350 results about "Lamellar structure" patented technology

The invention relates to the technical field of composite materials, in particular to a high-strength epoxy resin composite material and a preparation method thereof, and the high-strength epoxy resin composite material comprises the following raw materials in parts by weight: 50-80 parts of a base material, 10-20 parts of a curing agent, 5-10 parts of modified carbon nanotubes, 3-10 parts of a reinforcing sheet, 3-6 parts of a reinforcing material and 1-3 parts of a flame retardant. In the preparation method, the modified carbon nanotubes are in chemical bond connection with the base material through surface modification, the interface bonding force is enhanced, stress is effectively transmitted, the unique layered structure and surface modification treatment of the enhanced sheet are enhanced, the enhanced sheet is firmly combined with the resin matrix, and a three-dimensional enhanced network is formed through the synergistic effect of mechanical interlocking and stress dispersion. The vermiculite sheet layer prevents crack propagation, and the modified carbon nanotubes and the reinforcing material effectively transfer stress, so that the tensile strength and bending strength of the composite material are greatly improved, and the high-strength application requirement is met.

The invention discloses a regulation and control method for a TiAl alloy double-peak lamellar structure, and belongs to the technical field of TiAl alloy heat treatment. A TiAl alloy sample is firstly subjected to heat treatment to prepare a conventional lamellar structure composed of coarse gamma lamellas, then the conventional lamellar structure is heated to 5-50 DEG C below a T alpha / (alpha + gamma) or T (alpha + beta) / (alpha + beta + gamma) phase transformation point, heat preservation is conducted for 5-120 min, rapid cooling is conducted, and a metastable lamellar structure containing a small amount of gamma coarse lamellas is obtained; and finally, low-temperature tempering treatment is conducted, heat preservation is conducted for 5 min to 300 min at the temperature of 700 DEG C to 1000 DEG C, furnace cooling is conducted to the room temperature, and the TiAl alloy with the double-peak lamellar structure is obtained. Through the regulation and control method, the formation of a discontinuous precipitation zone and a non-equilibrium structure is effectively inhibited while the gamma lamellas of the TiAl alloy are refined, and compared with a conventional lamellar structure composed of coarse gamma lamellas, the yield strength of the TiAl alloy can be improved by at least 50 MPa through the prepared double-peak lamellar structure, and the steady-state creep rate of the alloy is reduced by more than 5 times.

The invention relates to the field of preparation of lubricating materials, in particular to a preparation method of composite phase change lubricating gel based on temperature-friction force synergistic response. The lubricating gel adopts a sandwich layered structure; the bottom layer is a porous ceramic layer formed by micro-arc oxidation, is filled with a disulfide bond dynamic network polymer and is anchored on a metal substrate; the middle layer comprises a microencapsulated phase change material which is dispersed in a polyurethane network containing dynamic disulfide bonds and is wetted with ionic liquid; the surface layer is an epoxy resin coating rich in boron nitride nanosheets, and a rapid heat conduction channel is constructed. Compared with the prior art, the lubricating state can be automatically adjusted in the friction process without external energy input, and the method has the advantages of being sensitive in multi-field coupling response, capable of achieving automatic antifriction protection, high in extreme working condition adaptability and the like.

The invention relates to the technical field of layered products, and particularly discloses a skin material for wave-absorbing hiding and a preparation method. The skin material is of a layered structure and comprises a bionic micro-forest wave-transparent layer, a gradient transition layer, a wave-absorbing layer with a'skeleton-matrix 'dual-network structure, a reflecting layer and a heat-insulating layer which are sequentially arranged from top to bottom. A micro-cone array is arranged on the surface of the bionic micro-forest wave-transparent layer, so that broadband impedance matching is realized; the wave-absorbing layer comprises a three-dimensional ceramic skeleton and a magnetic-dielectric composite matrix filled in pores of the skeleton, and magnetic absorbents in the wave-absorbing layer are directionally arranged in the layer plane direction through a magnetic field auxiliary technology. The skin material prepared by the invention has excellent comprehensive performance of ultra-wideband wave absorption, high mechanical strength, light weight and high temperature resistance, and is particularly suitable for stealth requirements in the field of aerospace.

