In order to develop high thermal conductivity materials, Al-Si/CNGCF composites were fabricated by infiltrating Al-Si alloy (JIS-AC3A) into carbon and vapor grown carbon fiber composite (C/VGCF) foam. There was not any void and Al₄C₃ compound layer on an interface between Al-Si alloy and the foam. The composites achieved higher thermal conductivity (129.5 W/mK) and lower coefficient of thermal expansion (16.4-19.7 ppm/K) than Al-Si alloy (121.0 W/mK-22.4 ppm/K), although the flexural strength was decreased to about 1/3 times that of Al-Si alloy.

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The effect of the kind of electrolyte ions and carbon surface on electric double layer capacitance was investigated using graphitized carbon black (GCB), multi-walled carbon nanotube (MWCNT), or activated carbon (ACF) as active material and (C₂H₅) ₄NBF₄, (C₄H₉) ₄NBF₄, (C₆H₁₃) ₄NBF₄, (C₂H₅) ₄NCF₃SO₃, or (C₂H₅) ₄N (CF₃SO₂) ₂N as electrolyte salt for propylene carbonate solution. The GCB and MWCNT, which have no or less microporosity, showed no dependence of the capacitance on the kinds of the electrolyte ions. This suggests that the capacitance is not related to the size of ions adsorbed on carbon surface in the absence of micropores. In the case of the ACF, the smaller capacitances were observed when bulkier ions adsorbing/desorbing. This tendency was more prominent for narrower micropore width, which can be explained by the ion sieving effect of micropores.

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Magnesium loaded activated carbon was prepared to increase the adsorption capacity of lead (II) ions from aqueous solution. In case of sufficient amounts of surface acidic functional groups existing on the carbon, no significant improvement of heavy metal removal was observed even if the magnesium was loaded on it, but removing surface oxygen compounds by out-gassing in helium flow at 1173 K before magnesium loading, considerable enhancement of the heavy metal adsorption affinity onto the activated carbon could be observed. The amount of magnesium impregnation in the aqueous solution was also increased using the out-gassed carbon in the preparation. Any detrimental effect was not observed for aromatics adsorption by the introduction of magnesium. All adsorption equilibrium results at 293 K obeyed Langmuir isotherms. Heavy metal ions adsorption onto the magnesium loaded activated carbons progressed via ion exchange mechanism. Based on the Boehm titration surface analysis, the strong heavy metal adsorption sites might be generated forming the magnesium bound to carbon surface via oxygen bridge by means of calcining the magnesium nitrate impregnated out-gassing carbon in air at 653 K.

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A furnace for the carbonization under a flow of super-heated steam was constructed. For the carbonization in this furnace, the following factors, temperature of super-heated steam, supplying rate of the precursor and transferring rate of carbonizing materials in carbonization furnace, were possible to be changed. Cypress charcoals prepared in this carbonization furnace were compared with those prepared in Ar gas flow. BET surface area of the charcoal increased above 800°C under superheated steam and reaches about 900 m²/g, which was much higher than that obtained in Ar gas flow. The present results on the carbonization of cypress revealed that carbonization and activation could proceed in one heating process by using super-heated steam.

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Cypress charcoals were prepared under super-heated steam at different conditions; different temperatures of super-heated steam of 700-950°C, supplying rates of cypress chips of 15 and 30 kg/h, and transferring rates with the rotation of the paddles of 4.7-18.8 rpm. Pore structure of cypress charcoals was studied by α_s plot analysis of adsorption isotherm of N₂ gas at 77 K. Pores were developed in the charcoals at temperatures above 800°C; abrupt increase in external surface area S_ext. at about 800°C and then increase in microporous surface area S _micro. above 850°C. Total surface area S_total reached up to 1000 m²/g and external surface area S_ext. obtained was more than 300 m²/g. Particularly, very high external surface area S_ext. of 400-500 m²/g was obtained under a mild condition, i.e., cypress chips are supplied by a rate of 15 kg/h and transferred by a rotation rate of the paddles of 4.7 rpm in carbonization furnace.

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We have developed the lithium ion battery system using amorphous carbon in negative electrode and its management technology for hybrid electric vehicle (HEV) applications. The cell has an output power density as high as 3000 W/kg at 50 % state of charge (SOC) and 25 deg.C, and the 48-cell battery module has an output power of 43 kW. To enable effective and adequate use of this high power battery, we have developed new architecture characterized by the newly developed battery control IC, daisy chain communication circuit without isolator and the decentralized control configuration of cell controller and battery controller. Then, we have determined suitable battery control parameters, such as SOC, state of health (SOH) and allowable current/power, taking into consideration the battery characteristics which mainly result from amorphous carbon, system particulars of IIEVs, and the purpose of these parameters. They were adopted into the software of the battery controller. Both software and hardware of the battery controller is made in the form of platform. Because of the excellent characteristics of this battery, its intrinsically reliable controllability, and the platform for battery control technologies, the battery system is promising not only for HEVs, but also for other applications that require both high power and reliability such as a hybrid electric train.

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