I-003

Diana Golodnitsky

golod@tauex.tau.ac.il

Elazar Cohen, David Stark, Olga Kondrova-Guchok, Pini Shekhter

School of Chemistry, Tel Aviv University, Israel

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

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. Our experiments showed that better homogeneity and smaller size aggregates were obtained during square-wave AC-EPD method than in traditional DC-EPD due to the lower number of defects caused by suppressed gas bubble evolution. In traditional electrophoretic deposition of low-electrical-conductivity materials from polar solvent suspension, the deposit resistance increases with deposit thickness. This results in the self-limiting effect, which is less pronounced at AC-EPD and is reflected in the linear increase of deposit mass over the deposition time.

40kHz was found to be an optimal frequency, which enables improved rearrangement of the LTO particles with higher by about 2% carbon content and its more homogeneous distribution between LTO entities. Specific capacity of the LTO/Li cells is 160 mAh/g LTO, close to the theoretical value, and the power capability of 40kHz-EPD LTO electrode outperforms its counterparts