1524 results about "Silicon particle" patented technology

Apparatus and method for forming a polycrystalline silicon thin film by converting an amorphous silicon thin film into the polycrystalline silicon thin film using a metal are provided. The method includes: a metal nucleus adsorbing step of introducing a vapor phase metal compound into a process space where the glass substrate having the amorphous silicon formed thereon is disposed, to adsorb a metal nucleus contained in the metal compound into the amorphous silicon layer; a metal nucleus distribution region-forming step of forming a community region including a plurality of silicon particles every metal nucleus in a plane boundary region occupied by the metal compound by a self-limited mechanism due to the adsorption of the metal nucleus; and an excess gas removing step of purging and removing an excess gas which is not adsorbed in the metal nucleus distribution region-forming step.

The subject of the invention is an anode material of the silicon-carbon composite type, for a lithium cell, having a high mass capacity and good cycling stability. This material is obtained by a preparation method comprising the steps consisting of:

• • a) providing a silicon powder obtained by the plasma-enhanced chemical vapour deposition (PECVD) technique or by CO₂ laser, the size of the silicon particles being less than 100 nm; b) mixing the silicon powder with a carbon-containing polymer, and c) carrying out the pyrolysis of the mixture. The invention also proposes a lithium cell containing at least one anode the material of which contains the nanocomposite material produced by this method.

The present invention is a method for manufacturing a negative electrode material for a secondary battery with a non-aqueous electrolyte comprising at least: coating a surface of powder with carbon at a coating amount of 1 to 40 mass % with respect to an amount of the powder by heat CVD treatment under an organic gas and/or vapor atmosphere at a temperature between 800° C. and 1300° C., the powder being composed of at least one of silicon oxide represented by a general formula of SiO_x (x=0.5 to 1.6) and a silicon-silicon oxide composite having a structure that silicon particles having a size of 50 nm or less are dispersed to silicon oxide in an atomic order and/or a crystallite state, the silicon-silicon oxide composite having a Si/O molar ratio of 1/0.5 to 1/1.6; blending lithium hydride and/or lithium aluminum hydride with the powder coated with carbon; and thereafter heating the powder coated with carbon at a temperature between 200° C. and 800° C. to be doped with lithium at a doping amount of 0.1 to 20 mass % with respect to an amount of the powder. As a result, there is provided a method for manufacturing a negative electrode material for a secondary battery with a non-aqueous electrolyte that enables a silicon oxide negative electrode material superior in first efficiency and cycle durability to conventional ones to be mass-produced (manufactured) readily and safely even in an industrial scale.

There are provided a silicon-film-forming composition containing silicon particles and a dispersion medium and a method for forming a silicon film by forming a coating film of the silicon-film-forming composition on a substrate and subjecting the coating film to instantaneous fusion, a heat treatment or a light treatment. According to the composition and the method, a polysilicon film with a desired thickness which may be used as a silicon film for a solar battery can be formed efficiently and easily.

A negative active material thin film provided on a collector layer directly or via an underlying layer has a multi-layered configuration including at least two silicon thin films containing silicon as a main component. Because of this, even when the thickness of the negative active material thin film is increased, the increase in thickness of one silicon thin film can be prevented by increasing the number of silicon thin films. Thus, the diameter of silicon particles substantially in an inverse truncated cone shape is not enlarged in the silicon thin film. Accordingly, in an energy device having a thin film mainly containing silicon as a negative active material, even when the thickness of the negative active material layer is increased to obtain a larger capacity, cycle characteristics are not degraded.

