Layered Cathode for Improving Safety of Li-Ion Batteries

To improve the safety performance of Li-ion batteries using LiCoO 2 cathodes without sacrificing battery capacity, a new electrode concept using a multilayered cathode as an alternative to a mixture of different kinds of powder is introduced. Results from a double-layered cathode consisting of a LiCoO 2 main layer with a LiFePO 4 sublayer on top of an aluminum current collector are presented. The mechanism of how the LiFePO 4 layer improves the tolerance of the batteries against overcharging is discussed.