Kumar Raju, Singh Satyendra
Special Centre for Nanoscience, Jawaharlal Nehru University, New Delhi, 110067, India.
Sci Rep. 2018 Feb 16;8(1):3186. doi: 10.1038/s41598-018-21305-0.
Electrocaloric (EC) refrigeration, an EC effect based technology has been accepted as an auspicious way in the development of next generation refrigeration due to high efficiency and compact size. Here, we report the results of our experimental investigations on electrocaloric response and electrical energy storage properties in lead-free nanocrystalline (1 - x)KNaNbO-xLiSbO (KNN-xLS) ceramics in the range of 0.015 ≤ x ≤ 0.06 by the indirect EC measurements. Doping of LiSbO has lowered both the transitions (T and T) of KNN to the room temperature side effectively. A maximal value of EC temperature change, ΔT = 3.33 K was obtained for the composition with x = 0.03 at 345 K under an external electric field of 40 kV/cm. The higher value of EC responsivity, ζ = 8.32 × 10 K.m/V is found with COP of 8.14 and recoverable energy storage of 0.128 J/cm with 46% efficiency for the composition of x = 0.03. Our investigations show that this material is a very promising candidate for electrocaloric refrigeration and energy storage near room temperature.
电热制冷是一种基于电热效应的技术，由于其高效率和紧凑的尺寸，已被认为是下一代制冷技术发展中的一种有前景的方式。在此，我们通过间接电热测量报告了在0.015≤x≤0.06范围内的无铅纳米晶(1 - x)KNaNbO₃ - xLiSbO₃（KNN - xLS）陶瓷中电热响应和电能存储特性的实验研究结果。LiSbO₃的掺杂有效地将KNN的两个转变温度（Tₘ和Tₑ）降低到室温一侧。在40 kV/cm的外部电场下，对于x = 0.03的成分，在345 K时获得了最大电热温度变化值ΔT = 3.33 K。对于x = 0.03的成分，发现其电热响应率较高，ζ = 8.32×10⁻⁴ K·m/V，性能系数为8.14，可恢复储能为0.128 J/cm³，效率为46%。我们的研究表明，这种材料是室温附近电热制冷和能量存储的非常有前途的候选材料。