The invention provides a silicon-based composite material, which is prepared from silicon particles, silicate and optional carbon, wherein the mixture of the silicate and the optional carbon forms a massive body, and the silicon particles are dispersed in the massive body. A preparation method comprises the following steps of: dispersing the silicon particles into absolute ethyl alcohol and/or deionized water to form suspension liquid; dispersing the silicate and the optional carbon into the absolute ethyl alcohol and/or the deionized water to form suspension liquid; ultrasonically oscillating the two kinds of suspension liquid respectively, and then stirring; dropwise adding the suspension liquid of the silicon particles into the suspension liquid of the silicate and the optional carbon to form mixed liquid, heating and stirring the mixed liquid until evaporating the mixed liquid into paste; then, putting the paste in an oven to be dried to obtain masses, and grinding and sieving to obtain undersize particles; and conducting heat treatment in an inert atmosphere, and grinding and sieving to obtain the silicon-based composite material. According to the silicon-based composite material, a lattice structure of the silicon particles can be ensured, therefore the activity of the silicon particles is ensured, and the energy density, the first-time coulomb efficiency and the high-temperature storage performance of lithium ion batteries are increased.

The invention discloses a silicon-carbon composite cathode material with a three-dimensional preformed hole structure and a preparation method thereof. According to the composite cathode material, a carbon material having high electric conductivity and a stable structure is used as a matrix for dispersedly containing high-volume silicon particles, and proper three-dimensional expansion spaces are reserved around one or several silicon particles. The preparation method comprises the following steps of: carrying out surface modification on the silicon particles; coating the silicon particles by silicon dioxide; coating the silicon dioxide/silicon composite particles by carbon source precursors; carrying out high-temperature carbonization treatment; and removing a silicon dioxide template, and the like. When the composite material prepared by the preparation method is used for a lithium ion battery, the reversible specific capacity is high, and the cycle performance is excellent. The silicon-carbon composite cathode material has the advantages of simple preparation process and wide raw material resource and is suitable for industrial production.

The invention relates to a preparation method for a negative electrode active material of a lithium ion battery. The preparation method comprises the following steps: providing a silicon particle and a silane coupling agent which has a hydrolyzable functional group and an organic functional group; mixing the silicon particle with the silane coupling agent in water to form a first mixed liquor, wherein the hydrolyzable functional group of the silane coupling agent is hydrolyzed and chemically grafted onto the surface of the silicon particle; adding a polymer monomer or oligomer into the first mixed liquor to form a second mixed liquor, coating a polymer layer on the surface of the silicon particle by using in situ polymerization so as to form a silicon/polymer composite and allowing the polymer monomer or oligomer to react with the organic functional group of the silane coupling agent during polymerization so as to allow the generated polymer layer to be chemically grafted onto the surface of the silicon particle; and subjecting the silicon/polymer composite to heat treatment to carbonize the polymer layer so as to form a carbon layer coated on the surface of the silicon particle, thereby forming a silicon carbon composite.

Polysilicon is formed by pyrolytic decomposition of a silicon-bearing gas and deposition of silicon onto fluidized silicon particles. Multiple submerged spout fluidized bed reactors and reactors having secondary orifices are disclosed.

A silicon composite comprises silicon particles whose surface is at least partially coated with a silicon carbide layer. It is prepared by subjecting a silicon powder to thermal CVD with an organic hydrocarbon gas and/or vapor at 900-1,400° C., and heating the powder for removing an excess free carbon layer from the surface through oxidative decomposition.

The invention relates to a silicon-carbon composite negative pole material preparation method and a lithium ion battery. The preparation method comprises putting nanometer silicon and graphite micro-powder into a ball mill, carrying out ball milling uniform dispersion in an organic solvent environment, carrying out vacuum drying, putting the dried mixture and asphalt into a cone-type mixer, carrying out coarse mixing, putting the mixed powder subjected to coarse mixing into a mechanical fusion machine, carrying out mechanical fusion, carrying out heat treatment in an inert gas protective atmosphere and carrying out cooling to obtain the silicon-carbon composite negative pole material. The preparation method carries out asphalt softening coating on nanometer silicon so that silicon particle and electrolyte direct contact is avoided, a capacity reduction rate is delayed, a lithium ion diffusion path is shortened, an electrode material electron conduction loss is avoided, and first charge-discharge efficiency, a charge-discharge electric capacity and cycle performances are improved. Before coating, nanometer silicon is dispersed through graphite micro-powder so that it is avoided that in asphalt coating, nanometer silicon aggregation causes local capacity excess and nanometer silicon is uniformly dispersed.

