Abstract: from Groups 2, 3, 12, 13, or 14 of the Periodic Table. Preferred embodiments include those having where c=1, those where c=2, and those where c=3. Preferred embodiments include those where a ≦1 and c=1, those where a=2 and c=1, and those where a≧3 and c=3. This invention also provides electrodes comprising an electrode active material of this invention, and batteries that comprise a first electrode having an electrode active material of this invention; a second electrode having a compatible active material; and an electrolyte.

Abstract: Sodium ion batteries are based on sodium based active materials selected among compounds of the general formula:

Abstract: Stabilized lithiated manganese oxide (LMO) is prepared by reacting cubic spinel lithium manganese oxide particles and particles of an alkali metal compound in air for a time and at a temperature sufficient to decompose at least a portion of the alkali metal compound, providing a treated lithium manganese oxide. The reaction product is characterized as particles having a core or bulk structure of cubic spinel lithium manganese oxide and a surface region which is enriched in Mn+4 relative to the bulk. X-ray diffraction data and x-ray photoelectron spectroscopy data are consistent with the structure of the stabilized LMO being a central bulk of cubic spinel lithium manganese oxide with a surface layer or region comprising A2MnO3, where A is an alkali metal. Electrochemical cells containing the stabilized LMO of the invention have improved charging and discharging characteristics and maintain integrity over a prolonged life cycle.

Abstract: The invention provides novel lithium-mixed metal materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-mixed metal materials. Methods for making the novel lithium-mixed metal materials and methods for using such lithium-mixed metal materials in electrochemical cells are also provided. The lithium-mixed metal materials comprise lithium and at least one other metal besides lithium. Preferred materials are lithium-mixed metal phosphates which contain lithium and two other metals besides lithium.

Abstract: In one embodiment, the invention provides a novel active material which is a lithium-rich, manganese oxide active material in the form of a single phase tetragonal crystal structured Li.sub.2 Mn.sub.2 O.sub.4 compound having lattice parameters a=b=5.665 .ANG..+-.0.003 .ANG., and c=9.265 .ANG..+-.0.003 .ANG.. A unique characteristic of the compound is that when lithium ions are deintercalated (extracted) from the Li.sub.2 Mn.sub.2 O.sub.4 at first and second voltage plateaus, the crystal structure is transformed to a cubic structure characterized by lattice parameters a=b=c=8.235 .ANG..+-.0.004 .ANG.. On subsequent charge and discharge of the battery, corresponding to subsequent extraction and reinsertion of lithium into the electrode material at the second voltage plateau, the cubic structure is maintained.

Abstract: The invention provides an electrochemical cell which is at least partially charged and which comprises a first electrode having an active material in particle form consisting essentially of at least partially lithiated graphite. The lithiated graphite particles are prepared by chemically or electrochemically inserting lithium ions into the particles prior to assembly of the cell. A second electrode which is a counter electrode to the first electrode has an active material consisting essentially of vanadium oxide.