Shin‐ichi Orimo

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplex Hydrides for Hydrogen StorageShin-ichi Orimo, Yuko Nakamori, Jennifer R. Eliseo, Andreas Züttel, and Craig M. JensenView Author Information Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, Hawaii Hydrogen Carriers, LLC, Honolulu, Hawaii 96813, Department of Mobility, Environment, and Energy, EMPA Materials Sciences and Technology, 8600 Dübendorf, Switzerland, and Department of Chemistry, University of Hawaii, Honolul

Impedance measurements indicate that Na2B12H12 exhibits dramatic Na(+) conductivity (on the order of 0.1 S cm(-1)) above its order-disorder phase-transition at ≈529 K, rivaling that of current, solid-state, ceramic-based, Na-battery electrolytes. Superionicity may be aided by the large size, quasispherical shape, and high rotational mobility of the B12H12(2-) anions.

Solid electrolytes with sufficiently high conductivities and stabilities are the elusive answer to the inherent shortcomings of organic liquid electrolytes prevalent in today's rechargeable batteries. We recently revealed a novel fast-ion-conducting sodium salt, Na₂B₁₂H₁₂, which contains large, icosahedral, divalent B₁₂H₁₂^2- anions that enable impressive superionic conductivity, albeit only above its 529 K phase transition. Its li

Abstract Complex hydrides exhibit various energy‐related functions such as hydrogen storage, microwave absorption, and neutron shielding. Furthermore, another novel energy‐related function was recently reported by the authors; lithium fast‐ionic conduction, which suggests that complex hydrides may be a potential candidate for solid electrolytes in lithium‐ion batteries. This review presents the recent progress in the development of lithium fast‐ionic conductors of complex hydrides. First, the fa

Na2 B10 H10 exhibits exceptional superionic conductivity above ca. 360 K (e.g., ca. 0.01 S cm(-1) at 383 K) concomitant with its transition from an ordered monoclinic structure to a face-centered-cubic arrangement of orientationally disordered B10 H10 (2-) anions harboring a vacancy-rich Na(+) cation sublattice. This discovery represents a major advancement for solid-state Na(+) fast-ion conduction at technologically relevant device temperatures.

Both LiCB9H10 and NaCB9H10 exhibit liquid-like cationic conductivities (≥0.03 S cm−1) in their disordered hexagonal phases near or at room temperature. These unprecedented conductivities and favorable stabilities enabled by the large pseudoaromatic polyhedral anions render these materials in their pristine or further modified forms as promising solid electrolytes in next-generation, power devices.

The formation condition of an intermediate compound of LiBH4 during the partial dehydriding reaction and its local atomistic structure have been experimentally investigated. LiBH4 changes into an intermediate compound accompanying the release of approximately 11mass% of hydrogen at 700–730K. The Raman spectra indicate that the B–H bending and stretching modes of the compound appear at lower and higher frequencies, respectively, as compared to those of LiBH4. These features are consistent with th

Nanostructured graphite was prepared by mechanical milling under hydrogen atmosphere. Several samples obtained after different milling times were systematically examined to get fundamental information about the structures and hydrogen concentrations. After the expansion of the graphite interlayer, the long-range ordering of the interlayer disappears continuously with increasing milling time. The hydrogen concentration reaches up to 7.4 mass % (CH0.95) after milling for 80 h. Judging from the rad

Complex hydrides have energy storage‐related functions such as i) solid‐state hydrogen storage, ii) electrochemical Li storage, and iii) fast Li‐ and Na‐ionic conductions. Here, recent progress on the development of fast Li‐ionic conductors based on the complex hydrides is reported. The validity of using them as electrolytes in all‐solid‐state lithium rechargeable batteries is also examined. Not only coated oxides but also bare sulfides are found to be applicable as positive electrode active mat

Two desorption peaks of hydrogen molecule (mass number=2), starting at about 600 and 950 K, respectively, are observed in thermal desorption mass spectroscopy of nanostructured graphite mechanically milled for 80 h under hydrogen atmosphere. It follows from a combined analysis of thermal desorption mass spectroscopy and thermogravimetry, that ∼6 mass % of hydrogen (corresponding to 80% of the total amount of hydrogen) is desorbed at the first desorption peak as a mixture of pure hydrogen and hyd