35results about How to "Strong liquid absorption and retention capacity" patented technology

The invention discloses a graphine composite electric conduction agent for an iron phosphate lithium battery, and simultaneously discloses a preparation method of the electric conduction agent. The electric conduction agent provided by the invention consists of graphine, active carbon and a bonding agent in a weight ratio of 1:(0.001-0.1):(0.01-1). The preparation method comprises the following steps: 1) preparing a solution A; 2) preparing a solution B; and 3) preparing the electric conduction agent. According to the invention, the preparation method is simple, the prepared electric conduction agent has the advantages of uniform dispersion, good stability, high electron conduction capability and uniform heat conduction, and the electric conduction agent has higher liquid absorption and liquid protection capabilities when being doped into the iron phosphate lithium battery; and the electric chemical property of the iron phosphate lithium battery which is prepared by adopting the electric conduction agent provided by the invention is improved prominently, compared with the iron phosphate lithium anode material in which the composite electric conduction agent is not doped, when the prepared graphite composite electric conduction agent is doped into the 50AH iron phosphate lithium anode material, the alternating current internal resistance is reduced by 20%, and the circulating service life is improved by 15%.

The invention relates to a graphene composite conductive agent and a preparation method thereof. The graphene composite conductive agent is prepared from the following components in parts by weight: 70-100 parts of graphene, 20-45 parts of carbon nano-tubes, 30-45 parts of epoxy resin, 10-25 parts of monoethanolamine, 200-300 parts of solvent, 2-3 parts of additives, 7-10 parts of conductive polymer agent, 2-4 parts of glass beads and 3-8 parts of iridium acetylacetonate. According to the conductive agent and the method, the graphene is taken as the master component, the carbon nano-tubes are taken as the secondary component, through utilization of the excellent electric conductivity of the graphene, the capacity of an electrode material is increased, the internal resistance of a battery is reduced, and the cycle life of the battery is prolonged. The 2C rate is improved by 6-10% when a lithium ion battery is prepared, the cost is reduced, and the lithium ion battery is highly competitive.

The invention provides a preparation method of a high-capacity silicon-carbon composite negative electrode material. The method comprises three preparation steps of a composite material A, a composite material B and the silicon-carbon composite negative electrode material, wherein polystyrene, a carboxylated carbon nano tube and nanosized silica spheres are used in the preparation process of the composite material A; the composite material A and a sucrose solution are used in the preparation process of the composite material B; an argon furnace and argon are used in the preparation process of the silicon-carbon composite negative electrode material; and the prepared silicon-carbon composite negative electrode material is doped with small-particle size silica in a large-particle size polystyrene gap, so that the contact area and the compaction density of the silicon-carbon composite material can be improved and the internal resistance of the silicon-carbon composite material is reduced. The silica is expanded in the charge and discharge processes, but the spherical polystyrene can buffer expansion of the silica. Meanwhile, the polystyrene has a double-bond structure, so that the transmission rate of electrons can be improved and the rate capability of the silicon-carbon composite negative electrode material is improved.

The invention discloses a lithium ion battery silicon composite negative electrode material and a preparation method thereof. The silicon composite negative electrode material comprises a matrix mixture and a carbon layer which is coated on the surface of the matrix mixture. The matrix mixture is composed of the following components in parts by weight: 1 to 5 parts of nano silicon, 1 to 5 parts of lithium-containing compound, 1 to 10 parts of hollow carbon sphere, and 70 to 95 parts of graphite. The capacity of the negative electrode material is increased by the nano silicon, the doped hollow carbon spheres reduce the expanding effect of silicon during the reaction process, and thus the conductivity and structure stability of the matrix material are both improved. The carbon layer, which is coated on the matrix surface, is used to connect different matrix parts. Each component in the matrix mixture cooperates with the carbon layer and generates a synergetic effect, so the silicon composite negative electrode material has the advantages of large capacity, strong ability of absorbing and maintaining liquid, low expansion rate, and good cycling performance, is capable of improving the comprehensive performance of lithium ion battery, and has a wind application prospect.

The invention discloses a lithium ion battery silicon-carbon negative electrode material and a preparation method thereof. The negative electrode material comprises a core-shell structure, and a middle layer is arranged between the core and the shell. The core comprises a silicon material, the middle layer is a buffer layer composed of hollow carbon spheres, and the shell is a graphite-coated layer. The core comprises a silicon material, and thus the gram volume of the negative electrode material is increased. Moreover, the buffer layer composed of hollow carbon spheres relieves the silicon expansion, and the liquid absorbing and maintaining performance of the negative electrode material is also improved. The graphite coated layer has very good mechanical strength and conductivity. The materials in each layer cooperate with each other and generate a synergetic effect, so that the structure of the negative electrode material becomes more stable, and the structure is not easy to destruct during the discharge / charge process. The negative electrode material has the advantages of high gram volume, strong liquid absorbing and maintaining performance, and low expansion rate. The lithium ion battery using the negative electrode material has the advantages of high capacity maintaining rate during the circle process, slow attenuation speed, and excellent cycling performance, and is especially suitable for the field of mobile communication.

The invention relates to the technical field of lithium-ion batteries. In order to solve the problem that the traditional lithium-ion battery separator easily causes a short circuit inside the battery and cannot meet the specific requirements of positive and negative electrodes, a Janus separator for lithium-ion batteries is provided. The Janus separator for lithium-ion batteries It consists of a high temperature resistant support layer and polar functional layers and nonpolar functional layers loaded on both sides of the high temperature resistant support layer. The Janus separator of the lithium ion battery of the present invention can promote the formation of a more stable and high-quality SEI film on the surface of the negative electrode, which is conducive to the higher capacity and rate performance of the positive electrode material, thereby improving the safety and high-temperature cycle performance of the battery.

The invention relates to a preparation method of the composite cathode material of a lithium ion battery, the composite cathode material of the lithium ion battery and the lithium ion battery and belongs to the technical field of lithium ion battery materials. The preparation method includes: dispersing silicon materials and polyacrylonitrile in a spinning solvent to obtain a core layer spinning solution, and dispersing polymethyl methacrylate in a spinning solvent to obtain a shell layer spinning solution; using the coaxial spinning technology to produce fibers so as to obtain a wrapping precursor; adding the wrapping precursor into a film-forming additive solution, mixing, and heating to remove the solvent so as to obtain a film-forming precursor; sintering the film-forming precursor under 500-800 DEG C for 1-24 hours to perform carbonization treatment so as to obtain the composite cathode material. The composite cathode material prepared by the method is high in gram volume, high in liquid absorbing and maintaining ability, excellent in circulation performance, high in low-temperature discharge ability, quite suitable for being applied to fields such as electric cars and energy storage, and the like.