30results about How to "Reduce compacted density" patented technology

The invention discloses a preparation method of high-compression high-capacity lithium iron phosphate. Weigh iron phosphate, lithium carbonate, polyethylene glycol and sucrose, then mix them, add alcohol for wet grinding; spray dry the slurry, and crush the spray-dried materials to obtain crushed materials; put the crushed materials into the roller The sintering is carried out in the first furnace, and the sintering is divided into four stages, namely, the heating section, the heat preservation section, the decarburization section and the cooling section. After crushing, screening, and iron removal in the wet room, vacuum packaging is carried out to obtain high-compression and high-capacity lithium iron phosphate. The method of the invention is simple and low in cost, and at the same time, the lithium iron phosphate with high compacted density and good electrical performance can be obtained through gas treatment of carbon dioxide.

The invention discloses a preparation method of a lithium-ion battery that improves high-voltage low-temperature discharge and cycle performance, and belongs to the technical field of lithium-ion batteries. The preparation method is as follows: a layer of negative electrode slurry A with a thickness of 170um~240um is coated on the paste surface of the negative electrode current collector, and the negative electrode slurry A is composed of negative electrode main material, high specific surface area conductive agent, CMC , SBR, and modified acrylic binder; a layer of negative electrode slurry B with a thickness of 170um~240um is coated on the short pasted surface of the negative electrode current collector, and the negative electrode slurry B is composed of negative electrode main material, low specific surface area Composed of conductive agent, CMC and SBR; rolling → sorting. The present invention uses two coating processes to coat different types of slurries on both sides of the negative electrode current collector to improve the bonding performance of the negative electrode active material and the current collector and the liquid absorption performance of the negative electrode sheet, especially improving the long-term coating The polarization effect between the paste surface and the negative electrode current collector improves the low-temperature discharge and cycle performance of the high-voltage battery.

The invention discloses a preparation method of a silicon-carbon anode material and a lithium ion battery. The preparation method includes: mixing nano-silicon with graphite solid phase, sieving the mixture, mixing the mixture with an amorphous carbon precursor solid phase, sieving the mixture, performing vibrating shaping, and sintering the product to obtain the silicon-carbon anode material. Bymeans of sieving, the graphite, nano-silicon and amorphous carbon precursor are dispersed, so that the surface of graphite can be uniformly coated with the nano-silicon and the surface of nano-siliconcan be uniformly coated with the amorphous carbon precursor; through the vibrating shaping, surface-to-surface contact between the amorphous carbon precursor and the nano-silicon and between the nano-silicon and the graphite is achieved without existence of a gap; through the sintering step, a volatile substance can be slowly volatilized from interior to exterior, so that a problem of forming pores since a huge gas pressure is generated from the volatile substance can be avoided. The silicon-carbon anode material, when being used for producing the lithium ion battery, shows excellent electrochemical cyclic stability.

The invention particularly relates to a preparation method for a ternary positive electrode material of a graphene composite lithium ion battery. The preparation method comprises the following steps of firstly preparing a ternary positive electrode material precursor by a crystallization control-coprecipitation method; performing multi-step sintering to prepare the ternary positive electrode material, wherein the mole ratio of nickel to manganese to cobalt (namely x to y to z) is equal to (0.30-0.90) to (0.50-0.80) to (0.05-0.50), and x+y+z=1; and finally preparing the ternary positive electrode material of the graphene composite lithium ion battery. According to the preparation method disclosed by the invention, the problem that graphene is difficult to disperse in the ternary positive electrode material is solved, the internal polarization resistance is greatly reduced, and high-current rate discharge is realized; furthermore, high discharge capacity and long cycle life are kept. The technology is simple, and the preparation method is low in energy consumption and favorable for large-scale production.

The invention discloses a preparation method of lithium iron phosphate. The method comprises the following steps: adding water into ferric chloride and lithium chloride in a molar ratio of 1: (1.03-1.05), and carrying out stirring and mixing to obtain a mixed solution; mixing tributyl phosphate and an N235 extracting agent according to a volume ratio of (6-10): 1, and carrying out uniform mixing under stirring to obtain an extracting agent; subjecting the mixed solution and the extracting agent to 6-8 stages of countercurrent extraction, and performing phase splitting to obtain an organic phase and a water phase; allowing the organic phase to enter a combustion furnace in a spray state, introducing air at the same time for combustion at a temperature of 300 DEG C to 450 DEG C, and performing dust collection to obtain a combustion material; and putting the obtained combustion material into a roller way furnace, performing calcining under the protection of an inert atmosphere, performingcooling to obtain a calcined material, carrying out jet milling on the calcined material, performing screening, and removing iron to obtain lithium iron phosphate. The method is simple in process andshort in process flow and can prepare the lithium iron phosphate material with high conductivity, low internal resistance, and excellent electrical properties.

The invention provides a preparation method of a lithium ion battery positive electrode with high rate performance, the positive electrode comprising a current collector and a first active material layer, a second active material layer and a passivation conductive layer which are located on the current collector, the first active material layer comprising lithium nickel oxide, the second active material layer comprising doped lithium manganese cobalt oxide and doped lithium iron phosphate, the passivation conductive layer comprising inorganic oxide particles and an organic conductive polymer.The preparation method of the invention obtains a positive electrode with high conductivity, stable structure and good cycling performance in a high-rate environment by controlling the production process.

The invention provides a method for preparing a lithium ion battery mixed positive electrode. Slurries comprise different proportions of a first active material, a second active material and a third active material, wherein the molecular formula of the first active material is LiNi0.8Mn0.1Co0.1O2, the molecular formula of the second active material is LiNi0.3Mn0.4Co0.3O2, and the molecular formulaof the third active material is LiMnPO4, and particles with two particle sizes exist in the first active material; the average particle size of the second active material is 50-200 nm, the length-to-diameter ratio of the second active material is 1.1-1.3, and the D90 / D10 value of the second active material is 1.6-2.2; and the average particle size of the third active material is 0.5-1 [mu]m, thelength-to-diameter ratio of the third active material is 1.5-2, and the D90 / D10 value of the third active material is 1.2-1.5. The slurries are respectively prepared according to the different structures of the active materials, a current collector is respectively coated with the slurries to sequentially obtain a first active material layer, a first active material and second active material mixedlayer and a third active material layer along a direction from a position adjacent to the current collector to a position away from the current collector. The slurries obtained in the invention havegood dispersibility and good retention performances, and the positive electrode has good high-rate performances and a high energy density.

A particle-based wax sweating method, comprising the following steps: 1) padding the bottom of a sweating device with water, 2) heating the raw wax to a liquid state, adding sweating particles, and then adding it to the sweating device; Cool down to 10-20°C below the melting point at a rate of h; 4) Drain the pad water, send the warm water pump to the sweating tank, heat at a rate of 0.5-2°C / h and collect sweating paraffins with different melting points; 5) Wait until the end of heating After waxing, the melted high melting point paraffin product flows into the intermediate tank; 6) use steam to purge the remaining sweat particles and the last fraction of the sweat tank, and then filter and separate the two to recover the sweat particles. The method of the invention reduces the compaction density of the perspiration raw material, is conducive to the outflow of oil and low-melting wax, improves the fluidity of the perspiration liquid, and doubles the separation effect; at the same time, the perspiration product has a relatively high yield and a melting range. Relatively narrow, the molecular weight of the wax product is concentrated, and the product enthalpy value is relatively high.