1936 results about "Carbon layer" patented technology

The invention discloses a LiAlO2 fast ion conductor coated silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery materials. The LiAlO2 fast ion conductor coated silicon carbon composite material has a core-shell structure; an inner core of the composite material is a silicon-carbon composite material, the silicon-carbon composite material is formed by coating a three-dimensional carbon material with an amorphous carbon layer and loading a nano silicon compound, a shell of the composite material is a LiAlO2 fast ion conductor layer, and the silicon-carbon composite material with a three-dimensional network structure is constructed, and the surface of the silicon-carbon composite material is coated with the LiAlO2 fast ion conductor layer, so that the composite material is obtained. According to the present invention, with the LiAlO2, the volume expansion of the nanometer silicon during the charge-discharge process can be effectively relieved, the stability of the silicon-carbon composite material structure can be improved so as to significantly improve the cycle performance of the battery, and the LiAlO2 can provide the rapid channel for the transmission of the lithium ion during the charge-discharge process so as to improve the rate performance of the battery;

The application relates to the technical field of material preparation, and discloses multi-element carbon-coated lithium manganate, a preparation method thereof and a secondary battery. The multi-element carbon-coated lithium manganate comprises a lithium manganate core and a carbon nanotube layer and a hard carbon layer which are sequentially coated on the lithium manganate core. The chemical formula of the lithium manganate core is LiAl a X b Mn 2‑a‑b O4, wherein 0.01<=a<=0.10, 0.01<=b<=0.05, and X comprises at least one of Co, Cr, Ti, V and B. The preparation method of the multi-element carbon-coated lithium manganate comprises the following steps: (I) preparing doped lithium manganate, (II) preparing carbon nanotubes and (III) multi-element carbon coating. The multi-element carbon-coated lithium manganate has high conductivity, rate performance, cycle performance and safety performance, and can be used as an alternative positive electrode material with high cycle and excellent fast-charging performance.

The invention provides a sphere-like silicon-carbon negative electrode material and a preparation method and application thereof, and particularly relates to the technical field of negative electrode materials, the negative electrode material comprises a sphere-like porous carbon skeleton, silicon nanoparticles distributed in the sphere-like porous carbon skeleton, and an amorphous carbon layer coating the surface of the sphere-like porous carbon skeleton, the particle appearance of the sphere-like porous carbon skeleton is of a round irregular or asymmetric polyhedral structure and comprises one or more of a potato shape, an ellipse shape, an olive shape, a long strip shape and a pomegranate shape, the particle of the sphere-like porous carbon skeleton is provided with a plurality of asymmetric faces, fillets are formed between the faces, and the radius of the fillets does not exceed 20 microns. The problem of structural damage of the material under the action of external force such as rolling can be effectively relieved, good mechanical stability is kept, excellent bonding performance can be achieved in the electrode coating process, the ion transmission path of the material is improved, and the electronic conductivity and the lithium ion diffusion performance are improved.

The invention belongs to the technical field of sodium-ion batteries, and particularly relates to a preparation method of a coal-based hard carbon material and application of the coal-based hard carbon material in a sodium-ion battery negative electrode. The preparation method of the hard carbon material comprises the following steps: carrying out acid-base chemical heat treatment on a coal-based material to obtain an ash-removed and dried precursor material, and activating the material by water vapor to obtain a target sample with etched micropore inner gaps, and in the subsequent carbonization process, the carbon layer is twisted to form a closed pore structure to obtain the electrode material. According to the invention, the application of the rich-resource coal precursor and the high carbon conversion rate in the sodium ion battery is realized, and the storage capacity of sodium and the cycling stability of the material are effectively improved. The coal-based hard carbon material can be used for preparing a sodium ion battery and has important application value.

The invention discloses a silicon-carbon composite negative electrode material, a negative electrode plate, a preparation method and application. The silicon-carbon composite negative electrode material is of a double-coating structure and sequentially comprises inner core silicon, a lithium phosphate layer and a fluorine-containing carbon layer from inside to outside, and the mass ratio of the lithium phosphate layer to the inner core silicon is (1-5): 100. When the composite material is applied to a lithium ion battery, the core silicon and the specific double coating layers can improve the fast charging performance and the first effect while optimizing an ion transmission path; a specific double-coating structure can be used as a buffer layer, stress generated by volume expansion of silicon can be released, and pulverization of particles is avoided; and moreover, LiF with high ionic conductivity and higher mechanical strength and an SEI film with more stable regulation and control are formed through reaction with an electrolyte, so that the structural integrity of the material is kept, and the cycle performance of the material is improved.

