65results about How to "Improve electronic conductance" patented technology

The invention discloses a lithium ion battery phosphatic composite cathode material and a preparation method thereof. The composite material is a multinuclear core shell structure composed of a plurality of cores and a housing layer, the cores are lithium iron phosphate particles wrapped by lithium vanadium phosphate and the housing layer is amorphous carbon. Preparation of the lithium iron phosphate particles wrapped by lithium vanadium phosphate comprises the following steps: preparing precursor sol with a sol gel method, adding lithium iron phosphate powder to disperse uniformly, carrying out spray drying on the above mixture, calcining the above resultant in inert gas, and followed by cooling and grinding to obtain the lithium iron phosphate particles wrapped by lithium vanadium phosphate. Preparation of the composite cathode material comprises the following steps: dissolving a carbon source compound into deionized water, adding core materials, dispersing the above resultant uniformly, carrying out second spray drying, calcining the above resultant in inert gas, and followed by cooling to obtain the composite cathode material. The composite material prepared in the invention has good electronic conduction performance, good ionic conduction performance and excellent electrochemistry performance. Because of existence of lithium vanadium phosphate, energetic density of a material is raised. Because of the multinuclear core shell structure like nano/micro structures, the composite material has good processing performance, and tap density of the material is greatly raised.

The invention provides a positive pole piece which is characterized by comprising a positive pole current collector, a buffer conducting layer and a positive pole active layer in a sequential stacking mode. The buffer conducting layer comprises phosphate, a first conductive agent and a first binder. The phosphate has the following general formula: LiMPO4, wherein M is selected from one of Fe, Mn and Co or a composite of a plurality of Fe, Mn and Co. The thickness of the buffer layer is 2-50 millimeters, and the grain size of the first conductive agent is smaller than 75 millimeters. In the buffer conductive layer, the phosphate content is 40-90wt%, the first conductive agent content is 5-10wt%, and the first binder content is 5-50wt%. Meanwhile, the invention further discloses a preparation method of the positive pole piece and a battery adopting the positive pole piece. The battery prepared from the provided positive pole piece has good over-charging performance and the safety of the battery is greatly promoted.

The invention relates to a titanium niobate composite material, a preparation method thereof, and a cathode and a battery containing the composite material. The titanium niobate composite material is represented as BxCyNz-LaTibMcNbdOe, wherein BxCyNz represents a compound containing boron carbon or carbon nitrogen or boron carbon nitrogen; L represents Li or Na, preferably Li; M is one element selected from Al, B, V, Cr, Mn, Fe, Co, Ni, Ce, Y, Zr, Mo, La, Ta, N and P; x, y, z, a, b, c, d and e represent mole percentages, x is no less than 0 and less than 1, y is larger than 0 and less than 1, z is no less than 0 and less than 1, a is no less than 0 and no larger than 0.2, b is larger than 0.8 and no larger than 1.1, c is no less than 0 and less than 0.2, d is larger than 1.95 and no larger than 2.1, e is no less than 6.8 and no larger than 7, and x and y are not 0 at the same time. The composite material disclosed herein and used as a cathode material of a lithium ion battery has the advantages of high coulombic efficiency, high ionic and electric conductance, good cycling performance of high-rate charge and discharge, high safety, no pollution, and low price.

The invention discloses a preparation method of a lithium ion battery cathode material SiOX-TiO2/C. The preparation method comprises steps as follows: analytically pure organic silicon sources, organic titanium sources and organic carbon sources are weighed in a certain mole ratio; the organic silicon sources are dissolved in a mixed solution of deionized water and absolute ethyl alcohol and stirred, the pH of the solution is adjusted to be alkaline, and a mixed solution A is obtained; the organic titanium sources are dissolved in the absolute ethyl alcohol and stirred for a period of time, and a mixed solution B is obtained; the mixed solution B is added to the mixed solution A and left to stand at the room temperature after being stirred for a period of time, and a colloidal mixed solution is obtained; after the colloidal mixed solution is mixed with the organic carbon sources, mechanical ball-milling treatment is performed; the mixed solution after mechanical ball-milling treatment is dried, and a precursor is obtained; the precursor is put in a crucible and calcined under the protection of inert atmosphere, thermal insulation is performed for multiple hours, and a product is cooled to the room temperature with the furnace. Compared with the prior art, the cathode material prepared with the method has good rate performance, the raw materials are cheap, the preparation process is simple, and the yield is high.

