Corrosion isolation" patented technology

A multielement composite cathode material for a lithium secondary battery and a preparation method thereof. The chemical formula of the multielement composite cathode material for a lithium secondary battery is LiaNixCoyMn1-x-yMzO2(PO4)b, wherein M is selected from one or two elements of Mg, Al, Zr, Ba. Sr and B; 0.8<=a<=1.2; 0<x<1; 0<y<1; x+y<=1; 0.0005<=z<=0.02; 0<b<=0.02. The preparation method comprises the following steps: weighing NixCoyMn1-x-y(OH)2, lithium salts or lithium oxide or lithium hydroxide, and compounds containing the element M, mixing, sintering at 700-950 DEG C for 6-24 hours, cooling, crushing, sieving to obtain a compound A expressed as LiaNixCoyMn1-x-yMzO2; testing residual lithium element content of the compound A, adding a phosphorus-containing compound, performing heat treatment at 300-900 DEG C for 2-10 hours, cooling, crushing, and sieving. The multielement composite cathode material for a lithium secondary battery has good cycle performance, and low expansion; a cathode of a lithium secondary battery prepared by the material has good working performance.

The invention discloses a hydraulic seal electrical connector, which comprises a housing, an interface sealing gasket and a contact pin, wherein a sintered single-core glass insulator is arranged in the housing; the contact pin is fixed in the middle of the single-core glass insulator; two ends of the contact pin extend to two sides of the single-core glass insulator respectively; the interface sealing gasket is arranged at the left side of the single-core glass insulator; the right side of the single-core glass insulator is filled with a sealant; the contact pin is fixed with the housing through a base; and one side, far away from the sealant, of the base is filled with a pouring sealant. The contact pin in the housing is doubly fixed through the single-core glass insulator and the base; the reliability of a product is ensured in structure; the sealant and the pouring sealant are respectively arranged at two ends of the base; the sealing property of a socket can be improved by the sealant; the electrical property of the socket can be improved by the pouring sealant; the condition that the connector can normally transmit an electric signal for a long period of time is ensured by the sealant and the pouring sealant; the interface sealing gasket is arranged between the housing and the contact pin, so that the interface sealing performance after the socket is inserted, and the operational capability at low air pressure are ensured.

The invention relates to a peeler centrifuge with a scraper rod sheath. The peeler centrifuge comprises a scraper box fixed to the top of a centrifuge housing, a scraper base installed on the scraper box, a scarper rod which is arranged on the scraper base and can extend, retract and rotate, a scraper fixedly connected to the tail end of the scraper rod and a driving mechanism installed on the scraper box for driving the scraper rod to extend, retract and rotate. The scraper rod sheath is further arranged outside the scraper rod. The scraper rod sheath comprises multiple sets of sliding sleeves, the sliding sleeves are connected in a sliding and sleeved mode, and sealing rings are arranged between the sliding sleeves. The peeler centrifuge can isolate a working area in a rotary drum from a scraper rotating area so that materials in the rotary drum cannot be polluted by lubricating grease in the scraper working area, and meanwhile corrosion of the materials to the scraper rod is isolated.

The invention discloses a cleaning and sterilizing method of a circulating water system. The cleaning and sterilizing method comprises the following steps of (1) stripping slime: cleaning the circulating water system by high-pressure spray, feeding a biological slime stripping agent to strip the biological slime; (2) carrying out descalling and derusting treatment: feeding neutral cleaning fluid, a copper corrosion inhibitor and a dispersing agent to descale and derust; (3) membrane pretreatment: feeding a composite prefilming agent to carry out membrane pretreatment; and (4) killing legionella: feeding a bactericide for killing the legionella to sterilize. By adopting the method disclosed by the invention, the legionella in the circulating water system can be completely and thoroughly killed; and a corrosion problem of the circulating water system in the treatment process can be solved at the same time. Meanwhile, the legionella bactericide for the cleaning and sterilizing method is also provided by the invention; and the legionella bactericide is divided into the bactericide for killing the legionella and the bactericide for operating the legionella. The two bactericides can be used in a matching manner; the legionella in the circulating water system can be thoroughly killed, and meanwhile, the situation that the legionella does not reappear in the circulating water system is effectively ensured.

