172 results about "Silicon monoxide" patented technology

The invention provides a preparation method of a silicon monoxide negative electrode material and an external-pressure-free silicon-based solid-state battery, low-volume-expansion silicon monoxide is used as a negative electrode, a polymer solid-state electrolyte with high ionic conductivity is used as an electrolyte, and a positive electrode is combined to finally assemble a soft package battery or a cylindrical battery. And the silicon monoxide negative electrode has a relatively low volume expansion effect and excellent electrode structure stability, so that the cycle life and the stability of the battery are favorably improved. The polymer solid electrolyte shows excellent stress buffering capability in a solid electrolyte system due to low Young modulus and excellent flexibility, and can effectively adapt to volume change of a silicon-based negative electrode in an electrochemical cycle process. The technology can help the silicon-based solid-state battery get rid of dependence on external pressure, and the technology is relatively simple, high in applicability and wide in application value.

The application provides a negative electrode material and a preparation method thereof and a secondary battery, and relates to the technical field of battery materials. The negative electrode material comprises a silicon-based inner core and a carbon layer coated on the surface of the silicon-based inner core, wherein the silicon-based inner core comprises nanosilicon and a silicate containing a metal element M; the negative electrode material is subjected to section analysis and energy spectrum analysis, and meets the conditions of k1<=10, k2<=5 and 0.1 The preparation method of the negative electrode material comprises the following steps: heating and evaporating pre-disproportionated silicon monoxide material and M metal source material to obtain silicon monoxide gas and metal source gas; mixing and condensing the two kinds of gas to obtain an inner core material; and performing carbon coating treatment to obtain the negative electrode material. In the negative electrode material prepared by the application, the metal silicate effectively separates the nanosilicon domain and the silicon oxide domain, and is uniformly distributed, and the negative electrode material has high initial efficiency and excellent cycle performance.

The invention discloses an integrated Brillouin narrow linewidth laser and a preparation method thereof, and belongs to the field of integrated photonics. The integrated Brillouin narrow linewidth laser is composed of two layers of silicon nitride micro-rings, a silicon oxide spacing layer is arranged between the two layers of silicon nitride micro-rings, the free spectral path of the two layers of silicon nitride micro-rings is designed to be Brillouin frequency shift, and coupling waveguides are designed beside the micro-rings. The invention also provides a corresponding preparation method, which comprises the following steps of: sequentially depositing the first silicon nitride layer, the first silicon oxide layer, the second silicon nitride layer, the second silicon oxide layer and the etching pattern on the substrate, and finally depositing silicon oxide as a protective layer. The TM mode is intensively distributed in the silicon oxide between the two layers of silicon nitride through the constraint of the two layers of silicon nitride micro-rings, the defect that the Brillouin gain of a silicon nitride material is weak is overcome, the mode size is reduced, the Brillouin threshold value is reduced, and high-efficiency output of the Brillouin narrow linewidth laser is achieved.

The invention relates to the technical field of solar cells, in particular to a solar cell and a preparation method thereof, which can improve the passivation performance, the light utilization rate and the antireflection performance of the solar cell to the greatest extent while giving consideration to the ultraviolet attenuation resistance of the solar cell. A solar cell includes a substrate and a first optical adjustment layer; the first optical adjustment layer comprises a first sub-layer, a second sub-layer, a third sub-layer, a silicon oxynitride layer and a first silicon oxide layer which are sequentially stacked in the direction gradually away from the substrate; the refractive index of the first sub-layer is 2.3-2.42, the refractive index of the second sub-layer is 2.12-2.2, the refractive index of the third sub-layer is 2.0-2.1, and the thickness ratio of the first sub-layer to the second sub-layer to the third sub-layer is (10-15): (6-10): (16-24); the refractive index of the silicon oxynitride layer is 1.75-2.0, the refractive index of the first silicon oxide layer is 1.54-1.75, and the thickness ratio of the silicon nitride layer to the silicon oxynitride layer to the first silicon oxide layer is (32-49): (18-26): (10-15).