The invention belongs to the technical field of polymer composite materials, and particularly relates to a high-strength bismaleimide resin material and a preparation method thereof. The bismaleimide resin composition comprises the following components in parts by weight: 50-60 parts of bismaleimide resin, 40-50 parts of an allyl compound, 1-3 parts of modified graphene and 0.1-0.5 part of a dispersing filler, the dispersing filler is prepared from modified inorganic nanoparticles and modified tetrapod-like zinc oxide whiskers in a mass ratio of (0.1-1): 1. Wherein the tetrapod-like zinc oxide whiskers can promote the dispersion of the graphene with a large lamellar structure from the macroscopic aspect, so that the graphene is uniformly dispersed in a bismaleimide resin matrix, and the inorganic nanoparticles can play a role in lubrication and isolation, so that the agglomeration among graphene lamellas in a small range is prevented. By adding the graphene composite reinforcing filler, the rigidity of the bismaleimide resin material is improved, and the toughness of the composite material can be improved at the same time.

The invention discloses a forging method for regulating and controlling the structure uniformity of a TiAl alloy, and belongs to the technical field of TiAl alloy material processing. According to the method, a TiAl alloy ingot is coated with a soft sheath, X-Y-Z three-dimensional six-pass reversing forging is carried out, then the sheath is removed, long-time annealing is carried out, X-Y-Z three-dimensional six-pass reversing forging is carried out again, and a TiAl alloy forging stock with a fine and uniform equiaxed structure is obtained; according to the method, the first round of six-pass forging is conducted on the blank through the X-Y-Z three-dimensional multi-pass reversing forging technology, short-time annealing is conducted between the passes, through the mode of combining dynamic recrystallization and sub-dynamic recrystallization, evolution of a thick and large as-cast structure in a TiAl alloy ingot is promoted, a fine equiaxed structure is formed, the uniformity of the forging stock is improved, and the yield of the TiAl alloy ingot is increased. And the blank is subjected to long-time annealing treatment, growth and spheroidization of residual lamellar structures are achieved, second-round six-pass forging is conducted, the grown equiaxed structures are refined, it is ensured that the TiAl alloy forging stock has the fine and uniform equiaxed structures, and the mechanical property of the TiAl alloy forging is improved.

The invention discloses a heat treatment method for regulating and controlling lamellar structures of TiAl alloy forgings, and belongs to the technical field of heat treatment of alloy materials. According to the method, the obtained forged TiAl alloy is placed in a heat treatment furnace with the temperature of T alpha + / -10 DEG C, after heat preservation is conducted for 5-30 min, multi-stage step-by-step cooling is conducted, the TiAl alloy with the fine near-lamellar structure is obtained, the multi-stage step-by-step cooling mode comprises two modes, the first mode is furnace cooling + air cooling, and the second mode is furnace cooling + air cooling + oil cooling; by regulating and controlling the critical temperature point, the cooling speed and possible short-time heat preservation of each cooling stage, accurate control over lamellar regularity, lamellar cluster size and grain refinement degree is achieved, generation of Widmannstatten structures and metastable structures is effectively inhibited, and the structure uniformity and the strength and plasticity matching performance are remarkably improved.

The invention relates to the technical field of layered products, and particularly discloses a heat-insulating and wave-absorbing skin material as well as a preparation method and application thereof. The heat-insulating and wave-absorbing skin material is of an integrated layered structure based on an aluminum oxide-mullite system, comprising a functional gradient layer with double gradients of fiber density and aperture, an impedance matching layer with a gradient dielectric constant, a resonance wave absorbing layer with a periodic dot matrix formed by silicon carbide and aluminum oxide core-shell microspheres, and a heat insulation layer with a nano-micron double-scale pore structure. According to the preparation method, a green body is constructed mainly through tape casting and silk-screen printing, and then co-sintering integrated forming is carried out. The material has the excellent characteristics of high temperature resistance, toughness, efficient heat insulation, broadband wave absorption and the like, and is suitable for extreme environments such as hypersonic aircraft skin and the like.

The invention provides a chromium-titanium bimetallic layered sulfide positive electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion battery materials. The chemical general formula of the material is LiCrxTiyS2, x + y = 1, the material belongs to a hexagonal crystal system O1 type structure, and the space group is Pm1. Microtopography analysis shows that the material is granular, the particle size distribution is 2-15 [mu] m, the particle surface has a layered structure characteristic, and each element is uniformly distributed on the particle surface and in a bulk phase. The capacity of the material mainly comes from oxidation reduction between titanium and sulfur, and chromium has the effect of stabilizing a structural framework and does not participate in the charge compensation process. Electrochemical analysis shows that the reversible capacity of the LiCr2 / 3Ti1 / 3S2 positive electrode material reaches up to 223 mAh g <-1 > and is close to the theoretical value of the positive electrode material of the system. In addition, the material shows excellent rate capability and cycling stability, and still keeps the capacity retention ratio of 80% after 330 times of cycling.

