98results about How to "Low closed cell temperature" patented technology

The invention relates to a novel ceramic coating polyolefin composite film which comprises a polyolefin substrate with micro pores, wherein one side or both sides of the polyolefin substrate is/are compounded with ceramic coating(s); the ceramic coating comprises porous ceramic particles, an inorganic filler and an adhesive. The invention also relates to a method for preparing the novel ceramic coating polyolefin composite film. The method comprises the following steps: a, dissolving the adhesive in a solvent, thereby preparing an adhesive solution; b, adding the porous ceramic particles and the functional inorganic filler into the adhesion solution prepared in the step a, and performing dispersing treatment, thereby preparing coating slurry; and c, coating one or two surfaces of the polyolefin substrate with the coating slurry prepared in the step b, and drying and curing to prepare the product. The novel functional composite film has high liquid absorption and retention performance, has the functions of reducing harmful gases inside a battery, improving the performance of the battery and prolonging the service life of the battery, and has the safety characteristics of low closed pore temperature, high melting temperature and low hot-shrinkage rate.

The invention discloses a preparation method of an irradiation cross-linking polyethylene porous diaphragm. According to the method, the polyethylene porous diaphragm is soaked in and adsorbs a volatile solvent containing initiator and cross-linking agent to lead initiator and cross-linking agent into the surface and the interior of the polyethylene porous diaphragm, and is then treated with irradiation cross-linking underwater or under the protection of inert gas, and a locally cross-linked diaphragm is obtained by controlling the cross-linking condition. The irradiation cross-linking lithium-ion battery diaphragm has the advantages that the tensile strength and the hydrophily are greatly improved; the high-temperature hot-shrinkage rate is greatly reduced; the defect of low membrane rupture temperature is overcome; the membrane rupture temperature is greatly raised while the normal hole closing of the diaphragm is guaranteed; the hole closing temperature of the diaphragm is 120 to 140 DEG C; the membrane rupture temperature is raised to be higher than 160 DEG C.

The invention relates to an inorganic composite microporous membrane serving as a lithium ion battery diaphragm and a preparation method of the inorganic composite microporous membrane. The inorganic composite microporous membrane is a co-extruded inorganic composite microporous membrane, and includes an intermediate layer and two outer layers, wherein the intermediate layer is mainly made of polyethylene, or the copolymer of ethylene and other olefins, or the mixture of polyethylene and other polyolefin; the two outer layers is mainly made of the mixture of polypropylene and inorganic nanoparticles; and the inorganic nanoparticles are selected from at least one of aluminum oxide, magnesium oxide, calcium oxide and silicon oxide. The inorganic composite microporous membrane provided by the invention has good unity, and can prevent shedding of the inorganic nanoparticles so as to ensure the stability of the battery performance during application of the inorganic composite microporous membrane. The preparation method provided by the invention can form the multilayer structure of the inorganic composite microporous membrane in one step by adopting co-extrusion method, thereby simplifying the production process, improving the production efficiency and improving the performance of the inorganic composite microporous membrane.

The invention provides a silane crosslinked polymer separation film, which comprises crosslinked polymerized ultrahigh molecular weight polyethylene, high-density polyethylene, an antioxidant, an assistant crosslinker and a silane crosslinking agent, wherein the molecular weight of the ultrahigh molecular weight polyethylene is 1.0*10<6> to 10.0*10<6>; the density of the high-density polyethyleneis 0.940-0.976g/cm<3>; and on the basis of 100 parts by weight of a mixture of the ultrahigh molecular weight polyethylene and the high-density polyethylene, the weight of the antioxidant is 0.5-20 parts, the weight of the assistant crosslinker is 0.1-10 parts and the weight of the silane crosslinking agent is 0.1-10 parts. The separation film is prepared through a chemical crosslinking method, sothat a difference value between the film rupture temperature and the obturator temperature of the prepared silane crosslinked polymer separation film and the hot shrinkage rate are improved and the safety performance of a battery is higher.

The invention provides a battery diaphragm. The base material of the diaphragm is a polyvinylidene fluoride non-woven fabric, coating layers are arranged on two sides of the polyvinylidene fluoride non-woven fabric, and the material of the coating layers includes an ultra high molecular weight polyethylene and a linear low density polyethylene. A fabrication method of the battery diaphragm is further provided. According to the battery diaphragm and the fabrication method thereof, the provided battery diaphragm has the advantages that the air permeability is remarkably improved, the closed pore temperature is remarkably lowered, the puncture strength and diaphragm breaking temperature are remarkably improved, a safe protective property is provided for a battery, and the battery diaphragm is applicable to power batteries.