The invention discloses a waste lithium ion battery silicon-carbon negative electrode material regeneration method and application thereof, and the method comprises the following steps: S1, mixing a waste lithium ion battery silicon-carbon negative electrode material with an alkaline substance, and calcining in a non-oxidizing atmosphere to obtain a calcined mixture; s2, washing the calcined mixture to be neutral, and performing solid-liquid separation to obtain a graphite material and a silicon-containing solution; s3, adjusting the pH value of the silicon-containing solution to a level at which silicate is precipitated, reacting under heating, carrying out solid-liquid separation, and collecting silicic acid precipitate; s4, mixing the silicic acid precipitate with a silicon simple substance, grinding the mixture into micron-scale powder, calcining the micron-scale powder under a vacuum condition, and collecting generated silicon monoxide; and S5, carrying out carbon coating treatment on silicon monoxide and the graphite material prepared in the step S2 to obtain the regenerated silicon-carbon negative electrode material. According to the scheme, the waste silicon-carbon negative electrode material is successfully converted into a high-quality regenerated material, and the material can be directly applied to production and manufacturing of new batteries.

An anode material, including a matrix material, and the matrix material comprises carbon-doped silicon monoxide, and a content of the carbon ranges from 0.5% to 10% based on a total mass of the carbon and silicon monoxide. The anode material can significantly improve the cycle performance of an electrochemical device at room temperature and high temperature.

The invention provides a porous carbon material for a silicon-carbon negative electrode. The porous carbon material comprises a porous carbon skeleton with a graded pore structure; the silicon-based active units are uniformly dispersed in mesopores and macropores of the porous carbon skeleton, and each silicon-based active unit is composed of a nanometer silicon particle inner core and a silicon monoxide layer coating the surface of the nanometer silicon particle inner core; and the conductive reinforced shell is a gas-phase cracking carbon layer which is completely coated on the outer surface of the complex of the porous carbon skeleton and the silicon-based active unit. The preparation method of the porous carbon material comprises the following steps: preparing a porous carbon skeleton precursor, carrying out graded pore-forming treatment, carrying out surface functionalization treatment, compounding the silicon-based active units, constructing a conductive reinforced shell, carrying out element doping treatment and functionalizing pore channels. The cycle stability and environmental protection property of the silicon-carbon negative electrode are synergistically improved through graded pore constrained expansion, carboxyl bonding stable interface and vapor deposition carbon layer optimized conductivity.

An etching method includes: providing, to an interior of a chamber, a substrate having a three-layered film formed by stacking a first silicon oxide-based film, a silicon nitride-based film, and a second silicon oxide-based film; and collectively etching the three-layered film using a HF—NH3-based gas in the interior of the chamber while adjusting a gas ratio in each of the first silicon oxide-based film, the silicon nitride-based film, and the second silicon oxide-based film.

The invention provides a coated modified ternary positive electrode material as well as a preparation method and application thereof. The coated modified ternary positive electrode material comprises a ternary positive electrode material core as well as a silicon monoxide layer, a transition layer and a carbon layer which are sequentially coated on the surface of the ternary positive electrode material core, the transition layer is composed of silicon monoxide and carbon. In the coated modified ternary positive electrode material, the surface of the ternary positive electrode material core is sequentially coated with the silicon monoxide layer, the transition layer and the carbon layer which are uniform in component, and the three coating layers effectively prevent interaction between the ternary positive electrode material core and electrolyte, so that side reaction is reduced, and the cycling stability of the battery is improved; in addition, the silicon monoxide layer and the silicon monoxide in the transition layer provide relatively high lithium ion capacity, so that the lithium ion capacity of the coated modified ternary positive electrode material is improved; in addition, the carbon layer has good electronic conductivity, so that the electronic conductivity of the coated modified ternary positive electrode material is improved, and the rate capability is improved.

