Shibata Takayuki, Fukuzumi Yuya, Moritomo Yutaka
National Institute of Technology, Gunma College, Maebashi, Gunma, 371-8530, Japan.
Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8571, Japan.
Sci Rep. 2018 Oct 3;8(1):14784. doi: 10.1038/s41598-018-33091-w.
Recently, it was reported that a thermocell can convert temperature into electric energy by using the difference in the thermal coefficient (α = dV/dT) of the redox potential (V) between the cathode and anode materials. Among battery materials, Prussian blue analogues (PBAs) are promising materials for thermocell, because α changes from approximately -0.3 mV/K in NaMn[Fe(CN)] 3.5 HO (NMF83) to approximately 1.3 mV/K in NaCo[Fe(CN)]2,9HO (NCF90). In this work, we systematically investigated the thermal efficiency (η) of the NMF83/NCF90 thermocell relative to the difference (ΔT) between low (T = 282 K) and high (T = 292-338 K) temperatures. We found that the thermal efficiency (η) increased proportionally with ΔT. The linear increase in η is ascribed to the linear increase in the cell voltage (V) and the charge (Q) extracted from NCF90. Moreover, η reached 3.19% at ΔT = 56 K, which corresponds to 19% of the Carnot efficiency (η = 17.0%). We further confirmed that the magnitude of Q is quantitatively reproduced by the slopes of the discharge curves of NMF83 and NCF90.
最近，有报道称热电池可以通过利用阴极和阳极材料之间氧化还原电位（V）的热系数（α = dV/dT）差异将温度转化为电能。在电池材料中，普鲁士蓝类似物（PBAs）是热电池的有前景的材料，因为α在NaMn[Fe(CN)]₃.₅H₂O（NMF83）中从约-0.3 mV/K变化到在NaCo[Fe(CN)]₂.₉H₂O（NCF90）中的约1.3 mV/K。在这项工作中，我们系统地研究了NMF83/NCF90热电池相对于低温（T = 282 K）和高温（T = 292 - 338 K）之间的温差（ΔT）的热效率（η）。我们发现热效率（η）与ΔT成比例增加。η的线性增加归因于电池电压（V）和从NCF90提取的电荷（Q）的线性增加。此外，在ΔT = 56 K时，η达到3.19%，这相当于卡诺效率（η = 17.0%）的19%。我们进一步证实，Q的大小可以通过NMF83和NCF90的放电曲线斜率定量再现。
