Zero-Strain Insertion Anode Material of Lithium-Ion Batteries

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.