Surface coating of LiMn2O4 spinel via in situ hydrolysis route: effect of the solution

Thin SiO 2 shell consisting of nano-SiO 2 particles can be deposited on to LiMn 2 O 4 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 SiO 2 -coated LiMn 2 O 4 . Coated LiMn 2 O 4 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.