Ben Welter - Thursday, July 30, 2015
A University of Tokyo research team has identified a ceramic material that can store thermal energy for long periods and release it on demand. The material, which can also absorb light and electrical current, has the potential to be used in a variety of energy storage systems.
Upon absorption of heat, light or electrical energy, the material undergoes a solid–solid phase change, transforming from beta-trititanium pentoxide to lambda-trititanium pentoxide. The latter can store that energy stably for long periods of time. Applying "a relatively weak pressure of just 60 MPa" releases the stored energy and returns the material to its beta phase.
The research was published in the journal Nature Communications earlier this year. Here's an excerpt from the abstract:
"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."