1092results about How to "Good thermal stability" patented technology

The invention relates to the field of graphene electrode materials, and in particular relates to a doped graphene electrode material, a macro preparation method as well as an application of the doped graphene electrode material in a high-capacity high-multiplying-power lithium ion battery. In the invention, graphene is taken as a raw material. The preparation method comprises the following steps: controlling the temperature rising speed rate through shielding gas; introducing gas containing nitrogen or boron elements in different concentrations at high temperature so as to realize the doping of heteroatoms of the graphene, and get the nitrogen or boron doped graphene; mixing the doped graphene, conductive carbon black and a bonding agent; adding a solvent; coating the mixture on a current collector after grinding; taking the mixture after drying, shearing and tabletting as a working electrode; adding electrolyte containing a lithium salt by taking a lithium plate as a counter electrode /reference electrode; assembling into a button-type lithium ion half-battery in a glove box; and carrying out constant current charge and discharge tests under the condition of high current density. According to the invention, the electrode stability of the material under the condition of high current density is improved, and the fact that the doped graphene has higher specific capacity and excellent cycle performance in a shorter time is realized.

The invention relates to a method for preparing polyol ester lubricating oil by using a composite solid acid catalyst. The method comprises the following steps of: adding a water carrying agent into polyol ester and monobasic fatty acid, performing esterification reaction under the action of the composite solid acid catalyst, and dehydrating and esterfying to obtain raw ester; performing filter pressing on the raw ester to separate the raw ester from the solid acid catalyst, wherein the catalyst can be recycled; and performing reduced pressure distillation on the raw ester to remove the residual fatty acid, and then deacidifying and decolorizing to refine with heating by using a refining adsorption bed layer respectively to obtain low-acid value polyol ester lubricating oil. The method has the advantages that the catalyst can be recycled, the esterification rate is high, an aftertreatment process is simple, and a product is low in acid value, high in purity, environment-friendly and suitable to be produced industrially. The reaction esterification rate can reach over 99 percent, and the acid value of the ester product obtained through refining can be controlled to be less than 0.01mg KOH/g. The product is excellent in visco-temperature performance, high in lubricity and thermal stability, strong in hydrolytic stability, low in volatility and excellent in electrical insulation property.

The invention discloses a positive material for a lithium ion battery and its preparation method, concretely relates to a modified cobalt acid lithium material and its preparation method, and relates to a lithium ion battery containing the material. The general formula of the material is LiMxLyNwCozO2, wherein 0.001<=x<=0.1, 0.005<=y<=0,05, 0<=w<=0.05, 1-x-y-w<=z<=1, M is one or more transition metals selected from Mn, Ni, Ti, Zr, Cr, Fe, Cu, Zn, Y, Ce, Sm, Pr, La, Mo or Nb and the like, L is one or more main group metal elements selected from Na, K, Ca, Mg, Sr, Ba, B, Ga, Sn, Sb, Bi or Al and the like; N is one or more of Li, Mn, Ni, Zr, Ti, Y, Ce, Sm, Mo, Nb, Na, K, Ca, Mg, Sr, Ba, B or Al. The material has the advantages of high specific capacity, excellent cycle performance and heat stability, simple preparation method and easy industrialization production.

The composite lubricating oil stabilizer includes the following components: ultraviolet ray absorbent and light stabilizer of hindered amine in the weight ratio of 1-5 and total content inside the composite lubricating oil stabilizer of 40-80 wt%; antioxidant selected from the shielding phenol, aromatic amine, phenolic ester, metal phosphate-sulfate and carbamate sulfide in 15-45 wt%; and phenyl phosphite as chelating agent in 3-18 wt%. The composite lubricating oil stabilizer of the present invention may be added into the base oil of hydrogenated lubricating oil in the amount of 0.01-2.0 wt% to improve the light stability of the hydrogenated lubricating oil obviously.

