Study of square-wave AC electrophoretic deposition of lithium titanate anodes for Li-ion batteries

Abstract

Electrophoretic deposition (EPD), while being a scientifically interesting technique due to its inherent versatility, has only limited success in industrial applications. This is partly due to the need to employ expensive and potentially hazardous organic solvents in traditional suspensions. Recently, a significant effort has been focused on the use of aqueous systems and AC-EPD approaches. In this article we present a study and characterization of square-wave electrophoretic deposition at different frequencies of the lithium titanate water-based suspension for application in lithium-ion batteries. We have found that the mass of the deposit linearly increases with time. This reveals that depletion zones are less prone to form in an alternating field, hence enabling formation of homogeneous films and diminishing a growth in bath resistance as compared to DC mode. The EPD performed at critical frequency of 40kHz results in higher content of carbon co-deposited with LTO, improved capacity and power capability and of Li/LTO cells.