Rechargeable lithium batteries have rapidly risen to prominence as fundamental devices for green and sustainable energy development. Lithium batteries are now used as power sources for electric vehicles. However, materials innovations are still needed to satisfy the growing demand for increasing energy density of lithium batteries. In the past decade, lithium-excess compounds, Li 2 MeO 3 (Me = Mn 4+ , Ru 4+ , etc.), have been extensively studied as highcapacity positive electrode materials. Although the origin as the high reversible capacity has been a debatable subject for a long time, recently it has been confirmed that charge compensation is partly achieved by solid-state redox of nonmetal anions (i.e., oxide ions), coupled with solid-state redox of transition metals, which is the basic theory used for classic lithium insertion materials, such as LiMeO 2 (Me = Co 3+ , Ni 3+ , etc.). Herein, as a compound with further excess lithium contents, a cation-ordered rocksalt phase with lithium and pentavalent niobium ions, Li 3 NbO 4 , is first examined as the host structure of a new series of high-capacity positive electrode materials for rechargeable lithium batteries. Approximately 300 mAh·g −1 of high-reversible capacity at 50°C is experimentally observed, which partly originates from charge compensation by solid-state redox of oxide ions. It is proposed that such a charge compensation process by oxide ions is effectively stabilized by the presence of electrochemically inactive niobium ions. These results will contribute to the development of a new class of high-capacity electrode materials, potentially with further lithium enrichment (and fewer transition metals) in the close-packed framework structure with oxide ions.battery | lithium | anion redox | positive electrode T o realize sustainable energy development in the future, it is widely admitted that the substitution of energy sources for fossil fuels must be considered. An efficient energy storage system using an electrochemical method, such as rechargeable lithium batteries (Li-ion batteries, LIBs), potentially provides the solution to meet these tough challenges. Now, electric vehicles equipped with an electric motor and LIB have been launched in the market, and LIBs are starting to substitute for fossil fuels as power sources in the transportation system using the technology of internal combustion engines. Since their first appearance as power sources for portable electronic devices in 1991, the technology of LIBs has now become sufficiently sophisticated. Nevertheless, the demands for a further increase in energy density are still growing to extend the driving distance for electric vehicles.In 1980, LiCoO 2 with a cation-ordered rocksalt structure (layered type) was first proposed as a positive electrode material for LIBs (1) , etc.), which are also classified as having cation-ordered rocksalt-type structures (2), have been extensively studied as potential high-capacity electrode materials, especially for the Mn 4+ system (Li 2 MnO 3 ) (3-7). Li 2 MnO 3...

Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g−1 based on solid-state redox reaction of oxide ions.

Stoichiometric LiMnO2 and NaMnO2 with a cation-disordered rocksalt-type structure as metastable polymorphs were successfully prepared by mechanical milling.

Advances in genomic microbial taxonomy have opened the way to create a more universal and transparent concept of species but is still in a transitional stage towards becoming a defining robust criteria for describing new microbial species with minimum features obtained using both genome and classical polyphasic taxonomies. Here we performed advanced microbial taxonomies combined with both genome-based and classical approaches for new agarolytic vibrio isolates to describe not only a novel Vibrio species but also a member of a new Vibrio clade. Two novel vibrio strains (Vibrio astriarenae sp. nov. C7T and C20) showing agarolytic, halophilic and fermentative metabolic activity were isolated from a seawater sample collected in a coral reef in Okinawa. Intraspecific similarities of the isolates were identical in both sequences on the 16S rRNA and pyrH genes, but the closest relatives on the molecular phylogenetic trees on the basis of 16S rRNA and pyrH gene sequences were V. hangzhouensis JCM 15146T (97.8% similarity) and V. agarivorans CECT 5085T (97.3% similarity), respectively. Further multilocus sequence analysis (MLSA) on the basis of 8 protein coding genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, and topA) obtained by the genome sequences clearly showed the V. astriarenae strain C7T and C20 formed a distinct new clade protruded next to V. agarivorans CECT 5085T. The singleton V. agarivorans has never been included in previous MLSA of Vibrionaceae due to the lack of some gene sequences. Now the gene sequences are completed and analysis of 100 taxa in total provided a clear picture describing the association of V. agarivorans into pre-existing concatenated network tree and concluded its relationship to our vibrio strains. Experimental DNA-DNA hybridization (DDH) data showed that the strains C7T and C20 were conspecific but were separated from all of the other Vibrio species related on the basis of both 16S rRNA and pyrH gene phylogenies (e.g., V. agarivorans CECT 5085T, V. hangzhouensis JCM 15146T V. maritimus LMG 25439T, and V. variabilis LMG 25438T). In silico DDH data also supported the genomic relationship. The strains C7T also had less than 95% average amino acid identity (AAI) and average nucleotide identity (ANI) towards V. maritimus C210, V. variabilis C206, and V. mediterranei AK1T, V. brasiliensis LMG 20546T, V. orientalis ATCC 33934T, and V. sinaloensis DSM 21326. The name Vibrio astriarenae sp. nov. is proposed with C7 as the type strains. Both V. agarivorans CECT 5058T and V. astriarenae C7T are members of the newest clade of Vibrionaceae named Agarivorans.

The exciton model for the pre-equilibrium emission of light composite particles proposed and applied to the (p,n) reaction of Iwamoto-Harada is further investigated for the energy spectra of the (p,d), (p,t), and (p, 'He) reactions with incident energy of several tens of MeV's. Calculated results could reproduce an overall feature of those spectra. The dominance of the pickup-type contribution which occurs in the course of the equilibration process was found to be common for all composite particles. The degree of fitting to the data is excellent for (p, t) reactions to the same extent as for (p,a) reactions, and is somewhat less for the high energy part of energy spectra of (p, He) and (p,d) reactions. The relative ratio of yields of high energy composite particles was also reproduced fairly well with our model. These facts suggest that the simple reaction mechanism assumed in our model accounts for characteristics of the pre-equilibrium emission of light composite particles.