Ultrahigh energy-storage density of a lead-free 0.85Bi_0.5Na_0.5TiO₃–0.15Ca(Nb_0.5Al_0.5)O₃ ceramic under low electric fields

Abstract

Ultrahigh recoverable energy storage density (Wrec = 4.41 J cm−3) and efficiency (η = 88%) at low electric field (210 kV cm−1), over wide frequency (10–100 Hz) and temperature (20–200 °C) were achieved simultaneously for 0.85Bi0.5Na0.5TiO3-0.15Ca(Nb0.5Al0.5)O3 ceramics.

Ultrahigh energy storage performance of a 0.75Bi0.47Na0.47Ba0.06TiO3-0.25CaTi0.8Sn0.2O3 ceramic under moderate electric fields

“…Also, the modes at 278 cm −1 are related to Ti-O vibrations. 9 The modes related to octahedral TiO 6 vibrations are around 550 cm −1 . 23 Furthermore, the modes above 700 cm −1 are associated with A 1 and E overlap bands.…”

“…The stability of energy storage capacity under harsh conditions is a key question in the practical application. 9 For example, the energy systems of hybrid vehicles can operate in the temperature range up to 140 °C. As a result, the ceramics having outstanding thermal stability can operate well with no additional cooling systems.…”

“…where R, I, t and V refer to resistance, overall current, detection time and specimen volume, respectively. 9 The load R is 300 Ω.…”

“…2(b) shifts to the right as x increases and the cell volume decreases because Ca 2+ with a smaller radius (1.00 Å) replaces Bi 3+ (1.36 Å) and Na + (1.39 Å). 9 The cleavage (200) peak indicates that the structure of the ceramic is not cubic, but shows the coexistence of a rhombic ferroelectric phase and a pseudo-cubic paraelectric phase, which facilitates the formation of polymorphic nanodomains. 22 To exactly analyze the influence of CTS doping on the crystal lattice, Rietveld refinement data were obtained using the P 4 bm and R 3 c space groups.…”

“…The Bi 0.5 Na 0.5 TiO 3 (BNT) ferroelectric (FE) is regarded as one of the most suitable dielectric energy storage ceramics due to the high intrinsic polarization generated by Bi6p and O2p orbital hybridization, which can lead to a high P max value. 9 Nevertheless, the large P r seriously prevents the improvement of the energy storage capacity of ceramics. In recent years, the application potential of BNT ceramics in energy storage has been explored.…”