The present disclosure relates to a method of manufacturing a layered structure for a MEMS apparatus, a layered structure manufactured by the method, and a MEMS apparatus 200 (300, 400, 500) comprising the layered structure. For the layered structure, a high-temperature curing step is provided in the manufacturing process, for example, after structuring the functional layer 3. The structured regions and trenches of the functional layer 3 and in particular the spring structure formed in the functional layer 3 have smoothened side walls and / or rounded corners in regions 3a after the curing step, so that their fracture limits can thus be increased and early fractures of the functional layer 3 during operation of the MEMS apparatus 200 (300, 400, 500) can be avoided.

The invention discloses a superhard wear-resistant B2 + Laves nanosheet layer eutectic high-entropy alloy coating and a laser cladding controllable preparation method thereof, and belongs to the technical field of high-entropy alloy coatings. The alloy coating is composed of Al, Co, Fe, Ni and Nb according to the atomic ratio of 1: 1: 1: 1: x, x is equal to 0.08, 0.2, 0.4 or 1; the alloy coating is increased to x = 1 along with x = 0.08, the microhardness of the alloy coating is remarkably improved to 907 HV from 477 HV, and the distribution range of eutectic lamellar structure spacing is 100-160nm. By regulating and controlling the atomic ratio of the Nb element in the coating, accurate control over formation of a primary phase and a eutectic structure can be achieved. Along with the increase of the Nb content, the microstructure of the coating is formed by compounding a B2 primary phase and a B2 / Laves nanometer eutectic wafer layer, and is gradually converted into a composite structure of a Laves primary phase and the B2 / Laves nanometer eutectic wafer layer.

The invention belongs to the technical field of hydrophobic electromagnetic shielding materials, and particularly relates to an asymmetric electromagnetic shielding composite film and a preparation method and application thereof. The PNTs are polypyrrole nanotubes, after Na2MoO4. 2H2O and CH4N2S are added and subjected to a high-temperature reaction, a MoS2 flower-shaped shell structure can grow on the PNTs, the layered structure and the high specific surface area of MoS2 contribute to enhancing scattering and absorption of electromagnetic waves, and rich defect sites can induce dielectric polarization to achieve dielectric loss. Introducing the PNTs (at) MoS2 core-shell nanowire as an electromagnetic wave absorbent into a polylactic acid / dichloromethane system, then putting the system into a culture container in which a conductive filler is pre-paved, and standing and volatilizing at room temperature by adopting an ethanol solution as a volatile agent to finally obtain a three-layer asymmetric electromagnetic shielding composite film comprising the conductive filler, the PNTs (at) MoS2 structure and a polylactic acid matrix from bottom to top. And an asymmetric conductive gradient network is constructed, and the EMI shielding performance which mainly focuses on absorption is remarkably improved, so that the secondary radiation problem of electromagnetic waves is reduced.

The invention relates to the technical field of metal material connection and surface engineering, in particular to MAB phase reinforced Cu-Sn-Ti active brazing filler metal and a preparation method thereof. According to the MAB phase enhanced Cu-Sn-Ti active brazing filler metal, an MAB phase serves as a strengthening phase and is layered ternary boride ceramic, M is Mo or Cr, A is Al, and the brazing filler metal comprises, by mass, 60%-65% of Cu powder, 15%-18% of Sn powder, 10%-12% of Ti powder and the balance MAB powder. The MAB phase ceramic with a unique layered structure and chemical activity is introduced, the interface reaction of a diamond / steel substrate can be actively regulated and controlled while dispersion strengthening of the brazing filler metal substrate is achieved, a tough and tough combined gradient interface is formed, and therefore the diamond composite wear-resistant coating with excellent comprehensive performance is obtained.

The invention relates to the technical field of composite materials, in particular to a sound-insulation and heat-insulation composite material and a preparation method thereof.Multiple modified filler components with special structures and performance are introduced into the composite material, and a good sound-insulation and heat-insulation effect is achieved through the synergistic effect; modified hollow glass beads in the modified filler component have a hollow structure, and the structure can effectively block the transmission of sound and heat and play a role in sound insulation and heat insulation; the sulfur-loaded modified multi-walled carbon nanotube has a unique tubular structure, can increase the scattering and reflection paths of sound waves and heat flow in the material, and reduces the conduction efficiency of sound and heat; the nano silicon dioxide modified graphene oxide has a layered structure, and a large number of tiny pores can be formed between layers, so that transmission of sound and heat is further hindered; meanwhile, cesium tungsten bronze nano-powder is selected as the PVC heat insulation agent, and the substance has excellent optical performance and can reflect and scatter infrared rays and reduce heat transfer through radiation.

