The invention relates to an article comprising: a) one or more stacks of battery plates comprising one or more bipolar plates: b) located between each plate is a separator and a liquid electrolyte; further comprising one of more of the features: 1) c) the one or more stacks of battery plates having a plurality of channels passing transversely though the portion of the plates having the cathode and/or the anode deposited thereon; and d) i) one or more seals about the periphery of the channels which prevent the leakage of the liquid elelctrolyte into the channels, and/ or posts located in one or more of the channels having on each end an overlapping portion that covers the channel and sealing surface on the outside of the monopolar plates adjacent to the holes for the transverse channels and applies pressure on the sealing surface of the monopolar plates wherein the pressure is sufficient to withstand pressures created during assembly and operation of electrochemical cells created by the stacks of battery plates; 2) c) a membrane comprising a thermoplastic polymer is disposed about the entire periphery of the edges of the stack of plates; 3) wherein the separator is in the form of a sheet having adhered to its periphery a frame; and 4) c) an integrated valve and integrated channel communicating with the valve.