In this paper, we introduce the use of surface treatments to improve the elevated temperature storage characteristics of the Li1+xMn2-xO4 spinel in Li-ion batteries. Two approaches are introduced, the first consists of the application of an inorganic lithium berate glass composition to the surface, the second utilizes an acetylacetone complexing agent. All surface treatments were found to improve the elevated temperature performance of the Li1+xMn2-xO4 spinel to some degree. Results are discussed with respect to the active failure mechanisms.