Rebalancing of lithium/silver vandium oxide (Li/SVO) cells for improved performance

• US 5,458,997 A
• Filed: 08/19/1994
• Issued: 10/17/1995
• Est. Priority Date: 08/19/1994
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Crespi, Ann M., Skarstad, Paul M.
• Primary Examiner(s): Kalafut, Stephen
• Assistant Examiner(s): CHANEY, CAROL DIANE
• Application Number:
  US08/293,354
• Time in Patent Office: 424 Days
• Field of Search: 429/219, 429/60
• US Class Current: 429/219
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 6/10 with wound or folded electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

An electrochemical cell using a lithium anode and a silver vanadium oxide cathode is provided in which the cell is anode limited. Preferably, only enough lithium and electrolyte are provided in an Li/SVO cell to allow it to discharge only to the start of the second voltage plateau of its discharge curve. This provides a cell with improved performance in implantable defibrillator applications.

Claims

1. A Li/SVO battery comprised of an anode, a cathode, and an electrolyte in relative amounts wherein the battery is anode limited such that the battery discharge is substantially completed as the open circuit battery voltage drops to about 2.6 volts.

3. The Li/SVO battery of claim 1 wherein the quantity of the electrolyte is provided only in the amount needed for the electrochemical reaction involving the cathode.

2. A Li/SVO battery having a ##EQU1## of about 0.45-0.70;

and a ##EQU2## of about <

1 cm³ /Ah

4. In an implantable cardiac defibrillator, said defibrillator including a capacitor capable of providing an intense shock for terminating a tachyrhythmia in a patient and a battery which charges the capacitor upon detection of the tachyrhythmia by providing a pulse of energy to the capacitor, the improvement which comprises:

an anode limited Li/SVO battery charging the capacitor.

5. A cardiac defibrillator according to claim 4 wherein the Li/SVO battery is comprised of components in predetermined relative limited amounts whereby discharge is substantially completed as the open circuit battery voltage drops to about 2.6 volts.

6. A cardiac defibrillator according to claim 4 wherein the Li/SVO battery has a ##EQU3## of about 0.45-0.70;

and a ##EQU4## of about <

1 cm³ /Ah.

7. A cardiac defibrillator according to claim 4 wherein the Li/SVO battery is limited in electrolyte so as to provide only the electrolyte amount needed for the electrochemical reaction involving the cathode.