The invention is applicable to the field of novel materials, and provides a silicon carbon composite negative electrode material for a lithium ion battery, as well as a preparation method and applications of the material. The negative electrode material is of a nuclear-shell-type composite structure, and consists of nano silicon in the core, amorphous carbon at the middle layer and a one-dimensional nano carbon material at the outermost layer, wherein the amorphous carbon at the middle layer forms an elastic loose surface structure, and thus the circulating performance and multiplying performance of silicon are improved; a network structure built by the one-dimensional nano carbon material at the outermost layer not only plays a role in buffering mechanical stress, but also provides a rapid electric conducting channel for active silicon particles, and improves the circulating performance and multiplying performance of silicon further; and meanwhile, a three-dimensional electric-conducting heat-conducting network formed by the one-dimensional nano carbon material can conduct heat generated by a battery during the discharging process to the space around, and the safety performance of the battery is improved. The preparation method of the silicon carbon composite negative electrode material for the lithium ion battery is simple and feasible in process, environment-friendly and energy-saving, low in cost, and easy for industrialization.

The invention relates to the technical field of lithium-ion cathode material, in particular to silicon cathode material coated with graphene and a preparation method of the silicon cathode material coated with the grapheme. The preparation method comprises the following steps: A, preparing oxidized graphene suspension liquid; B, preparing nanometer silicon particle suspension liquid; and C, preparing silicon cathode material coated with grapheme. The preparation method adopts the electrostatic self-assembly synthetic technology and is wide in source of raw material, low in price, simple in synthetic method, easy for control of process conditions, strong in operability and good in repeatability. The silicon cathode material coated with grapheme is high in specific capacity and good in cycle performance and rate capability, wherein the specific discharge capacity for the first time under the electric current density of 0.01-1.2V, 200mA/g can reach 2746mAh/g, and the specific discharge capacity after 100 times of cycles can maintain 803.8mAh/g.

The invention provides a nano suspension liquid concrete early strength agent and a preparation method thereof. The nano suspension liquid concrete early strength agent is prepared from transition metal element doped nano calcium metasilicate suspension liquid, the suspension liquid is mainly composed of nanometer silicon particles, the chemical structure of the nanometer silicon particles is aCaO.bAl2O3.cZnO.SiO2.6H2O, 1<=a<=2, 0.50<=b<=1, and 0.25<=c<=0.50. The nanometer silicon particles are prepared from soluble calcium salt, soluble silicate, soluble aluminum salt, soluble zinc salt and a high polymer dispersing agent. On the one hand, the early strength agent contains no chlorine salt and has no corroding function on steel bars in concrete; on the other hand, an extremely stable suspension liquid system is achieved, adding is facilitated, and the early strength agent can be evenly dispersed easily in the concrete preparation process. The early strength of concrete can be remarkably improved, the early strength effect on concrete adopting highly-doped mineral admixtures is especially obvious, the early strength agent is especially suitable for production of precast concrete components, and a steam maintenance process can be effectively reduced and even omitted.

The invention provides a lithium ion battery cathode material and a preparation method of the lithium ion battery cathode material as well as a lithium ion battery. The lithium ion battery cathode material comprises an inner core, a middle layer outside the inner core and an outer shell wrapping the middle layer, the inner core is Si-C particles, the middle layer is a foam layer, the outer shell is an amorphous carbon layer and the Si-C particles are formed by Si particles and C materials. Compared with the prior art, a middle carbon foam layer existing between the Si-C particle inner core and the amorphous carbon outer shell can form an conductive network structure, thus improving conductivity of a material and buffering enormous volume change of Si particles in the charge-discharge processes; and the amorphous carbon outer shell layer can maintain the core-shell structure of the cathode material, and the cladding layer of the core-shell structure can buffer the volume change, improve cycling stability of electrodes, reduce contact between active substances and an electrolyte, improve first coulombic efficiency of an electrode, prevent nanoparticle aggregation and enhance electrode conductivity.