Keisuke Yamanaka

Learn More
Low electrical efficiency for the lithium-oxygen (Li-O2) electrochemical reaction is one of the most significant challenges in current nonaqueous Li-O2 batteries. Here we present ruthenium oxide nanoparticles (RuO2 NPs) dispersed on multiwalled carbon nanotubes (CNTs) as a cathode, which dramatically increase the electrical efficiency up to 73%. We(More)
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(More)
Japanese horse chestnut (Aesculus turbinata: Hippocastanaceae) is one of the typical woody plants that grow in temperate riparian forests in the Japanese Archipelago. To analyze the phylogeography of this plant in the Japanese Archipelago, we determined cpDNA haplotypes for 337 samples from 55 populations covering the entire distribution range. Based on(More)
The application of conventional solid polymer electrolyte (SPE) to lithium-oxygen (Li-O2) batteries has suffered from a limited active reaction zone due to thick SPE and subsequent lack of O2 gas diffusion route in the positive electrode. Here we present a new design for a three-dimensional (3-D) SPE structure, incorporating a carbon nanotube (CNT)(More)
In lithium-oxygen (Li-O2) batteries, it is believed that lithium peroxide (Li2O2) electrochemically forms thin films with thicknesses less than 10 nm resulting in capacity restrictions due to limitations in charge transport. Here we show unexpected Li2O2 film growth with thicknesses of ∼60 nm on a three-dimensional carbon nanotube (CNT) electrode(More)
A perfluorinated alkyl chain grafted to carbon nanotubes is employed in the lithium-oxygen (Li-O2) cell. We demonstrate a highly localized Li-O2 electrochemical reaction in close proximity to the perfluorinated moiety owing to its high O2 affinity. This hydrophobic modification can provide an enhancement in capacity for a very thin microbattery system.
Department of Chemistry, Graduate Schoo Osaka 560-0043, Japan. E-mail: konno@che Department of Biomedical Information Sc Sciences, Hiroshima City University, Asa-Mi Department of Chemistry, Graduate Scho Bunkyo-ku, Tokyo 113-0033, Japan Division of Materials Physics, Graduate University, Toyonaka, Osaka 560-8531, Japa Synchrotron Radiation Center,(More)
For purposes of enlightenment and publicities on disaster rescue activities, we proposed a robot competition named "the Rescue Robot Contest" in 1999, and have organized the competition every year since 2000. We terminated the first phase of this contest at the 5th competition in 2005 and decided to go toward a new phase. At the 6th and 7th(More)
Unique heterogeneous catalase-like activity was observed for metallosupramolecular ionic crystals [AuI4CoIII2(dppe)2(d-pen)4]X n ([1]X n ; dppe = 1,2-bis(diphenylphosphino)ethane; d-pen = d-penicillaminate; X n = (Cl-)2, (ClO4-)2, (NO3-)2 or SO42-) consisting of AuI4CoIII2 complex cations, [1]2+, and inorganic anions, X- or X2-. Treatment of the ionic(More)
Somatic cells have been reprogrammed into pluripotent stem cells by introducing a combination of several transcription factors, such as Oct3/4, Sox2, Klf4, and c-Myc. Induced pluripotent stem (iPS) cells from a patient’s somatic cells could be a useful source for drug discovery and cell transplantation therapies. However, most human iPS cells are made by(More)
  • 1