NOVELTY - Battery cell (1) comprises: a cathode (3) comprising copper coated in carbon; an anode (2) comprising aluminum coated in carbon; a separator (4) between the cathode and the anode; and an electrolyte (5) electrically connecting the anode and the cathode through the separator, where the electrolyte comprises a lactone.    USE - The battery cell is useful in a battery (claimed), which is useful in portable devices and rapid transit vehicle.    ADVANTAGE - The battery cell: has negligible memory effect and a cell discharge rate of not more than 10%, preferably not more than 2% per month; has negligible capacity degradation after 5000 cycles of discharge and an ultimate life cycle of 50000, preferably 100000 cycles i.e. loses not more than 5% of its capacity after 5000 cycles, preferably not more than 20% of its capacity after 100000 cycles; has an energy density of not less than 600 Watt-hours(Whrs)/l, preferably not less than 1000 Whrs/l; utilizes the materials that are cheaper than the cost of materials of a comparable lithium-ion cell of a similar capacity, hence economical; utilizes the electrolyte that prevents the parasitic reaction of water with aluminum to form hydrogen; and provides the battery having adequate life for continuous regenerative operation at high charge and discharge rates.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a battery comprising many battery cells; and    (2) making the battery cell, comprising providing a first electrode layer comprising copper coated in carbon, applying a first separator layer to both sides of the first electrode layer, applying a second electrode layer comprising aluminum coated in carbon to an outer surface of the separated layer, applying a second separator layer to the outer surface of the second electrode layer, placing the layers into a pouch, introducing a controlled volume of electrolyte into the pouch and sealing the pouch.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the battery cell.    Battery cell (1)    Anode (2)    Cathode (3)    Separator (4)    Electrolyte (5)