Characterization of lithium zinc titanate doped with metal ions as anode materials for lithium ion batteries.

Abstract

With the aim of improving the ionic and electronic conductivities of Li2ZnTi3O8 for high performance lithium ion battery applications, Li2Zn0.9M0.1Ti3O8 (M = Li+, Cu2+, Al3+, Ti4+, Nb5+, Mo6+) compounds are successfully fabricated using facile high temperature calcination at 800 °C. Physical characterization and lithium ion reversible storage demonstrate that Zn-site substitution by multivalent metal ions is beneficial for improving the migration rate of ions and electrons of Li2ZnTi3O8. X-ray diffraction analysis and scanning electron microscopy reveal that the crystal structure and microscopic morphology of bare Li2ZnTi3O8 do not change by introducing a small amount of foreign metal ions. As a result, Li2Zn0.9Nb0.1Ti3O8 retains a reversible capacity as high as 198 mA h g-1 at the end of the 500th cycle among all samples. Even when cycled at high temperatures, Li2Zn0.9Nb0.1Ti3O8 still maintains excellent reversible discharge capacities of 210 mA h g-1 and 196 mA h g-1 at 1000 mA g-1 for the 100th cycle at 50 °C and 60 °C, respectively. All the conclusions indicate that Li2Zn0.9Nb0.1Ti3O8 is a high-performance anode material for large-scale energy storage devices.