Anode materials CxN with graphite-like structure for secondary lithium batteries

CxN (X=7.3, 11.7, 12.5) with graphite-like structure have been synthesized by chemical vapor deposition (CVD) from pyridine or pyridine with chlorine at 800 degrees C. The composition and structure of these materials have been investigated by chemical analysis, X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical behavior of CxN have been investigated in organic electrolyte solutions. Cyclic voltammetric curves and charge(li insertion)/discharge(Li extraction) curves of CxN showed cathodic and anodic currents. In addition, CxN had larger capacity than pyrolytic carbon synthesized by CVD from benzene at 800 degrees C. The capacity of CxN increased with nitrogen contents. Especially C7 3N had a discharge capacity of 507mAh/g in the potential range of 0-3V vs, Li/Li+ which exceeds the theoretical capacity of graphite (372mAh/g), The average layer spacing of C x N increased during charging and decreased during discharging as well as pyrolytic carbon. CxN rich in nitrogen are regarded as interesting anode materials for high energy density secondary lithium batteries.