Fabrication of an all-oxide thermoelectric power generator

Abstract

An oxide thermoelectric device was fabricated using Gd-doped Ca3Co4O9 p-type legs and La-doped CaMnO3 n-type legs on a fin. The power factors of p legs and n legs were 4.8×10−4 Wm−1 K−2 and 2.2×10−4 Wm−1 K−2 at 700 °C in air, respectively. With eight p–n couples the device generated an output power of 63.5 mW under the thermal condition of hot side temperature Th=773 °C and a temperature difference ΔT=390 °C. This device proved to be operable for more than two weeks in air showing high durability.

Metal oxides for thermoelectric power generation and beyond

“…The simplest design of TEG consists of a p-leg and n-leg connected by conducting strips in series and covered by ceramic plate with heat conduction in perpendicular. Matsubara et al [112] reported that a fin-type-oxide thermoelectric device was fabricated by using Ca 2.75 Gd 0.25 Co 4 O 9 as p-leg and Ca 0.92 La 0.08 MnO 3 as n-leg. The high power density of the TE device was achieved at 21 mW/cm 2 at ΔT = 390 K. This high performance was observed in oxide-based thermoelectric generators, because the power factor of both p-and n-type materials increased with temperature, with no bipolar effect observed.…”

Fabrication and thermoelectric characteristics of [(Bi,Pb)2Ba2O4±w]0.5CoO2 bulks with highly aligned grain structure

“…To improve the thermoelectric properties of polycrystalline bulks, grain texturing has been considered to be effective: Matsubara et al 11 fabricated a grain-aligned bulk sample of ͓͑Ca, Bi͒ 2 CoO 3− ͔ 0.62 CoO 2 through uniaxial pressure sintering to yield ZT = 0.29 at 700°C, being much higher than those for conventionally sintered samples. Xu et al 12 also reported an excellent TE performance ͑ZT = 0.32 at 730°C͒ for a Bi/ Na-substituted ͓Ca 2 CoO 3− ͔ 0.62 CoO 2 bulk with aligned grains.…”

First-Principles Modeling of SrTiO3Based Oxides for Thermoelectric Applications

“…Consequently, efforts have been devoted over the last 15 years to the optimization of TE properties of both n-type and p-type oxide materials. Good candidates for n-type materials include Nb-, W-, La-, Ce-, Pr-, Nd-, Sm-, Gd-, Dy-, and Ydoped SrTiO 3 [1][2][3][4][5][6][7][8][9][10][11][12][13], Nb-, La-, Nd-, Sm-, and Gd-doped Sr 2 TiO 4 , and Sr 3 Ti 2 O 7 [14], La-doped CaMnO 3 [15] or Al-, Ge-, Ni-and Co-doped ZnO [16][17][18][19][20], Ce-doped In 2 O 3 [21], Er-doped CdO [22,23], TiO 2 [24], Nb 2 O 5 [24], WO 3 [24], while for p-type materials the most promising compounds are Ca 3 Co 4 O 9 [25] with ZT ∼ 0.3 at 1000 K [26], and BiCuSeO with ZT ∼ 1.4 at 923 K. [27] Many studies have concerned doped SrTiO 3 , demonstrating the largest ZT ∼ 0.4 in SrTi 0.8 Nb 0.2 O 3 films at 1000 K [2], and ZT ∼ 0.41 in bulk Sr 1−3x/2 La x TiO 3 at 973 K. [12] Different strategies have been proposed to further increase TE efficiency. Attempts to decrease the lattice thermal conductivity κ l by atomic substitution of Sr by Ba have been envisaged but seem to negatively affect the TE performance.…”