86results about How to "Increased ZT value" patented technology

The invention relates to a Cu-S-Se ternary thermoelectric material and a preparation method of the material, belonging to the technical field of energy material. The method for preparing the Cu-S-Se ternary thermoelectric material is characterized in that high-pure metal simple substance Cu powder, high-pure Se powder and high-pure S powder are taken as raw materials and are proportioned according to the chemical general formula Cu 1.8 S 1-x Se x (wherein x is the mole fraction of Se component element and is more than or equal to 0.01 and less than or equal to 0.99); and the compound powder is synthesized by a mechanical alloying method, and a block is prepared by spark plasma sintering. The method can be used for preparing the Cu-S-Se ternary thermoelectric material simply, conveniently and accurately, and the Cu-S-Se ternary thermoelectric material has the excellent thermoelectric property at the medium temperature area.

The invention relates to a bismuth telluride based bulk nano crystalline thermoelectric material and preparation method thereof. The technical scheme includes that: firstly simple substance powder with mass percent more than 99.99% is taken as raw material, burdening is carried out according to the chemical formula (SbxBi1-x)2Te3 or Bi2(SeyTe1-y)3, wherein x is more than or equal to 0.75 and less than or equal to 0.85, y is more than or equal to 0.04 and less than or equal to 0.06, mixing to be uniform is carried out, and then ball milling is carried out by a ball mill, thus obtaining bismuth telluride base alloy nano powder; secondly, the bismuth telluride base alloy obtained in the first step is loaded into a graphite mould or ceramic mould to be sintered in a micro wave irradiation pressure sintering device; temperature rises to 300-550 DEG C by heating under the condition that the pressure applied to the powder is 10-40MPa, and then heat preservation is carried out for 10-60min under the condition that the pressure applied to the powder is 30-60MPa, thus obtaining the bismuth telluride based bulk nano crystalline thermoelectric material. The invention has the characteristics of less investment, low production cost, simple technology and short period; and the obtained bismuth telluride based bulk nano crystalline thermoelectric material has high performance.

The invention discloses a nanophase doped bismuth telluride-based thermoelectric material and a preparation method thereof. The bismuth telluride-based thermoelectric material is characterized in taking the bismuth telluride-based thermoelectric material containing a tellurium element, a bismuth element and a doped chemical element, as a matrix. The doped nanophase is a one-dimensional nanophase,and the weight of the one-dimensional nanophase accounts for 0.01-5 percent of the weight of the matrix. Attapulgite or a zinc oxide nanowire or a single-wall carbon nanotube or a multi-wall carbon nanotube is preferable to the one-dimensional nanophase. Compared with the prior art, in the bismuth telluride-based thermoelectric material, the lattice heat conductivity within the whole temperature zone range is reduced, thereby a ZT value is greatly improved and the thermoelectric performance of the bismuth telluride-based thermoelectric material is improved. The preparation method is simple and easy to implement, and compared with other methods of balling milling or liquid phase and the like, impurities are not easy to introduce in the preparation method so that the one-dimensional nanophase is evenly staggered and distributed in the matrix and the mechanical property of the material is effectively improved.

The invention relates to a high-performance thermoelectric composite material and a preparation method thereof, belonging to the field of thermoelectric materials. The composite material consists of two phases. A first phase is n-type Bi2Te3-Bi2Se3 or p-type Bi2Te3-Sb2Te3, and a second phase is nanometer powder of a metallic oxide. The nanometer powder of the metallic oxide accounts for 0.05-10% in terms of the total weight of the thermoelectric composite material. According to the preparation method provided by the invention, the n-type Bi2Te3-Bi2Se3 or p-type Bi2Te3-Sb2Te3 powder is ultrasonically mixed with the nanometer oxide, and discharge plasma sintering is carried out on the mixture to obtain a dense block material. Compared with the bismuth-telluride-based thermoelectric base material, under the condition that the electric conductivity of the thermoelectric base material is maintained to be unchanged basically in the invention, the high-performance thermoelectric composite material, provided by the invention, achieves the advantages of obviously reduced lattice heat conductivity and increased Seeback coefficient, and therefore the thermoelectric performance of the material can be greatly improved.

