Nature Communications 6, Article number: 7037 doi:10.1038/ncomms8037
Published 12 May 2015
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-ti3O5, which exhibits a solid–solid phase transition to beta-trititanium pentoxide, β-Ti3O5. 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.

http://www.nature.com/ncomms/2015/150512/ncomms8037/full/ncomms8037.html