Vol.2 No.1 2009

50/88

Research paper : Basic materials research for the development of ubiquitous-energy devices (M. Kohyama et al.)−47−Synthesiology - English edition Vol.2 No.1 (2009) are accumulated and systematized in long-term from the stance of (2). The latter findings must be shared by everyone including the members of the material development group.As tasks to be achieved by the basic analysis group, we conducted the specification and clarification of issues through collaboration with development group, as well as the establishment of observation technology of the actual materials and system. This involved pioneering the original TEM observation method for the fuel cells and the Li-ion batteries that will be described later. Second, we worked on the review and establishment of first-principles calculation technique of complex structure. Also, we worked on the collaborative analysis technology of theoretical calculation and TEM observation and surface science methods. Such pioneering of the basic analysis technology for energy and environment materials is not easy, but must be tackled simultaneously to solve the issues of various phenomena and functions of the materials.The three issues described in the beginning of this chapter could not be solved easily. However, when efforts spent while the researchers were fully aware of the issues, improvements and solutions did progress. Specific results will be described in the next chapter, and the lessons learnt from the effort will be discussed in chapter 5.4 Some examples of significant resultsIn this research, we obtained several significant results that were utilized in the development of functional materials, and were highly evaluated academically as demonstrated by reception of various awards. Some examples are explained herein. The example of positive electrode materials for Li-ion batteries was a result that leads directly to new material development, while the examples of Pt/C electrode catalysts for fuel cells and gold/oxide catalysts had great impact on the construction and systematization of theories for metal/inorganic nano-hetero interfaces as well as the improvement and development of materials. Both helped advance the basic analysis technology.4.1 Mechanism for increasing capacity of positive-electrode materials for Li-ion batteriesA Li-ion battery is a storage cell that uses transition metal oxides including Li for its positive electrode, and carbon or Li metal or alloy for its negative electrode. The capacity and power density in comparison to weight are outstanding compared to conventional storage cells. It is expected to be used widely in automobiles as well as mobile devices, and further increase in capacity and power density, and improvement in durability and safety are necessary. In the charge process, Li ions move from the positive to negative electrodes through electrolytes, and return from the negative to positive electrodes in the discharge process. The development of excellent positive electrode materials that can absorb and release high density of Li ions repeatedly is the most important. Currently, LiCoO2 is commonly used as the positive electrode material, but a material that is capable of achieving high capacity and high power density without using Fig. 1 Outline of research activities of basic material analysis for the development of ubiquitous energy devices.CCCCCCPtPtPtPtPtCreative development of basic material analysis as part of Clarification of role of basic material research: ① Clarification and search to overcome the valley of death. ② Discovery and generalization/systematization of new phenomena of materials ⇒(a) Flexible collaboration with development, and (b) continuous activity for systematizationTask ①: Construction of closecollaboration with materialdevelopment group⇒ Clarification of issuesTask ②: Establishment of observation technology for actual materials and systems (pioneering of original TEM observation method for fuel cell and Li-ion battery)Material development groupClose collaborationFirst-principlescalculationTEM observation andsurface-scienceanalysisDevelopment of basicresearch frontiersTask③: Establishment offirst-principles calculationtechniques for complexsystems, and developmentof collaborative analysistechniques of theoreticalcalculation and TEMobservationContribution to both materials development and advancement of basic researchInorganicMaterialsMetalMetalInorganicMaterialsHetero-interface effectNano-size effectConstruction of theories for metal/inorganic nanohetero interfacesAu-nanocatalystsNano-coatingHetero-CatalystsFuel cellElectro-catalystsTiO2Pd/MnO2etc.Au/TiO2etc.Cu/AI2O3etc.Pt/C, Pt-Ru/C,etc.TEM image of Au/CeO2catalysAuCeO2First-principlescalculationClarification of catalytic mechanismDevelopment of storage and catalyticmaterials for portable energy devicesDevelopment of polymer-electrolyte fuel cellClarification of electrode deterioration mechanismMaterials development for new energystoragedevices such as Li-ion batteryTEM image of Pt/CelectrodeFirst-principlescalculationFe-Mn positiveelectrode materialsObservation ofcompositional distributionClarification of high-capacity mechanismof positive electrode materials①Clarification of issues inmaterials development,establishment of materials design guideline②High academicachievement: various awardsDevelopment of ubiquitous energy devicesPt/C[at. %]Full Research

※このページを正しく表示するにはFlashPlayer9以上が必要です