The invention provides a photovoltaic module based on perovskite solar cells and a packaging method thereof. The photovoltaic module comprises a laminated piece and a frame arranged around the laminated piece, wherein the laminated piece comprises a protection layer, a first bonding layer, a perovskite solar cell string, a filling layer, a second bonding layer and a back plate layer which are overlapped in order, the perovskite solar cell string comprises a plurality of perovskite solar cells, a bottom electrode of one cell is connected with a top electrode of an adjacent cell, or bottom electrodes of adjacent two cells are connected and top electrodes of the adjacent two cells are connected, and a space between the adjacent cells is filled with the filling layer.

The invention belongs to a multilayer fuel gas storage well cylinder used for a high-pressure underground fuel gas storage well and a molding-fixing method of the fuel gas storage well cylinder. The fuel gas storage well cylinder comprises an inner-layer fuel gas storage cylinder, a cement protecting-reinforcing layer and an outer cylinder. The molding-fixing method comprises the following steps: drilling a foundation well and lowering the outer cylinder, fixing the outer cylinder, preparing extended slurry used for the protecting-reinforcing layer, and lowering the fuel gas storage cylinder and the multilayer fuel gas storage well cylinder for molding and fixing. In the invention, the cement protecting-reinforcing layer which tightly wraps the outer surface of the fuel gas storage cylinder and fastens the fuel gas storage cylinder and the outer cylinder integrally is additionally arranged on the basis of a traditional double-tube underground fuel gas storage well, so that the multilayer fuel gas storage well cylinder has the advantages that in the using process, the corrosion of the fuel gas storage cylinder caused by the underground water is isolated completely, the well fixing effect is improved effectively, the deformation amplitude of the fuel gas storage cylinder caused by alternating load is reduced greatly, the safety and reliability of the fuel gas storage and the running of the underground fuel gas storage well is ensured, not only the service life of the fuel gas storage well is prolonged, but also the breakage or explosion in the using process of the shaft of the fuel gas storage well can be prevented, and the like.

The invention discloses an environment-friendly car washing liquid, a preparation method of the car washing liquid and a car washing method. The environment-friendly car washing liquid is prepared from, by weight, 0.5-1.5 parts of emulsifying wax, 1.5-5 parts of an active agent, 2-6 parts of a silicone emulsion, 2-5 parts of macromolecule silicone, 2-5 parts of an environment-friendly organic solvent and 77-92 parts of deionized water. The environment-friendly car washing liquid cannot generate a large amount of foam, during car washing, flushing with water is not needed, the water resource issaved, and when acting on the surface of car paint, the car washing liquid can make a car body bright and smooth; after washing, a protection membrane layer can be formed on the car body to isolate corrosion, to the car body, of various kinds of dirt, the effects of washing and maintenance are achieved, during car washing, the dirt can be removed through wiping of a towel, and the water resourcecannot be polluted. According to the environment-friendly car washing liquid, the environment-friendly and degradable materials are adopted and meet the requirement of environmental protection, the car washing liquid can be used for on-the-spot car washing, during car washing, there is no site and time limitation, and the time and gasoline cost consumed in the process that a car owner drives his / her car to a car washing station for car washing is saved.

The invention relates to the field of manufacturing of exterior wall waterproof and protective paints for buildings and specifically discloses a cured type waterproof protective and thermochromic paint and a preparation method thereof. The cured type waterproof protective and thermochromic paint is prepared from a component A and a component B; the component A is prepared from 50-90 parts of curing agent and 0-100 parts of diluent in parts by weight; the component B is prepared from 100 parts of waterproof film forming agent, 0.5-40 parts of ultraviolet separant, 0-25 parts of thermochromic color-changing agent and 0-5 parts of dispersant in parts by weight. The cured type waterproof protective and thermochromic paint has the capabilities of effectively isolating moisture from seeping into a protected inkjet decoration coating and effectively isolating the corrosion of acid rain to the inkjet decoration coating, is remarkable and adjustable in thermochromic effect and has the isolation rate to ultraviolet up to 83%. The preparation method disclosed by the invention is simple and feasible and can be applied to industrial production.

