Electrochimica Acta, Vol.178, 353-360, 2015
Hierarchical structured LiMn0.5Fe0.5PO4 spheres synthesized by template-engaged reaction as cathodes for high power Li-ion batteries
Porous hierarchical LiMn0.5Fe0.5PO4 spheres were synthesized via a novel template-engaged method using pre-synthesized hollow spherical Li3PO4 as template and FeCl2 center dot 4H(2)O/MnCl(2 center dot)4H(2)O as Fe2+/Mn2+ source. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the porous hierarchical spheres exhibit hollow structure and have a size distribution of 0.4-1 um consisting of aggregated similar to 50 nm nanoparticles. A mechanism of the reaction from Li3PO4 to LiMn0.5Fe0.5PO4 was proposed on the basis of the phase and morphology transformation of the intermediates. With the short Li+ diffusion path and porous structure, the carbon coated LiMn0.5Fe0.5PO4 spheres show high specific capacity and superior rate capability with the discharge capacities of 159.3 mA h g(-1) at 0.1C and 80.6 mA h g(-1) at 20C. The porous hierarchical spheres also exhibit an excellent cycling stability with about 90.7% of the initial value at 1C after 100 cycles. (C) 2015 Elsevier Ltd. All rights reserved.