The present disclosure relates to a method for manufacturing a layered structure for a MEMS apparatus, a layered structure which is a layered structure produced by the method, and a MEMS apparatus 200 which comprises such a layered structure. For the layered structure or the MEMS apparatus 200, an exemplary starting substrate is used in the manufacturing process, which forms the mechanically effective functional layer 10, wherein the mechanically effective functional layer 10 comprises a ferroelectric and / or piezoelectric material.

The present invention provides a method for producing a patterned film disposed on a support. The method comprises the steps of providing a layered structure comprising a sacrificial protection layer disposed on the film, and a photoresist layer disposed on the sacrificial protection layer. The sacrificial protection layer selected to be free (or substantially free) of residues upon removal without damaging film layer, at least partially soluble or swellable in a solvent, and preferably clear to photolithographic alignment. The photoresist layer is then patterned to produce masked and un-masked areas of the layered structure, and in the unmasked areas the sacrificial protection layer and the film are removed to reveal the support, and in the masked areas the sacrificial protection layer is exposed to the solvent such that the sacrificial protection layer is released from the underlying film, thereby resulting in the patterned film disposed on the support. Also disclosed is the use of a layered structure for producing a patterned film disposed on a support, and a method for making the layered structure. The present invention enables the suppression or elimination of fabrication-induced photoresist (PR) residues on the contacts and / or at the interfaces of material layers, which finds particular utility in the fabrication of two-dimensional (2D) electronic devices such as field-effect transistors (2D-FETs).

The invention relates to the technical field of metal material additive manufacturing, in particular to an additive manufacturing TiAl alloy structure homogenization method. According to the method, 1.5 at.%-2.5 at.% of an Al element is added into a TiAl alloy for compensation, then TiAl alloy powder is prepared, electron beam selective melting printing is carried out, short-time circulating heat treatment is carried out after hot isostatic pressing treatment is carried out, the temperature in the short-time circulating heat treatment process is 5-20 DEG C higher than T alpha / (alpha + gamma), and heat preservation is carried out for 3-10 min; according to the method, the problem of non-uniform structure of the TiAl alloy formed by SEBM is synergistically solved by compensating the content of Al element and a short-time circulating heat treatment process, a uniform and fine lamellar structure can be obtained without a complicated process parameter optimization process, the size of a lamellar cluster is smaller than 100 microns and is far lower than that of a lamellar cluster prepared by conventional heat treatment, and the method is suitable for large-scale production. The room-temperature tensile strength of the alloy is at least improved by 150MPa, and the tensile strength at 750 DEG C is at least improved by 80MPa. The process method is simple and high in adaptability, and can be widely applied to additive manufacturing of the TiAl alloy.

To overcome the technical problems existing in the prior art ternary material, the present disclosure provides a ternary material, the chemical formula of which is LiNi 1‑x‑y Co x Mn y M a O2, wherein 0 < x ≤ 0.1, 0 < y ≤ 0.1, 0 < a ≤ 0.05, M is selected from one or more of Zr, Ti, Zn, Mg, Ta, V, W, Al and B; the ternary material comprises polycrystalline particles; in the X-ray diffraction spectrum of the ternary material, the (108) diffraction peak at a diffraction angle 2θ of (64±0.5)° and the (110) diffraction peak at a diffraction angle 2θ of (65±0.5)° satisfy the following relationship: The present disclosure provides a ternary material, and the satisfaction of this relationship can ensure that the material has good crystallinity and stability of layered structure, so that the prepared ternary material has high cycle life, rate performance and specific capacity.

The application belongs to the technical field of polymer composites, and discloses a low linear expansion coefficient polyphenylene sulfide composite material, a preparation method and application thereof. The composite material comprises 20-60 parts of polyphenylene sulfide resin, 40-80 parts of a low expansion filler system, 0.5-5 parts of a coupling agent, 0.1-1 part of a lubricant and 0.1-1 part of a toning agent. The low expansion filler system is at least two of a lamellar structure filler, a fibrous structure filler and a nano-sized filler. The polyphenylene sulfide composite material obtained has a low linear expansion coefficient while maintaining good mechanical properties through the limiting effect of the lamellar structure filler on the thermal expansion of the resin matrix, the reinforcing effect of the fibrous structure filler on the strength and modulus of the material and the improvement effect of the nano-sized filler on the filling structure and the interface state. The polyphenylene sulfide composite material can be applied to the fields of precision instruments, electronic packaging, electronics and electrical appliances, automobiles and aerospace, etc. which have high requirements for thermal dimensional stability.

