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Dielectric film capacitors are considered as potential candidates for advanced power electronics technology due to their extremely high-power densities and outstanding mechanical and thermal stability, but the further improvement of energy storage density is still needed. Here, a strategy is proposed to enhance the energy storage properties by introducing nanoscale polarization regions into amorphous films, which can significantly improve the maximum polarization and maintain a high breakdown strength. The (1−x) BaTiO3-xBi(Ni0.5Zr0.5)O3 ((1−x)BT-xBNZ) thin films are fabricated by the sol– gel method and the amorphous films with nanoscale polarization regions are obtained by adjusting the preparation process. Consistent with the conjecture, amorphous phase and nanoscale polarization regions in the (1−x) BT-xBNZ films are clearly observed by electron diffraction. Results show that giant recoverable energy density of 103.7 J cm−3 with high energy efficiency of 88.3% are simultaneously achieved at 8.3 MV cm−1 in 0.92BT-0.08BNZ thin films. Furthermore, the 0.92BT-0.08BNZ thin film exhibits excellent thermal stability in a wide temperature range of 20–200°C, ΔWrec/Wrec20°C < 2.2%. This work provides a novel method for dielectric thin film capacitors applied in high temperature and electric field. [ABSTRACT FROM AUTHOR]

Dielectric materials with large maximum polarization but small lossy hysteresis, high electrical breakdown, and postponed maximum polarization can store a large amount of electrical energy and are thus promising candidates for energy storage applications. In this work, a dielectric capacitor based on (Sr0.98Ca0.02)(Ti,Zr)O3 system achieved the elevated energy storage performances calculated from the polarization-electric field hysteresis loops due to enhanced breakdown strength by Zr substitution. Dielectric relaxation could be ascribed to the appearance of the doubly ionized oxygen vacancies verified by activation energy. For the studied system, dielectric breakdown dominated for the enhancement of energy storage performances because of the difference of ferroelectric activity and cation stability between Zr and Ti ions. The optimal Zr-modified composition exhibited better energy storage performances in contrast with pure (Sr0.98Ca0.02 )TiO3,suggesting that they might be an emerging candidate for next-generation high-energy devices. [ABSTRACT FROM AUTHOR]

A steady nano organic-inorganic perovskite hybrid with [H23-AMP]3/2Fe(CN)6 (3-AMP = 3-methylaminopyridine) was prepared in the air. The structure is an unusual layered organic-inorganic type. The resulting hybrid enveloped in paraffin to prepare [H23-AMP]3/2Fe(CN)6 paste electrode (HPE) shows good electrochemical activity and a couple of oxidation and reduction peaks with potential of cyclic voltammometry (CV) at around 440mV and 30mV. Compared with that on CPE, oxidation potential of Fe(CN)63- on HPE shifts negatively 259.7mV and that of reduction shifts positively 338.7mV, which exhibits that [H23-AMP]3/2Fe(CN)6 can accelerate the electron-transfer to improve the electrochemical reaction reversibility. Such characteristics of [H23-AMP]3/2Fe(CN)6 have been employed to prepare the DNA biosensor. The single-strand DNA (ssDNA) and double-strand DNA (dsDNA) immobilized on HPE, respectively, can improve the square wave voltammometry (SWV) current and SWV potential shifts positively. The effect of pH was evaluated. And there is hybridization peak on SWV curve using HPE immobilized ssDNA in the complementary ssDNA solution. And HPE immobilized ssDNA can be utilized to monitor the DNA hybridization and detect complementary ssDNA, covering range from 3.24 × 10-7 to 6.72 × 10-5 g/mL with detection limit of 1.57 × 10-7 g/mL. The DNA biosensor exhibits a good stability and reproducibility. [ABSTRACT FROM AUTHOR]