基于弛豫型铁电三元共聚物聚(偏氟乙烯-三氟乙烯-氯代偏氟乙烯)热释电性能的能量采集研究

研究了利用弛豫型铁电三元聚合物薄膜P(VDF-TrFE-CFE)的热释电性质,以温度波动作为初始能量形式进行热电能量的采集。由于该聚合物薄膜在发生由温度变化诱导的纳米极性区极化机制转换时,介电常数表现出明显的非线性变化,所以可以结合Ericsson循环实现热电能量采集。实验结果显示,最佳能量采集温度区间为20~-20℃,利用不同温度下的单极性电滞回线进行Ericsson循环模拟,两种模拟方式分别实现能量采集最大值和最小值,并从微观角度给出了两种模式的解释。同时研究了温度波动和外加电场对能量采集的影响。在外加电场100 kV·mm^-1、温度波动为40℃的情况下,能量采集值达到3483 mJ·cm^-3。与单晶材料相比,能量采集值提高了10倍。当工作温度降低至室温时,材料具有柔性,在能量采集方面具有应用潜力。

Giant Energy Harvesting by Pyroelectric Effect in Relaxor Ferroelectric Terpolymer Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)

Energy harvesting was investigated in relaxor ferroelectric terpolymer P( VDF-TrFE-CFE) by pyroelectric effect. Original energy was the temperature fluctuations. Due to the non-linear die-lectric property in the vicinity of polarization mechanism transition of nanopolar regions, we can har-vest energy by operating Ericsson cycle. Experimental results show that the best energy harvesting temperature range is from 20 to -20 ℃. Ericssion cycle was simulated using the unipolar cycle at different temperatures. Two modes of energy harvesting were presented and analyzed:modeⅠmaxi-mizing and modeⅡminimizing harvested energy, modeⅠis idealized, by applying a low voltage, the harvested energy can reach nearly maximum. The explanation of the two modes was given from the view of microstructure. Temperature and electric field dependence was also given, at 100 kV· mm-1 , temperature from 20 to -20 ℃, giant energy can be harvested around 3 483 mJ · cm-3 . Compared with the single crystals, the advantages, such as the harvested energy increased by 10 times, working temperature decreased to room temperature, and the material flexibility, make it pos-sible as a good candidate for energy harvesting.