Method for making an electrochemical cell

• US 5,455,123 A
• Filed: 02/14/1994
• Issued: 10/03/1995
• Est. Priority Date: 02/14/1994
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Michels, Daniel D., Helgeson, William D., Schmidt, Craig L., Heller, Bernard F.
• Primary Examiner(s): Kalafut, Stephen
• Assistant Examiner(s): LILLEY, RICHARD
• Application Number:
  US08/195,957
• Time in Patent Office: 596 Days
• Field of Search: 429/199, 429/48, 429/191, 429/213, 429/52
• US Class Current: 429/52
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for making a primary cell comprising a lithium anode and an iodine containing cathode. The cell is first subjected to a preliminary conditioning at a predetermined time/temperature to effect a reduction in the impedance of the cell followed by cell discharge of at least 2 mAh per cm² of the lithium anode surface prior to use or extended storage of the cell. The resulting primary cell has reduced variation in cell voltage and resistance and slower and more consistent self-discharge characteristics.

Claims

1. A method for making an electrochemical cell having a lithium anode and an iodine cathode comprising the steps of:

(a) conditioning the cell at a temperature of at least 30°

C. for a period of time which is effective to produce a reduction in cell impedance; and

(b) subjecting the conditioned cell to discharge until the amount of such discharge reaches at least 2 mAh per cm² of the lithium anode surface,

the conditioning and discharge steps carried out as separate steps prior to placing the cell into service or storage.

2. A method according to claim 1 wherein the cell is conditioned to reduce impedance at least 15%.

3. A method according to claim 2 wherein the cell is conditioned to reduce impedance in the range of about 50-80%.

4. A method according to claim 1 wherein the cell is conditioned at a temperature in the range of about 45°

-75°

C.

5. A method according to claim 1 wherein the cell is conditioned at a temperature of about 75°

C. for one to four hours.