Hierarchically structured lead-free barium strontium titanate for low-grade thermal energy harvesting
| Autor: | Dou Zhang, Christopher R. Bowen, Eleanor Roake, Baiyun Huang, Kechao Zhou, James Roscow, Yinxiang Bao, Yan Zhang, M. A. Hopkins |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Permittivity
Materials science 02 engineering and technology 01 natural sciences Heat capacity Pyroelectrics Waste heat 0103 physical sciences Materials Chemistry Ceramic Composite material Porosity 010302 applied physics Aligned porosity Energy harvesting Process Chemistry and Technology Lead-free ferroelectrics 021001 nanoscience & nanotechnology Pyroelectricity Electronic Optical and Magnetic Materials Surfaces Coatings and Films Electricity generation visual_art Volume fraction visual_art.visual_art_medium Ceramics and Composites 0210 nano-technology |
| Zdroj: | Bao, Y, Huang, B, Zhou, K, Roscow, J, Roake, E, Hopkins, M, Zhang, D, Zhang, Y & Bowen, C 2021, ' Hierarchically structured lead-free barium strontium titanate for low-grade thermal energy harvesting ', Ceramics International, vol. 47, no. 13, pp. 18761-18772 . https://doi.org/10.1016/j.ceramint.2021.03.211 |
| Popis: | Low-grade heat conversion is one of the most promising strategies to realise carbon-neutral electricity production. Here we present a study on a hierarchically structured porous pyroelectric barium strontium titanate (BST) ceramic with a low Curie temperature and improved thermal energy harvesting performance. The aligned porous structure is beneficial to achieve a greatly reduced permittivity and heat capacity, combined with a high degree of polarisation to maintain a high pyroelectric coefficient. These characteristics contributed to significantly improved sensing and harvesting pyroelectric figures-of-merit, where the thermal energy harvesting figure-of-merit (F E ′) increased by 510% when the porosity reached to 54 vol%, compared to that of the dense BST ceramic. After rectification of the AC pyroelectric current to a DC current, the electric output was stored on a 1 μF capacitor whose voltage after 20 s increased with increasing volume fraction of porosity; namely 5.8 V (dense, 3 vol% porosity), 6.9 V (30 vol%), 7.5 V (43 vol%) and 9.2 V (54 vol%). A maximum energy density of 4.26 μJ/mm 3 was obtained from the BST with 54 vol% porosity, which was 1.6 times higher than that of the dense counterpart (2.71 μJ/mm 3). This aligned porous structure therefore represents a new and promising architecture for facile harvesting and conversion of low-grade waste heat into electrical power. |
| Databáze: | OpenAIRE |
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