The invention relates to a preparation method of a lithium ion battery negative electrode material silicon oxide-carbon/graphite. The preparation method comprises the steps of taking tetraethyl orthosilicate as a silicon source and sucrose as a carbon source, performing in-situ combination on a gel-state silicon oxide, the sucrose and the graphite by hydrolysis-condensation reaction of the tetraethyl orthosilicate, and performing ball-milling to disperse the graphite to obtain a uniform silicon-oxygen-sucrose-graphite precursor; and allowing the sucrose to split and reducing silicon oxide during the subsequent thermal treatment process so as to prepare the uniformly-combined silicon oxide-carbon/graphite material. The in-site process of the silicon oxide and the graphite is simple in process and low in cost, and the prepared silicon oxide-carbon/graphite material is uniform in combination; with the introduction of the graphite, the electron conductivity of the composite material can beimproved, the coulombic efficiency of the composite electrode material is effectively improved, so that the electrochemical performance of the electrode material is remarkably improved; and the silicon oxide-carbon/graphite material can be used as a potential high-performance lithium ion battery negative electrode material and is expected to be widely applied to the fields of various types portable electronic equipment, an electric automobile and aerospace.

The invention discloses a K ion-doped and high-voltage spinel/carbon double-layer coated lithium-rich anode material and a preparation method thereof. The lithium-rich anode material comprises a K ion-doped modified core and a high-voltage spinel/carbon double coating layers, wherein the surface of the core is coated with the high-voltage spinel/carbon double coating layers, the core is Li1.2-xKxMn0.6-yNi0.2-yCo2YO2, x is equal to 0.00-0.1, and y is equal to 0.00-0.05; the component of the high-voltage spinel layer in the high-voltage spinel/carbon double coating layers is Li1-xKxMn1.5-yNi0.5-yCo2yO4, x is equal to 0.0-0.2, and y is equal to 0.0-0.1; the carbon coating layer is of a composite structure of dopamine polymer pyrolytic carbon and reduced graphene oxide. The preparation method includes the steps that through a spraying drying technology, the K ion-doped modified core is prepared, the surface of the core is coated with dopamine polymer, coating of graphene oxide is carried out on the basis, and through follow-up sintering, the K ion-doped and high-voltage spinel/carbon double-layer coated lithium-rich anode material is prepared. A modification step is easy to control, and the electrochemical performance of the lithium-rich anode material can be obviously improved.

The invention discloses a transition metal cobalt single atom/cluster embedded nitrogen-doped carbon skeleton material, and a preparation method and application thereof. The preparation method comprises the following steps: adding a cobalt source, a nitrogen-containing carbon source and silicon dioxide into a solvent, and carrying out ultrasonic stirring; carbonizing the obtained mixture in an inert atmosphere; carrying out pickling and etching on the obtained product in hydrochloric acid and hydrofluoric acid, and then washing and drying to obtain the transition metal cobalt single atom/cluster embedded nitrogen-doped carbon skeleton material. The method is simple in step and high in repeatability, and for the transition metal cobalt single atom/cluster embedded nitrogen-doped carbon skeleton, a mixed structure is endowed with enhanced electron conduction, and a large amount of uniformly dispersed N-C and Co-Nx active sites are introduced, thereby facilitating absorption of lithium ions and promotion of the interface reaction of the electrode material and the electrolyte. When being used as a lithium ion battery negative electrode material, the metal cobalt single atom/cluster embedded carbon hybrid material shows ultrahigh electrochemical activity and has very high potential application value.

The invention discloses an iron fluoride/carbon composite positive electrode material, a preparation method thereof and a lithium ion battery. The method comprises the following steps of: (1) reacting steam of a fluorine source and steam of a carbon-containing organic matter with an iron source to prepare a precursor; and (2) carrying out heat treatment on the precursor to obtain the iron fluoride/carbon composite positive electrode material. A fluorine source and a carbon source are introduced through gas-phase reaction, the powder morphology is controlled, and the high-performance iron fluoride positive electrode material is obtained. The lithium ion battery positive electrode material provided by the invention has the advantages of high reversible specific capacity and good cycling stability.

The invention discloses a preparation method of silicon-graphene compound conductive paste. The preparation method comprises the following steps: (1) pre-treating graphite: putting the graphite into a mixed solution composed of an oxidant and an intercalation agent; carrying out ultrasonic stirring treatment to obtain a product; washing, filtering and drying the product and then putting the product into a muffle furnace; carrying out high-temperature treatment in nitrogen atmosphere to obtain a graphene dispersed solution for later use; (2) preparing the silicon-graphene compound conductive paste: putting micron-grade high-purity silicon powder and a grinding ball into a grinding pot at the mass ratio of (1-50) to 1; after vacuumizing the system by a vacuum pump, introducing protective atmosphere; driving a stirring rod by a motor and driving the grinding ball by the stirring rod to grind and crush raw material power; adding a carbon binding agent and the graphene dispersed solution; and further stirring and crushing for 0.1h-3h to finally obtain the silicon-graphene compound conductive paste. The conductive paste can be directly prepared into an electrode through forming a film on a current collector without the utilization of the binding agent and the electronic conduction of the electrode is greatly improved.