The invention relates to a doping molybdenum antimonide-based thermoelectric material and the preparation method, which is characterized in that the invention adopts arc melting and discharging plasma rapid sintering method for combination. The preparation method which is provided by the invention is the arc melting and the discharging plasma rapid sintering; Sb and Te/Se are firstly melted to form Sb2Te3Sb2Se3 and then are treated with the arc melting with the stoichiometric ratio of Mo and Sb; finally, the discharging plasma rapid sintering technology is introduced for preparing a dense single-phase material. The invention provides the rapid, simple and effective preparation method of the molybdenum antimonide-based thermoelectric material, which has good practical prospect.

The invention provides a composite material. The composite material comprises a skutterudite filling substrate shown as the following formula (I): IyCo4Sb12 (1), wherein I is at least one of Yb, Eu, Ce, La, Nd, Ba and Sr, and y is less than 1 and not more than 0.05. The composite material further comprises GaSb particles distributed in the skutterudite filling substrate, wherein the composite material contains 0.05-5 mol% GaSb particles. Compared with the thermoelectric material substrate without compounding a nanometer GaSb phase, the Seebeck coefficient of the composite material is improved to a large extent, the total heat conductivity is slightly reduced, the thermoelectric performance index ZT value is greatly increased in the whole high temperature and low temperature zone range, and the thermoelectric conversion efficiency of the material is greatly improved. The composite material has simple process and favorable industrialization prospect and is easy to control.

The invention relates to a hole compensation type skutterrudite thermoelectric material and a preparation method of the hole compensation type skutterudite thermoelectric material. The hole compensation type skutterudite thermoelectric material is shown in the following description: RyA(4-x)BxSb12/z NC, wherein x is equal to or greater than 0.01 and equal to or less than 0.5, y is equal to or greater than 0.01 and equal to or less than 1 and z is equal to or greater than 0% and equal to or less than 10%; R is selected from at least one of the following group of elements: Ca, Ba, La, Ce, Pr, Nd and Yb; A is selected from at least one of the following group of elements: Fe, Co and Ni; B is selected from at least one of the following group of transition metal elements: Ti, V, Cr, Mn, Fe, Nb, Mo, Tc and Ru, and electron number of the element B is less than that of the element A; and NC is in phase II, wherein z is mole% in the phase II of the thermoelectric material. The invention also provides the preparation method of the hole compensation type skutterrudite thermoelectric material.

The invention relates to a zinc antimony based porous p-type thermoelectric material and a preparation method thereof. The general chemical formula of the material is R (Zn2-xTx) 2 (Sb2-yMy) 2, wherein R denotes an element Yb, Eu or Ca; T denotes In, Mn or Cd, x denotes T doping stoichiometric ratio, and x is more than or equal to zero and is less than or equal to 2; and M denotes Si, Ge or As, y denotes M doping stoichiometric ratio, and y is more than or equal to zero and is less than or equal to 2. The method adopts a technology of mother alloy high-temperature fusion in vacuum or under the protection of inert gas, a melt-quenching technology and a discharge plasma mother alloy sintering and quenching technology to prepare the zinc antimony based porous p-type thermoelectric material with aperture of 20-200nm. The ZT value of the material not doped with YbZn2Sb2 material can reach 0.59, the ZT value of the doped material can be further improved and the material can be used in the thermoelectric conversion power generation or refrigeration field. The invention has the advantages that the technology is simple, the preparation cycle is short, the energy consumption is low and the industrialized production can be realized.

Disclosed are new compound semiconductors which may be used for solar cells or as thermoelectric materials, and their application. The compound semiconductor may be represented by a chemical formula: In_xM_yCo_4-m-aA_mSb_12-n-z-bX_nQ_z, where M is at least one selected from the group consisting of Ca, Sr, Ba, Ti, V, Cr, Mn, Cu, Zn, Ag, Cd, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, A is at least one selected from the group consisting of Fe, Ni, Ru, Rh, Pd, Ir and Pt, X is at least one selected from the group consisting of Si, Ga, Ge and Sn, Q is at least one selected from the group consisting of O, S, Se and Te, 0<x<1, 0≦y<1, 0≦m≦1, 0≦a≦1, 0≦n<9, 0≦z≦4, 0≦b≦3 and 0<n+z+b.

