New ~7Li-nmr evidence for lithium insertion in disordered carbon

摘要

In fully-charged carbon materials, we tried to determine the nature of the interaction between Li species and carbon using variable temperature measurements of the Li Knight shift. Only one interaction between the Li species and graphite cargbon was observed rom room temperature to-100 deg C. Towever, while only one average interaction between the Li species and the disordered carbon was observed at room temperature, three kinds of interactions were observed at low temperature. These results provide direct evidence for the model which explains why the discharge capacity of the carbon electrode with a disordered structure as an anode can exceed the theoretical capacity of a graphite anode in lithium ion rechargeable batteries.