Preparation of Ca₃Co₄O₉ and Improvement of its Thermoelectric Properties by Spark Plasma Sintering

Abstract

The precursor powders of Ca3Co4O9 were synthesized by a sol–gel method. The results of X‐ray diffraction and thermogravimetric and differential thermal analyses patterns indicate that pure Ca3Co4O9 powders could be obtained by calcining the precursor at 800°C for 2 h. High dense Ca3Co4O9 ceramic samples (∼99% of theoretical density) were prepared by the spark plasma sintering (SPS) method. Compared with the conventional sintering (CS), the SPS samples exhibit much higher electrical conductivity and power factor which are respectively about 118 S/cm and 3.51 × 10−4 W·(m·K2)−1. The SPS method is greatly effective for improving the thermoelectric properties of Ca3Co4O9 oxide ceramics.

Enhancing the thermoelectric performance of Cu3SnS4-based solid solutions through coordination of the Seebeck coefficient and carrier concentration

“…Ternary chalcogenides Cu-Sn-S based compounds [1][2][3] or oxide ceramics 4,5 have attracted much attention in thermoelectrics in recent years, due to earth-abundance of constituent elements or thermal stability in air. Therefore, the development of these materials is crucial if thermoelectrics is to supply a significant fraction of the world's energy needs.…”

Field‐Assisted Sintering Technology/Spark Plasma Sintering: Mechanisms, Materials, and Technology Developments

“…One main idea was to reduce the manufacturing costs by applying a rapid sintering technique [169] to process thermoelectric oxides like Ca 2.75 Gd 0.25 Co 4 O 9 [171] or Ca 3 Co 4 O 9 . [172] These oxide samples had a density of more than 96% resp. 99% of the single crystalline material.…”

Optimization of Sintering Temperature for Maximizing Dimensionless Figure of Merit of La-Doped Strontium Titanate Thermoelectric Material in the Combination of Combustion Synthesis with Post Spark Plasma Sintering

“…However, these conventional methods involve many processes therefore they are time and energy consuming. Zhang et al 1,11) have proposed a combination of combustion synthesis (CS) 12) and spark plasma sintering (SPS) [13][14][15][16][17][18] for the synthesis of thermoelectric materials. CS is one of chemical reaction method using the energy of exothermic reaction from raw materials.…”