695results about How to "Shorten the diffusion path" patented technology

The invention discloses a hydrothermal synthesis method of lithium-ion battery anode material of lithium iron phosphate, relating two kinds of metal phosphate. The steps are as follows: lithium source and phosphorus source are dissolved in water or mixed with water, and added into the reaction autoclave, the quaternary cationic surfactants and the alkylphenols polyoxyethylene ethers nonionic surfactant is also added into the reaction autoclave, the air in the dead volume of the autoclave inside is purged by the inert gas, the autoclave is sealed and heated to 40-50 DEG C with stirring, a feed valve and an exhaust valve are opened, pure ferrous salting liquid is added into the autoclave, and then the autoclave is sealed for the reaction of the material at 140 to 180 DEG C for 30 to 480 minutes; the mixture ratio of the invention is set as follows: the molar ratio of Li, Fe and P is 3.0-3.15:1:1.0-1.15, and then the resultant is filtered, washed, dried and carbon-coated, thus the lithium iron phosphate is obtained. The lithium iron phosphate which is produced by the invention has the advantages that: the electrochemical performance is excellent, the particle size distribution of which the D50 is between 1.5 um to 2 um is even, the phase purity is above 99 percent and the electronic conductivity of the material is improved.

The invention relates to a silicon-carbon composite negative pole material preparation method and a lithium ion battery. The preparation method comprises putting nanometer silicon and graphite micro-powder into a ball mill, carrying out ball milling uniform dispersion in an organic solvent environment, carrying out vacuum drying, putting the dried mixture and asphalt into a cone-type mixer, carrying out coarse mixing, putting the mixed powder subjected to coarse mixing into a mechanical fusion machine, carrying out mechanical fusion, carrying out heat treatment in an inert gas protective atmosphere and carrying out cooling to obtain the silicon-carbon composite negative pole material. The preparation method carries out asphalt softening coating on nanometer silicon so that silicon particle and electrolyte direct contact is avoided, a capacity reduction rate is delayed, a lithium ion diffusion path is shortened, an electrode material electron conduction loss is avoided, and first charge-discharge efficiency, a charge-discharge electric capacity and cycle performances are improved. Before coating, nanometer silicon is dispersed through graphite micro-powder so that it is avoided that in asphalt coating, nanometer silicon aggregation causes local capacity excess and nanometer silicon is uniformly dispersed.

The invention relates to a SiOx-based composite material, a preparation method and a lithium ion battery. The SiOx-based composite material comprises a SiOx/C material, wherein the SiOx/C material comprises SiOx nano particles, organism cracked carbon, nano conductive particles and amorphous conductive carbon layers, the SiOx nano particles, the organism cracked carbon and the nano conductive particles are wrapped in the amorphous conductive carbon layers, the SiOx/C material is in a spherical shape and comprises a porous structure, and x is more than or equal to 0.5 and less than or equal to 1.3. The composite material is used as a negative electrode material of the lithium ion battery, excellent in cycling performance, excellent in rate performance and low in size expansion effect, applicable to the fields such as top-grade digital electrons, electric tools and next-generation vehicle-mounted devices and wide in market prospect.

The invention discloses a nano ZSM-5 molecular sieve based catalyst and preparation and use methods. The molecular sieve catalyst consists of molecular sieves and metal components, wherein the molecular sieves are nano ZSM-5 molecular sieves with a short b-axis, a medium high silica-alumina ratio, less strong acid, high Lewis acid content, and resistance to hydrothermal deactivation. The preparation method is as follows: mixing a silicon source, an aluminum source, a template agent, a structure promoter, an additive and alkali with water, and stirring to prepare a precursor solution, then crystallizing, separating solid from liquid, and calcinating to obtain molecular sieve raw powder; mixing the molecular sieve raw powder with an ammonium salt solution, stirring, filtering, mixing with the ammonium salt solution for several times, stirring, filtering, and calcinating to obtain hydrogen-type ZSM-5 molecular sieves; mixing with the metal precursor solution, drying and calcinating to obtain the aromatization catalyst. The use method is as follows: transforming oxy-compound raw materials to aromatic hydrocarbon through the catalyst under the reaction conditions. The nano ZSM-5 molecular sieve based catalyst has the characteristics of being high in aromatics yield (reaching up to 99%) and long in service life (the catalyst is alive after 300 hours, and the aromatics selectivity reaches up to 70% after the catalyst is subjected to hydrothermal aging at 760 DEG C for 4 hours).

The invention relates to a monox/carbon composite material, comprising monox/graphene particles, organic matter pyrolysis carbon and graphite powder, wherein monox particles are adhered to the surface of a grapheme sheet; the organic matter pyrolysis carbon coats the monox/ graphene particles, and then is compounded with graphite. The preparation method of the monox/carbon composite material comprises the steps of: mixing monox particles with graphene to obtain the monox/graphene particles; coating organic carbon by obtained monox/graphene particles, thereby obtaining the monox/graphene material coated by the organic matter pyrolysis carbon; and mixing the obtained monox/graphene material coated by the organic matter pyrolysis carbon with the graphite powder, so as to obtain the monox/carbon composite material. The monox/carbon composite material is used as a lithium ion battery cathode material. Thus, the monox/carbon composite material has the characteristics of high first charge and discharge efficiency, excellent cycle performance and power charge and discharge properties, and low volume expansion effect.

