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tichi Hydrogen Absorption Properties of Lithium by nikeborome


									   Hydrogen Absorption Properties of Lithium Intercalated Graphite

     Takayuki Ichikawaa, Wataru Ishidab, Hiroki Miyaokab and Yoshitsugu Kojimaa
               Institute for Advanced Materials Research, IAMR, Hiroshima University,
                        1-3-1Kagamiyama, Higashi-Hiroshima, 739-8530, Japan
                      Department of Quantum Matter, ADSM, Hiroshima University,
                        1-3-1Kagamiyama, Higashi-Hiroshima, 739-8530, Japan

Hydrogen absorption properties of lithium intercalated graphite were examined in this
work. In advance, two kinds of nano-structural graphite were prepared from graphite
powder by ball-milling under hydrogen or argon atmosphere, where each product is
denoted as HG or AG, respectively. And then, non-treated graphite powder (G), HG or
AG was milled with Li to synthesize lithium-graphite intercalation compounds, which are
denoted as Li-G, Li-HG and Li-AG, respectively. As shown in Fig. 1, the peaks
corresponding to LiC6 and LiC12 were observed in XRD measurements for Li-G and Li-
HG, while no peaks were observed in the case of Li-AG. However, similar thermal
decomposition reactions were revealed for all the compounds under an inert gas,
indicating that Li-AG includes the lithium intercalated graphite species.

            Figure 1. XRD profiles of starting materials and lithium intercalation compounds

After hydrogenating treatments, the formation of LiH was confirmed by XRD
measurements for all the compounds, suggesting that the intercalated lithium reacts with
hydrogen. These hydrogenated compounds desorbed hydrogen with heating up to 500 °C.
Furthermore, lithium carbide (LiC) was formed as dehydrogenated phase of all the

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