20786 results about "Lithium electrode" patented technology

A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 μm. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life.

A lithium ion battery electrode includes silicon nanowires used for insertion of lithium ions and including a conductivity enhancement, the nanowires growth-rooted to the conductive substrate.

Disclosed are a laminated lithium ion battery, a battery pack comprising the same and a pole piece of the laminated lithium ion battery. The pole piece comprises a current collector and an active material layer, wherein the current collector is coated with the active material layer. A section of continuous uncoated area is arranged at the tail end of a first width end portion of the pole piece, the top face and the bottom face of the uncoated area are not coated with the active material layer, the current collector is exposed in the uncoated area, and the exposed current collector serves as a pole lug of the pole piece. By the pole piece, internal resistance of the lithium ion battery is reduced and heat dissipation performance of the battery is improved.

Combinations of materials are described in which high energy density active materials for negative electrodes of lithium ion batteries. In general, metal alloy/intermetallic compositions can provide the high energy density. These materials can have moderate volume changes upon cycling in a lithium ion battery. The volume changes can be accommodated with less degradation upon cycling through the combination with highly porous electrically conductive materials, such as highly porous carbon and/or foamed current collectors. Whether or not combined with a highly porous electrically conductive material, metal alloy/intermetallic compositions with an average particle size of no more than a micron can be advantageously used in the negative electrodes to improve cycling properties.

A method of modifying the surface of carbon materials such as vapor grown carbon nanofibers is provided in which silicon is deposited on vapor grown carbon nanofibers using a chemical vapor deposition process. The resulting silicon-carbon alloy may be used as an anode in a rechargeable lithium ion battery.

The present invention provides an exfoliated graphite-based hybrid material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing alkali or alkaline metal ions (particularly, lithium ions); and (b) exfoliated graphite flakes that are substantially interconnected to form a porous, conductive graphite network comprising pores, wherein at least one of the particles or coating resides in a pore of the network or attached to a flake of the network and the exfoliated graphite amount is in the range of 5% to 90% by weight and the amount of particles or coating is in the range of 95% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, excellent reversible capacity, and long cycle life.

Positive electrode active materials are described that have a very high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCO_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the cell. Methods for producing these materials include, for example, a co-precipitation approach involving metal hydroxides and sol-gel approaches.

Provided are nanostructures containing electrochemically active materials, battery electrodes containing these nanostructures for use in electrochemical batteries, such as lithium ion batteries, and methods of forming the nanostructures and battery electrodes. The nanostructures include conductive cores, inner shells containing active materials, and outer shells partially coating the inner shells. The high capacity active materials having a stable capacity of at least about 1000 mAh/g can be used. Some examples include silicon, tin, and/or germanium. The outer shells may be configured to substantially prevent formation of Solid Electrolyte lnterphase (SEI) layers directly on the inner shells. The conductive cores and/or outer shells may include carbon containing materials. The nanostructures are used to form battery electrodes, in which the nanostructures that are in electronic communication with conductive substrates of the electrodes.

Compositions are described that can provide high energy density active materials for use in negative electrodes of lithium ion batteries. These materials generally comprise silicon and/or tin, and may further comprise carbon and/or zinc as well as other elements in appropriate embodiments. The active materials can have moderate volume changes upon cycling in a lithium ion battery.

The present invention provides a lithium ion battery that exhibits a significantly improved specific capacity and much longer charge-discharge cycle life. In one preferred embodiment, the battery comprises an anode active material that has been prelithiated and pre-pulverized. This anode may be prepared with a method that comprises (a) providing an anode active material (preferably in the form of fine powder or thin film); (b) intercalating or absorbing a desired amount of lithium into the anode active material to produce a prelithiated anode active material; (c) comminuting the prelithiated anode active material into fine particles with an average size less than 10 μm (preferably <1 μm and most preferably <200 nm); and (d) combining multiple fine particles of the prelithiated anode active material with a conductive additive and/or a binder material to form the anode. Preferably, the prelithiated particles are protected by a lithium ion-conducting matrix or coating material. Further preferably, the matrix material is reinforced with nano graphene platelets.

