35results about How to "Lower grain boundary resistance" patented technology

The invention discloses a graphene fiber and a preparation method thereof, wherein the graphene fiber is a composite fiber obtained by doping graphene fiber with metal nanowires, the composite fiber comprises the main components of graphene and the metal nanowires, wherein the mass ratio of the metal nanowires is 0.1% ~ 50%, the graphene is in lamellar morphology, and the metal nanowires and the graphene layers are parallelly and simultaneously arranged along the axial direction of the graphene fiber. The metal nanowire doped graphene fiber is a new high performance and multifunctional fiber material, by doping of the metal nanowires, fiber conductive rate is greatly improved, meanwhile the graphene fiber exhibits good tensile strength and excellent toughness, has the very strong potential application value in many fields such as use as lightweight flexible wires and the like.

The invention discloses silicon carbide ceramic with adjustable resistance and a preparation method thereof. The ceramic material mainly comprises a silicon carbide phase as a main phase, boron carbide as a sintering aid phase, and a carbon phase as a conductive phase, and the ceramic material can be prepared and has the bulk resistivity adjustable from 10<-2> to 10<8> Omega.cm. The silicon carbide ceramic has a density of 3.00 to 3.20 g/cm<3>. The core of the method is to coat the surface of silicon carbide raw material powder with a graphene-based material layer, and to adjust the content ofthe conductive phase in the silicon carbide ceramic to obtain the silicon carbide ceramic with adjustable bulk resistivity.

The invention relates to a doped BKT-BT series lead-free positive temperature coefficient resistance ceramic material and a prepration method thereof, the general formula of the composition of the material is (Bi0.5K0.5)*1(Ba1-*1-*2)AX2)Ti1-yMyO3+Zmol%D, wherein, x1 is more than 0 and not more than 0.7, x2 is more than 0 and not more than 0.6%, y is more than 0 and less than 0.2%, Z is not less than 0 and less than 1, A is one or more of Ce, Y, La and Bi, M is one or more of Nb, Sb, Ta and Mo, and D is one or more of MnO2, TiO2, SiO2 and B2O3. For a series of the lead-free ceramic materials, TC, alpha, betaRT and resistance sudden jump Rmax/Rmin are respectively changed between 140 and 250 DEG C, between 10 and 45%/DEG C, between 20 and 60 omega.Cm and between 10<2> and 10<5> along with the change of x1, x2, y and Z.

The invention relates to the technical field of solid electrolyte, and in particular, relates to a high-conductivity solid electrolyte prepared by a sol-gel method. Any one or a composition of more oflithium nitrate, germanium oxide and tetraethoxysilane is used as a doping agent, lithium titanium aluminum phosphate is used as a main material, the doping agent is embedded into the lithium titanium aluminum phosphate framework by the sol-gel method, and an NASICON structure is formed; the solid electrolyte disclosed by the invention is small in grain boundary impedance, high in ionic conductivity, low in sensitivity to heat treatment temperature and suitable for industrial production, and integrates the characteristics of low synthesis temperature, low energy consumption, high product purity, small particle size and high density of traditional sol-gel; citric acid and ethylene glycol are adopted as auxiliary agents, environmental pollution is prevented, the temperature and the stirringrate are reasonably controlled, and the cost is reduced.

The invention discloses a composite coated nickel-rich positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The composite coated positive electrode material comprises a nickel-rich positive electrode base material, a transition layer and a composite coating layer coated on the surface of the base material. The composite coating layer is composed of the composite solid electrolyte and the lithium-boron compound, the positive electrode material can be effectively protected through the combined action of the composite solid electrolyte and the lithium-boron compound, the safety performance of the material is improved, and the rate capability of the material can be further improved.

The invention relates to a NASICON type solid electrolyte with high ionic conductivity and a preparation method thereof. The method comprises the following steps that B2O3 is introduced into Li1+xAlxGe2-xP3O12 (x is greater than or equal to 0 and less than or equal to 1, and the following x is within the range) microcrystalline glass to further lower the activation energy of Li+ ions, so that theionic conductivity of the microcrystalline glass is improved. The NASICON solid electrolyte main body is Li1+xAlxGe2-xP3O12 microcrystalline glass, which comprises the following molar components: 14.82-25.00mol% of Li2O, 24.69-45.00mol% of GeO2, 2.47-12.50mol% of Al2O3, 37.04-37.50mol% of P2O5 and 0.01-1.23mol% of B2O3. According to the preparation method disclosed by the invention, a platinum crucible is adopted to prepare a glass precursor, and then the glass precursor is subjected to heat treatment in a muffle furnace to obtain the microcrystalline glass solid electrolyte with the NASICON structure. By controlling the doping concentration of B2O3, the ionic conductivity of the NASICON type solid electrolyte at normal temperature is improved by about four times; and the solid electrolytehas the advantages of high ionic conductivity, no toxicity, safety, stability, easiness in processing and the like, and has a great application prospect in all-solid state lithium batteries.

