Electrochimica Acta, Vol.49, No.21, 3487-3496, 2004
Layered lithium transition metal nitrides as novel anodes for lithium secondary batteries
We report the approach to overcome the deterrents of the hexagonal Li2.6Co0.4N as potential insertion anode for lithium ion batteries the rapid capacity fading upon long cycles and the fully Li-rich state before cycling. Research reveals that the appropriate amount of Co substituted by Cu can greatly improve the cycling performance of Li2.6Co0.4N. It is attributed to the enhanced electrochemical stability and inter-facial comparability. However, doped Cu leads to a slightly decreased capacity. High energy mechanical milling (HEMM) was found to effectively improve the reversible capacity associated with the electrochemical kinetics by modifying the active hosts' morphology characteristics. Moreover, the composite based on mesocarbon microbead (MCMB) and Li2.6Co0.4N was developed under HEMM. The composite demonstrates a high first cycle efficiency at 100% and a large reversible capacity of ca. 450 mAhg(-1), as well as a stable cycling performance. This work may contribute to a development of the lithium transition metal nitrides as novel anodes for lithium ion batteries. (C) 2004 Elsevier Ltd. All rights reserved.
Keywords:layered lithium transition metal nitrides;mesocarbon microbead;composite materials;lithium ion batteries;initial coulombic efficiency