The invention relates to a selenium and silicate co-doped high-nickel cathode material, and a preparation method and application thereof. The cathode material is a selenium and silicate co-doped modified high-nickel cathode material, and has a chemical formula of LiNixM1-xSea (SiO4) bO2-a-b, wherein M is at least one of Mn, Co or Al, and 0.5 <= x < 1, 0 < a <= 0.05, 0 < b <=0.05. The high-nickel cathode material is doped with low-valence anions by the selenium and silicate so as to improve the lattice structure of the material. The selenium and the silicate have good synergistic effect, can improve the structural stability of the material under high voltage, and obviously improve the electrochemical performance of the high-nickel cathode material. The obtained cathode material has a firstcycle discharge specific capacity greater than or equal to 185mAh/g and a capacity retention rate greater than or equal to 85% after 200 cycles at a 2.5-4.2V voltage window and 0.1C current density, and has a good application prospect.

The invention discloses a lithium ion battery positive electrode slurry as well as a preparation method and application thereof. The preparation method comprises the following steps of (1) mixing a positive active material, a binder, a first conductive agent and a solvent to obtain the mixed slurry; and (2) mixing the mixed slurry with a second conductive agent so as to obtain the lithium ion battery positive electrode slurry, wherein the first conductive agent is composed of carbon nanotubes, graphene, conductive carbon black, a dispersing agent and the solvent, and the second conductive agent is conductive carbon black. By adopting the method, the distribution of the conductive agent in a positive plate can be remarkably improved, and the problem of poor electronic conductivity and ion transmission of the positive plate is solved, so that the positive plate can exert higher gram volume, and has better rate capability, low-temperature performance and cycle performance.

The invention discloses a carbon-containing sulfide solid electrolyte for a solid-state lithium battery and a preparation method of the carbon-containing sulfide solid electrolyte. The carbon-containing sulfide solid electrolyte is obtained by mixing a sulfide solid electrolyte with an organic matter and then sintering. The electronic conductivity of the carbon-containing sulfide solid electrolyte is obviously improved, the carbon-containing sulfide solid electrolyte is mixed with an oxide positive electrode to form an ion-electron hybrid network positive electrode with higher electronic conductivity, the interface resistance is reduced, and the stability of the positive electrode is improved.

The invention discloses a silicon anode of a lithium ion battery. The silicon anode is formed by bonding a conductive agent and an anode material, the anode material comprises anode active matter and a binding material, the anode active matter comprises graphite and silicon dioxide, and the binding material is an organic solvent type binding agent. A conductive agent is of a silicon nanotube ball structure and comprises a plurality of evenly distributed silicon nanotubes, and the anode material is attached to the surfaces of the silicon nanotubes. A carbon material has high electronic conductivity and ionic conductivity, the rate capacity of the silicon material can be improved, and the volume effect of silicone in the circulating process can be inhibited. The silicon anode has high battery capacity and circulating stability.

The invention discloses a lithium ion battery, a lithium ion battery negative electrode material and a preparation method thereof. The lithium ion battery negative electrode material comprises a composite microsphere of silicon/silicon oxide compound and graphite, an amorphous carbon layer coated on the surface of the composite microsphere and a copper layer coated outside a part of the amorphouscarbon layer. A copper-carbon double-layer coating structure is successfully constructed by coating the amorphous carbon layer on the composite microsphere of silicon/silicon oxide compound and graphite and then plating the copper layer outside the amorphous carbon layer. The copper can be used as a good conductor and can improve the electron conductance of the lithium ion battery, and the coppercan also be used as a ductile metal to provide a high-strength coating layer, effectively suppress the volume expansion of silicon, avoid the powdering of active materials such as silicon/silicon oxide compound, reduce the specific surface area of the composite microsphere by double-layer coating, reduce the contact area between the active materials such as silicon/silicon oxide compound and electrolyte and improve the first coulomb efficiency, rate performance and cycle performance of the lithium ion battery negative electrode material.

The invention provides a low-temperature carbon-coated composite material, its preparation method and application, and a secondary lithium battery containing the composite material. Specifically, the preparation method includes: leaving a carbon-containing precursor to react at a temperature of 200-600DEG C to generate a carbon material with high conductivity, and coating the surface of a used material evenly with the carbon material, thus obtaining the low-temperature carbon-coated composite material. The lithium secondary battery containing the composite material provided in the invention has the advantages of high reversible capacity, good circulation, outstanding rate performance, safety and reliability.

