battery cell the coated cathode particles are combined with binder and electronically conductive particles such as carbon to form a porous cathode layer a separator layer such as celgard u00ae is positioned onto the cathode layer and an anode layer such as graphite silicon lithium titanate or lithium metal is placed over the separator to form a stack the stack is placed into a sealed container and liquid electrolyte is added to form a cell fig3 is a cross sectional schematic drawing of an electrochemical cell 300 with a positive electrode 310 whose active material particles 320 include a protective polymer layer which includes both an ionically conductive polymer and an electronically conductive polymer and optionally an intervening layer as described above according to an embodiment of the invention the positive electrode 310 may also contains small electronically conductive particles not shown such as carbon black and binder particles not shown there is a current collector 340 adjacent to and in electronic communication with the positive electrode 310 there is a negative electrode 360 that can be a metal such as lithium or some other material that can absorb and release li ions such as graphite silicon or tin there may also be a negative electrode current collector.