NOVELTY - Lithium-ion electrochemical cell comprises negative and positive electrodes each having current collector carrying active material (300); a liquid electrolyte containing lithium ions; and a separator that prevents electrical contact between electrodes while providing transport of lithium ions between the electrode materials. The electrode active material is formed of different compositions, where each electrode active material composition is subjected to lithiation and de-lithiation during discharge and charge cycling of the electrochemical cell.    USE - As lithium-ion battery for powering electric and hybrid electric vehicles e.g. electric motors in automotive vehicles.    ADVANTAGE - The cell pertains to the formation of such shapes of electrode materials, anchored in elastic shape memory alloy substrate, to enable longer and more effective cycling of such electrode materials. The active electrode material permits good contact with liquid lithium-ion containing electrolyte that infiltrates the closely-spaced thin shapes, thus the stresses arising from volume changes in the long shapes with lithiation and de-lithiation of the active material is mitigated by strategic placement of shape memory apply forms between attachment surfaces of the active electrode material and other members of the electrode assembly.    DETAILED DESCRIPTION - Lithium-ion electrochemical cell comprises negative and positive electrodes each having current collector carrying electrode active material; liquid electrolyte containing lithium ions; and separator preventing electrical contact between electrodes while providing transport of lithium ions between the electrode materials; where the negative and positive electrode active material are formed of different compositions, where each electrode active material composition is subjected to lithiation and de-lithiation during discharge and charge cycling of electrochemical cell. At least one of the negative and positive electrode further comprises 1) metallic current collector sheet having opposing sheet surfaces and is formed of metal composition that is not subjected to lithiation, or volume change due to lithiation, in the cycling of the electrochemical cell; 2) electrode active material formed on at least one of current collector sheet surfaces and 3) body of an elastic shape memory alloy formed against at least one portion of each body of electrode active material. The electrode active material is formed as nano-sized bodies that extend outwardly from the sheet surface at a distance of at least one micrometer, with each body being in electrical contact with the current collector sheet and having cross-sectional thickness less than five hundred nanometers, where the bodies of electrode active material experience repeated volume changes during lithiation and de-lithiation of cell cycling.    DESCRIPTION OF DRAWING(S) - The figures show schematic cross- sectional diagram of forming nanowires of negative electrode material on copper current collector.    Current collector material (300)    Upper surface current collector material (302)    Aluminum layer (303)