The invention relates to a heat-insulating film (2) for a pressure sensor (1) for determining the pressure of a fluid medium (F), comprising a film body (3) and a coating (5), a film surface (6) of the film body (3) facing the fluid medium (F) when the heat-insulating film (2) is used. The coating (5) has a layer-like structure (7), the longitudinal extension (DL) of which perpendicular to the film plane (XY) is at most half of the transverse extension (DQ) of which parallel to the film plane (XY) for a plurality of layers (9).

A cutting tool comprising a base material and a coating film disposed on the base material, wherein: the coating film includes a first layer; the first layer is formed of a plurality of hard particles; the hard particles are each formed of titanium, silicon, carbon, and nitrogen; the hard particles have a cubic crystal structure; the first layer has a columnar structure; in the first layer, the average of the ratio NSi / (NTi+NSi) of the number NSi of silicon atoms with respect to the total of the number NTi of titanium atoms and the number NSi of silicon atoms is 0.01-0.10; in the first layer, the average of the ratio NC / (NC+NN) of the number NC of carbon atoms with respect to the total of the number NC of carbon atoms and the number NN of nitrogen atoms is 0.60-0.85; the hard particles each have a laminate structure in which a first unit layer and a second unit layer are alternately laminated; the first unit layer and the second unit layer are each formed of the titanium, the silicon, the carbon, and the nitrogen; the ratio x1 of the number of silicon atoms with respect to the total of the number of titanium atoms and the number of silicon atoms in the first unit layer is greater than the ratio x2 of the number of silicon atoms with respect to the total of the number of titanium atoms and the number of silicon atoms in the second unit layer; and the ratio y1 of the number of carbon atoms with respect to the total of the number of carbon atoms and the number of nitrogen atoms in the first unit layer is greater than the ratio y2 of the number of carbon atoms with respect to the total of the number of carbon atoms and the number of nitrogen atoms in the second unit layer.

This provides a structure that exhibits a high degree of balance between durability, conductivity, and quantum efficiency. [Solution] A layered structure comprising a substrate and a high-density particle layer on the substrate, wherein the high-density particle layer contains nanoparticles with an inorganic film formed on its surface, the nanoparticles having a particle size of 1 nm to 50 nm, the high-density particle layer having a packing density of nanoparticles per unit volume of 30 vol% to 80 vol%, the inorganic film having a thickness of 0.1 nm to 5 nm, the energy level at the upper end of the valence band of the inorganic film being the same as or lower than the energy level at the upper end of the valence band of the nanoparticles, and the energy level at the lower end of the conduction band of the inorganic film being the same as or higher than the energy level at the lower end of the conduction band of the nanoparticles.

The invention relates to a frame (8) of a roof system (3) of a vehicle roof (1), wherein the frame (8) has a frame base element (11) which is formed as a plastic component and has at least one front frame cross member (12) and two lateral frame longitudinal members (13). According to the invention, at least one functional component (23) made of plastic is arranged on the frame base element (11), the frame base element (11) and the functional component (23) form a layered structure with mutually associated common contact surfaces (24, 25) and are connected to each other via the common contact surfaces (24, 25) by means of a material-bonded joining connection, in particular an adhesive bond or a plastic welding connection.

The invention discloses a four-phase composite ceramic heating element and a preparation method thereof, and relates to the technical field of ceramic heating materials, the composite ceramic heating element comprises the following components: 30%-40% of titanium diboride, 30%-40% of titanium carbide, 10%-28% of silicon carbide, 1%-12% of hexagonal boron nitride, 0.5%-3% of nano zirconium dioxide and 1%-4% of silicon nitride. A four-phase composite system of TiB2 (titanium diboride), TiC (titanium carbide), SiC (silicon carbide) and hBN (hexagonal boron nitride) is constructed, basic expansion reduction is achieved through the low expansion characteristic of SiC, thermal expansion mismatching stress between different phases is dispersed in combination with the interface regulation and control effect of an h-BN layered structure, compared with an existing ternary system, the minimum thermal expansion coefficient is reduced to 5.8 * 10 <-6 > K <-1 >, and the thermal expansion coefficient is reduced to 5.8 * 10 <-6 > K <-1 >. And the interfacial compatibility is remarkably improved, and thermal stress is prevented from being gathered at the interface.

