NOVELTY - An electrochemical energy storage device comprises stacked of electrodes arranged in electrode plate pairs, each pair comprising positive and negative electrodes separated by matrix of electrolyte; positive bus bar interconnecting positive electrodes; and negative bus bar interconnecting negative electrodes. At charging and discharging rates between 0.5-2degreesC, the bus bars (201, 202) contact the corresponding electrode to provide uniform current density between each corresponding contacted electrodes and to maintain a relative orientation of the bus bar and electrodes constant over time.    USE - As large capacity electrochemical cell for hybrid vehicles, e.g. hybrid locomotives used in yard and/or road switching service.    ADVANTAGE - The bus bar(s) contact a length of the electrode edge to provide proper inter-electrode spacing, uniform current density between each corresponding contacted electrodes, efficient internal heat dissipation and desired electrode structural rigidity. The device reduces the base electrochemical, electrical, thermal and mechanical conditions that lead to premature capacity loss; and has improved lifetime under partial state-of-charge operation, enhanced dissipation of internally generated heat and improved stability to shock and vibration loads.    DETAILED DESCRIPTION - An electrochemical energy storage device comprises stacked of electrodes arranged in electrode plate pairs, positive bus bar interconnecting positive electrodes, and negative bush bar interconnecting negative electrodes. Each electrode pair comprises positive and negative electrodes separated by a separator matrix of electrolyte. At charging and discharging rates between 0.5-2degreesC, the following conditions are met: the bus bar(s) contact the corresponding electrode to provide uniform current density between each corresponding contacted electrodes and to maintain a relative orientation of the bus bar and electrodes constant over time; a length of bus bar edge contacts the electrode pairs to remove thermal energy generated by the flow of electricity; a constant electrical potential gradient exists normal to bus bars and across any grid structure of the surface of the electrodes; a constant electrical potential exists between opposing points on the bus bars and between any opposing points on the electrode pair; and a constant electrochemical reaction exists at any point in an enclosed volume of the device. An INDEPENDENT CLAIM is included for a method for manufacturing an electrochemical energy storage device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the large capacity cell showing typical current flow path.    Bus bars (201, 202)    Bus bar segment (203)    Flow of current (204)