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a high-first-efficiency and high-conductivity silicon monoxide negative pole piece, which comprises the following steps: 1, improving the conductivity of silicon monoxide powder in a fluorine-doped carbon coating manner, and enhancing the structural stability of an SEI film formed by the first charge and discharge of the silicon monoxide negative pole piece; 2, through a powder pre-lithiation mode, the lithium content of the silicon monoxide powder is improved, and the initial coulombic efficiency of the silicon monoxide negative electrode plate is enhanced; 3, by introducing a polymer binder containing a conjugated structure, the ion / electron conductivity of the silicon monoxide negative electrode plate is improved, the resistance of the negative electrode plate is reduced, and the volume expansion of silicon monoxide particles in the lithium intercalation and deintercalation process is buffered; and 4, mixing the powder prepared in the step 2 with the conductive polymer binder prepared in the step 3 to obtain the silicon monoxide negative pole piece. The negative pole piece prepared by the preparation method disclosed by the invention has relatively high first coulombic efficiency, relatively high conductivity and relatively high rate capability.

The present invention discloses a secondary gas-phase coated silicon monoxide anode material and a preparation method thereof, belonging to the technical field of lithium-ion battery electrode materials. A zinc metal framework is in-situ generated on the surface of graphene oxide nanosheets to obtain zinc metal framework / graphene nanosheets. Then, the zinc metal framework / graphene nanosheets are mixed into water-based epoxy resin to coat the lanthanum-doped magnesium secondary gas-phase coated silicon monoxide powder, and then carbonized to obtain carbon-coated lanthanum-doped magnesium silicon monoxide powder. The carbon-coated lanthanum-doped magnesium silicon monoxide powder, binder, conductive carbon black agent and deionized water are added to a mixing and defoaming machine, stirred and mixed, and dried to prepare the secondary gas-phase coated silicon monoxide anode material; it has higher electrical conductivity, first Coulomb efficiency, 100-cycle capacity retention rate and lower volume change percentage.

A technique enabling wet etching of a first silicon oxide film with high selectivity with respect to a metal film and a second silicon oxide film is provided. A substrate processing method of wet-etching a substrate having a stacked structure including a metal film, a first silicon oxide film, and a second silicon oxide film having a moisture content lower than that of the first silicon oxide film is provided. The substrate processing method includes performing an etching while increasing etching selectivity of the first silicon oxide film with respect to the second silicon oxide film and the metal film by supplying an etching liquid, which is prepared by diluting sulfuric acid, hydrogen peroxide and hydrofluoric acid in an anhydrous organic solvent, to the substrate such that the metal film, the first silicon oxide film, and the second silicon oxide film are simultaneously exposed to the etching liquid.

Embodiments of this disclosure relate to a method for selectively depositing polysilicon after forming a fluid polymer film to protect a substrate surface within a feature. A first silicon (Si) layer is deposited by physical vapor deposition (PVD). A fluid polymer film is formed on the first silicon (Si) layer on the bottom. A portion of the first silicon (Si) layer is selectively removed from the top surface and at least one side wall. The fluid polymer film is removed. In some embodiments, a second silicon (Si) layer is selectively deposited on the first silicon (Si) layer to fill the feature. In some embodiments, the remaining portion of the first silicon (Si) layer on the bottom is oxidized to form a first silicon oxide (SiO₂) on the bottom. x ) forms a layer, and a silicon (Si) layer or a second silicon oxide (SiO) layer x The ) layer is the first silicon oxide (SiO x It is deposited on top of layers.

The invention provides an MEMS suspended heating bearing structure for characterization of a projection electron microscope (TEM) and a preparation method of the MEMS suspended heating bearing structure. An SOI silicon wafer comprises device layer silicon, a buried oxide layer and substrate layer silicon. A first silicon oxide layer is arranged on the surface of the device layer, and a heating electrode is arranged on the first silicon oxide layer; the surface of the substrate layer is provided with a second silicon dioxide layer used for back patterning and etching control. The device layer silicon is provided with a first cavity to form a suspended supporting structure, and comprises a central bearing region, a transmission window region and a plurality of supporting beams connected with the central bearing region; the substrate layer silicon is etched from the back surface to form a second cavity, and the second cavity covers the bearing area, the transmission window and the projection range of the supporting beam in the thickness direction. And the second cavity is communicated with the first cavity, so that a through type cavity heat insulation structure is formed. According to the invention, while the permeability of the electron beam transmission window is maintained, stable bearing and controllable heating of the to-be-tested sample are realized, and the requirements of structural reliability, low power consumption and electrical parasitic suppression are considered.

