NOVELTY - Lithium-ion cell comprises positive and negative electrodes with lithium-reaction active electrode material, and array of discrete reference electrodes carried on substrate for determining state of charge of positive/negative electrode material; where electrodes and array of reference electrodes are connected with electrolyte; reference electrode array having first and second composition; and are grouped for determining electrochemical potential of positive and negative electrode material and each reference electrode is separately connectable with positive and negative electrode material.    USE - As rechargeable lithium-ion battery for use in automotive applications to provide energy for electric motors to drive vehicle wheels.    ADVANTAGE - The reference electrodes in lithium-ion cell monitors state of charge and state of life of battery containing the cell; and help manage discharge and re-charge of the cell; maintains a constant lithium-reaction potential while the electrochemical potentials of the positive and negative electrodes change as they furnish the transfer of ionic charge inside of the cell that is matched with the transfer of electric charge through an external circuit that does useful work like powering a motor to drive the wheels of a passenger vehicle.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for measuring state of charge of positive or negative electrode in lithium-ion cell when cell is used in discharge or charge mode, involving during such use connecting first reference electrode with positive or negative electrodes of cell and measuring electrochemical potential between first reference electrode and positive or negative electrodes; separately connecting second reference electrode with one of the electrodes and measuring electrochemical potential for comparison with first measured potential; and repeating such separate measurements with succession and/or combination of reference electrodes to establish credible potential value for positive or negative electrode.    DESCRIPTION OF DRAWING(S) - The figure shows diagram of positional relationship and electrical connection relationships of reference electrode with respect to positive and negative electrode in electrochemical cell.