New high capacity cathode material with improved operating voltage
AssigneeGreatbatch Ltd.
InventorsMarcus J. Palazzo, Ashish Shah
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Abstract
The present invention relates to an electrochemical cell comprising an anode of a Group IA metal and a cathode of a composite material prepared from an aqueous mixture of iron sulfate, nickel sulfate, and sulfur. The cathode material of the present invention provides for a lithium electrochemical cell having an increased operating voltage and power performance with high discharge capacity as compared to a lithium cell comprising nickel disulfide cathode material. In addition, the cathode material of the present invention exhibits a smaller initial irreversible voltage loss as compared to iron disulfide. This makes the cathode material of the present invention particularly useful for implantable medical applications.
Claims32
An electrochemical cell, comprising:
- a) an anode of a Group IA metal which is electrochemically oxidizable to form metal ions in the cell upon discharge to generate an electron flow in an external electrical circuit electrically connected to the cell;
- b) a cathode of electrically conductive material, wherein the cathode comprises a metal matrix material comprising a first metal salt comprising iron, a second metal salt comprising nickel, and sulfur;
- and
- c) an ionically conductive electrolyte solution activating the anode and the cathode.
An electrochemical cell having an anode comprising lithium electrochemically oxidizable to form metal ions in the cell upon discharge to generate an electron flow in an external electrical circuit electrically connected to the cell, a cathode of electronically conductive material, and an ionically conductive electrolyte solution activating the anode and the cathode, the cathode comprising a metal matrix material characterized as a reaction product of iron sulfate, nickel sulfate, and sulfur, wherein the metal matrix material has a stoichiometric formulation consisting of either Fe0.015Ni0.85S2 or Fe0.25Ni0.75S2.
A cathode for an electrochemical cell, the cathode comprising a metal matrix material characterized as a reaction product formed by either a hydrothermal decomposition reaction or a hydrothermal addition reaction of an aqueous mixture of a first metal salt comprising iron, a second metal salt comprising nickel, and sulfur, the metal matrix material having a general formula FexNi1-xS2 wherein x≧0.10.
A method of making a cathode for an electrochemical cell, the cathode comprising a metal matrix material, which method comprises:
- a) combining a first metal salt comprising iron, a second metal salt comprising nickel, and a sulfate to provide a metal salt matrix admixture;
- b) reacting the metal salt matrix admixture to provide the metal matrix material having the general formula FexNi1-xS2 wherein x≧0.10;
- and
- c) forming the metal oxide matrix material into a cathode.
Dependencies are inferred from the claim text.