Efficiency of energy harvesting and storage using a multilayer capacitor based on BaTi0.86Sn0.14O3 ferroelectric lead-free ceramics

https://doi.org/10.1016/j.ceramint.2022.07.227

The study of the parameters of energy harvesting and storage in the lead-free solid solution BaTi0.86Sn0.14O3 (BTSnO) was performed. The permittivity shows the behavior similar to a diffuse phase transition with the critical exponent γ = 1.84, which is close to the value characteristic of relaxors. Large values of the recoverable energy density, Wrec=(5.8–7.0)∙104 J/m3, and the energy storage efficiency coefficient, η=(82–94) %, are implemented in a wide temperature range, 30–87°С, at a low electric field, E = 18.5 kV/cm. For the first time, the analysis of the Olsen cycle was performed using two phase diagrams: polarization – electric field and entropy – temperature. A fairly good agreement was found between the values of the energy conversion density, ND ≈ 0.15 J/cm3, which was determined using two approaches. A universal parameter is proposed for comparing the energy harvesting density for the materials studied in different ranges of temperature and electric fields.