Transition metal phosphides with mesostructured architectures are extremely promising as high power and high capacity electrode materials for lithium ion batteries. Reduction of crystallite size has been shown to significantly enhance mass transport rates and promote faster lithium ion reaction kinetics. We present a new low temperature approach to the synthesis of mesoporous lithium manganese phosphide by the reaction of phosphine gas (PH3) with a s-bonded manganese alkyl complex. Variation of reaction conditions such as annealing temperature and addition of block copolymer or long chain alkyl amine structure directing agents was shown to cause differences in the morphology of the material. The material was structurally characterized with XPS, XRD and SEM to correlate grain size, crystal structure/phase and elemental composition, and was further evaluated as an anode material using various electrochemical methods.