The invention relates to a graphite silicon carbon composite negative electrode material, a negative electrode plate and a lithium ion battery, and belongs to the technical field of battery negative electrode materials. The graphite silicon carbon composite negative electrode material comprises a graphite inner core and a composite shell layer, the composite shell layer coats the surface of the inner core, the composite shell layer comprises a continuous carbon layer, the carbon layer is of a porous structure, and the porous structure is filled with nano silicon particles. According to the core-shell structure, through a three-stage synergistic mechanism of graphite inner core conductive supporting, porous carbon layer expansion buffering and nanometer silicon capacity contribution, the cycling stability of the negative electrode material is remarkably improved while the high specific capacity is maintained.

The invention discloses a graphite crucible silicon infiltration resistant coating based on a gradient boron nitride-silicon carbide composite structure and a preparation method thereof. The coating is composed of hexagonal boron nitride nanosheets, beta-type silicon carbide nanowires, yttrium aluminum garnet precursor sol and the like, and effective blocking of 1500-1600 DEG C silicon melt is achieved through gradient structural design and an in-situ self-repairing mechanism. The preparation process comprises the steps of h-BN activation, S C carbon layer deposition, slurry mixing and spraying and segmented heat treatment. The molten silicon contact angle of the coating reaches 158 + / -2 degrees at the temperature of 1550 DEG C, through cracks do not exist after 50 times of thermal shock circulation, the coating is effective after being continuously used for 48 batches under the industrial working condition, the problems of silicon infiltration interface adhesion and thermal shock failure of a traditional graphite crucible are solved, and the coating has remarkable industrial application value.

An electrode structure for a solid-state or semi-solid-state battery is provided in which NCM electrode particles coated with an interphase layer and a nitrogen-containing carbon layer are disposed. [Solution] The NCM electrode particles comprise NCM (nickel-cobalt-manganese oxide) particles (15), primary particles (30) that coat the outer surfaces of the NCM particles, an interphase layer (16) that includes a glass phase layer (241) and a plurality of ceramic particles (242), and a nitrogen-containing carbon layer (35) that coats the exterior of the primary particles. Nitrogen-doped carbon molecules in the nitrogen-containing carbon layer aid in the conduction of electrons and lithium ions, modifying the electrical potential of the NCM particles. The nitrogen-containing carbon layer is formed by coating the surfaces of the primary particles with a nitrogen-containing polymer material and calcining the material in an inert atmosphere. Conjugated bonds are formed between the carbon and nitrogen, modifying the energy band structure, reducing the energy required for electrons to transition to the conduction band, and improving overall electronic conductivity.

The invention relates to the technical field of batteries, in particular to a negative electrode material, a preparation method thereof and a battery. The negative electrode material comprises a silicon nano material; the metal silicide layer at least partially coats the surface of the silicon nano material; the nitrogen and sulfur doped carbon layer at least partially coats the surface of the metal silicide; and the thickness of the metal silicide layer is greater than that of the nitrogen and sulfur doped carbon layer. According to the negative electrode material, the preparation method thereof and the battery provided by the invention, the coating structure of the negative electrode material is optimized, and the metal silicide / heteroatom doped carbon double-layer coated silicon nano material can be prepared by adopting a synthesis method which is low in energy consumption and capable of constructing a functional multi-layer coating structure, so that the long cycle life and the high-rate fast charging performance can be considered at the same time.

The invention provides a Cu2O-based heterogeneous composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: coating the surface of a Cu2O hollow sphere substrate with a carbon layer, and depositing layered double hydroxides (LDHs) and metal palladium (Pd) nanoparticles on the carbon layer. According to the material, through a Cu2O-carbon layer-LDHs-Pd multistage heterostructure design, space optimization of light absorption, charge transfer and catalytic sites is realized; cu2O-carbon layer-LDHs interface coupling promotes directed migration of photo-induced electron-hole pairs, and the surface plasmon resonance effect of Pd nanoparticles enhances the charge separation efficiency; the LDHs optimizes a charge transfer path through surface oxygen vacancy or metal valence cycle, so that synergistic oxidation of non-free radicals and free radicals is realized, the organic matter degradation efficiency is remarkably improved, the oxidation path is widened, and the performance bottleneck of a single material is broken through.

