Directly Applied Separator in Lithium Ion Battery Manufacturing

Physical Sciences, Inc. (PSI) proposes a new process to apply the separator layer as a coating directly to the surface of battery electrodes. The directly applied (DA) separator method will simplify the traditional process of “stacking,” in which separator films are woven through stacks of battery electrodes.  The DA method will improve manufacturing speeds and reduce the cost of lithium ion batteries in the DLA supply chain. The DA separator will also mitigate safety risks associated with traditional stacking and improve cell performance. The separator layer is deposited on the surface of the electrode via electrophoretic assembly (EPA); a rapid, low-cost manufacturing process in which charged particles suspended in a solution assemble onto a substrate under an electric field.  EPA can readily be inserted into the back end of the electrode coating/calendaring line. In Phase I of the program, feasibility of the DA method will be demonstrated in multi-Ah cells, designed to meet the requirements of batteries currently purchased by DLA. The results of the Phase I studies will guide scale up efforts and the transition to roll-to-roll production in Phase II. PSI will demonstrate roll-to-roll production of the DA separator-electrode supporting production of cells for multiple DLA applications.