Experimental Determination of the Formation Enthalpy of Calcium Cobaltate from Sol–Gel Precursors

Tim C. Holgate, NingYu Wu, Ngo Van Nong, Nini Pryds

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Calcium cobaltate (Ca3Co4O9) remains one of the most promising p-type oxide materials for high-temperature thermoelectric energy conversion. While much progress has been made in refining our understanding of the unique structure of the material, as well as optimization of the transport properties for thermoelectric efficiency, there remains a gap in the knowledge, both experimental and theoretical, of the thermodynamics of the system. Presented herein is an analysis of the heat of formation of the Ca3Co4O9 phase from sol–gel precursors using a highly sensitive differential scanning calorimeter, as well as observations of its decomposition into the Ca3Co2O6 phase. The reaction enthalpy of forming Ca3Co4O9 from CaCO3 and Co3O4 sol–gel precursors was determined to be +284 (±2%) kJ/mol, leading to a standard enthalpy of Ca3Co4O9 of −3307 (±3.5%) kJ/mol.
Original languageEnglish
JournalJournal of Electronic Materials
Volume46
Issue number2
Pages (from-to)1413–1417
Number of pages5
ISSN0361-5235
DOIs
Publication statusPublished - 2017

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