Electrochemistry of LiMn2O4 nanoparticles made by flame spray pyrolysis.

Crystalline LiMn2O4 nanoparticles with specific surface areas between 53.9 and 203.4 m2 g(-1) (particle size of 25.9-6.9 nm) were produced in a one-step flame spray pyrolysis process by varying the specific combustion enthalpy. An optimized nano-sized powder retained the highest galvanostatic discharge capacity of over 80 mAh g(-1) beyond 60 cycles at 50 C, a suitable positive material for high power Li-ion batteries. Due to the increase in specific surface area, nanoparticles have the advantages of decreased diffusion path lengths and improved charge transfer, however, it is seen in this work that the lack of crystalline bulk present in LiMn2O4 nanoparticles less than 15 nm in size does not justify the advantages of higher specific surface area between the current densities of 0.5-50 C.