Thermal efficiency of a thermocell made of Prussian blue analogues

• Shibata, Takayuki

• Fukuzumi, Yuya

• MORITOMO, Yutaka

Abstract

Recently, it was reported that a thermocell can convert temperature into electric energy by using the difference in the thermal coefficient ( α  = d V /d T ) 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 Na x Mn[Fe(CN) 6 ] 0.83 3.5 H 2 O (NMF83) to approximately 1.3 mV/K in Na x Co[Fe(CN) 6 ] 0.9 2,9H 2 O (NCF90). In this work, we systematically investigated the thermal efficiency ( η ) of the NMF83/NCF90 thermocell relative to the difference (Δ T ) between low ( T L  = 282 K) and high ( T H  = 292–338 K) temperatures. We found that the thermal efficiency ( η ) increased proportionally with Δ T . The linear increase in η is ascribed to the linear increase in the cell voltage ( V cell ) and the charge ( Q NCF90 ) extracted from NCF90. Moreover, η reached 3.19% at Δ T  = 56 K, which corresponds to 19% of the Carnot efficiency ( η carnot  = 17.0%). We further confirmed that the magnitude of Q NCF90 is quantitatively reproduced by the slopes of the discharge curves of NMF83 and NCF90.

Journal

• Scientific Reports

  Scientific Reports 8 14784-, 2018-10

  Nature Publishing Group

Keywords

• Multidisciplinary

Details

• CRID: 1050001202627590528
• NII Article ID: 120007133679
• DOI: 10.1038/s41598-018-33091-w
• ISSN: 20452322
• HANDLE: 2241/00154039
• Web Site: https://tsukuba.repo.nii.ac.jp/records/48551
• Web Site: https://www.nature.com/articles/s41598-018-33091-w.pdf
• Web Site: https://www.nature.com/articles/s41598-018-33091-w
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN