In recent years, with the introduction and development of some new thermoelectric transport effects and new mechanisms, many new high-performance thermoelectric material systems have also been discovered. Among them, the diamond-like structure compound is derived from the diamond structure. Due to the different atomic radius and chemical valence state of the constituent elements, the lattice of the material is distorted from the cubic structure of the diamond to the non-cubic structure. The intrinsic low thermal conductivity and tunable electrical properties of diamond-like structural compounds make them promising as excellent thermoelectric materials. Since 2009, the thermoelectric research team of the Shanghai Institute of Ceramics, Chinese Academy of Sciences, reported for the first time the thermoelectric properties of the quaternary compounds Cu2CdSnSe4 and Cu2ZnSnSe4, and the diamond-like structural compounds gained widespread attention in the field of thermoelectric research. To date, the thermoelectric properties of more than 20 kinds of diamond structure compounds have been reported. Among them, many p-type materials have higher thermoelectric figure of merit than 1, which is comparable to traditional thermoelectric materials. However, the thermoelectricity value of n-type diamond-like structure compounds is generally low, which limits the development of highly efficient diamond-like compound thermoelectric devices.
Recently, associate researcher Qiu Pengfei of Shanghai Silicate Institute, researchers Shi Xun and Chen Lidong cooperated with Shanghai University professor Yang Yi and others and discovered a high-performance n-type with intrinsic low lattice thermal conductivity and electrical properties that can be controlled. Diamond structure compound AgInSe2. At 900 K, the highest thermoelectricity value of the AgInSe2 based compound reaches 1.1, which is equivalent to the best reported p-type diamond like structure compounds such as CuGaTe2 and CuInTe2. On this basis, the research team has for the first time prepared a thermoelectric device with diamond-like structure that exhibits good application prospects.
The band gap of AgInSe2 is about 1.2 eV. Previous researches on AgInSe2 have mainly focused on applications in the field of optoelectronics. It was found that AgInSe2 has far lower lattice thermal conductivity than other diamond-like structure compounds. At room temperature, the lattice thermal conductivity of AgInSe2 is only 0.99 W m-1K-1, which is comparable to that of amorphous glass. The first-principles calculations show that there are a large number of low-frequency optical branches in the phonon spectrum of AgInSe2, and the strong scattering of lattice phonons close to its frequency is the root cause of the low lattice thermal conductivity of AgInSe2. Further research found that these low-frequency optical branches come from the "Ag-Se cluster" of the coordinated vibration. In the AgInSe2 crystal structure, Ag and Se combine with stronger chemical bonds, while In and the above two atoms have weaker chemical bonds. Therefore, Ag and Se can form an "Ag-Se cluster" with a large overall mass, and they are subjected to weaker binding forces, thus exhibiting low phonon vibration frequencies. On the other hand, by introducing the Se vacancy in AgInSe2 or introducing the Cd element in the Ag site for doping, the order of magnitude of conductivity of the material can be improved. Preliminary studies have shown that the thermoelectricity value of the AgInSe2 compound with a small amount of Se vacancy reaches 1.1 at 900K.
Based on a high-performance n-type AgInSe2 compound and a p-type CuInTe2-based compound previously reported by the research team (J. Mater. Chem. A, 2016, 4, 1277), this study for the first time produced a diamond-like structure having two pairs of thermoelectric singlets. Compound thermoelectric components. Using electroplating and brazing techniques, Ni electrodes and Mo-Cu electrodes were successfully connected to the cold and hot ends of the thermocouples. Preliminary test results show that the maximum output power of the device is 0.06W at a temperature difference of 520K. If you can further optimize the contact resistance and contact thermal resistance at the device interface, its performance will be further improved.
Related research results were published on Advanced Science. The study was supported by the National Natural Science Foundation of China, the key deployment projects of the Chinese Academy of Sciences, the Youth Innovation Promotion Association, and the Shanghai Outstanding Discipline Leader Program.
Figure 1. (a) Thermoelectric properties of n-type AgInSe2 diamond-like compound; (b) First diamond-like compound thermoelectric device
Figure 2. (a) Phonon spectra of n-type AgInSe2 diamond-like structure compounds; (b) Lattice thermal conductivity
Galvanized Iron Wire
Zinc coat:7g-300g/m2
Wire gauge: hot gal:8#--36# electro gal:8#--38#
Galvanized iron wire/hot-dipped galvanized iron wire/electro galvanized iron wire
Galvanized iron wire can be divided into two categories: electro galvanized iron wire and hot dipped galvanized iron wire.
Electro galvanized iron wire: 8#--38# (3.8mm, 0.15mm)
Hot galvanized iron wire : 8#--36# (3.8mm, 0.19mm)
Purpose: Widely used in communication equipment, medical equipment,weaved mesh,bursh,tightwire,filter silce, high pressure pipe,architecture,artcraft and so on.
Specification:100kg--1000kg
Introduction: Its solid and durable.Widely used in indutry, agriculture and stock raising. We mainly produce the galvanized wire (16#--22#) in architecture. The daily capacity is 200 tons.We can customize U type and other type according to your requirement
Galvanized Iron Wire Specification |
|||
Wire Gauge |
SWG(mm) |
BWG(mm) |
Metric(mm) |
8 |
4.05 |
4.19 |
4.00 |
9 |
3.66 |
3.76 |
4.00 |
10 |
3.25 |
3.40 |
3.50 |
11 |
2.95 |
3.05 |
3.00 |
12 |
2.64 |
2.77 |
2.80 |
13 |
2.34 |
2.41 |
2.50 |
14 |
2.03 |
2.11 |
2.50 |
15 |
1.83 |
1.83 |
1.80 |
16 |
1.63 |
1.65 |
1.65 |
17 |
1.42 |
1.47 |
1.40 |
18 |
1.22 |
1.25 |
1.20 |
19 |
1.02 |
1.07 |
1.00 |
20 |
0.91 |
0.84 |
0.90 |
21 |
0.81 |
0.81 |
0.80 |
22 |
0.71 |
0.71 |
0.70 |
Galvanized Wire,Galvanized Iron Wire,Galvanized Wire Mesh,12 Gauge Galvanized Wire
Anping Bochuan Wire Mesh Co., Ltd. , https://www.wiremeshbocn.com