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Research paper : Development of high power and high capacity lithium secondary battery based on the advanced nanotechnology (I. Honma)−231 Synthesiology - English edition Vol.1 No.4 (2009) [1][2][3][4][5]M. Okubo, J. Kim, M. Enomoto, N. Kojima, T. Kudo, H. Zhou and I. Honma: Nanosize effect on high-rate Li-ion intercalation in LiCoO2 electrode, J. American Chemical Society, 129, 7444 (2007).C. Jiang, M. Wei, Z. Qi, T. Kudo, I. Honma and H. Zhou: Particle size dependence of the lithium storage capability and high rate performance of nanocrystalline anatase TiO2 electrode, J. Power Sources, 166, 239 (2007).C. Jiang, I. Honma, T. Kudo and H. Zhou: Nanocrystalline rutile TiO2 electrode for high-capacity and high-rate lithium storage, Electrochemical and Solid State Letters, 10, A127 (2007).C. Jiang, Y. Zhou, T. Kudo, I. Honma and H. Zhou: Preparation and rate capability of Li4Ti5O12 hollow-sphere anode materials, J. Power Sources, 166, 514 (2007).C. Jiang, M. Ichihara, I. Honma and H. Zhou: Effect of particle dispersion on high rate performance of nano-sized Li4Ti5O12 anode, Eletrochimica Acta, 52, 6470 (2007).Received original manuscript June 23, 2008Revision received October 27, 2008Accepted October 27, 2008Referencesyears. This scenario is also effective R&D process in other industries such as bio, information, nanotech, manufacturing, environment, and energy, particularly in short range project where the final product goal is clear.7 AcknowledgementsI thank all people who cooperated in this industry-academia-government vertical collaboration development for high-power lithium secondary battery. Particularly, Zhou Haoshen, Group Leader of Energy Interface Technology Group, AIST contributed greatly for the property data when titanium oxide nanocrystal material was used as electrode material. Tetsuichi Kudo, Professor Emeritus of The University of Tokyo gave us essential idea for the concept of high-speed charge transfer that takes place within active material. I am grateful to the people of Hitachi Maxell, Ltd. for fabricating the prototype laminated battery and testing the battery properties. We received advice from Professor Moriguchi of Nagasaki University on the synthesis of porous electrode structure. I am also thankful to people of Nanotech Division, NEDO and Collaboration Promotion Department, AIST who gave us various advices in conducting this project.Itaru Honma Graduated from the Department of Metallurgy and Materials Science, Faculty of Engineering, The University of Tokyo in 1984. Research assistant at Faculty of Engineering, The University of Tokyo from 1985 to 1991, then Lecturer from 1991 to 1995. Joined Electrotechnical Laboratory, Agency of Industrial Science and Technology in 1995. Became leader of Energy Material Research Group, Energy Electronics Institute, AIST from 2001. Currently, leader of Nanoenergy Material Research Group, Energy Technology Research Institute, AIST. Doctor of Engineering. While at university, worked widely on new material for amorphous silicon solar cell and functional material process. After joining Electrotechnical Laboratory, worked on R&D for innovative power source devices based on nanotechnology such as polymer electrolyte fuel cell and super capacitor. Currently works on material development for high-capacity high-power lithium ion secondary battery. Worked as leader of R&D in the vertical collaboration project by four organizations, Nagasaki University, AIST, Hitachi Maxell, Ltd., and Fuji Heavy Industries Ltd. as “Research and Development of High Capacity & High Power Density Secondary Battery by Low Resistance, High Ion Diffusion Nanoporous Electrode” under R&D for Practical Utilization of Nanotechnology and Advanced Materials, NEDO conducted from 2005 to 2007.Discussion with Reviewers1 The flow of vertical collaborationQuestion and Comment (Koichi Mizuno)Joint research in vertical collaboration style is method that has been addressed frequently. Can you indicate if there was any reverse transfer of R&D from the company to AIST, since collaborative research is not mere one-way flow from AIST to the company (battery manufacturer)? Of course, I see that the main topics of development were suggested by the company, but I think it will help explain vertical collaboration if you explain any bi-directional exchange of technological contents.Answer (Itaru Honma)AIST selected titania TiO2, which was appropriate material for basic research since it was available in various sizes, to academically clarify the nanosize effect of electrode material, and systematically studied the electrode property of this oxide. In the basic research phase, we studied the appearance of surface capacity accompanying nanosizing, clarified that the nanocrystal active materials were suitable for high-speed charge-discharge, and explored optimal nanosize. Joint development was done by communicating to the companies in this industry-academia-government project the fact that excellent high capacity and high output properties of nanosize active material could be used in actual active material.In fact, Hitachi Maxell was using Li4Ti5O12, which is similar titanium oxide to titania on which AIST was working, for negative electrode material, but to downsize this material to nano level and optimize capacity and output properties, AIST and companies pointed out the necessity for clarifying which Li4Ti5O12 size was optimal for use in commercial battery by exploring the missing range of active material size, as shown in Fig. 8.Optimal nanosizing of practical electrode material listed in the commercialization plan was conducted through bi-directional information exchange and development plan of technological transfer of sizing effect of titania (fore-cast from AIST to Hitachi Maxell) and practical exploration of nanosize active material (back-cast from Hitachi Maxell to AIST). The 55 nm LiMn2O4 and 100 nm Li4Ti5O12 used in prototype cell data were results for optimal nanosize found in this collaborative development, and as described in the paper, output property that far surpassed the conventional battery performance was obtained.2 Surface pseudo-capacityQuestion and Comment (Koichi Mizuno)The “pseudo-capacity” on surface is the key point in increasing charge-discharge capacity rather than intercalation (11)−

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