Research On （1-x）BaTiO₃-xBiYO₃ Dielectric Ceramics For Energy Storage Properties

Energy storage dielectric ceramic materials involved in two areas: material and energy, and has the extremely widespread application. In civil, it can be used in hybrid vehicles, large-scale interconnected power system stability control as well as new energy systems; In the military, as the main part of pulse power high pulsed power source it can be used for tanks, electromagnetic guns, directed energy weapons, integrated electric propulsion ships, laser controlled nuclear fusion, etc. At present, the development of science and technology is in the direction of miniaturization, integration and lightweight. Therefore, the development of dielectric ceramics with higher energy storage density is a hot topic in current research.In this paper, based on the principle of ceramic energy storage capacitor, this article introduced the current research progress of domestic and foreign energy storage ceramics materials at present, and then analyzes the advantages and disadvantages of various material. In order to obtain higher energy storage density dielectric materials, this paper takes（1-x）BaTiO₃-x BiYO₃ as the research object, hoping to obtain high dielectric constant, high breakdown strength and high energy storage density of dielectric ceramics. Then the best ratio of（1-x）BaTiO₃-x BiYO₃ ceramic with Ba-B-Al-Si alkali-free glass modified was researched further to improve the breakdown strength of ceramic. Specific research works is as follows:（1-x）BaTiO₃-xBiYO₃（0≤x≤0.5） ceramics were prepared by conventional solid-state method and the effect of BiYO₃ doping content on the phase structure、dielectric and energy storage properties was studied. BaTiO₃ sintering temperature was decreased with BiYO₃ added. With the increase of BiYO₃ concentration, relaxation phenomenon is more obvious, the dielectric peak broadening, and dielectric constant changes with the temperature gradually stabilized. The decline amplitude of dielectric constant with increasing electric field intensity become smaller and smaller, electric hysteresis loop becomes more and more thin, and tends to be linear, such that the effective storage capacity of ceramic increases.Components of x=0.2, which got densest at the sintering temperature of 1100 ℃ for 1 h, a small amount of the second phase gathered at grain boundary and liquid glass phase were on the grain surface. The solubility limit for BiYO₃ into the BaTiO₃ perovskite structure was about x=0.1. Composite of x = 0.2 was beyond of solid solubility, but has higher relaxation properties. Its dielectric constant was about 1340 and dielectric constant declined little with the increase of voltage. Breakdown field strength and energy density of composition x=0.2 were 571.4kV / cm and 13.139 J / cm3 which were both largest. 0.8BaTiO₃-0.2BiYO₃ was used as ceramic substrate materials and researched on its modification.Ba-B-Al-Si alkali-free glass powder was prepared using conventional solid-state method, according to different quality percentage（1 wt %, 3 wt %, 5 wt %, 7 wt %） added to the 0.8Ba TiO₃-0.2BiYO₃ ceramic samples. Ba-B-Al-Si alkali-free glass could reduce the sintering temperature of the ceramics. While the glass content was 3wt %, the miscellaneous phase peak was minimal and the polarization intensity was improved. The over all system performance declined with added Ba-B-Al-Si alkali-free glass ceramics. The analysis should be Al³⁺ among alkali-free glass enterd the lattice structure of ceramic and reacted with ceramic, so that the density porosity decreases and impurity phase appeared. Breakdown strength and energy density were both decreased.