The invention relates to an oxa-phosphaphenanthrene flame retardant containing cyclotriphosphonitrile structure, and a preparation method and application thereof. The preparation method comprises the following steps: under the actions of K2CO3 and acetone, reacting hexachlorocyclotriphosphonitrile and 2,2'-diphenyldiphenol to obtain an intermediate I, reacting the intermediate I with p-hydroxybenzaldehyde to obtain an intermediate II, and reacting the intermediate II and DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) to obtain the target compound. The appearance of the compound is white, and the melting point is 186-188 DEG C; and the product has the advantages of favorable thermal stability, high flame retardancy and high purity (up to 99%). The invention has the advantages ofaccessible raw materials and advanced technique, and can easily implement industrial production. The flame retardant can be used as a reactive flame retardant to be connected to epoxy resin, polyurethane and other thermosetting resins, and can also be used as an additive flame retardant for halogen-free flame retardancy of ABS (acrylonitrile-butadiene-styrene), nylon and other engineering plastics with high heat resistance requirements.

The invention relates to a polymer mobility control agent suitable for an ultrahigh-salinity oil deposit and a preparation method thereof, and the polymer mobility control agent is mainly used for solving the problem that a polymer can not meet the requirement for tertiary oil recovery due to poor temperature resistant property, salt resistant property and shearing resistant property in the prior art. In order to better solve the problem, the technical scheme adopted by the invention is as follows: the control agent for an amphoteric hydrophobic associated polymer comprises the following components in parts by weight of the amphoteric hydrophobic associated polymer: 5-99.9 parts of nonionic water-soluble monomers, 0-50 parts of anionic monomers or/and cationic monomers, 0.1-10 parts of hydrophobic monomers with surface activity, 0.1-5 parts of inorganic substances and 1-20 parts of surface active agents. The preparation method disclosed by the invention can be used for the industrial production of the polymer mobility control agent suitable for the ultrahigh-salinity oil deposit.

The invention relates to a light-color quenching oil complexing agent composition and a preparation method thereof. The light-color quenching oil complexing agent composition comprises the following materials according to proportion by weight: 40 to 88 parts of refrigerant catalyst, 1 to 10 parts of brightener, 1 to 15 parts of antioxidant and 10 to 40 parts of anti-precipitation agent. The prepared composition product has high-temperature and low-temperature refrigeration catalysis functions and favorable brightness property and high-temperature and low-temperature anti-oxygen property and is suitable for preparing common and fast quenching oil with fast brightening.

The invention relates to a method for machining micro holes in a ceramic matrix composite through femtosecond lasers. According to the method, the silicon carbide ceramic matrix composite sample is placed on a working table and machined layer by layer in a spiral line mode through the femtosecond lasers or machined in a linear scanning mode, wherein the thickness of the sample is smaller than 3 mm; in the micro-machining process, the wave length of femtosecond laser machining ranges from 400 nm-1500 nm, the pulse width ranges from 80 fs to 500 fs, the output power of the lasers is determined according to the requirements of micro-machining and ranges from 20 mW to 20 W, and the repetition frequency of the lasers is determined according to the requirements of micro-machining and ranges from 50 K to 25 MHz; the sample is machined in a layer-by-layer removal mode, wherein the rotation speed of a machining head is 2400 rev/s. In the machining process, the method has the advantages that machining damage is small, and because material around the damage region is still in a cold state after machining, the heat effect is small; machining precision is high, energy of the femtosecond lasers is in Gaussian distribution, absorption and action of the energy in the machining process are limited within the size of which the focus center is quite small, and the machining dimension is expressed from a micro form to a sub-micro form.

The invention discloses a preparation method of bacterial cellulose based carbon nanofibers and relates to a preparation technology of a carbon fiber material. The preparation method comprises the following steps: carrying out purification treatment on bacterial cellulose obtained by bacterial fermentation and carrying out freeze drying, carrying out carbonization treatment by putting the dried bacterial cellulose material into an atmosphere furnace and heating to 600-1200 DEG C, further heating the processed material to graphitize the material, and cooling to obtain the bacterial cellulose based carbon nanofiber material having a three-dimensional net structure. The preparation technology is simple and easy to carry out, is convenient to operate and has low cost. The obtained bacterial cellulose based carbon nanofiber has a good spatial net structure, has excellent mechanical property, thermal stability and conductivity, and can be applied in fields of electron devices, special composite materials, high efficient catalytic materials, biological materials and the like.