摘要 |
The present invention includes improved cathode means for reversibly storing charge at a positive potential relative to a Hg/HgO reference for use in a rechargeable cell utilizing an aqueous electrolyte. The cathode means include an active material having a reversibly oxidizable cation species which releases electrons through successive oxidation reactions during charging. One embodiment provides means for releasing more than one electron per molecule of the active material to achieve a full state of charge. Another embodiment provides means for decreasing the operating potential of the reactions oxidizing the active material for a given state of charge. The active material includes a reversibly oxidizable cation species and an electropositive metal element selected from a group consisting of lithium, sodium, potassium, magnesium, and calcium. The electropositive metal element is intercalated in the active material. These intercalated active materials are used to fabricate electrodes, cells, and batteries. Methods of preparing the intercalated active material and using a cathode including the active material are contemplated. |