Electrochemical systems with electronically and ionically conductive layers have electronic, mechanical and chemical properties useful for a variety of applications including electrochemical storage and conversion. Electronically and ionically conductive layers may be introduced between an electrode and the separator. Embodiments provide structural, physical and electrostatic attributes useful for managing and controlling dendrite formation and for improving the cycle life and rate capability of electrochemical cells including silicon anode based batteries, air cathode based batteries, redox flow batteries, solid electrolyte based systems, fuel cells, flow batteries and semisolid batteries and may include multilayer, porous geometries supporting excellent ion transport properties, providing a barrier to prevent dendrite initiated mechanical failure, shorting or thermal runaway, or providing improved electrode conductivity and improved electric field uniformity. An electronically and ionically conductive layer may provide electronic conductivity greater than or equal to 1 S/cm and ionic resistance less than or equal to 10 Ωcm2.