External stimulation-controllable heat-storage ceramics

TLDR

Conventional heat‑storage materials cannot retain energy for long periods, limiting their application potential. The system employs a pressure‑induced solid–solid phase transition between λ‑Ti₃O₅ and β‑Ti₃O₅, reversible by heat, light, or electric current. The λ‑Ti₃O₅/β‑Ti₃O₅ material stores latent heat up to 530 K, releases it at only 600 bar, holds 230 kJ L⁻¹, and is reversible by pressure, heat, light, or current, making it promising for heat storage and sensor applications.

Abstract

Abstract Commonly available heat-storage materials cannot usually store the energy for a prolonged period. If a solid material could conserve the accumulated thermal energy, then its heat-storage application potential is considerably widened. Here we report a phase transition material that can conserve the latent heat energy in a wide temperature range, T <530 K and release the heat energy on the application of pressure. This material is stripe-type lambda-trititanium pentoxide, λ-Ti 3 O 5 , which exhibits a solid–solid phase transition to beta-trititanium pentoxide, β-Ti 3 O 5 . The pressure for conversion is extremely small, only 600 bar (60 MPa) at ambient temperature, and the accumulated heat energy is surprisingly large (230 kJ L −1 ). Conversely, the pressure-produced beta-trititanium pentoxide transforms to lambda-trititanium pentoxide by heat, light or electric current. That is, the present system exhibits pressure-and-heat, pressure-and-light and pressure-and-current reversible phase transitions. The material may be useful for heat storage, as well as in sensor and switching memory device applications.