33results about How to "Prevent co-embedding" patented technology

The invention discloses a coke powder-based cathode material of a lithium ion power battery and a preparation method thereof. The cathode material has a D50 of 10-30 [mu]m, a minimum granularity of 5 [mu]m, a maximum granularity of 30 [mu]m, and a tap density of 1.1-1.5 g/cm<3>. The cathode material has a core-shell structure, wherein a core is graphitized coke powder, and a shell is composed of coal pitch pyrolytic carbon and metal particles. The cathode material contains 95.00-99.00 % of solid carbon and 1-5 % of metal or metal oxide particles by mass percent. The preparation method comprises crushing, grading and purifying the coke powder, cladding coal pitch on the coke powder particles, graphitizing under a high temperature, attaching metal or metal oxide on the particles, etc. The cathode material is excellent in rate performance, good in high-temperature and low-temperature performances, low in manufacture cost and suitable for large-scale industrialization.

The invention relates to a low-temperature electrolyte for LiFePO4 (lithium iron phosphate) lithium-ion batteries, belonging to the technical field of low-temperature electrolytes for lithium batteries. The electrolyte comprises dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, a film-forming additive and lithium polyoxometallate, wherein the lithium polyoxometallate refers to lithium phosphomolybdate Li3PMo12O40, lithium phosphotungstate Li3PW12O40, lithium silicotungstate Li4SiW12O40 or lithium silicomolybdenate Li4SiMo12O40. For solving the problems that in the prior art, the lithium ion transport of an electrolyte is blocked, slow in speed and low in efficiency and the electrolyte is poor in low-temperature performance, the invention provides a novel fluoride-free low-temperature electrolyte for LiFePO4 lithium-ion batteries; and by taking the non-fluoride lithium polyoxometallate with a three-dimensional skeleton structure as an electrolytic lithium salt and selectively adopting a low-viscosity carbonate solvent, through optimized proportioning, the migration rate of lithium ions is increased, and the low temperature properties of LiFePO4 batteries can be significantly improved.

The invention discloses modified natural graphite and a preparation method thereof. The preparation method comprises the following steps: (1) adding a wetting dispersant and a bonding agent in a weight ratio of 1: 10 to 3: 10 into water and carrying out full mixing so as to prepare a mixed solution with a mass concentration of 30 to 60%; (2) adding natural graphite into the mixed solution prepared in the step (1) and successively carrying out mixing and drying; (3) fully mixing a substance obtained in the step (2) with an amorphous carbon precursor and a graphitization catalyst in a cladding kettle, carrying out heating to 300 to 400 DEG C and then carrying out thermal condensation polymerization at a constant temperature; (4) subjecting a substance obtained in the step (3) to compression molding and then carrying out hot isostatic pressing; and (5) subjecting a substance obtained in the step (4) to carbonizing treatment at first and graphitization treatment next under the protection of inert gas. A lithium ion battery negative electrode material prepared from the modified natural graphite has high initial charge and discharge efficiency, long cycle performance and good application prospects.

The invention relates to a method for recovering a lithium ion battery anode material. The method comprises the following steps: S1: collecting, crushing and sifting the graphite slag left after recovering metal of the lithium ion battery to obtain finer and more uniform graphite slag; S2: mixing graphite slag: asphalt: catalyst at a mass ratio of 100:1-20:1-10 to obtain a mixture; S3: under the protection of an inert gas atmosphere, carbonizing the graphite slag mixture at 500-1100 DEG C for 2-20 hours; then at 1500 DEG C-2250 DEG C graphitizating for 10-35 hours to obtain a graphite material. The method can obtain graphite anode material with excellent performance by using less asphalt, lower graphitization temperature and shorter graphitization time, and the performance of the obtainedgraphite anode material can directly meet the requirements for manufacturing a new lithium ion battery anode.

The invention discloses a composite graphite negative electrode material for lithium ion batteries and a preparation method thereof. The preparation method comprises the following steps: mixing a synthetic graphite raw material, a natural graphite raw material and an adhesive in a mass proportion of 100: (55 to 65): (3 to 7); under inert gas shielding, putting the mixed materials into a low-temperature surface modification reaction kettle, warming and stirring to obtain a cladding body; carrying out carbonizing treatment on the cladding body; enabling the cladding body through carbonizing treatment to enter into a fusing machine for normal temperature modification to prepare a fusing body, and carrying out graphitization treatment on the fusing body in inert gas to prepare the negative electrode material for lithium ion batteries. According to the graphite negative electrode material for lithium ion batteries disclosed by the invention, the specific capacity is not smaller than 355 mAh/g, and the first charging and discharging efficiency is more than 91.0%; and the graphite negative electrode material has relatively high gram volume, is extremely high in rate capacity and cycle performance and stable in performance, and can be widely applied to negative electrode materials of the lithium ion batteries.