The invention provides an electrochemical device and electronic equipment. The electrochemical device comprises an electrolyte layer, a positive electrode layer and a negative electrode layer, the electrolyte layer comprises a near-positive-electrode-side electrolyte layer, an intermediate electrolyte layer and a near-negative-electrode-side electrolyte layer which are sequentially stacked, the electrolyte layer is arranged between the positive electrode layer and the negative electrode layer, the near-positive-electrode-side electrolyte layer is close to the positive electrode layer, and the near-negative-electrode-side electrolyte layer is close to the negative electrode layer; the near-positive-electrode-side electrolyte layer and the near-negative-electrode-side electrolyte layer are polymer electrolyte layers; the positive electrode layer comprises a positive electrode electrolyte skeleton and a positive electrode active layer filling the positive electrode electrolyte skeleton, and the composition of the positive electrode electrolyte skeleton is the same as that of the near positive electrode side electrolyte layer; and the intermediate electrolyte layer is an inorganic solid electrolyte layer. The electrochemical device is high in mechanical property, the physical contact between the electrolyte layer and the electrode layer is good, the interface stability is good, and the lithium ion transmission capacity and the cycling stability are high.

The invention provides an Mg-Bi-based lamellar block crystal material and a growth method thereof. The crystal structure of the crystal material is Mg3Bi2 configuration and presents a shale-shaped morphology. The growth method comprises the following steps: under the protection of vacuum or inert atmosphere, heating a vacant non-metal crucible for growing crystals to a preset temperature; and injecting a molten Mg-Bi-based crystal growth raw material solution into the non-metal crucible which is heated to the preset temperature, and carrying out crystal growth through a Bridgman-Stockbarger method or a seed crystal oriented growth method to obtain the Mg-Bi-based lamellar block crystal material. The growth method is simple in process and low in cost, crystals can be prepared in an amplified mode, and the Mg-Bi matrix block crystal material obtained through the growth method has a large-size, high-quality and regular layered structure, shows excellent thermoelectric performance near the room temperature and can be directly applied to preparation of thermoelectric devices.

The invention discloses an all-solid-state three-layer electrolyte and a preparation method of an all-solid-state battery. The composite electrolyte has a three-layer structure, and comprises a compact layer in the middle and porous layers located at two sides of the compact layer, the whole preparation process is simple, the preparation cost is low, and no pollution is caused to the environment.The solid electrolyte with the composite structure can effectively improve the interface compatibility of the electrolyte/electrode and reduce the interface impedance, and is beneficial to rapid transmission of metal ions (lithium, sodium, potassium ions and the like) on an interface; the electrolyte comprises the porous layer which is crosslinked with the anode and the cathode, so that the electrolyte has an ion conduction phase and an electron conduction phase at the same time, and the electrode activity and the structural stability can be improved; the effective contact area between the cathode and anode active materials and the electrolyte is increased, so that reaction activation sites are increased, the capacity and rate capability of the solid-state battery are improved, and the electrolyte can be used in all-solid-state lithium, sodium, potassium, Al and Zn plasma solid-state batteries.

The invention relates to a solid electrolyte, a preparation method thereof and a lithium ion battery, the solid electrolyte comprises the following raw materials: an oxide electrolyte, and a sintering aid, a polymer and a lithium salt which are filled in the oxide electrolyte, the solid electrolyte provided by the invention has relatively small grain boundary resistance and good interface performance, when applied to a lithium ion battery, the solid electrolyte has high ionic conductivity, can effectively inhibit the growth of lithium dendrites, and improves the comprehensive properties such as safety, cyclicity and stability of the battery.

The invention discloses a preparation method of a high-conductivity perovskite type BaZrO3-based proton conductor material with a controllable grain size. According to the method, (ZrO2)1-x(Y2O3)x (x is larger than or equal to 0.05 and smaller than or equal to 0.08) powder is adopted as an initial raw material, and the BaZrO3-based proton conductor powder material with the controllable grain size is synthesized at the low temperature. According to the invention, the problems of wide grain size distribution and non-uniform chemical composition in the traditional solid-phase synthesis process, tedious steps and difficult grain growth in the wet-chemical synthesis process. and the like are solved; the perovskite type BaZrO3-based proton conductor material prepared by the method is regular in shape, high in crystallinity and uniform in dispersion; and after densification treatment, the proton conductivity is good, the grain boundary impedance is greatly reduced, and the conductivity at 600 DEG C can reach 4.92*10<-3> S cm<-1>.

The invention provides a preparation method of a soft magnetic ferrite material, which comprises the following steps: S1, primary ball milling of a main material: grinding the main material in a ball mill to a micron level, drying, and cooling to room temperature; s2, pre-sintering: pre-sintering the cooled main material for a period of time, taking out, cooling, and blending with the auxiliary material; s3, secondary ball milling: putting the mixed main material and auxiliary material into a ball mill for secondary ball milling, and drying to obtain a pre-sintered mixture; and S4, mixing and grinding: grinding the pre-sintered mixture in a ball mill, drying after grinding, granulating, pressing, sintering and molding to obtain the target soft magnetic ferrite material. The invention provides the preparation method of the soft magnetic ferrite material with high saturation magnetic flux density and excellent magnetic performance.