  Wearable electronic devices and gadgets raise the need for flexible, thin and
lightweight batteries. In this article we present for the first time, a unique,
single-step method for the preparation of a membrane-electrode assembly for
flexible-batteries application. Concurrent electrophoretic deposition (EPD) of
positive and negative battery electrodes (LFP and LTO) on opposite sides of a
commercial nanoporous membrane (Celgard 2325) results in the formation of a
three-layer-battery structure. The cell comprising this electrophoretically
deposited structure ran for more than 150 cycles with 125-140mAh/g capacity,
which approaches the theoretical value of lithium iron phosphate. The
electrodes can be deposited either cathodically or anodically by replacing the
interchangeable charging agents, like polyethyleneimine and polyacrylic acid.
These polyelectrolytes, when adsorbed on the particles of the active material,
serve also as the binders. The simultaneous EPD, which we developed, can be
used for the simple and low-cost manufacturing of a variety of cathode and
anode materials on nanoporous polymer- and ceramic ion-conducting membranes for
energy storage devices.
