Method for making a composite cathode active material/current collector product

A method for making a composite cathode active material/current collector product which comprises the following steps:

• (a) heating a transition metal wire having a minimum diameter of 0.1 cm under a vacuum of about 1.times.10.sup.-6 torr and then contacting the wire with an approximately stoichiometric amount of a vapor of a chalcogen or of a vapor of a hydrogen chalcogenide at a temperature of from about 500.degree. C. to about 1000.degree. C. and at a vapor pressure of from about 0.3 atmosphere to about 3 atmospheres for from about 4 hours to about 63 hours;
• (b) removing any unreacted vapor;
• (c) cooling the wire to room temperature;
• (d) packing the wire with excess chalcogen and providing a vacuum of about 1.times.10.sup.-6 torr around the packed wire;
• (e) raising the temperature of the packed wire at a rate of about 10.degree.-25.degree. C. per minute to a temperature of from about 450.degree. C. to about 1000.degree. C. and holding said temperature for from about 8 hours to about 48 hours;
• and
• (f) cooling the wire to room temperature under its own thermal inertia;
• whereby there is formed a wire having a conductive interior portion of a transition metal capable of serving as a current collector and having an exterior portion of an intercalatable layered transition metal chalcogenide extending inwardly toward the interior portion over a distance of from about 10% to about 45% of the wire diameter capable of serving as a cathode active material.