A lithium ion conductive solid electrolyte formed by sintering a molding product containing an inorganic powder and having a porosity of 10 vol % or less, which is obtained by preparing a molding product comprising an inorganic powder as a main ingredient and sintering the molding product after pressing and/or sintering the same while pressing, the lithium ion conductive solid electrolyte providing a solid electrolyte having high battery capacity without using a liquid electrolyte, usable stably for a long time and simple and convenient in manufacture and handling also in industrial manufacture in the application use of secondary lithium ion battery or primary lithium battery, a solid electrolyte having good charge/discharge cyclic characteristic in the application use of the secondary lithium ion battery a solid electrolyte with less water permeation and being safe when used for lithium metal-air battery in the application use of primary lithium battery, a manufacturing method of the solid electrolyte, and a secondary lithium ion battery and a primary lithium battery using the solid electrolyte.

This invention provides a hybrid nano-filament composition for use as an electrochemical cell electrode. The composition comprises: (a) an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, or percolated to form a porous, electrically conductive filament network comprising substantially interconnected pores, wherein the filaments have an elongate dimension and a first transverse dimension with the first transverse dimension being less than 500 nm (preferably less than 100 nm) and an aspect ratio of the elongate dimension to the first transverse dimension greater than 10; and (b) micron- or nanometer-scaled coating that is deposited on a surface of the filaments, wherein the coating comprises an anode active material capable of absorbing and desorbing lithium ions and the coating has a thickness less than 20 μm (preferably less than 1 μm). Also provided is a lithium ion battery comprising such an electrode as an anode. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life.

The invention disclosed herein provides for methods and apparatuses that yield electrodes having at least one functional gradient therein. In many embodiments, the electrodes comprise an electrode matrix having a plurality of layers, where at least two of the layers differs functionally, in composition, structure, or, organization. High-throughput electrode screening apparatuses are disclosed that include array formers and testers. Electrodes and battery cells arising from the methods and apparatuses disclosed herein are likewise disclosed. The methods, apparatuses, and resulting electrode and cell devices are, in some embodiments, ideally suited for use in lithium-ion batteries.

The invention provides a method for preparing lithium cobaltate by directly using an invalid lithium ion battery. The method comprises the following steps: crushing the invalid lithium ion battery or scraps generated when a lithium cobaltate battery is produced by a mechanical crusher at normal temperature; adding water and one or more of acetic acid, sulfuric acid, hydrochloric acid or nitric acid to produce mixed aqueous solution of the battery scraps and acid; filling the mixed aqueous solution into a hermetic pressure reactor, and controlling the temperature in the reactor to be between 50 and 150 DEG C; introducing or adding one leaching additive of sulfur dioxide or hydrogen, or adding hydrazine hydrate; stirring and leaching, cooling, and filtering; adding one precipitator of sodium carbonate, potassium carbonate and ammonium carbonate, or adding composite precipitator consisting of one of the sodium carbonate, the potassium carbonate and the ammonium carbonate and one of sodium hydroxide and potassium hydroxide to obtain mixture of lithium carbonate, cobalt carbonate and cobalt hydroxide; drying and calcining at high temperature to produce a lithium cobaltate product. The method is particularly suitable for the treatment scale of medium-sized and small enterprises, and is an effective method for directly materializing cobalt secondary resources.

A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m²/g to about 200 m²/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm² to about 3.5 mg/cm². In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.

The invention discloses alumina-coated granules, as well as a preparation method and application thereof. The alumina-coated granules consist of cores and shells which coat the cores. The cores are made of at least one of materials of metals, oxides, metal hydroxides, metal inorganic salts, non-metals, carbides, nitrides, lithium salts, semiconductors and organic compounds; the shell is made of Al2O3. By adopting a liquid phase method, the cores to be coated are mixed with aluminum salts, metal aluminum is precipitated by producing an alkaline environment in situ or externally adding alkaline, so that uniform, continuous and controllable coating can be formed on the surfaces of the cores. The coating method provided by the invention is simple, and has mild conditions and high universality; the coating layer has controllable thickness, completeness and uniformity; the alumina-coated granules has high practicability and a great application prospect in the field of catalysis, lithium ion batteries, surface-enhanced Raman, biomedicine and the like.

The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

Positive electrode active materials are described that have a high tap density and high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCo_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the battery.

