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US 6,783,888 B2Granted
Control of cell swelling by the proper choice of carbon monofluoride (CFx) cathode materials in high rate defibrillator cells
AssigneeWilson Greatbatch Ltd.
InventorsHong Gan, Sally Ann Smesko, Esther S. Takeuchi, Steven M. Davis
Life of this patent
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Abstract
The minimization or elimination of swelling in lithium cells containing CFx as part of the cathode electrode and discharged under high rate applications is described. When CFx materials are synthesized from fibrous carbonaceous materials, in comparison to petroleum coke, cell swelling is greatly reduced, and in some cases eliminated. Preferred precursors are carbon fibers and MCMB.
Claims31
An electrochemical cell, which comprises:
- a) an anode;
- b) a cathode of a first fluorinated carbon of a first energy density and a first rate capability and a second cathode active material of a second energy density and a second rate capability, wherein the first energy density of the first fluorinated carbon is greater than the second energy density while the first rate capability is less than the second rate capability of the second cathode active material;
- c) a cathode current collector comprising spaced apart major sides with the first fluorinated carbon positioned proximate one of the major sides and the second cathode active material proximate the other major side;
- and
- d) an electrolyte comprising at least one solvent for activating the anode and the cathode, wherein the fluorinated carbon is characterized as having been synthesized from a fibrous carbonaceous material having sufficient spacing between graphite layers to substantially restrict expansion due to solvent co-intercalation.
2 more elements
An electrochemical cell, which comprises:
- a) a lithium anode;
- b) a cathode of a first cathode active material of CFx sandwiched between a first and second current collectors with a second cathode active material selected from the group consisting of SVO, CSVO, V2O5, MnO2, LiCoO2, LiNiO2, LiMnO2, CuO2, TiS, Cu2S, FeS, FeS2, CVO, and mixtures thereof, contacting the first and second current collectors opposite the first cathode active material;
- and
- c) an electrolyte comprising at least one solvent for activating the anode and the cathode, wherein the fluorinated carbon is characterized as having been synthesized from a fibrous carbonaceous material having sufficient spacing between graphite layers to substantially restrict expansion due to solvent co-intercalation.
1 more element
A method for powering an implantable medical device, comprising the steps of:
- a) providing the medical device;
- b) providing an electrochemical cell comprising the steps of:
- i) providing an anode of an alkali metal;
- ii) providing a cathode of CFx as a first cathode active material of a first energy density and a first rate capability sandwiched between first and second current collectors with a second cathode active material of a second energy density and a second rate capability, wherein the first energy density of the CFx is greater than the second energy density while the first rate capability is less than the second rate capability of the second cathode active material;
- and
- iii) activating the anode and cathode with an electrolyte comprising at least one solvent, wherein the fluorinated carbon is characterized as having been synthesized from a fibrous carbonaceous material having sufficient spacing between graphite layers to substantially restrict expansion due to solvent co-intercalation;
- and
- c) electrically connecting the electrochemical cell to the medical device.
5 more elements
Dependencies are inferred from the claim text.