The demands for large-scale energy storage devices have increased significantly for the past decade [1]. Olivine structured lithium iron phosphate, LiFePO 4 , has been recognized as a promising cathode material for lithium ion batteries because of its advantages of high power capability, low cost, non-toxicity, excellent thermal safety, and high reversibility [2]. In addition to LiFePO 4 ,
... [Show full abstract] various amorphous and crystalline phases of iron phosphates, FePO 4 and FePO 4 ·nH 2 O have been proposed as the cathode materials in lithium ion batteries [3].
Among various phases of iron phosphates, the exact crystal structure of crystalline FePO 4 ·2H 2 O (metastrengite I) is still unknown as first mentioned by Rémy et al. [4]. It was determined that an orthorhombic olivine-type LiFePO 4 ( Pnma ) and metastrengite I FePO 4 ·2H 2 O ( Pbnm ) belong to the same space group #62. Here, we use the recently developed genetic-algorithm-based FPASS method [5] to determine the crystal structure of crystalline FePO 4 ·2H 2 O (metastrengite I) and discuss the possible applications of the crystalline FePO 4 ·2H 2 O (metastrengite I) for the LIBs system.
References
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[3] C. Delacourt, P. Poizot, D. Bonnin, and C. Masquelier, J. Electrochem. Soc. , 156 , A595 (2009).
[4] P. Rémy, Ph.D. Thesis, University of Paris, France (1971).
[5] B. Meredig and C. Wolverton, Nature Mater. , 12 , 123 (2013).