The invention discloses a coating modification method for reducing metal dissolution of a high-voltage ternary positive electrode material. The method comprises the following steps of: (1) adding metal hydroxide into a phosphoric acid solution to prepare a metal phosphate solution, adding a ternary positive electrode material into the metal phosphate solution, stirring, and carrying out spray drying treatment to obtain a core layer solid mixture pre-coated with metal phosphate; and (2) mixing the core layer solid mixture obtained in the step (1) with a metal oxide and fluoride, carrying out ball milling for 1-20 hours, and sintering to obtain the coated modified ternary positive electrode material of which the inner layer is coated with metal phosphate and of which the outer layer is coated with metal oxide-fluoride. According to the core-shell structure coating method adopting the composite coating process, the coating form of a core-shell structure with the phosphate as the inner coating layer and the metal oxide-fluoride as the outer coating layer is adopted, uniform coating can be achieved, and the coating layers are high in strength and good in effect.

The invention provides an electrode plate and a preparation method thereof, and a lithium ion battery. The electrode plate comprises a current collector and active substance layers positioned on two sides of the current collector, wherein the active substance layers are provided with holes, and the thickness of the electrode plate is more than 0.30 mm. The preparation method comprises the following steps: 1) coating two surfaces of the current collector with electrode slurry, and carrying out drying and rolling to obtain an unpunched electrode plate, wherein the thickness of the electrode plate which is not punched is 0.30 mm or above; and 2) punching the active substance layers of the unpunched electrode plate to obtain the electrode plate. According to the electrode plate provided by theinvention, by increasing the thickness of the electrode plate, the proportion of the current collector is reduced, and specific energy is improved; the electronic conductivity of the electrode plateis improved through the variety and proportion of a conductive agent; by punching holes in the active substance layers, the liquid absorption property of the electrode plate is improved, the polarization internal resistance of the electrode plate is reduced, the optimization of the ionic conductance of the electrode plate is improved, and the rate capability of the battery is maintained.

The invention provides a coated lithium ion battery positive electrode material as well as a preparation method and application thereof. The coated lithium ion battery positive electrode material comprises a lithium oxide core and a coating layer coating the lithium oxide core, the coating layer comprises a combination of Li4Ti5O12, TiO2 (titanium dioxide) and Ti4O7 (titanium dioxide). In the preparation process, a lithium oxide is used as a substrate, and a titanium source, an oxygen source and a lithium source are deposited on the substrate by using a deposition system to obtain the coated lithium ion battery positive electrode material. According to the positive electrode material provided by the invention, the Li4Ti5O12, the TiO2 and the Ti4O7 are coated on the inner core, so that the coating of a high-ionic-conductivity and high-electron-conductivity material is realized, the overall structural stability of the material can be improved, the reversible specific capacity and the cycling stability of the material are further improved, and the positive electrode material has a good application prospect.

The invention discloses a modified lithium-ion battery and a modifying method thereof. The invention aims at providing the modified lithium-ion battery which has good conductivity and is capable of increasing electronic conductivity of a material and improving rate performance of the material and the modifying method thereof. According to the technical scheme, the modified lithium-ion battery is characterized in that Li2CrO4 is added in a conventional electrolyte, the Li2CrO4 is subjected to spontaneous reaction on the surface of a positive electrode material so as to form an Li2+xCrO4 coating layer, and an Li2+xCrO4 coating layer is formed after the Li2CrO4 is subjected to charging and lithium-embedding on the surface of a negative electrode material. The modified lithium-ion battery and the modifying method thereof belong to the technical field of batteries.

The invention relates to the field of lithium ion battery electrode materials, in particular to a carbon-coated nanofiber material, a preparation method thereof and a battery. The preparation method of the carbon-coated nanofiber material comprises the following steps: dissolving metal organic salt, lithium salt, a first polymer binder and a first organic carbon source in a first organic solvent, and preparing a spinning core layer solution, wherein metal elements in the metal organic salt are Fe, Ni, Mn, Co or V; dissolving a second polymer binder and a second organic carbon source in a second organic solvent to prepare a spinning shell solution; and spinning the spinning core layer solution and the spinning shell layer solution under a preset condition by using a coaxial electrostatic spinning technology to form fibers, and sintering the fibers in an inert atmosphere. According to the method, the fiber can be subjected to in-situ carbon coating, and the electrical property of the battery is improved. The invention also provides the carbon-coated nanofiber material prepared by the preparation method and a battery comprising the material.