The present invention relates to a method for preparing silicon monoxide nanopowder, and belongs to the technical field of non-metallic powder material preparation. The present invention uses SiO2 aerogel powder with a three-dimensional continuous structure surface as raw material, adsorbs hydrogen molecules on the surface of the powdered SiO2 aerogel, and axially feeds an argon-excited inductively coupled plasma torch. The hydrogen molecules are excited by the argon plasma torch to form a highly active hydrogen-rich plasma, which undergoes a reduction reaction with the SiO2 aerogel powder having the characteristics of high specific surface area and high porosity. The generated silicon monoxide vapor is quenched by argon downstream of the reaction device to obtain highly dispersible silicon monoxide nanopowder. This method overcomes the defects of the traditional solid-solid reaction method for preparing silicon monoxide, which has a slow reaction rate and low raw material conversion rate, and at the same time solves the safety problems existing in the traditional method of producing silicon monoxide by hydrogen reduction, thereby greatly improving production efficiency and safety.

The present invention discloses a silicon monoxide nanomaterial and a preparation method thereof, belonging to the technical field of nanomaterials. The silicon monoxide nanomaterial comprises the following raw materials in parts by weight: metal silicon powder: 80 - 120 parts, silicon dioxide powder: 20 - 40 parts, binder: 0.5 - 3 parts, surfactant: 2 - 8 parts; in the present invention, intermediate 1 is prepared by the substitution reaction of 3 - allyl - 2 - hydroxybenzaldehyde and epichlorohydrin, then intermediate 2 is prepared by the ring - opening reaction of intermediate 1 and n - decanol, then intermediate 3 is prepared by the sulfonation reaction of intermediate 2 and 1,3 - propane sultone, and finally the surfactant is prepared by the polymerization reaction of 2 - methacryloyloxyethyl phosphorylcholine, 2 - acrylamide - 2 - methylpropanesulfonic acid and intermediate 3. The silicon monoxide nanomaterial prepared by the present invention has a high initial Coulomb efficiency and good cycle performance.

Technologies for epitaxial perovskite ferroelectric transistors on buffered silicon are disclosed. In an illustrative embodiment, a barrier layer of titanium nitride is deposited on a silicon substrate using domain matching epitaxy, which allows the titanium nitride to grow with relatively low stress and a low number of defects, despite a 22% misfit between the lattice constant for titanium nitride and that lattice constant for silicon. The barrier layer prevents silicon monoxide (SiO) from forming when oxides are grown as later layers. In some embodiments, some or all of the titanium nitride barrier layer may be used as a gate electrode for the transistor.

The invention relates to a grid side wall and a preparation method and application thereof. The method comprises the following steps: depositing a first silicon oxide layer on a semiconductor substrate with a grid structure; depositing a silicon nitride layer on the first silicon oxide layer; depositing a second silicon oxide layer on the silicon nitride layer; the first silicon oxide layer and the second silicon oxide layer are deposited through a TEOS (tetraethyl orthosilicate) process, and the TEOS process comprises n times of precursor gas deposition and (n-1) times of clean gas purging. Stacked growth of the silicon dioxide layer is carried out through n times of precursor gas deposition and n-1 times of clean gas purging, surface silicon dioxide with poor uniformity is repeatedly eliminated, then silicon dioxide is supplemented, and the steps are repeated for several times so that the thickness uniformity of the side wall of the grid electrode can be optimized, and the step covering performance can be improved.