The invention discloses a graphite negative electrode material of a lithium-ion battery and a preparation method of the graphite negative electrode material. The method comprises the steps of mixing an artificial graphite raw material with a binder and a catalyst SiC (the content is greater than 92%) at the mass ratio of 100:(6-12):(3-8) during preparation, putting the evenly mixed materials into a low-temperature surface modification reaction kettle in an inert gas and carrying out warming and stirring to obtain a coated body; carrying out graphitization treatment on the coated body; and fusing the coated body subjected to graphitization treatment and the binder at the mass ratio of 100:(2-6) to prepare a fusion body and carrying out carbonizing treatment on the fusion body in the inert gas to obtain the graphite negative electrode material of the lithium-ion battery. According to the prepared graphite negative electrode material of the lithium-ion battery, the initial discharge capacity is not smaller than 355mAh/g; the initial charge-discharge efficiency is greater than 92.0%; the graphite negative electrode material has the advantages of high electric capacity, low irreversible capacity and very good and stable battery cycle performance, especially has great advantages in a low-temperature cycle, and is used as the negative electrode material of the lithium-ion battery and the like.

The invention discloses a fluoro-alkyl sulfonamide additive, with a structural formula as shown in a formula I, for a lithium-ion battery electrolyte for promoting film formation of a graphite carbonanode; the formula I is as shown in the specification, wherein R1 is hydrogen, a benzene ring and a pentabasic or hexahydric heterocyclic group; the pentabasic or hexahydric heterocyclic group is selected from furan, thiophene, pyrrole, thiazole, imidazole, pyridine, pyrazine, pyrimidine and pyridazine; and R2 and R3 are F atoms or fluorinated alkyl of which 1-3 hydrogen atoms in methyl, ethyl andpropyl are substituted by F. The performance of an SEI film formed by the fluoro-alkyl sulfonamide additive is superior to that of an SEI film formed by VC, the cycling stability of the graphite carbon anode is better improved, the safety performance of a lithium-ion battery is improved and the fluoro-alkyl sulfonamide additive has good practicability and economic value.

The invention belongs to the field of lithium ion batteries, and discloses a non-aqueous electrolyte for a lithium ion battery with a ternary positive electrode material and a negative silicon-oxygen-carbon composite negative electrode material, which comprises a non-aqueous organic solvent, an electrolyte lithium salt and an electrolyte additive; the non-aqueous organic solvent comprises ethylene carbonate and methyl ethyl carbonate; and the electrolyte additives comprise vinylene carbonate, fluoroethylene carbonate, 1, 3-propane sultone, vinylethylene carbonate and lithium difluorophosphate. The non-aqueous electrolyte contains cyclic carbonate, a negative electrode film-forming agent, a positive electrode film-forming agent and three lithium salts. The lithium ion non-aqueous electrolyte can be applied to improvement of high-temperature and normal-temperature cycle performance.

The invention relates to a preparation method of a modified ternary anode material. According to the anode material, a ternary anode material is coated with polyvinylpyrrolidone resin to form an amorphous carbon coating layer on the surface of the ternary anode material; polyvinylpyrrolidone is organic silicon modified polyvinylpyrrolidone; the ternary anode material is LiNixCoyMnzO2, wherein x ismore than or equal to 0.3 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.5, and z is more than or equal to 0 and less than or equal to 0.5, and x+ y+ z=1. The preparation method specifically comprises the following steps: mixing the polyvinylpyrrolidone and the ternary anode material in ethanol, then stirring and filtering the mixture, heating the mixture tocarbonize the mixture, and finally cooling and smashing the product. The preparation method disclosed by the invention has the advantages that the modified polyvinylpyrrolidone and the ternary anodematerial are treated to prepare the modified ternary anode material, and the initial efficiency of the modified ternary anode material is 13 percent higher than that of a non-modified material; the initial efficiency of a ternary anode material coated sample is higher than that of a non-modified ternary material, and the later cycle efficiency of the sample is also 60 percent higher than that of the non-modified material; the defect of low cycle stability of the ternary anode material can be effectively improved.

The invention discloses an electrolyte of a lithium ion battery for improving the safety performance of the battery. The electrolyte comprises an organic solvent, a lithium salt dissolved in the organic solvent and an additive, the additive is dithiocyano alkane, the corresponding molecular formula of the additive is CNR1SSR2CN, R1 and R2 are alkane with the carbon atom number ranging from 0 to 4,or hydrogen atoms on the alkane are replaced by fluorine atoms, and the number of the replaced fluorine atoms is within 1-5. In the actual experiment process, the added dithiocyano alkane additive can form surface protective films on the surfaces of the positive electrode and the negative electrode of the lithium ion battery as a sulfur-containing substance, so that the co-intercalation of solvents is prevented under the conditions of battery formation, circulation and the like, and the side reactions are reduced. Meanwhile, the nitrile substance can inhibit gas production of the battery under a high-voltage condition, and can effectively solve the problem of gas expansion of the battery under high voltage when being used as an additive of the electrolyte of the lithium ion battery.

The invention discloses an additive of lithium ion battery electrolyte, containing allyl ethyl carbonate (AEC). The invention also discloses the lithium ion battery electrolyte containing the additive. The additive and electrolyte of the invention can improve the compatibility of propylene carbonate (PC) and the natural graphite cathode materials, thus effectively prolonging the cycle life of thelithium ion battery.