The effect of crystallinity on the reversible discharge capacity of nickelhydroxide

The higher reversible discharge capacity exhibited by beta(bc) (bc: badly c rystalline)-nickel hydroxide (400 mAh g(-1) of Ni; theoretical: 456 mAh g(- 1)) compared to that of beta-nickel hydroxide (180 mAh g(-1)) can be attrib uted to the presence of regions characterized by turbostratic disorder in t he former. These regions comprise the alpha-modification of nickel hydroxid e existing in an inter-stratified form within the beta(bc) sample. The a-mo tifs in the beta(bc) are anion-free, but hydrated, by virtue of which beta( bc)-nickel hydroxide exhibits a higher water content (11% by weight) compar ed to the beta-form (<1%). (C) 2000 The Electrochemical Society. S0013-4651 (99)11-003-6. All rights reserved.