The invention discloses a preparation method of a carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material, which is specifically implemented according to the following steps: step 1, dissolving sodium salt, ferric salt and phosphate in deionized water in proportion, then adding a carbon source into the solution, and uniformly stirring to obtain a mixed solution; step 2, fully drying the mixed solution obtained in the step 1 to obtain precursor powder; and 3, carrying out heat treatment on the precursor powder in a protective atmosphere, and cooling to obtain the carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material. The invention also discloses a coating prepared by the method, a single-crystal structure is combined with uniform carbon coating, grain boundary defects are eliminated, conductivity is improved, high specific capacity and long cycle life are realized, single-crystal growth and carbon layer in-situ coating are synchronously realized by a synthesis process, and structural integrity and efficient conductive network construction can be ensured.

The invention belongs to the field of battery negative electrode materials, and particularly relates to a sodium ion battery hard carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: mixing phenolic resin and asphalt, and carrying out pre-oxidation treatment to obtain a pre-oxidized precursor; and under a protective atmosphere, sequentially carrying out pre-carbonization treatment and carbonization treatment on the precursor subjected to the pre-oxidation treatment to obtain the sodium-ion battery hard carbon negative electrode material. In the pre-oxidation process, the asphalt and the phenolic resin are crosslinked, so that the foaming phenomenon of the phenolic resin in the subsequent carbonization process is reduced, the escape of small molecule gas in the phenolic resin is inhibited, the surface defects of the phenolic resin-based derived hard carbon material are further reduced, more closed pores are formed, and the sodium storage performance is improved. Meanwhile, a graphite-like carbon layer formed in the high-temperature carbonization process of the asphalt can be effectively inserted into a rigid framework of the phenolic resin hard carbon to construct a three-dimensional continuous conductive network, so that the electronic conductivity of the phenolic resin-based hard carbon is greatly improved, and the electrochemical performance of the sodium ion battery is improved.

The invention discloses a phenolic resin-based hard carbon microsphere material as well as a preparation method and application thereof. The hard carbon microsphere material is synthesized through high-temperature carbonization of a block copolymerization cross-linked network of phenolic resin and natural starch. The phenolic resin provides a highly cross-linked carbon network, and the addition of the starch regulates and controls the internal pore structure of the microsphere material, so that the obtained hard carbon material has appropriate carbon layer spacing and optimized surface defects. Besides, by reasonably controlling a carbonization process, the material can form a rich closed pore structure, so that the problem of volume expansion in the embedding / de-embedding process of sodium ions is effectively relieved, and the cycling stability and the sodium storage capacity of the material are improved. The method is easy to expand and suitable for large-scale production, the used raw materials are cheap and easy to obtain, and the method has the remarkable cost advantage. Meanwhile, excellent electrochemical performance can be achieved, and the material is suitable for being applied to negative electrodes of large-scale energy storage devices and has wide industrial application prospects.

The invention provides a silicon-based material and a preparation method thereof, a negative pole piece and a solid-state battery. The silicon-based material comprises an inner core and a surface coating layer, the inner core comprises a silicon-based negative electrode material, the surface coating layer is a carbon fluoride layer, the carbon fluoride layer internally comprises Li-M, LiF and LiX, M represents a metal element and is selected from at least one of Ag, Mg, Zn and Al, and X represents a non-metal element and is selected from at least one of N, S and P. The silicon-based negative electrode material is used as a core, the surface of the silicon-based negative electrode material is coated with the carbon fluoride layer, and the Li-M alloy / LiF / LiX composite lithium compound is introduced into the carbon fluoride layer, so that triple effects of ion-electron double-conduction network construction, interface chemical stabilization and mechanical buffer enhancement are achieved; and the chemical stability of an interface between the silicon negative electrode and sulfide solid electrolyte is improved while the rate capability of the negative electrode is improved and the expansion and shrinkage of the silicon negative electrode are relieved, and the cycling stability is improved.

The invention relates to a silicon-carbon negative electrode material and a preparation method thereof. The silicon-carbon negative electrode material comprises a carbon skeleton, silicon particles distributed in pores of the carbon skeleton and a carbon layer coating the carbon skeleton, wherein the carbon skeleton adopts porous carbon, and the carbon layer is of a double-layer gradient coating structure. According to the silicon-carbon negative electrode material and the preparation method thereof, by controlling the deposition mode, deposition temperature, deposition time and the like of the silicon source gas and the coating mode, coating flow, coating time and the like of the coating gas, uniform deposition of silicon particles in pores of a carbon skeleton and uniform coating of a gradient coating type carbon layer are realized; the growth of silicon grains and the formation of rich silicon on the surface are inhibited, the gas production of the material is reduced, the tap density of the material is improved, the tar residue in the material is eliminated, and the comprehensive electrochemical performance is considered.

