Nanocrystalline mesoporous LiFePO4 thin-films as cathodes for Li-ion microbatteries

Mesoporous LiFePO4 thin films prepared using a facile and low-cost synthesis approach have been studied as electrodes for Li-ion batteries. LiFePO4 mesoporous films (similar to 300 nm) were synthesized by a template-directed sol-gel chemistry coupled with the dip-coating approach, followed by heat-treatment under a reducing atmosphere (10% H-2/N-2) at temperatures ranging from 400 to 760 degrees C. These mesostructured LiFePO4 films are constituted of a connected network of mesopores (similar to 60 nm) and an assembly of crystalline nanoparticles (similar to 50 nm) in the pore wall. In addition, the presence of carbon, evidenced by Raman spectroscopy, provides efficient electron pathways along the 3-D nanoarchitectures. Cycling performance was evaluated for optimal nanocrystalline LiFePO4 thin films showing an excellent high rate performance after 1000 cycles (158 mA h g(-1)). These data provide important information on new types of porous architectures for the design of efficient electrodes for micro-batteries.