Long‐Term Heat‐Storage Ceramics based on Zr‐Substituted λ‐Ti3O5

• Published in: European journal of inorganic chemistry Vol. 27; no. 16
• Main Authors: Otake, Tomu, Wang, Lidong, Jia, Fangda, Yoshikiyo, Marie, Kawakami, Koutarou, Namai, Asuka, Tokoro, Hiroko, Ohkoshi, Shin‐ichi
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 03.06.2024
• Subjects: ceramics; Environmental protection; heat-storage; Industrial wastes; Latent heat; Materials substitution; phase transition; Phase transitions; Power plants; titanium oxide; Titanium oxides; Zirconium; λ-Ti3O5
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202400047

Heat‐storage materials are important for energy saving to protect the environment. Here, we show a long‐term heat‐storage material based on zirconium‐substituted lambda‐trititanium‐pentoxide (λ‐ZrxTi3−xO5, 0 < x≤0.06). λ‐ZrxTi3−xO5 exhibits a phase transition to zirconium‐substituted beta‐trititanium‐pentoxide (β‐ZrxTi3−xO5) upon application of pressure. The transition pressures were 600 MPa (x=0.04) and about 1 GPa (x=0.06). When the pressure‐produced β‐phase is heated, the β‐phase returns to λ‐phase. The phase transition temperatures (i. e., heat‐storage temperatures) were 185 °C (458 K) and 183 °C (453 K) for x=0.04 and 0.06, respectively. These heat‐storage temperatures are suitable for the reuse of low‐temperature industrial waste heat, which is considered to be a difficult temperature region to be efficiently collected and reused. The present pressure‐sensitive heat‐storage ceramic, which can store the latent heat energy for a prolonged period, is effective for the sustainable reuse of heat energy that are wasted in power plants and industrial factories. Long‐term heat‐storage ceramic based on Zr‐substituted λ‐Ti3O5 (λ‐ZrxTi3−xO5) was synthesized. The crystal structure, morphology, and heat‐storage properties were investigated. The mechanism of the long‐term heat storage was understood by thermodynamic simulations using the mean field model. The present material may contribute to the efficient use of waste heat from industrial factories and power plants.