The invention discloses an activated carbon anoxic pyrolysis and steam regeneration process method and device, and relates to the field of activated carbon regeneration. The process method comprises the following steps: S1, dehydration preparation: reducing the moisture content of a carbon layer to 45% through hydraulic conveying and negative pressure dehydration; s2, drying pyrolysis and air stripping, wherein a carbon layer is heated to 300-400 DEG C through circulating heating of superheated steam and tail gas; s3, steam activation: introducing 900 DEG C tail gas to raise the temperature of the carbon layer to 800-850 DEG C for activation reaction; and S4, cooling, namely sequentially cooling to 100 DEG C or below through steam and cold water to complete regeneration of the activated carbon. The energy efficiency utilization rate is excellent, the pore structure is fully recovered, the specific surface area, the polar group content and the adsorption performance of the regenerated activated carbon can be remarkably improved, and the service life of the activated carbon is prolonged.

The invention relates to the field of refractory castable, in particular to mullite-based modified high-strength refractory castable and a preparation process thereof. The refractory castable is used for solving the problems of low strength and poor wear resistance of the existing refractory castable. The niobium-zirconium alloy and the benzoxazine-PAMAM copolymer are added into the refractory castable, the benzoxazine-PAMAM copolymer wraps a matrix in a three-dimensional network structure, so that the cohesive force is improved, a carbon layer is formed among matrix particles after sintering to improve the overall compactness of the material, micropores in the matrix of the refractory castable can be filled with the niobium-zirconium alloy, the porosity is reduced, and the porosity of the refractory castable is improved. The refractory castable disclosed by the invention can be used for reducing stress concentration, remarkably improving normal-temperature compression resistance and breaking strength, maintaining long-term high-temperature strength and ensuring that the refractory castable can still be kept stable in severe environments such as high temperature, high pressure and corrosion, so that the service life is prolonged, and the production safety is improved.

The invention relates to the technical field of sodium-ion batteries, in particular to a hard carbon negative electrode material, a preparation method thereof and a sodium-ion battery. The preparation method comprises the following steps: preparing a porous carbon matrix by taking a carbon source as a raw material; crushing the porous carbon matrix, dipping the porous carbon matrix in a doping solution containing a first doping source, and carrying out heat treatment at 250-350 DEG C in an inert atmosphere to obtain a doped precursor; the first doping source is selected from at least one of a rubidium source and a cesium source; carrying out carbonization treatment on the doped precursor at the temperature of 1100-1700 DEG C to obtain a hard carbon intermediate; and carrying out carbon coating on the hard carbon intermediate to obtain the hard carbon negative electrode material. Large-radius ions (such as Rb < + > / Cs < + >) are introduced to be embedded into carbon layer gaps, the carbon layer gaps are enlarged through the strut effect of the ions, and the cycle performance is improved.

The present application relates to a negative electrode active material and a preparation method therefor, a negative electrode sheet, a secondary battery, and an electric device. The negative electrode active material comprises expanded graphite, a porous carbon layer, and silicon particles; the expanded graphite comprises a plurality of graphite layers; the porous carbon layer is at least distributed on an interlayer surface of one graphite layer, and the silicon particles are at least distributed in pore channels of porous carbon of the porous carbon layer.

The invention provides a mixed negative electrode material. The mixed negative electrode material comprises a silicon carbon material and a graphitized material, the silicon-carbon material takes porous carbon as a matrix, and a silicon layer and an ordered layered carbon layer are sequentially deposited on the surface of the porous carbon matrix; the compaction density of the mixed negative electrode material is 1.0-2.0 g / cm < 3 > and the conductivity is 0.80-118 S / cm under the pressure of more than or equal to 5 Mpa; the ratio of the mass ratio of the graphitized material to the mass ratio of the silicon-carbon material is greater than or equal to 1.6 and less than or equal to 8.5, and the particle size Dv10 of the mixed negative electrode material is 1.1-5.2 mu m; dv50 is 5.3 [mu] m to 16 [mu] m; dv90 is from 16 [mu] m to 35 [mu] m; the porosity of the mixed negative electrode material is 0.005%-0.1%; the specific surface area is 1.2-3.2 m < 2 > / g, and the surface of the negative electrode is provided with a cutting area. The problems that the negative electrode interface stability is reduced, the impedance is increased, the lithium ion conducting capacity is low, and the battery cycle performance is poor are solved.

