Atomic Insights into Ti Doping on the Stability Enhancement of Truncated Octahedron LiMn(2)O(4) Nanoparticles

Ti-doped truncated octahedron LiTi(x)Mn(2-x)O(4) nanocomposites were synthesized through a facile hydrothermal treatment and calcination process. By using spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), the effects of Ti-doping on the structure evolution and stability enhancement of LiMn(2)O(4) are revealed. It is found that truncated octahedrons are easily formed in Ti doping LiMn(2)O(4) material. Structural characterizations reveal that most of the Ti(4+) ions are composed into the spinel to form a more stable spinel LiTi(x)Mn(2−x)O(4) phase framework in bulk. However, a portion of Ti(4+) ions occupy 8a sites around the {001} plane surface to form a new TiMn(2)O(4)-like structure. The combination of LiTi(x)Mn(2−x)O(4) frameworks in bulk and the TiMn(2)O(4)-like structure at the surface may enhance the stability of the spinel LiMn(2)O(4). Our findings demonstrate the critical role of Ti doping in the surface chemical and structural evolution of LiMn(2)O(4) and may guide the design principle for viable electrode materials.