The invention discloses a three-layer lithium battery diaphragm and a preparation method thereof. The diaphragm is prepared by adopting a three-layer coextrusion technology, and comprises an outer layer, a middle layer and an inner layer, wherein the outer layer is prepared from 92-93% of polypropylene A, 5-6% of polypropylene B and 1-3% of a reinforcing agent which are taken as raw materials; the middle layer is prepared from 83-86% of polypropylene A, 13-14% of polypropylene B and 1-4% of an additive which are taken as raw materials; the inner layer is prepared from 93-95% of polypropylene A, 3-4% of polypropylene C and 1-4% of a reinforcing agent which are taken as raw materials. The preparation method comprises the following steps of a) mixing and absorbing materials; b) extruding and stretching; c) baking; and d) stretching. The middle layer of the three-layer lithium battery diaphragm provided by the invention is a polypropylene layer, and the three-layer lithium battery diaphragm is prepared from the polypropylene layers of the outer layer and the inner layer in a three-layer coextrusion mode. The obturator temperature decreases greatly and reaches 138 DEG C minimally.

The invention provides a polyene microporous multilayer diaphragm and a manufacturing method thereof. The diaphragm is formed by combing three or more than three polyene layers, wherein in a plurality of polyene layers, at least one polyene layer is a polyethylene layer, and at least one polyene layer is a polypropylene layer; the polyethylene layer and the polypropylene layer are tightly attached to each other; and in adjacent polyethylene and polypropylene layers, at least one layer is a polymer blend layer which contains a certain amount of ethylene-propylene copolymer. The invention has the advantages that: in the integrated structure of the polyene microporous multilayer diaphragm, the properties of porosity, puncture strength, pore size, ventilation ratio, tensile strength, breaking elongation and the like are also identical to the high properties of a single-layer diaphragm; simultaneously, the defects of the single-layer diaphragm is overcome, namely the safety of the diaphragm is improved.

The invention discloses a coating composite for a lithium ion secondary battery membrane and a method for manufacturing the membrane. The coating composite comprises heat resistant resins and inorganic non-conducting insulation particles, molecular chains of the heat resistant resins comprise oleophylic structural units, hydrophilic structural units and functional group structural units, and a thermal decomposition temperature is larger than 250 DEG C. The inorganic non-conducting insulation particles have the advantages of being high temperature resistant, low in density, rigidity and water absorption and the like; composite micro porous membranes prepared through the coating composite has the advantages of being low in hole closing temperature, high in membrane breaking temperature, low in thermal shrinkage rate, high in combining force between a heat resistant coating and a substrate, good in wettability of the heat resistant coating surface and the like simultaneously; and the membrane used for manufacturing a lithium ion secondary battery has good comprehensive properties and reliable safety performances.

The invention relates to a battery polyolefin isolating membrane. The composite isolating film with high fused mass strength of the invention is a microporous membrane which takes the structure of B/A two-layer or B/A/B three-layer, wherein, A layer is a copolymer membrane of polyethylene or ethylene and 5 to 50 percent other olefins or a mixture membrane of the polyethylene or the ethylene and the 5 to 50 percent other olefins, and B layer is a copolymer membrane of propylene and 0.1 to 10 percent other olefins. The invention has the advantages that: a polymer A which provides low obturator temperature and a polymer B which provides high membrane rupture temperature and high fused mass strength are led in a formulation for preparation of the polyolefin composite microporous isolating membrane, thereby the isolating membrane with low obturator temperature, high membrane rupture temperature, high fused mass strength and high use safety is obtained.

The invention discloses a polypropylene microporous membrane with a three-layer compound structure and a preparation method of the polypropylene microporous membrane. The polypropylene microporous membrane with the three-layer compound structure comprises surface layers A and C and a core layer B, wherein the surface layers A and C are made from beta crystal form homo-polypropylene and the core layer B is made from beta crystal form co-polypropylene; or, the surface layers A and C are made from beta crystal form co-polypropylene and the core layer B is made from beta crystal form homo-polypropylene. The preparation method comprises the following steps: (1) respectively melting and mixing the beta crystal form homo-polypropylene and the beta crystal form co-polypropylene, carrying out co-extrusion via a three-layer compound die head and cooling the extruded molten membrane; and (2) stretching the three-layer compound beta crystal form polypropylene membrane. The polypropylene microporous membrane with the three-layer compound structure, disclosed by the invention, has high fusing temperature and low closed pore temperature simultaneously and has the advantages that when the membrane is used for battery diaphragms, closed pores can be timely molten to terminate the battery reaction and the internal short caused by fusing can be avoided, so that the safety is greatly increased.