The invention provides a phase change enhanced ablation-resistant modified liquid silicone rubber material as well as a preparation method and application thereof, and belongs to the field of advanced materials. According to the invention, paraffin is adopted as a phase change filler, so that the ablation resistance and heat insulation performance of the expanded ceramic liquid silicone rubber material are remarkably improved, and the prepared silicone rubber composite material has the advantages of low density, low ablation surface temperature, strong carbon layer and high heat absorption capacity. The phase-change reinforced modified expanded ceramic flexible ablation-resistant material further improves the ablation resistance and high-temperature heat insulation performance of a liquid silicone rubber material, and has a good application prospect in the fields of aerospace thermal protection, building heat insulation and the like.

The invention provides a treatment method for recovering high-purity graphite from black powder leaching residues. The treatment method comprises the following steps: removing impurity elements in graphite from the black powder leaching residues in a Joule heat flash evaporation manner; the black powder leaching residues obtained after impurity removal are put into a ball mill, liquid phenolic resin is added, full mixing is conducted, and ball milling is conducted; and putting the ball-milled mixture into flash evaporation Joule thermal equipment, and carbonizing and graphitizing the phenolic resin to obtain regenerated graphite. According to the method, the temperature of the black powder leaching residues can be increased within an extremely short time, metal impurities in the black powder leaching residues are gasified, and impurities in graphite are removed. Phenolic resin is used for carbonization and graphitization, generated disordered carbon can fill up particle cracks in waste graphite and internal lattice defects, a conductive network among graphite particles is established, a compact carbon layer is formed on the surface of graphite, and graphite structure transformation can also be induced in the step. The regenerated graphite obtained by the method is similar to commercial graphite in capacity and good in cycling stability.

The invention relates to a flame-retardant high-temperature-resistant fiber woven fabric and a preparation process thereof, and belongs to the technical field of textiles. The preparation method comprises the following steps: grafting and crosslinking a self-made grafting monomer and polyvinyl chloride, and then weaving to obtain the modified polyvinyl chloride fiber fabric; a phosphate group in the monomer can promote surface carbonization to form a protective carbon layer, silicate generated by decomposition of a siloxy group at a high temperature is combined with the carbon layer to improve the strength and melt viscosity of the carbon layer, and the phosphate group and the siloxy group synergistically enhance the flame retardance and the molten drop resistance of the fabric; a cyclic phosphate group and a pyridine ring are connected to form a rigid structure with relatively high thermal stability, chain segment movement is limited, a plurality of siloxy groups in a monomer are crosslinked to form a crosslinked network, molecular chain segments are difficult to move, and the combination of the rigid group and the crosslinked network improves the high temperature resistance of the fabric and effectively improves the mechanical properties of the fabric; in addition, the positively charged quaternary ammonium salt structure in the monomer improves the antistatic performance of the fabric, and cooperates with trifluoromethyl to destroy the structural integrity of bacterial cells, so that the fabric achieves efficient bacteriostasis.

The invention relates to a battery and an electric device comprising the same, and belongs to the technical field of batteries. The battery comprises a positive electrode plate, the positive electrode plate comprises a positive electrode material, the positive electrode material comprises an iron-containing lithium supplementing material, and a carbon layer is arranged on the surface of the iron-containing lithium supplementing material. By controlling the peak area ratio a of a Fe < 3 + > characteristic peak to an O1s peak in an XPS graph, the thickness b of a surface carbon layer of an iron-containing lithium supplementing material and the ID / IG ratio g of the positive plate to meet a specific relationship when XPS etching analysis is carried out on the positive plate at the etching depth of 210 nm, the negative influence of the lithium supplementing material on the conductivity of the positive plate is effectively weakened while the lithium supplementing efficiency of the lithium supplementing material is fully exerted; the low impedance and long cycle life of the battery system are both improved, and the comprehensive electrochemical performance of the battery is remarkably improved.