The invention discloses a conductive polymer / zinc oxide composite counter electrode and a preparation method thereof. The composite counter electrode has a sandwich structure in which three layers are sequentially stacked. The composite counter electrode comprises a conductive substrate, a composite catalyst layer with a cross-linked pore structure and a compact zinc oxide layer located between the conductive substrate and the composite catalyst layer, wherein the composite catalyst layer comprises a nanometer porous zinc oxide film and a layer of poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonate) (PEDOT:PSS) adsorbed to the surface of the nanometer porous zinc oxide film. In the composite counter electrode, the nanometer porous zinc oxide film enables the composite catalyst layer to be crosslinked porous in shape so as to be conducive to adsorbing more PEDOT:PSS, and the excellent electron mobility of the nanometer porous zinc oxide film provides guarantee for transmitting external circuit electrons to the PEDOT:PSS surface from the conductive substrate more quickly and enabling the external circuit electrons to participate in electrolyte reduction; and the compact zinc oxide layer not only can improve contact between the composite catalyst layer and the conductive substrate, but also can significantly improve open-circuit voltage of a dye-sensitized solar cell assembled by the composite counter electrode and corrosion imposed on a substrate material by an electrolyte in a completely isolated device.

The invention discloses a wireless passive temperature sensing system for a main transformer cabinet of an electric locomotive. The wireless passive temperature sensing system comprises a surface acoustic wave temperature sensing unit, an antenna unit and an acquisition unit, the surface acoustic wave temperature sensing unit is mounted at a to-be-measured temperature in a main transformer cabinetof the electric locomotive, and is connected with the acquisition unit through the antenna unit; and the surface acoustic wave temperature sensing unit comprises a substrate, a piezoelectric substrate, an antenna module, an interdigital transducer and a reflecting grating. The piezoelectric substrate comprises a sound wave conduction substrate and a piezoelectric film positioned on the sound waveconduction substrate; the sound wave conduction substrate is located on the substrate, and the antenna module, the interdigital transducer and the reflecting grating are located on the piezoelectricfilm; and a sound absorption layer is laid on the surface of the piezoelectric film and used for absorbing bulk acoustic wave signals in the acoustic surface waves. The system has the advantages of high frequency, low time delay, high sound velocity, high reliability, high adaptability and the like.

The invention discloses a pre-buried pipeline anchor sealing construction method of a reversed anchor pocket. The pre-buried pipeline anchor sealing construction method comprises the following steps that firstly, before a pretressed concrete structure is poured, at least one pipeline which can directly abut against the highest position of the reversed anchor pocket to be formed from the top face of the pretressed concrete structure is fixed; secondly, after the pretressed concrete structure is poured and solidified, a formwork is used to seal the reversed anchor pocket; and thirdly, concrete is poured into the anchor pocket through the pre-buried pipeline. The anchor sealing formwork is fully closed for one time. Vibrating is conducted through an attached vibrator. The integrity of an anchor sealing body is good. The concrete is poured from top to bottom. Bubbles produced by vibrating of the concrete can be discharged out of the reversed anchor pocket through the pre-buried pipeline. The anchor sealing body makes full contact with the interface of original concrete, and holes and fall-off faces do not exist, therefore the anchor sealing body can well isolate corrosion of water vapor in the air to a prestressed anchorage device, and structural durability is strengthened.

The invention belongs to the technical field of fuel additives, and particularly relates to a multifunctional automotive fuel additive, which is prepared from the following raw materials in parts by weight: 10 to 18 parts of bis-alkenyl succinimide, 8 to 16 parts of butylated hydroxytoluene, 6 to 14 parts of benzotriazole, 5 to 10 parts of dodecyl dimethyl betaine, 4 to 12 parts of butyric acid isoamyl ester, 3 to 11 parts of antidetonant, and 1 to 8 parts of combustion improver. The additive provided by the invention has multiple functions of antidetonation, purification, combustion supporting, corrosion resistance, antioxidation, lubrication and the like, and is energy-saving and emission-reduction.

The invention discloses a composite coated nickel-rich positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The composite coated positive electrode material comprises a nickel-rich positive electrode base material, a transition layer and a composite coating layer coated on the surface of the base material. The composite coating layer is composed of the composite solid electrolyte and the lithium-boron compound, the positive electrode material can be effectively protected through the combined action of the composite solid electrolyte and the lithium-boron compound, the safety performance of the material is improved, and the rate capability of the material can be further improved.

