Patent ID: 8440350

Claim:
A lithium-ion electrochemical cell comprising a negative electrode comprising a current collector carrying a negative electrode active material; a positive electrode comprising a current collector carrying a positive electrode active material; a liquid electrolyte containing lithium ions, the liquid electrolyte contacting both electrode materials and providing transport of lithium ions between the negative electrode active material and positive electrode active material; and a separator preventing electrical contact between the positive and negative electrodes while providing transport of lithium ions between the electrode materials; the negative electrode active material and positive electrode active material being formed of different compositions with each electrode active material composition being subject to lithiation and de-lithiation during discharge and charge cycling of the electrochemical cell; at least one of the negative electrode and positive electrode further comprising: a metallic current collector sheet having opposing sheet surfaces and being formed of a metal composition that is not subject to lithiation, or volume change due to lithiation, in the cycling of the electrochemical cell; electrode active material formed on at least one of the current collector sheet surfaces; the electrode active material being formed as nanosized bodies that extend outwardly from the sheet surface a distance of at least one micrometer, with each body being in electrical contact with the current collector sheet and having a cross-sectional thickness less than five hundred nanometers, the bodies of electrode active material experiencing repeated volume changes during lithiation and de-lithiation of cell cycling; and a body of an elastic shape memory alloy formed against at least one portion of each body of the electrode active material.