Crystal alignment of a LiFePO cathode material for lithium ion batteries using its magnetic properties.

We suggest a way to control the crystal orientation of LiFePO using a magnetic field to obtain an advantageous structure for lithium ion conduction. We examined the magnetic properties of LiFePO such as magnetism and magnetic susceptibility, which are closely related to the crystal rotation in an external magnetic field, and considered how to use these properties for desired crystal orientation; thus, we successfully fabricated the crystal-aligned LiFePO, in which the -axis was highly aligned perpendicular to the surface of a current collector. Considering the low lithium ion conductivity of LiFePO inherently originated from its one-dimensional path for lithium ion diffusion, the crystal-aligned LiFePO potentially facilitates favorable transport kinetics for lithium ions during the charge/discharge process in lithium ion batteries. The crystal-aligned LiFePO should afford lower electrode polarization than pristine LiFePO, and thus the former consistently exhibited higher reversible capacity than the latter.