Prussian blue analogues as battery materials for energy science

4^th European Chemistry Congress

May 11-13, 2017 Barcelona, Spain

Yutaka Moritomo

University of Tsukuba, Japan

Scientific Tracks Abstracts: Chem Sci J

Abstract :

Prussian blue analogues (PBAs:NaxM[Fe(CN)6]y where M is a transition metal) have three-dimensional (3D) jungle-gymtype host framework and cubic nanopores, 0.5 nm at the edge. PBAs are promising cathode materials for lithium ion (LIBs) and sodium ion (SIBs) secondary batteries,[1-3] reflecting their nanoporous host framework. Actuially, thin film of NaxCo[Fe(CN)6]0.90 shows high capacity of 135 mAh/g,[3] which is comparable to the value (= 140mAh/g) of actually-used LiCoO2. The thin film electrode exhibits a high capacity of 121 mAh/g (90 % of the OCV value) even at 60 C. The discharge curve exhibits two plateaus at 3.8 and 3.4 V. By means of ex situ X-ray diffraction and absorption measurements, we have ascrived them the the redox processes of Fe and Co.[3] The thin film battery electrode is a nice platform for energy science, becauase the electrode is free free from carbonbased conducting material and polymer-based binder. With use of an optical battery cell and microscopy, we clarified the structural dynamics in the charge process (Li intercalation process) of LixCo[Fe(CN)6]0.90.[4] We cleary observed phase separation into the Li-rich and Li-poor domains of iorder of 10,000 nm. With use of the inelastic X-ray scattering technique, we clartified that local structures around CO2+ and Co3+ in NaxCo[Fe(CN)6]0.90. [1] T. Matsuda and Y. Moritomo, Appl. Phys. Express 4 (2011) 047101 [2] T. Matsuda, M. Takachi and Y. Moritomo, Chem. Comm. 49 (2013) 2721. [3] M. Takachi, T. Matsuda, and Y. Moritomo, Jpn. J. Appl. Phys. 52 (2013) 090202. [4] M. Takachi and Y. Moritomo, Sci. Rep. in press.

Biography :

Yutaka Moritomo has completed his PhD in physics at the age of 27 years from University of Tokyo and postdoctoral studies from University of Tokyo. Now, he is the director of divivion of materials for energy storage and conversion, Center for Integrated Research in Fudamental Science and Engineering (CiRfSE), University of Tsukuba. He has published more than 300 papers (total citation is more than 20,000).
Email:moritomo.yutaka.gf@u.tsukuba.ac.jp