The invention discloses a vacuum auxiliary anchor sealing construction method of a reversed anchor pocket. The vacuum auxiliary anchor sealing construction method comprises the following steps that firstly, an air exhausting hole is punched in the position, directly facing the highest position of the anchor pocket, of an anchor sealing formwork, an air exhausting pipe for vacuumizing is mounted in the air exhausting hole, the tail end of the air exhausting pipe can directly abut against the highest position of the anchor pocket, a grouting hole is punched in the position, directly facing the lowest position of the anchor pocket, of the anchor sealing formwork, and a slurry inlet pipe for grouting is mounted in the grouting hole; secondly, the anchor sealing formwork is buckled on the anchor pocket to seal the anchor pocket; and thirdly, the slurry inlet pipe is sealed, the anchor pocket is vacuumized through the air exhausting pipe, and after the vacuum degree reaches the set threshold value, the slurry inlet pipe is opened to pour concrete into the anchor pocket. The anchor sealing formwork is fully closed for one time, the integrity of an anchor sealing body is good, the anchor sealing body makes full contact with the interface of original concrete, and holes and fall-off faces do not exist, therefore the anchor sealing body can well isolate corrosion of water vapor in the air to a prestressed anchorage device, and structural durability is strengthened.

The invention relates to the field of preparation of waterproof and protective coatings of exterior walls of buildings, and particularly discloses a single-component moisture-curable waterproof, protective and thermochromic coating and a preparation method thereof. The single-component moisture-curable waterproof, protective and thermochromic coating comprises the following components in part by weight: 100 parts of waterproof filmogen, 0.5-25 parts of ultraviolet isolating agents, 0-15 parts of thermochromic agents, 0-3 parts of dispersing agents and 0-100 parts of diluents. By the single-component moisture-curable waterproof, protective and thermochromic coating, water can be effectively isolated from a protected inkjet decorative coat, corrosion of acid rain on the inkjet decorative coat is also avoided, and a thermochromic effect is obvious and adjustable. When the thickness of the coat of the coating ranges from 0.1-0.5 micrometers, half-life period of tensile strength and elongation at break is longer than 8 years, and rate of isolation on ultraviolet rays can reach 86%. The preparation method is simple and practicable, and can be used for industrial production.

The invention belongs to the technical field of liquid fuel, and more specifically relates to a high-energy alcohol-based fuel additive for military use and a preparation method thereof. The additivecomprises the following raw materials in parts by weight: 5-10 parts of ethanol, 3-5 parts of triacetin, 4-7 parts of a cation fluorocarbon surfactant, 1-4 parts of ferric nitrate, 10-15 parts of a hydrocarbon compound, 10-15 parts of a combustion improver, 3-5 parts of a stabilizing agent, 3-5 parts of an anti-knock agent, and 1-4 parts of a deodorant. The composite additive can be added into thealcohol-based fuel, in order to substantially improve calorific value of the fuel, ensure fully and thoroughly combustion without generation of carbon deposition phenomenon, and improve corrosion resistance and stability of the fuel.

The invention discloses a glue pouring method and glue pouring assembly of a propeller. The propeller comprises a stator and a stator shell arranged on the outer side of the circumference of the stator. The glue pouring method further comprises the steps that the stator is arranged on a sealing positioning piece in a sleeving mode, wherein a glue pouring channel is formed between the outer wall face of the sealing positioning piece and the stator shell; the stator shell is provided with an inlet and an outlet which communicate with the glue pouring channel; seal glue is poured into the glue pouring channel from the inlet; and air in the glue pouring channel is extracted through negative pressure adsorption at the position of the outlet. By means of the technical scheme, corrosion of external water vapor and air to the stator of the propeller can be effectively reduced, and the service life of the stator of the propeller is prolonged.

The invention discloses a waterproof floor which comprises a floor body. A waterproof layer is arranged on the upper surface of the floor body, a separation layer is arranged on the upper surface of the waterproof layer, and the waterproof layer is thinner than the separation layer which is thinner than the floor body. The waterproof layer is a plastic film protection layer, and the separation layer is made of phenolic resin materials. According to the waterproof floor, the waterproof layer is arranged on the upper surface of the floor body, the separation layer is arranged on the upper surface of the waterproof layer, and therefore corrosion of moisture on the wood floor can be effectively avoided, and the service life of the floor is prolonged.

