Jinhan Yao

Surface coating of LiMn 2 O 4 spinel via in situ hydrolysis route: effect of the solution

Thin SiO2 shell consisting of nano-SiO2 particles can be deposited on to LiMn2O4 through the facile hydrolysis of tetraethoxysilane (TEOS) as a solution in either methanol or ethanol. The structure and surface morphologies of the modified and pristine materials were characterized by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The choice of solvent (methanol vs. ethanol) for TEOS hydrolysis has a profound effect on the physical and electrochemical properties of the resultant SiO2-coated LiMn2O4. Coated LiMn2O4 demonstrated an improved cycling ability compared to the uncoated counterpart. Moreover, samples coated using a TEOS–methanol solution showed better cycling ability in extended potential windows and at an elevated temperature than that coated using ethanol.