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a power lithium battery diaphragm. The preparation method comprises the following steps of dissolving, assistant adding, extruding, sheeting casting, diaphragm forming by drawing, shaping and the like, and a polyolefin resin microporous membrane, namely a lithium battery diaphragm, is formed finally. The diaphragm prepared by the method is 10-25 mu m thick, has a preferential porosity being 40-70%, and 105 DEG C heat shrinkage rate below 5%. The prepared diaphragm has the advantages of low closed-pore temperature, high fusing temperature, low heat shrinkage rate, good mechanical properties and has excellent safety performance when used as a power lithium battery diaphragm. In addition, the power lithium battery diaphragm is a polyolefin resin microporous sinlge-layer membrane which has good heat stability after being subjected to process steps such as drawing and shaping.

The invention discloses a special composite coating diaphragm for a lithium battery. The special composite coating diaphragm comprises a microporous membrane, resin layers, ceramic layers and acrylicadhesive layers; the special composite coating diaphragm is characterized in that the resin layers coat the upper surface and the lower surface of the microporous membrane; one ceramic layer coats theouter side of each resin layer; one acrylic adhesive layer coats the outside of each ceramic layer; first micropores are formed in the microporous membrane; second micropores are formed in each resinlayer; third micropores are formed in each ceramic layer; and fourth micropores are formed in each acrylic adhesive layer. A preparation method of the special composite coating diaphragm for the lithium battery comprises the following steps of surface modification of boehmite alumina, preparation of the microporous membrane, preparation of a polymer composite membrane, preparation of modified boehmite alumina slurry, coating of the modified boehmite alumina slurry and bonding forming of an acrylic adhesive, thereby obtaining the special composite coating diaphragm for the lithium battery. According to the composite coating diaphragm, the security problem of a high-energy density battery core can be well solved.

The invention provides coating slurry for a diaphragm, a composite heat resisting diaphragm, and a preparation method of the composite heat resisting diaphragm, wherein the coating slurry for the diaphragm comprises and is prepared from the following materials: organic particles, ceramic particles, a binder and water; by solid content, the organic particles account for 24.5%-99.5% by weight, the ceramic particles account for 0-75% by weight, and the binder accounts for 0.5%-15%; the solid content is 20%-50% of the total weight of the coating slurry. Compared with a diaphragm in the prior art, the closed pore temperature in an electrolyte/battery is lower, and a current is cut off before the accelerated heat release of the battery.

The invention discloses a lithium ion battery diaphragm and a preparation method thereof. The ion battery diaphragm comprises a diaphragm base material, wherein the surface of the diaphragm base material is coated with a polyolefin coating, and the coating thickness of the polyolefin coating is 1 to 4 micrometers. The diaphragm base material is coated with the polyolefin coating, and an effect for reducing the obturator temperature can be realized, so that the worsening of a thermal runaway can be prevented, when the temperature in a lithium ion battery reaches the obturator temperature, current can be disconnected at the first time, an effect for protecting the lithium ion battery can be realized, the thermal shrinkage rate of the lithium ion battery diaphragm after being roasted for 1h under the temperature of 150DEG C is less than 5 percent; compared with a non-coated lithium ion battery diaphragm, for the lithium ion battery diaphragm disclosed by the invention, the liquid absorption addition rate is 10 to 28 percent, and the charging-discharging cycling efficiency of the lithium ion battery can be further improved.

