Preparation and properties of strontium barium niobate based glass-ceramics for energy storage capacitors

Abstract

Na 2 O-BaO-SrO-Nb 2 O 5 -B 2 O 3 -SiO 2 glassceramics were prepared by melt-casting followed by controlled crystallization. X-ray diffraction results show that Ba 0.27 Sr 0.75 Nb 2 O 5.78 with tungsten bronze structure formed as the dielectric phases from the glass matrix at 800°C. However, a secondary phase NaSr 1.2 Ba 0.8 Nb 5 O 15 occurs when crystallization temperature exceeds 850°C. The glass-ceramics exhibit excellent stability in permittivity values from room temperature to 200°C and low dielectric losses below 0.05. Electrical testing demonstrates that the breakdown strength increases with crystallization temperature. The P-E characteristics at room temperature do not show any clear ferroelectric behavior. The glass-ceramic material heated at 800°C/3 h+950°C/3 h shows a breakdown strength of 1400 kV/cm and its energy storage density can reach up to 4.0 J/cm 3 , which may be a strong candidate for high energy density storage capacitors for portable or pulsed power applications.

Dielectric Properties of Melt and Heat Treated K2O-Al2O3-SiO2-CaO-CuO-TiO2 Samples

“…Glass-ceramics, which are prepared via quenching followed by crystallization upon heat-treatment, have high dielectric constants and large breakdown strengths [2][3][4][5]. As a result, glass-ceramics can be used as energy storage capacitor [6][7][8]. Therefore, dielectric glass-ceramics are greatly concerned.…”

Effect of Microwave Processing on the Crystallization and Energy Density of BaO‐Na2O‐Nb2O5‐SiO2‐B2O3 Glass‐Ceramics

“…Glass-ceramic materials are excellent candidates for such dielectric materials because of their potential for high energy density. [2][3][4][5][6][7][8][9][10] The melt casting used to obtain these materials is advantageous because cast amorphous bodies are normally pore free, and defects, such as pores, are detrimental to the breakdown strength of dielectric materials made through conventional solid-state processing. 11 The controlled crystallization of glass-ceramics also allows for tailoring of dielectric properties to help improve energy density.…”

“…10,12 Particularly, glass-ceramics that contain a crystalline ferroelectric phase have been studied due to their large dielectric constant, and based on the phase the materials exhibited an energy density ranging from 0.9 to 4.0 J/cm 3 , depending on the measuring method, and these energy densities can be orders of magnitude higher than porous conventional ceramic dielectrics made with the same phase. 4,5,10,13,14 A material with high values for both breakdown strength and permittivity would be desirable, unfortunately there is an inverse relationship between the E b and e r . 15 In glass ceramic systems the crystallization allows for the tailoring of these two variables, in order to achieve an optimized energy density.…”

“…have high breakdown strength ( E b ), have a high relative permittivity (ε r ), and have high‐energy efficiency through a charge/discharge cycle. Glass‐ceramic materials are excellent candidates for such dielectric materials because of their potential for high energy density . The melt casting used to obtain these materials is advantageous because cast amorphous bodies are normally pore free, and defects, such as pores, are detrimental to the breakdown strength of dielectric materials made through conventional solid‐state processing .…”

Mechanical and dielectric behaviors of perovskite (Ba,Sr)TiO3 borosilicate glass ceramics

“…Glass ceramics barium/lead based sodium niobates and barium titanate based silicates are investigated, whose dielectric constant are ranging from 20 to 700 [12][13][14]. The breakdown strength of 1400 kV/cm and the energy storage density of 4.0 J/cm 3 show strontium barium niobate based glass ceramics as strong candidate for high energy density storage capacitors for portable or pulsed power applications, and the breakdown strength increases with crystallization temperature [15]. The increase of Sr/Ba ratio supports the formation of uniform dense and fine-grained structure in glass ceramics, suppresses the crystallization of strontium barium niobate based borate glass, and leads to raised breakdown strength but decreased dielectric constant [16].…”