Microfabrication process with the following steps: Providing a structure (800) comprising a layer stack (30, 40, 50) containing, from bottom to top, a first silicon oxide layer (30), a stoichiometric silicon nitride layer (40), and a second silicon oxide layer (50), and a conductive material part (20) below the layer stack (30, 40, 50) and above a substrate (10); Producing a patterned etch mask layer (57) having an opening through this layer over the layer stack (30, 40, 50); and Producing a via cavity (59) extending through the layer stack (30, 40, 50) and downwards to a top side of the conductive material part (20) by isotropic etching of parts of the second silicon oxide layer (50), the silicon nitride layer (40) and the first silicon oxide layer (30) with an isotropic etching process in which an etch rate of the silicon nitride layer (40) is 1 / 10 to 1 / 2 of the etch rate of the first silicon oxide layer (30), wherein: the first silicon oxide layer (30) comprises a first silicon oxide material produced by decomposition of tetraethyl orthosilicate, the stoichiometric silicon nitride layer (40) is produced by chemical vapor deposition at a temperature of less than 300°C, in which a silicon precursor gas and a nitrogen precursor gas are used together to produce a silicon nitride material, and the second silicon oxide layer (50) comprises a second silicon oxide material produced by decomposition of tetraethyl orthosilicate.

The invention relates to the technical field of photovoltaic waste silicon regeneration, in particular to a preparation method of a pre-magnesium-silicon-oxygen negative electrode material based on photovoltaic waste silicon recycling, which comprises the following steps: obtaining waste silicon materials from different sources, and immersing the waste silicon materials with the purity of 80-96% into an alkaline solution of a dehydrogenation additive to obtain a pure silicon wafer; soaking the pure silicon wafer in a hydrofluoric acid solution, adding a sodium hydroxide solution, soaking the common-purity silicon wafer in aqua regia, filtering the solution, and locally melting a silicon rod by adopting high-frequency induction heating to obtain high-purity silicon powder with the purity of 99.9999%; the mixture is added into a vacuum furnace to be heated, silicon monoxide steam and magnesium steam are obtained, and SiO / alpha Mg is obtained through condensation; and adding the SiO / alpha Mg material into a CVD (Chemical Vapor Deposition) furnace to obtain the Mg-SiOx-C composite material. According to the photovoltaic waste silicon disclosed by the invention, the pollution of the photovoltaic waste silicon to the environment is avoided, the secondary pollution easily caused by an immature recovery technology is avoided, the recovery cost is effectively reduced, and the utilization of the photovoltaic waste silicon is improved.

The invention provides an electric furnace thermal reduction magnesium smelting co-production silicon carbon negative electrode material and a device thereof. MgO, SiO2, coke, biological pyrolytic carbon and methane gas are used as raw materials and are added into a magnesium smelting electric arc furnace for carbon thermal reduction to obtain mixed furnace gas; the mixed furnace gas enters a quenching condenser to be subjected to isentropic expansion and cooling treatment after being subjected to heat compensation through a heat compensation chamber, and solid-phase particles and cooling furnace gas are obtained; the solid-phase particles and the cooling furnace gas are cooled by a first cooling chamber to obtain ternary mixed powder, and the ternary mixed powder is subjected to the operations of metal magnesium vacuum distillation, magnesiothermic reduction and silicon monoxide disproportionation reaction offline; residual gas in the first cooling chamber is secondarily cooled through the second cooling chamber, and a primary material required by the silicon-carbon negative electrode material is co-produced in a gas-phase reaction mode in the magnesium smelting process, so that near-full continuous production of main links of the silicon-carbon negative electrode material and co-production coupling of carbon thermal reduction of magnesium metal are realized.

The invention discloses a preparation method of a carbon-coated lithium titanate composite silicon negative electrode material, which comprises the following steps: mixing raw materials, carrying out two-stage high-temperature calcination, converting a lithium source and a titanium source into lithium titanate, carrying out disproportionation reaction to convert silicon monoxide into silicon simple substance silicon dioxide, removing silicon dioxide by acid etching, and carrying out carbon coating by chemical vapor deposition to obtain the carbon-coated lithium titanate composite silicon negative electrode material. A final product is obtained. The porous lithium titanate has the characteristics of zero volume expansion, high safety, long service life and low energy density, and the nano silicon has the characteristics of high specific capacity, large volume expansion and poor cycle performance, so that the comprehensive performance of high capacity, long cycle and high safety is finally realized by utilizing the synergistic effect of the porous lithium titanate and the nano silicon; compared with a silane chemical vapor deposition silicon process, the process is safe and low in cost; compared with a process of respectively preparing porous lithium titanate and nano silicon and then mixing, the preparation method disclosed by the invention has the advantages that the problem that nano silicon is easy to agglomerate is avoided, and the electrochemical performance of a finished product is effectively improved.