The invention discloses a silicon-carbon composite material, a preparation method of the silicon-carbon composite material, and a lithium ion battery containing the silicon-carbon composite material. The preparation method comprises the following steps of: (1) reducing silicon dioxide by using metal with activity larger than that of silicon, so as to obtain a porous silicon-metal oxide composite; (2) corroding the metal oxide by acid, so as to obtain porous silicon; and (3) coating the surface of the porous silicon by carbon by taking a carbon source as a raw material, so as to obtain the silicon-carbon composite material. The silicon in the silicon-carbon composite material is prepared through using a metallothermic reduction method and porous silicon particles prepared through using the metallothermic reduction method are micron-sized and hardly agglomerate; the pore walls and the pore diameters in the porous silicon particles are nano-sized; compared with imporous micron-sized silicon powder, for the silicon-carbon composite material, the porous silicon particles have the characteristics that a diffusion path of a lithium ion in a silicon substrate is shortened, thus being beneficial to charging and discharging with large current, the pores can hold the volume expansion of silicon during silicon intercalation and the charging and discharging cycle life of the material is prolonged. The surfaces of the porous silicon particles are coated with a carbon layer with the certain pores and the conductivity of the silicon-carbon composite material is enhanced.

The invention relates to a preparation method of a carbon-coated sodium-micron-scale lithium titanate composite anode material. The method comprises steps as follows: lithium salt is dissolved in an aqueous solution of absolute ethyl alcohol, and the solution is marked a solution a; an organic titanium compound and a carbon source are dissolved in absolute ethyl alcohol, and the solution is marked a solution b; a chelating agent M is dissolved in absolute ethyl alcohol, ultrasonic dispersion is performed, and the solution is marked a solution c; the solution c is slowly dropwise added to the solution b while stirring, and white sol is obtained; then the solution a is slowly dropwise added to the white sol; after the sol is aged, heating, stirring, drying, grinding, sieving and calcination are performed, and the carbon-coated lithium titanate composite anode material is obtained. Lithium titanate has narrower particle size distribution and more uniform particle distribution, and sodium-micron-scale particles are uniformly inlaid to form particles with high tap density; the particle structure is loose and porous, the specific surface area of a formed electrode is larger, getting off of lithium ions in the lithium titanate material is facilitated, and the stability of the crystal structure of the lithium ions in the charge and discharge process is guaranteed.

The invention discloses a lithium-titanium oxide type lithium ion sieve absorbent and a method for preparing a precursor thereof, and relates to a method for preparing an inorganic absorbent for absorbing enriched lithium from salt lake brine, seawater and other liquid lithium resources. The method is characterized in that: titanium dioxide and lithium salt are taken as raw materials, ground by a ball grinder and dried so as to prepare a precursor Li2TiO3 of an ion sieve through a high-temperature solid-phase roasting method; and the lithium is eluted from the precursor Li2TiO3 by inorganic acid to prepare an ion sieve H2TiO3. The method has the advantage of simple technology, and the obtained ion sieve has the advantages of low solution loss and high adsorption capacity.

The invention discloses a preparation method of a soft/hard carbon modified anode material for lithium ion batteries. The method comprises the following steps: (1) carrying out mixed granulation; (2)screening and crushing; (3) mixing; (4) treating at high temperature; (5) screening; (6) modifying; (7) carrying out secondary carbonization. The method is characterized in that a soft carbon precursor and a hard carbon precursor are both used as binding agents, kneading and granulating are carried out at a certain temperature and under other conditions, small graphite particles are polymerized soas to enable the internal structure to be further densified and increase the volume density, high-temperature graphitization is then performed, and asphalt and resin are converted to pyrolytic carbon, so that a soft/hard carbon graphite composite systems is formed; the surface of the modified soft/hard carbon composite anode material is evenly coated with a layer of Ti3SiC2, having good electrical conductivity and stable chemical properties, and a conductive network, so that the improvement of the discharge capacity, discharge efficiency and cycling stability of the graphite anode material isbetter promoted.

The invention provides a ternary precursor with a composite hetero-structure. The molecular formula of the ternary precursor is Ni<1-a-b>CoM(OH)2@Ni<1-x-y>Co<x>M<y>O<z>, wherein 0<a<1, 0<b<1, 0<a+b<1, 0<x<1, ,0<y<1, 0<x+y<1, 1<z<1.5, and M represents Mn or Al. The ternary precursor comprises a ternary oxide precursor and a ternary hydroxide precursor. The ternary hydroxide precursor is coated on the surface of the ternary oxide precursor. The molecular formula of the ternary oxide precursor is Ni<1-x-y>Co<x>M<y>O<z>, and the molecular formula of the ternary hydroxide precursor is Ni<1-a-b>CoM(OH)2. The invention further provides a preparation method of the ternary precursor. According to the preparation method, a spray pyrolysis method and a co-precipitation method are combined, the ternary oxide precursor obtained by spray pyrolysis is taken as the seed crystal, then a layer of ternary hydroxide precursor is coated on the surface of the ternary oxide precursor through theco-precipitation method to obtain the ternary precursor, and the ternary precursor and lithium salts are mixed and sintered to prepare the ternary cathode material. The ternary cathode material has the advantages of good layered structure, high initial efficiency, high specific capacity, and excellent circulating ratio performance.