The performances of two unconventional non-graphitic carbon materials as an anode for lithium ion battery were examined to correlate to their structure. Fullerene soot after extracted fullerene and pyrolytic product of ethylene dichloride both heat-treated at 2400°C, carried relatively thick turbostratic layers of small hexagonal planes to form periphery of hollow spheres. Such structural characteristics provided the charge / discharge characteristics such as very lower discharge capacity, lower Coulombic efficiency and short plateau around 1.0V at the discharge, which are very close to those of carbons heat-treated around 1000-1400°C. Mechanisms of lithium insertion into non-graphitic carbons is discussed in relation to their graphitic structure to explain no formation of C6Li intercalation to the turbostratic stacking of small carbon planes, very high reactivity to of carbon edge highly reduced lithium ion, poor Coulombic efficiency and cycleability. No charge in the hollow eliminates the characteristic charge / discharge profile of some hard carbons calcined at 1000-1400°C.
|出版済み - 1998
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