Microstructure and electrochemical properties of graphite and C-coated LiFePO4 films fabricated by aerosol deposition method for Li ion battery

Abstract

The aerosol deposition (AD) method is the room temperature process for the formation of thin/thick film. Graphite (for anode, thickness: 250nm) and C-coated LiFePO4 (C-LFP, for cathode, thickness: 1μm) AD films were deposited at room temperature without an annealing process. Nano-size grains were observed at their microstructures and especially a graphite AD film showed the nano-flake microstructure. The AD films showed not only the dense microstructure but also the space for electrolyte. The high capacities (a graphite AD film: 22μAhcm−2 at 1μAcm−2, a C-LFP AD film: 24μAhcm−2 at 50μAcm−2) were obtained at half cells and their rate capabilities were also excellent. Through the full cell test (the anode: a graphite AD film, the cathode: a C-LFP AD film), it was confirmed that the AD films could work well for the electrodes in Li ion battery. In addition, the high capacity (150μAhcm−2 at 5μAcm−2) was observed at the AD thick film of a C-LFP-based composite (thickness: 6μm). The AD thick film of a C-LFP-based composite is fabricated at room temperature without the use of N-Methyl-2-Pyrrolidone (NMP) which is a toxic material.