| 고전련 에너지 스토리지 커페시터 | |||||
| 작성자 | 전** | 작성일 | 2021-11-24 | 조회수 | 208 |
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- 무연계(Pb-free) 이완형 강유전체(relaxor-ferroelectric) 소재를 이용한 고전력 에너지 스토리지 커페시터 개발 "Thermally-stable high energy-storage performance over a wide temperature range in relaxor-ferroelectric Bi1/2Na1/2TiO3-based ceramics", Ceram. Inter. 47, 23488 (2021). DOI : 10.1016/j.ceramint.2021.05.065 Abstract In this study, lead-free zirconium (Zr)-modified Bi1/2(Na0.78K0.22)1/2TiO3 (BNKT) ceramics were synthesized by the conventional solid-state reaction method. The co-existence of two phases (tetragonal; P4mm and cubic phases; Pmm) with definite phase fractions were observed for all samples. The lattice parameters were gradually enhanced by the addition of Zr-content in the BNKT ceramics, which strongly support the relaxor-ferroelectric response. All of the samples are well-dense with no noticeable pores detected. Definite grains with clear grain boundaries were observed through SEM analysis. The temperature-dependent (25?200 °C) ferroelectric polarization response of all specimens were studied in detail under the constant applied electric field (60 kV cm-1). Thermally-stable high energy-storage properties (Wrec ? 0.72 J cm-3, and η ? 98%) with an extended operating temperature range (25?200 °C) within ±15% variation was observed for the Zr-modified BNKT composition. The enhancement of energy-storage properties can be attributed to the Zr addition, which increased the phase fraction of cubic crystal structure and assisted the ferroelectric to relaxor-ferroelectric phase transition. This study provides a comprehensive analysis of the energy-storage response of the lead-free ceramics for energy-storage devices. |
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