The application belongs to the technical field of nanometer material preparation, and particularly relates to a kind of nanometer silicon-silicon monoxide negative electrode material with inlay structure and a preparation method thereof, wherein nanometer white carbon black is used as raw material, Al powder is used as reducing agent, NaCl, KCl and AlCl3 are used as auxiliary molten salt, the mixture is put into a tube furnace and heat treated in argon atmosphere, the heat treated product is soaked in hydrochloric acid to remove excess Al powder and molten salt, then repeatedly washed with distilled water and centrifuged, and vacuum dried to obtain the nanometer silicon-silicon monoxide negative electrode material with inlay structure. The preparation method is scientifically and reasonably designed, and the nanometer silicon is inlaid in silicon monoxide, which greatly limits the bulk expansion of nanometer silicon. When the material with this structure is used as battery negative electrode material, it can not only ensure that the theoretical specific capacity is higher than that of pure SiO x , but also can relieve the bulk expansion of pure silicon, so that the cycle stability and rate performance are more excellent.

The present invention relates to the field of anode materials for lithium-ion batteries, and discloses a preparation method of a silicon-based anode material with high capacity and high initial efficiency, comprising: (1) mixing silicon monoxide with glucose and gluconate to obtain precursor A; (2) dispersing precursor A in deionized water to dissolve glucose and gluconate in water to form a dispersion, and freeze-drying the dispersion to obtain a material to be sintered B; (3) placing the material to be sintered in an atmosphere of protective gas, heating and holding the temperature, and finally cooling to obtain a finished product of a silicon-oxygen anode material for a lithium-ion battery with high capacity and high initial efficiency. The silicon-oxygen anode material prepared by the present invention has the characteristics of high capacity and high initial efficiency. When at a voltage of 0.8V, the initial efficiency of the prepared silicon monoxide anode material reaches 85%, and the capacity is greater than 1300 mAh / g.

This invention discloses a low-resistivity silicon suboxide lithium-ion battery anode material and its preparation method. Fluorinated silicon suboxide is mixed with a carbon precursor and a solvent, ground until dry, and the solvent is removed to obtain an intermediate material. The intermediate material is then calcined in a protective gas atmosphere using gradient heating and / or gradient pressurization to obtain the anode material. This invention constructs a fluorine gradient hole structure, which preferentially transforms into a stable LiF-rich solid electrolyte interphase (SEI) film during electrochemical cycling, significantly reducing the lithium-ion diffusion barrier and interfacial charge transfer impedance. The gradient heating and / or pressurization sintering process carbonizes the carbon precursor in situ on the surface of the fluorinated layer, forming a dense and robust coating layer. This coating layer forms a strong interfacial bond through vacancy bonding and mechanical interlocking, buffering volume expansion. The anode material obtained using this invention exhibits excellent electrochemical performance and significantly reduces impedance.

The invention discloses a method for improving process defects of an image sensor and a characterization method, and the method for improving the process defects of the image sensor at least comprises the following steps: S1, providing a substrate, depositing a polycrystalline silicon layer on the substrate, and placing the substrate in a reaction cavity; s2, at least introducing a silicon source precursor and an oxygen source precursor into the reaction cavity, and depositing a silicon monoxide layer on the polycrystalline silicon layer; and S3, stopping introducing the silicon source precursor, introducing oxygen-containing gas into the reaction cavity, applying radio frequency power into the reaction cavity, exciting the oxygen-containing gas into oxygen-containing plasma under the action of the radio frequency power, and reacting the oxygen-containing plasma with the silicon-rich core on the surface of the silicon oxide layer to obtain the silicon-rich core on the surface of the silicon oxide layer. And removing the silicon-rich inner core. By using the method, the defect of the silicon-rich core on the surface of the substrate can be effectively removed, so that the product yield of the image sensor is improved.

