| 摘要 |
A rechargeable current-generating cell is disclosed, composed of (a) an anode made of lithium or its alloys; (b) a non-aqueous electrolyte solution with a solid electrolyte or a molten electrolyte; and (c) a cathode of a vanadium-substituted alkali thiochromite having the general formula NayCrl-xVxS2, wherein x lies between 0.05 and 0.3 and y is 1 for the stoichiometric compound and from 0.1 to 0.4 for the non-stoichiometric one. The non-stoichiometric compound is obtained from the stoichiometric compound, by electrochemical oxidation thereof, either in the cell, after its assembly, or in a non-aqueous electrolyte solution in a separate vessel, prior to assembly of the cell. The non-stoichiometric compound can also be obtained by chemical oxidation of the stoichiometric one in a nonaqueous solution of iodine. The vanadium-substituted alkali thiochromite displays a substantially higher specific conductivity than the pure sodium thiochromite, whereby cathodes prepared with the new, substituted species can be discharged at higher current densities without reduction of energy density. Moreover, the open circuit voltage of the substituted species cathode is higher, resulting in a greater gravimetric energy density. |
