| 摘要 |
A process of making a lithium cell with a positive electrode that comprises a niobium chalcogenide (e.g., NbSe3) active material. The process comprises forming the active material by a procedure that comprises forming a layer of Nb powder on an inert substrate (e.g., an alumina plate), and reacting the powder with selenium or sulfur vapor such that the desired (fibrous) chalcogenide is formed. The powder layer typically is formed by depositing (e.g., by spraying) a layer of slurry on the substrate, with the slurry comprising a liquid such as propylene glycol and Nb powder, and removing the liquid from the deposited slurry. The resulting layer of Nb powder can be of uniform thickness, advantageously is less than 0.1 mm thick, and adheres relatively well to the substrate. In preferred embodiments reacting the Nb powder with Se vapor comprises a two-stage heat treatment, the first stage comprising maintaining the powder in contact with Se vapor for at least four hours at a temperature in the range 520-625 DEG C, and the second stage for at least two hours at a temperature in the range 625-780 DEG C. |
