A co-effective strategy to improve the energy storage performance and the electrocaloric effect of ceramic: Using strain-modified calcined powders as sintering precursor

Perovskite ferroelectric ceramics with large energy storage density and electrocaloric (EC) effect at a low-electric field are very attractive in modern electronic devices such as capacitors and solid refrigerators. In this work, it is demonstrated that the energy storage and EC performances of the BiFeO 3 (BFO)-doped Bi[Formula: see text]Na[Formula: see text]TiO 3 -BaTiO 3 (BNT-BT)-based ceramics near the MPB (0.89Bi[Formula: see text]Na[Formula: see text]TiO 3 –0.11BaTiO[Formula: see text] can be regulated by using the strain-modified calcined powders as sintering precursor. The 0.89Bi[Formula: see text]Na[Formula: see text]TiO 3 –0.11BaTiO 3 ceramic prepared from the strain-modified calcined powder with a nanoscaled size (abbreviated as nanoceramic) simultaneously obsesses a large energy density ([Formula: see text] 0.847 J/cm[Formula: see text] and a high-energy storage efficiency ([Formula: see text] 80%) in a broad temperature range (333–453 K) at a very low-electric field ([Formula: see text] 80 kV/cm). The high-energy storage performance maybe is related to the breaking of the ferroelectric long-range order inherited from the strain-modified calcined powder with an ultra-fine size ([Formula: see text] 110 nm). Moreover, a large negative EC effect ([Formula: see text]−1.1 K) at a very low-electric field ([Formula: see text] 29.8 kV/cm) was also achieved for the ceramic prepared by using the submicro-sized calcined powder with a BFO doping amount of 6% (mole ratio). It is concluded that using strain-modified calcined powder as a sintering precursor for ceramic preparing can be used as an alternative candidate strategy to improve and optimize the energy storage and EC performances.