The invention discloses a heat treatment method for improving matching of strength, plasticity and toughness of a Ti55531 alloy, which is specifically characterized in that the whole heat treatment is carried out under the protection of argon, so that the titanium alloy is effectively prevented from absorbing hydrogen and even nitriding at a high temperature, serious reduction of local performance is avoided, and the heat treatment method is suitable for heat treatment of titanium alloy bars, forging stocks and complex workpieces; and a two-section annealing process of first rapid cooling and then slow cooling is adopted, a fine lamellar layer is formed through rapid cooling to improve the strength, then slow cooling is performed to weave a part of thicker lamellar structures from a fine needle-shaped secondary alpha phase to improve the toughness of the material, so that strength and toughness matching is realized, a lamellar alpha-phase structure with an ideal thickness is formed more accurately, and the strength of the material is improved. And the challenging matching requirements of strength, plasticity and toughness can be met.

The wiring board includes an insulation layer made of ceramic and a conductor layer extending in a planar direction inside the insulation layer. The conductor layer is constituted by a sintered body of a plurality of crystallites containing a metal as a main component, and has a layered structure in which a dense layer, a non-dense layer, and a dense layer are layered in layers in this order in a thickness direction.

Systems and methods are provided for delivering material compositions comprising particularly-formed multi-layer micron-sized particles that are substantially transparent, yet that exhibit selectable coloration based on their physical properties suspended in substantially transparent matrix or binder materials to facilitate delivery onto substrates, particularly aerosol or aspirated delivery. The disclosed physical properties of the particles are controllably selectable refractive indices to provide an opaque-appearing energy transmissive material when pluralities of the particles are suspended in the substantially transparent matrix material. The multiply-layered (up to 30+ constituent layers) particles result in an overall particle diameter of less than 5 microns, substantially equivalent to paint pigment particles. When delivered, the material compositions form layers that uniquely implement optical light scattering techniques in energy (or light) transmissive layers that appear selectively opaque, while allowing 80+% of the energy impinging on the light incident side to pass through the layers.

This invention discloses an H-configuration multimodal noise-absorbing vibration damper and its design method, belonging to the field of vibration control technology. The vibration damper includes a composite-clad elastic plate, an elastic plate, a multimodal coupling structure, and movable counterweights. The elastic plate assembly includes a composite-clad elastic plate, which is a layered structure formed by combining fiberglass epoxy board and stainless steel, prepared by a molding process. The material ratio of fiberglass epoxy board to stainless steel is determined according to the formula for the stiffness of a simply supported beam spring. Both sets of movable counterweights can slide and adjust their positions along the length of the composite-clad elastic plate or the elastic plate, adapting to the vibration suppression requirements of different frequency bands by changing the mass distribution of the noise-absorbing vibration damper. The multimodal coupling structure is integrated into the elastic plate assembly, and frequency control of multiple modes is achieved through stiffness matching between the elastic plate assembly and the multimodal coupling structure. This invention can cover a wide frequency band, has high vibration reduction efficiency, and a reliable structure, providing technical support for the field of multi-frequency vibration suppression.

The invention belongs to the technical field of communication materials, and particularly relates to a composite wave-absorbing material and a preparation method and application thereof. The composite wave-absorbing material comprises a porous carbon material with a layered structure, wherein a material with a core-shell structure is inserted into the layered structure of the porous carbon material; the core in the material with the core-shell structure comprises metal particles; a shell layer in the material with the core-shell structure comprises a carbon layer and an alloy layer, and the alloy layer is coated with the carbon layer. The composite wave-absorbing material has a three-layer core-shell structure, an intercalation structure and a porous structure which are indispensable, and the three-layer core-shell structure, the intercalation structure and the porous structure jointly act to obtain a three-dimensional network structure, so that the composite wave-absorbing material has good electromagnetic absorption performance.

An active material of the positive electrode comprises a lithium transition metal composite oxide with a lamellar structure; in a volume-based particle size distribution of the active material of the positive electrode, the following relationship exists: 0.1 <f2 / f1≤25 erfüllt, wobei f1 eine maximale Frequenz in einem Bereich ist, in dem ein maximaler Feret-Durchmesser 1 µm oder mehr und 3 µm oder weniger beträgt, und f2 eine maximale Frequenz in einem Bereich ist, in dem der maximale Feret-Durchmesser 5 µm oder mehr und 25 µm oder weniger beträgt.