Zero-Strain Insertion Anode Material of Lithium-Ion Batteries.

Abstract

The insertion type materials are the most important anode materials for lithium-ion batteries, but their insufficient capacity is the bottleneck of practical application. Here, LiAl5 O8 nanowires with high theoretical capacity and Li-ions diffusion coefficient are prepared and studied as an insertion anode material, which exhibits zero-strain properties upon electrochemical cycling. However, the poor electronic conductivity of LiAl5 O8 definitely sacrifices the capacity and limits the rate performance. Therefore, compact LiAl5 O8 and carbon composite are further synthesized, in which nanosized LiAl5 O8 particles are uniformly embedded in an amorphous carbon matrix. It displays a reversible capacity of 490.9 mAh g-1 at 1 A g-1 , and the capacity rises continuously to 996.8 mAh g-1 after 1000 cycles due to the interfacial storage mechanism, that the excess Li+ ions can be accommodated in the grain boundaries and C/LiAl5 O8 interfaces.