Characterization of Unusually Large Pseudo-Single Crystal of β-Nickel Hydroxide

Unusually shaped and remarkably large, i.e., micrometric, pseudo-single crystals of beta-nickel hydroxide are synthesized following the original route proposed by Scholder and Giesler in 1962. The so-obtained hydroxide is investigated and compared to the standard product made of polycrystalline spherical particles. Structural, morphological, vibrational and electrochemical properties are examined by X-ray diffraction, scanning electron microscopy, mu-Raman spectroscopy, and cyclic voltametry. Our study reveals that this pseudo-single crystal of beta-nickel hydroxide is made of micrometric hexagonal plates constituted by extremely well ordered hexagonal nanocrystallites. This material shows high crystallinity and a single crystal type behavior in mu-Raman spectroscopy due to the coherent orientation of the nanocrystallites subunits. After a few tens of potentiodynamic cycles, this compound exhibits higher electrochemical capacity than the standard compound. These features make it a very promising candidate for use in rechargeable batteries.