The invention provides a preparation method of graphene, and particularly relates to a method for preparing biomass graphene employing cellulose as a raw material. The specific preparation method comprises the following steps: 1, preparing a catalyst solution; 2, carrying out ionic coordination and high-temperature deoxidization on cellulose and a catalyst, so as to obtain a precursor; 3, carrying out thermal treatment; 4, carrying out acid treatment, and drying to obtain the graphene, wherein the prepared graphene is uniform in morphology, has a single-layer or multi-layer two-dimensional layered structure; the dimension is 0.5-2 microns; and the electrical conductivity is 25,000-45,000S/m. The preparation method is simple in preparation technology, low in cost, high in yield, high in production safety, and controllable in product dimension and physical property; industrialized production can be realized; the graphene prepared by the method can be applied to electrode materials of super capacitors and lithium ion batteries, and can also be added to resin and rubber as an additive; and the physical property of the material can be improved.

Desirable electrolyte compositions are described that are suitable for high voltage lithium ion batteries with a rated charge voltage at least about 4.45 volts. The electrolyte compositions can comprise ethylene carbonate and solvent composition selected from the group consisting of dimethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, γ-valerolactone or a combination thereof. The electrolyte can further comprise a stabilization additive. The electrolytes can be effectively used with lithium rich positive electrode active materials.

The invention belongs to the fields of material synthesis and energy technology, and especially relates to a graphene/metal oxide composite cathode material for lithium ion batteries and a preparation method thereof. Grapheme is dispersed into various metal oxide precursor salt solutions; a graphene/metal oxide compound is obtained directly by a hydrothermal method, or an graphene/metal oxide compound is obtained by a liquid in-situ polymerization method or a coprecipitation process; and the graphene/metal oxide compound is obtained by heat treatment or hydrothermal treatment. In the invention, the novel three-dimensional composite cathode material of graphene-coated metal oxide or graphene-anchored metal oxide is prepared by carrying metal oxide particles with graphene as a carrier. The obtained composite material can be used as a lithium ion battery cathode, which has a high specific capacity, excellent cycle stability and rate capability, and is expected to be used as a lithium ion battery cathode material with a high energy density and a high power density.

A nanographitic composite for use as an anode in a lithium ion battery includes nanoscale particles of an electroactive material; and a plurality of graphene nanoplatelets having a thickness of 0.34 nm to 5 nm and lateral dimensions of less than 900 nm, wherein the electroactive particle has an average particle size that is larger than the average lateral dimension of the graphene nanoplatelets, and the graphene nanoplatelets coat at least a portion of the nanoscale particles to form a porous nanographitic layer made up of overlapping graphene nanoplatelets.

The invention provides a combined estimation method for lithium ion battery state of charge, state of health and state of function. The combined estimation method comprises the steps that the state of he---alth of a battery is estimated online: open circuit voltage and internal resistance are identified online by adopting a recursive least square method with a forgetting factor, the state of charge is indirectly acquired according to a pre-established OCV-SOC corresponding relation, and then the size of battery capacity is estimated according to cumulative charge and discharge electric charge between two SOC points; the state of charge of the battery is estimated online: the state of charge of the battery is estimated by adopting the Kalman filter algorithm based on a two-order RC equivalent circuit model, and the battery capacity parameter in the Kalman filter algorithm is updated according to the estimation result of battery capacity; and the state of function of the battery is estimated online: the maximum chargeable and dischargeable current is calculated based on the voltage limit and the current limit of the battery according to internal resistance obtained by online identification, and then the maximum chargeable and dischargeable function can be obtained through further calculation.

The invention provides a method for cladding surfaces of an active material of an anode and/or the anode and methods for manufacturing the anode and a battery. In the cladding method, an atomic layer deposition technology is adopted to deposit surface modification substances on the surfaces of the active material of the anode and/or the anode of a lithium battery. According to the invention, the cycle performance and the specific capacity of the lithium-ion battery can be improved obviously and electrode materials are more stable.

The invention relates to a graphene composite material and a preparation method thereof. The graphene composite material provided by the invention is characterized in that a graphene material plate fixed on a metallic matrix serves as a carrier, and the elementary substance and/or a compound are compounded on the graphene surface. Meanwhile, the invention also discloses a method for preparing the graphene composite material. The graphene composite material prepared by the invention is opened between graphene sheets and is compounded with a chemical substance under the condition that a space body structure is formed, and the obtained material has high conductivity, high specific surface area and excellent performance of low electrical resistivity between the sheets, and can be widely applied to the fields of energy storage materials such as lithium ion batteries, super-capacitors, super lead carbon batteries, super nickel-carbon electrodes, solar energy and fuel cells, the field of heat dissipation materials, the field of environment-friendly adsorbing materials, the field of sea water desalination materials, the field of photoelectric sensor materials, the biological relevance field, the field of catalyst materials and the fields of conductive ink and coating materials.