The invention relates to a CoSb3 thermoelectric material, in particular to a method for preparing a CoSb3 nanometer particle film. The method comprises the following steps of: firstly, weighing CoC12.6H2O powder and Sb powder according to the molar ratio of 1:3; respectively filling the powder into respective crucible; putting the crucibles and glass slide substrates into a quartz pipe; placing the quartz pipe into a horizontal pipe type furnace; vacuumizing and aerating mixed air of 95 percent of argon and 5 percent of hydrogen for multiple times and removing oxygen in the quartz pipe; raising the temperature of the tubular pipe; performing chemical vapor deposition on the glass slide substrates in a low-pressure state to acquire the CoSb3 nanometer particle film; and testing Seebeck coefficient, conductivity and heat conductivity of the CoSb3 nanometer particle film and calculating a zone time (ZT) value of the CoSb3 nanometer particle film. According to the invention, the CoSb3 nanometer particle film is synthesized by one step, the process is simple, and the diameter of the prepared CoSb3 nanometer particle is between 200 and 400nm; and moreover, the CoSb3 thermoelectric material has good conductivity and low heat conductivity, can be directly used for thermoelectricity researches, and is used for novel high-efficiency thermoelectric conversion devices.

The invention discloses a preparation method of a composite material based on a metal organic framework and carbon nanotubes, and a preparation method of a device. The preparation method comprises thefollowing steps: firstly, preparing a P-type Ni<3>(HITP)<2>/CNT composite material and an N-type Ni<3>(HITP)<2>/CNT composite material; then respectively tabletting the P-type Ni<3>(HITP)<2>/CNT composite material and the Ni<3>(HITP)<2>/CNT composite material by using a square tabletting mold at a pressure of 10-30 MPa for 5-30 minutes so as to obtain a P-type composite block material and an N-type composite block material, then assembling the P-type composite block material and the N-type composite block material; and connecting connecting parts by using a conductive silver adhesive or a copper wire so as to obtain the device. The N-type stable MOF/CNT composite material with the highest performance is successfully prepared and applied to device circuits, and the porous composite material with high conductivity and low thermal conductivity has potential application value in the fields of catalytic materials, gas adsorption materials, thermal insulation materials and high-performancethermoelectric materials.

The invention relates to an alkaline-earth-silicide thermoelectric material and a preparation method therefor. The chemical general formula of the thermoelectric material is ASi2, wherein A is either Sr or Ba. The preparation method comprises the steps of adopting a metal element with purity higher than 99% as a raw material, proportioning materials according to the stoichiometric ratio of the chemical formula ASi2, then, carrying out arc-discharge melting and water cooling so as to prepare a ASi2 block material, and then, carrying out heat treatment, grinding and sintering, thereby preparing the alkaline-earth-silicide thermoelectric material. Compared with the prior art, the alkaline-earth-silicide thermoelectric material and the preparation method therefor have the advantages that by applying an arc melting technology to the field of preparation of the alkaline-earth-silicide thermoelectric material, the problem of difficulty of preparation resulting from high melting point of alkaline-earth silicide is solved, meanwhile, the problem of safety of preparation caused by the high vapor pressure and high corrosiveness of alkali metal elements is solved, the process is simple, the preparation cycle is short, the safety is high, and the prospect for industrialization is good.

The invention aims to provide a simple preparation method for cadmium supported bismuth telluride nanowires with high thermoelectric conversion efficiency by screening. The method has the characteristics of short preparation time, simple process and large-scale production. The preparation method of the cadmium loaded bismuth telluride nanowires comprises the following steps: step 1, preparing tellurium nanowires; step 2, taking tellurium nanowires as a template agent, adding a bismuth source, and performing reaction under the hydrothermal condition to prepare the bismuth telluride nanowires; step 3, separating and washing the bismuth telluride nanowires prepared in the step 2, adding a cadmium source to a shaking table as a reaction container for cadmium support to obtain the final cadmiumsupported bismuth telluride nanowires.

The invention relates to a five element n-type thermoelectric material realizing powder alloy sintering phase transformation based on crystal topology and a preparation method thereof. The chemical formula of the n-type thermoelectric material is Bi<2-x-y>Sb<x>S<y>Te<3-z>Se<z>, wherein the x is greater than or equal to 0.74 and less than or equal to 1.2, y is greater than or equal to 0.04 and lessthan or equal to 0.06, z is greater than or equal to 0.2 and less than or equal to 0.45. Compared with other n-type thermoelectric materials, the five element n-type thermoelectric material disclosedby the invention undergoes the transformation of p-type alloy to p-type powder alloy embryo material to n-type thermoelectric material in the preparation process, therefore, the finally obtained fiveelement n-type thermoelectric material has the advantages of high Seebeck coefficient, high conductivity, low thermal conductivity, high ZT value and excellent thermoelectric performance.