Synthesis and Thermoelectric Properties of TiO2/Cu2SnSe3 Composites

Abstract

Thermoelectric (TE) materials are a kind of energy material which can directly convert waste heat into electricity based on TE effects. Ternary Cu 2 SnSe 3 material with diamond-like structure has become one of the potential TE materials due to its low thermal conductivity and adjustable electrical conductivity. In this study, the Cu 2 SnSe 3 powder was prepared by vacuum melting-quenching-annealing-grinding process. The nano-TiO 2 particles were introduced into the Cu 2 SnSe 3 matrix by ball milling. Spark plasma sintering (SPS) was employed to fabricate the TiO 2 /Cu 2 SnSe 3 composites. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM) were used to study the phase and microstructure of TiO 2 /Cu 2 SnSe 3 composites. Electrical resistivity, Seebeck coefficient, and thermal conductivity measurement were applied to analyze the thermoelectric properties. For the 1.4%TiO 2 /Cu 2 SnSe 3 composite, the electrical conductivity was improved whereas the Seebeck coefficient was lower than that of pure Cu 2 SnSe 3 . For other TiO 2 /Cu 2 SnSe 3 samples, the Seebeck coefficient was improved while the electrical conductivity was reduced. The thermal conductivity of TiO 2 /Cu 2 SnSe 3 composites was lower than that of Cu 2 SnSe 3 matrix, which is attributed to the lower carrier conductivity. A maximum ZT of 0.30 at 700 K for the 1.0%TiO 2 /Cu 2 SnSe 3 composite was obtained, which was 17% higher than that of the pure Cu 2 SnSe 3 at 700 K.

Recent advances in interface engineering of thermoelectric nanomaterials

“…5 Comparison of ZT values before and after doping of different oxides into different TE materials. [1][2][3][4][5][6][7][8][9][10] sintering (SPS) processes. Although the B 2 O 3 second phase boundary scattered carriers, resulting in a decrease in mobility, the increase in resistivity was acceptable.…”

Insights into the Classification of Nanoinclusions of Composites for Thermoelectric Applications

“…Rigid, thermally, and electrically impermeable inclusions such as oxide nanoinclusions have a maximum effect on the thermal and electrical carriers and enhance the mechanical stability . There are various oxide-based nanoinclusions such as TiO 2 , ,− WO 3 , ,, ZrO 2 , ,,,,,,, Al 2 O 3 , ,− CeO 2 , , Y 2 O 3 , , SiO 2 , ,, ZnO, ,,,, SrTiO 3 , SnO 2 , Yb 2 O 3 , NiO, and reduced graphene oxide to improve the thermoelectric performance of the composites. Here, α is expressed as ∝ = γ – ln­( n ), where γ is the scattering factor and n is the carrier concentration; after the addition of oxide nanoinclusions, γ enhances and n decreases to increase the α in two ways.…”

Enhanced Thermoelectric Properties of Cu2SnSe3-Based Materials with Ag2Se Addition

“…Furthermore, recent studies have reported a promising compositing strategy to achieve a further reduction in the lattice thermal conductivity of Cu 2 SnSe 3 -based materials. Recently, researchers have focused on developing Cu 2 SnSe 3 composites by introducing metal oxides, , chalcogenides, − and other additives , to enhance phonon scattering. Moreover, in situ formed Ag 2 S nanoprecipitates in p-type Ag-doped PbS have been proven effective in reducing the grain boundary barrier height, thus improving the carrier transport .…”