The invention relates to the technical field of lithium battery negative electrode materials, and discloses a preparation method of a lithium battery silicon-carbon composite negative electrode material with high cycle stability, and the preparation method comprises the following steps: carrying out magnesiothermic reduction and acid etching on micron silicon powder and magnesium powder to prepare porous silicon particles; growing carbon nanotubes on the surfaces of the porous silicon particles and in pore channels in situ to construct a three-dimensional conductive network; styrene butadiene rubber and glucose are adopted as a composite carbon source to coat the product, and a composite carbon layer is formed through drying and gradient carbonization; and finally grinding and sieving the carbonized product. According to the preparation method disclosed by the invention, pores are constructed in micron silicon, and the micron silicon is externally coated with the composite carbon layer with flexibility and rigidity, so that the volume expansion of silicon is effectively buffered; the in-situ grown carbon nanotube network provides a stable electron conduction path; the micron-sized substrate reduces the specific surface area of the material and improves the first coulombic efficiency. Therefore, the prepared negative electrode material has high cycling stability and excellent rate capability.

The invention discloses a method for preparing a lignin hard carbon negative electrode material through Joule thermal flash evaporation, and belongs to the technical field of negative electrode material preparation. The method mainly comprises the following steps: (1) reacting lignin with alkali liquor, adding acid, washing with water, and drying to obtain dried lignin; (2) preheating the dried lignin in a tubular furnace to obtain a hard carbon precursor; and (3) putting the hard carbon precursor into a graphite mold, and carbonizing through Joule heat flash evaporation to obtain the lignin-based hard carbon negative electrode material. According to the method, rapid temperature rise is realized by Joule heating, and the method is short in reaction time and high in reaction temperature. Compared with a radiation cooling mode of a traditional high-temperature furnace, black-body radiation can release most heat within milliseconds. Under the action of an electric field, lignin is recombined and stacked into a vortex layer carbon layer, and a three-dimensional continuous carbon network is formed. The ultrafast method can relieve the carbon layer accumulation phenomenon in the lignin pyrolysis process.

The invention discloses a high-potential-corrosion-resistant composite coating as well as a preparation method and application thereof. The high-potential-corrosion-resistant composite coating comprises a metal transition layer, a graphite-like amorphous carbon layer and a SnO2 hole sealing layer which are sequentially formed on the surface of the metal bipolar plate serving as a substrate, wherein the SnO2 hole sealing layer is prepared in an atomic layer deposition mode. According to the high-potential-corrosion-resistant composite coating provided by the invention, the SnO2 layer is deposited on the surface of the amorphous carbon coating, so that the effect of closing amorphous carbon defects is achieved, and the high-potential-corrosion-resistant composite coating has excellent corrosion-resistant protection performance under 1.6 V high-potential corrosion.

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 relates to the technical field of batteries, and discloses a secondary battery, a battery device and a power utilization device. The secondary battery comprises a positive electrode plate, the positive electrode plate comprises a positive electrode film layer, the positive electrode film layer comprises a positive electrode active material, the positive electrode active material comprises an inner core and a coating structure coating the surface of the inner core, and the coating structure comprises conductive phosphide and carbon. According to the secondary battery provided by the embodiment of the invention, by introducing the coating structure jointly formed by the conductive phosphide capable of assisting in improving the electronic conductivity and the carbon, the electronic conductivity of the positive electrode active material can be improved while the positive electrode active material has relatively high compaction density without increasing the content of a carbon layer; therefore, the volume energy density and the rate capability of the secondary battery can be improved.

The invention relates to the technical field of lithium ion battery fire extinguishing agents, and discloses a compound lithium ion battery fire extinguishing agent and a preparation method thereof.The compound lithium ion battery fire extinguishing agent is prepared from, by mass, 30-35 parts of vermiculite, 5-7 parts of fire extinguishing filler, 6-8 parts of modified zeolite, 0.5-1 part of a stabilizer, 1.5-2 parts of a dispersing agent, 1-2 parts of a thickening agent, 1-3 parts of a foaming agent and 40-50 parts of water. The fire extinguishing filler can form a barrier layer on the surface of the battery to prevent oxygen and heat transfer and achieve the fire extinguishing purpose, and starch and polydopamine in the fire extinguishing filler can form compact carbon layers, so that wrapped combustible molecules are distributed among the carbon layers, oxygen is further isolated, and the fire extinguishing efficiency is improved; the modified zeolite can complete fire extinguishing through a physical and chemical synergistic effect, and can form silicon dioxide to be distributed on the surface of the zeolite in the fire extinguishing process, so that the situation that the zeolite is subjected to thermal shock and thermal stress to cause collapse of a zeolite framework and influence the fire extinguishing performance is avoided.