The invention discloses a secondary gas phase coated silicon monoxide negative electrode material and a preparation method thereof, and belongs to the technical field of lithium ion battery electrode materials, a zinc metal frame is generated in situ on the surface of a graphene oxide nanosheet to obtain a zinc metal frame / graphene nanosheet, and the zinc metal frame / graphene nanosheet is coated with a secondary gas phase coated silicon monoxide negative electrode material. Mixing the zinc metal frame / graphene nanosheet with water-borne epoxy resin, coating the lanthanum-magnesium-doped secondary gas phase coated silicon monoxide powder, carbonizing to obtain carbon-coated lanthanum-magnesium-doped silicon monoxide powder, adding the carbon-coated lanthanum-magnesium-doped silicon monoxide powder, a binder, a conductive carbon black agent and deionized water into a mixing defoaming machine, stirring and mixing to obtain a mixture; and drying to obtain the secondary gas phase coated silicon monoxide negative electrode material. And the material has higher conductivity, first coulombic efficiency, 100-cycle capacity retention rate and lower volume change percentage.

A negative electrode material and a preparation method therefor, and a secondary battery, relating to the technical field of battery materials. The negative electrode material comprises: a silicon-based core; and a carbon layer coated on at least part of the surface of the silicon-based core, the silicon-based core comprising nano-silicon, and silicate containing a metal element M; the negative electrode material is sectioned and subjected to energy spectrum analysis, k1 is less than or equal to 10, k2 is less than or equal to 5, and k2 / k1 is greater than 0.1 and less than or equal to 1. The preparation method for the negative electrode material comprises: heating and evaporating a pre-disproportionated silicon monoxide material and an M metal source material, to obtain a silicon monoxide gas and a metal source gas; mixing the two gases, and performing condensation to obtain a core material; and performing carbon coating treatment, to obtain a negative electrode material. Metal silicate in the prepared negative electrode material effectively separates a nano silicon domain and a silicon oxide domain, and is uniformly distributed; thus, the negative electrode material has high first-time efficiency and excellent cycle performance.

The invention discloses a manufacturing method of a U-shaped groove, which is characterized in that a photoresist reserved on a field oxide in an X-direction photoetching process of the U-shaped groove can protect a hard mask on the field oxide of a Y-direction opening of a non-U-shaped groove region, the loss of the hard mask on the field oxide of the Y-direction opening of the non-U-shaped groove region cannot be caused, and a U-shaped groove process window is enlarged; in the process of performing X-direction silicon etching to form a U-shaped groove, silicon at an X-direction opening at a non-overlapping position of an X-direction opening pattern and a Y-direction opening pattern is protected by a mask first silicon oxide layer and a mask second silicon nitride layer, when the mask at the position is removed, the mask second silicon nitride layer is removed firstly, then the first silicon oxide layer is removed, and the first silicon oxide layer is removed after the mask second silicon nitride layer is removed. The SIN hard mask on the field oxide is not damaged, and the morphology standard of the U-shaped groove can be ensured.

The invention belongs to the technical field of micro electro mechanical systems and ultrasonic sensing, and discloses a CMUT preparation method and a CMUT. According to the method, a double-self-stop high-precision control system is established, the depth of the cavity is defined by using the thickness of the first silicon oxide layer, the doping layer is used as a stop surface during etching, and the problem of uneven etching depth is eliminated; and the atomic-scale uniformity of the thickness of the vibrating diaphragm is ensured by matching the doping layer with the wet etching selectivity. Besides, according to the method, through combination of a doping self-stop technology and a dual-common monocrystalline silicon wafer bonding technology, a high-performance CMUT with thickness uniformity and depth consistency is manufactured, and the preparation cost is remarkably reduced. Besides, the method structurally solves the problem of insulation failure, the thought that the structure and the function are defined through double wafers is adopted, the second silicon dioxide layer forming the insulation layer is arranged on the flat second wafer, and the risk that the insulation layer at the corner of the cavity is broken down due to insufficient step covering capacity in the traditional process is thoroughly eliminated.