The embodiment of the invention provides a battery diaphragm. The diaphragm comprises a polyolefin porous diaphragm base material, wherein the polyolefin porous diaphragm base material comprises polyethylene resin, the elongation of the polyolefin porous diaphragm base material in the MD direction is greater than 120%, the polyolefin porous diaphragm base material has an elongation rate of more than 120% in the TD direction, the polyolefin porous diaphragm base material has a primary heating crystallinity of less than 65% and a secondary heating crystallinity of less than 55%, which are measured by a differential scanning calorimeter, and the difference between the primary heating crystallinity and the secondary heating crystallinity is less than 12%. The battery diaphragm has the characteristics of high elongation and low hole closing temperature, and by implementing the embodiment of the invention, the diaphragm rupture risk can be reduced when a battery cell is mechanically abused,and meanwhile, diaphragm pores are closed in advance when the battery cell is thermally abused, so the safety of the battery cell is improved. The embodiment of the invention further provides a preparation method of the battery diaphragm as well as a battery and a terminal adopting the battery diaphragm.

The invention relates to the field of energy storage materials, in particular to a secondary battery which comprises an anode piece, a cathode piece, a diaphragm and electrolyte. The diaphragm comprises diaphragm matrixes and coatings, the coatings are arranged on the surfaces of the diaphragm matrixes and comprise polymer micro-spheres, and the softening temperatures of the polymer micro-spheres are 50-120 DEG C; the electrolyte comprises additives, and the decomposition voltages of the additives are 4.4V-4.8V. The secondary battery has the advantages that sufficient hole closing of the diaphragm can be synergistically promoted by the diaphragm with the polymer micro-sphere coatings and the additives, the polymer micro-spheres with the low softening temperatures are coated on the surfaces of the diaphragm, and accordingly the hole closing temperature of the diaphragm can be lowered; the voltages can be increased, accordingly, the reactive additives can be triggered, self-reaction can be quickly carried out at over-charge initial phases to generate heat, and melting of the polymer micro-spheres and large-area hole closing of the diaphragm can be promoted.

The invention provides a polyethylene composition for preparing a heat-shrinkage-resistant lithium ion battery diaphragm. The composition comprises high-molecular polyethylene, ultra-high-molecular polyethylene and an optional additive. The lithium ion battery diaphragm prepared from the composition has high heat shrinkage resistance, high tensile strength, high puncture strength, relatively high diaphragm-rupture temperature and relatively low closed-hole temperature, thereby ensuring safety in preparation and usage of the lithium ion battery.

The invention discloses a high-temperature resistant diaphragm material of a lithium ion battery and a preparation method of the high-temperature resistant diaphragm material. The diaphragm material comprises a modified nylon membrane and a cooling coating layer, wherein the two surfaces of the modified nylon membrane are coated with the cooling coating layer. The preparation method of the diaphragm material comprises the following steps of 1, taking the modified nylon membrane as a base membrane, and coating the two surfaces of the modified nylon membrane with a cooling coating to form the cooling coating layer and obtain a composite membrane; 2, carrying out vacuum drying on the composite membrane in the step 1, and then carrying out bidirectional stretching on the composite membrane; and 3, carrying out plasma processing on the stretched composite membrane in the step 2 to obtain the finished diaphragm. The diaphragm material has the characteristics of uniform pore distribution, excellent cooling performance, low high-temperature thermal shrinkage rate, high liquid absorption rate and high application safety.

The invention discloses a composite diaphragm with excellent high temperature performance and pore closing performance. The composite diaphragm is prepared by compounding a polyimide electrostatic spinning layer, a PE (Poly Ethylene) microporous membrane layer and a PP (Polypropylene) microporous membrane layer in sequence. The invention further discloses a preparation method of the composite diaphragm. The composite diaphragm has the advantages of high safety as well as excellent high temperature performance and pore closing performance.

The invention relates to the field of battery diaphragms, in particular to a high-safety diaphragm and a battery, the high-safety diaphragm comprises a porous base material, a heat-resistant coating coated on at least one side of the porous base material, and a low-hole-closing-temperature coating coated on the porous base material or the heat-resistant coating; the heat-resistant coating comprises heat-resistant resin; the low-hole-closing-temperature coating comprises a self-hole-closing material; and the self-closing material comprises cohesive self-closing resin with a low melting temperature or a low viscous flow temperature. The diaphragm rupture temperature and the heat-resistant shrinkage performance of the diaphragm are improved by arranging the heat-resistant coating, meanwhile, the low-pore-closing-temperature coating is introduced, and cohesive self-closing resin with low melting temperature or low viscous flow temperature can be rapidly melted or softened at a certain temperature to close pores of the porous base membrane, so that the purpose of reducing the pore closing temperature is achieved, the difference value between the hole closing temperature and the membrane breaking temperature is increased, and the high-safety diaphragm is obtained, so that the safety of the battery is enhanced.