The invention discloses a wall guard and an installation method thereof and solves the problems that the existing wall guard board is easily damped, molded and deformed, the product service life is short, the application scope is narrow and the like. The wall guard is characterized in that the wall guard comprises a wall guard board (1) and a hanging and fastening assembly, and the wall guard board (1) is installed on a wall through the hanging assembly, wherein the hanging and fastening assembly (11) comprises a first hanging piece (2) which is fixedly arranged on the wall body, and a second hanging and fastening piece (3) which is fixedly arranged on the back surface of the wall guard board (1); the installation of the wall guard board (1) is realized through the mutual fastening of the first hanging and fastening piece (2) and the second hanging and fastening piece (3). The wall guard and the installation method thereof have the advantages that not only is the structure simple and the cost low, but also the wall guard board is not in direct contact with the wall body, and the wall guard board is prevented from being damped, molded and deformed.

The invention provides a special salt-fog-resistant impact-resistant anticorrosive coating which is prepared from the following components in parts by weight: a component A comprises the following components in parts by weight: 35-45 parts of acrylic resin, 12-18 parts of titanium dioxide, 15-20 parts of conductive mica powder, 4-8 parts of coal tar, 4-6 parts of weather-resistant pigment, 0.3-0.7 part of flatting agent, 0.1-0.3 part of dispersing agent and 15-20 parts of ceramic aggregate I; a component B comprises the following components in parts by weight: 4-8 parts of a polyamide curing agent (651), 18-24 parts of a toughening agent, and 65-83 parts of a silane coupling agent; in the coating, the weight ratio of the component A to the component B is (8-12): 1. In addition, the invention also provides a preparation method and application of the special salt-fog-resistant impact-resistant anticorrosive coating.

The invention discloses a prestressed carbon plate-ECC combined reinforced concrete structure and a construction method. A cement-based composite material ECC layer, a prestressed plate and a cement-based composite material ECC layer outer protective layer are laminated at the bottom of a concrete beam; the plate is protected on the outer side of the plate reinforced by the prestressed plate by utilizing good durability such as crack resistance and impermeability of the cement-based composite material ECC, so that the erosion effect of the external severe environment on the plate is isolated, and meanwhile, the overall bearing capacity of the concrete beam and the crack resistance of the beam bottom can be improved; and the ECC layer is arranged between the prestressed plate and the concrete, so that the stripping of the plate can be delayed due to the characteristics of fine cracks, the interfacial shear stress is effectively transmitted, and the advantage of high tensile strength of the plate is better exerted.

The invention belongs to a multilayer fuel gas storage well cylinder used for a high-pressure underground fuel gas storage well and a molding-fixing method of the multilayer fuel gas storage well cylinder. The fuel gas storage well cylinder comprises an inner-layer fuel gas storage cylinder, a cement protecting-reinforcing layer and an outer cylinder. The molding-fixing method comprises the following steps: drilling a foundation well and lowering the outer cylinder, fixing the outer cylinder, lowering the fuel gas storage cylinder, pouring the cement protecting-reinforcing layer and molding and fixing the multilayer fuel gas storage well cylinder. In the invention, the cement protecting-reinforcing layer which tightly wraps the outer surface of the fuel gas storage cylinder and fastens the fuel gas storage cylinder and the outer cylinder integrally is additionally arranged on the basis of a traditional double-tube underground fuel gas storage well, so that the multilayer fuel gas storage well cylinder has the advantages that in the using process, the corrosion of the fuel gas storage cylinder caused by the underground water can be isolated completely, the well fixing effect is improved effectively, the deformation amplitude of the fuel gas storage cylinder caused by alternating load is reduced greatly, the safety and reliability of the fuel gas storage and the running of the underground fuel gas storage well is ensured, not only the service life of the fuel gas storage well can is prolonged, but also the breakage or explosion in the using process of the shaft of the fuel gas storage well is prevented, and the like.