A method of depositing silicon on carbon nanomaterials such as vapor grown carbon nanofibers, nanomats, or nanofiber powder is provided. The method includes flowing a silicon-containing precursor gas in contact with the carbon nanomaterial such that silicon is deposited on the exterior surface and within the hollow core of the carbon nanomaterials. A protective carbon coating may be deposited on the silicon-coated nanomaterials. The resulting nanocomposite materials may be used as anodes in lithium ion batteries.

The invention discloses a silicon graphene composite anode material of a lithium ion battery and a preparation method of the silicon graphene composite anode material. The material consists of the following components in percentage by weight: 10 to 99 percent of silicon powder with the particle size of between 20 nanometers and 5 micrometers, 1 to 90 percent of graphene and 0 to 40 percent of amorphous carbon, wherein the graphene forms a three-dimensional conducting network with an internal cavity, and wraps the silicon powder in the internal cavity to form spherical or sphere-like composite particles with the particle size of between 500 nanometers and 15 micrometers. The preparation method of the material comprises the following steps of: uniformly dispersing the silicon powder and graphene oxide in a solvent; and performing spray drying, reducing, and cladding by using the amorphous carbon. Compared with the prior art, the invention has the advantages that: the material has high capacity and high cycle performance and is subjected to a constant-current charge-discharge test at the current density of 200mA/g, the reversible capacity of the material after 30-times circulation is still 1502mA/g, and the capacity retention rate of the material is up to 98 percent; and the preparation method is simple and practicable, high in yield and suitable for mass industrial production.

Disclosed is a method of producing a hybrid nano-filament composition for use in a lithium battery electrode. The method comprises: (a) providing an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, physically contacted, or chemically bonded to form a porous network of electrically conductive filaments, wherein the filaments comprise electro-spun nano-fibers that have a diameter less than 500 nm (preferably less than 100 nm); and (b) depositing micron- or nanometer-scaled coating onto a surface of the electro-spun nano-fibers, wherein the coating comprises an electro-active material capable of absorbing and desorbing lithium ions and the coating has a thickness less than 10 μm (preferably less than 1 μm). The same method can be followed to produce an anode or a cathode. The battery featuring an anode or cathode made with this method exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life.

A lithium-ion battery includes a cathode that includes an active cathode material. The active cathode material includes a cathode mixture that includes a lithium cobaltate and a manganate spinel a manganate spinel represented by an empirical formula of Li_(1+x1)(Mn_1−y1A′_y2)_2−x2O_z1. The lithium cobaltate and the manganate spinel are in a weight ratio of lithium cobaltate: manganate spinel between about 0.95:0.05 to about 0.55:0.45. A lithium-ion battery pack employs a cathode that includes an active cathode material as described above. A method of forming a lithium-ion battery includes the steps of forming an active cathode material as described above; forming a cathode electrode with the active cathode material; and forming an anode electrode in electrical contact with the cathode via an electrolyte.

The invention discloses a preparation method of a multi-place doped lithium iron phosphate anode material and an application thereof, which belong to the technical field of the preparation of electrochemical power materials. The multi-place doped lithium iron phosphate anode material is expressed by the following formula: Li1-xAxFe1-yByP1-zCzO4Ddelta, wherein, at least two of x, y, x and delta can not be expressed zero at the same time. Multi-place doped anode material lithium iron phosphate powder which is used in a secondary lithium-ion battery and has good crystallization performance and even composition is prepared by adopting a solid phase method and a simple mixing and drying process; compared with the method doping in a certain crystal lattice place, the multi-place doped anode material lithium iron phosphate powder has wide doping material source, which can greatly improve the basic capacity and cycling electrical performance of matrix and is applied to a stable industrialized production and non-high-purity materials. The multi-place lithium iron phosphate of the invention is taken as the anode material and is usually used in the secondary lithium-ion battery and the secondary lithium-ion battery is taken as a power source.