The invention discloses a selenium absorption tower which comprises a tower body and a tower cover fixedly connected with the upper end of the tower body, wherein a feeding hole and an exhaust hole are formed in the tower cover; an in-tower insert pipe is inserted into the exhaust hole; at least one air hole communicated with an inner chamber of the in-tower insert pipe is formed in the lower end of the in-tower insert pipe; the highest point of the air hole is located on a liquid level line of the absorbing liquid in the absorption tower; a cooling jacket for circulating the cooling liquid is arranged on an outer wall of the tower body; and the liquid level line means the contour line of the liquid level when the absorbing liquid in the absorption tower reaches a specified containing volume. In the selenium absorption tower, the air hole is formed at the lower end of the in-tower insert pipe, and the highest point of the air hole is lower than the liquid level line of the absorbing liquid in the absorption tower; when the absorbing liquid in the absorption tower reaches the specified containing volume, the air hole is completely soaked into the absorbing liquid; and when the selenium absorption tower runs, the raw gas containing selenium dioxide is processed with the absorbing liquid and then is discharged from the absorption tower through the in-tower insert pipe, so that the recovery efficiency of selenium dioxide can be increased.

The invention discloses a sintering mixer cleaning device, a rotary thorn roller thereof and a thorn roller hanger and belongs to the technical field of sintering mixers. The sintering mixer cleaning device, the rotary thorn roller thereof and the thorn roller hanger have the advantages that the connecting manner of thorn rods and a thorn roller body is improved, special sleeves are arranged on the thorn roller and the thorn rods in an embedded manner, the material adhering problem of the cleaning device is solved thoroughly, and the thorn roller, thorn heads and the thorn rods are allowed to be exposed, a beating rotating mechanism adopts a multistage combined sealing structure, external materials and steam can be effectively prevented from corroding bearings, and the service life of the cleaning device is prolonged; an scraper cleaning mechanism is added between thorn rollers, materials adhered to the wall of a cylinder can be cleaned completely, and cleaning blind areas are eliminated; the sintering mixer cleaning device can effectively and reliably work for a long time, equipment maintenance workload is relieved greatly, the replacement cycle of main parts is prolonged from the original half a year to two years, and equipment performance is increased evidently.

The invention relates to functional paint and concretely relates to a novel blocking agent. The novel blocking agent is prepared from 0.5-2wt% of a corrosion inhibitor, 6-10wt% of a surfactant and 88-92.5wt% of a polymer by mixing. The novel blocking agent has excellent dispersibility, film forming ability and enclosing capability. After metal dip-coating and curing, a film is formed, has flat and pump surface, is transparent and bright, resists wear and corrosion, and can effectively prevent metal part corrosion caused by a corrosion medium in an environment.

The present invention discloses wave-absorption and long-service life composite paper, which comprises, by mass, 20-80% of structure fibers and 20-80% of adhesion fibers, wherein the adhesion fibers contain 0.1-20% by mass of a wave-absorption additive. The present invention further discloses a wave-absorption and long-service life composite paper preparation method. According to the wave-absorption and long-service life composite paper of the present invention, the wave-absorption additive having the wave-absorption performance is added to the adhesion fibers so as to uniformly disperse the additive in the composite paper, such that peeling resistance under the external force effect is provided; the structure fibers are added and have characteristics of fire retardation, high temperature resistance, and effectively isolation of corrosion of oxygen in air on the wave-absorption additive so as to prolong the service life of the composite paper; and the raw materials are the lightweight materials, such that the specific gravity of the composite paper is small.

A high-nickel multi-element positive electrode material for a lithium secondary battery comprises a base material and a composite cladding layer outside the base material, the general formula of the base material is LiaNi1-x-yCoxMyO2, wherein M is at least one of Mn and Al, a, x and y respectively represent the molar ratios of Li, Co and M in the base material, a is not smaller than 1 and not greater than 1.2, 1-x-y is not smaller than 0.6 and not greater than 1, x is greater than 0 and not greater than 0.4, and y is not smaller than 0 and not greater than 0.4; and the composite cladding layer is a mixture containing lithium phosphorus oxide and at least one of lithium zirconium / lithium titanium / lithium aluminum oxides. A preparation method of the positive electrode material comprises the following steps: preparing the base material; adding a metallic Zr / Ti / Al-containing compound, and carrying out high temperature heat treatment to obtain a lithium zirconium / lithium titanium / lithium aluminum oxide coated base layer; and adding phosphate, and carrying out low temperature heat treatment to obtain the high-nickel multi-element positive electrode material for the lithium secondary battery. The high-nickel multi-element positive electrode material has the advantages of low alkalinity, small gas swelling degree, good processability and good electrochemical performances.