Abstract:
The present invention is related to an electrochemical cell comprising an anode of a Group IA metal and a cathode of a composite material prepared from a combination of vanadium oxide and a mixture of nitric acid and at least one of a silver-containing constituent and a copper-containing constituent. The present cathode material is particularly useful for implantable medical applications.
Abstract:
Battery-powered implantable medical devices require a suitable method for indicating end-of-service of the power source so that there is ample time for elective replacement of the device and/or power source. The present invention utilizes mixed cathode materials preferably comprising a major portion of a fluorinated carbon and a minor portion of a metal-containing material. This mixed cathode formulation is characterized by two, discretely different operating voltages, the second of which may be used as an end-of-life indicator.
Abstract:
A cathode active material admixture comprising a metal, a metal oxide, a mixed metal oxide or a metal sulfide and fluorinated carbon, is described. A preferred admixture comprises copper-silver-vanadium oxide and CF.sub.x. Such a blended cathode active admixture is useful in a nonaqueous electrochemical cell discharged for extended periods under a light load interrupted by high rate pulse discharges, such as occurs in an implantable medical device.
Abstract:
An electrochemical cell including an alkali metal anode and a cathode, one of the anode or cathode being connected to a structure for making electrical connection from a load to the cell, the other of the anode or cathode having main and alternate portions, a main terminal connected to the main anode or cathode portion for making electrical connection between a load and the cell, and an alternate terminal connected to the alternate anode or cathode portion for making electrical connection between a load and the cell, so that the main anode or cathode portion first is discharged with the alternate portion held in reserve, whereupon when the main portion reaches end of life the alternate anode or cathode portion is discharged. The main and alternate anode or cathode portions are insulated from each other, and the anode preferably is of lithium. There is also provided a voltage responsive switch means in combination with the cell and connected electrically between a load and the main and alternate terminals for connecting the main terminal initially to the load and then disconnecting the main terminal and connecting the alternate terminal to the load when the main portion reaches end of life. The cell can be provided with a casing of electrically conductive material with one of the anode or cathode being connected to the casing for making electrical connection to the load through the casing.
Abstract:
A medical grasper device (10) that is useful for holding and manipulating a body organ is described. The grasper device is partially inserted into a body cavity and comprises a flexible strap (14) having a distal section (18) that is deployed from a tube (12) to form a partial closed loop (2). A terminal end of the strap has an aperture (42) that is manipulated by a separate forceps-type device to mate with a connection means (56) provided on the grasper device to complete the loop. The closed loop is then adjustable in size to provide for positioning the loop at a desired location around the target body organ to hold and manipulate the body organ. At such time as the grasper device is no longer needed in the surgical procedure, the strap is either removed from the connection means with the aforementioned forceps-type device or is cut by a separate cutting means to release the loop from the body organ and the grasper device is removed from the body cavity.
Abstract:
A new anode material known as "hairy carbon" for use in a secondary electrochemical cell, is described. The hairy carbon electrode material is developed by growing submicron carbon filaments on a carbon substrate. A catalyst is used to initiate hair growth with carbonaceous gases serving as the carbon source. The hairy carbon submicron filaments typically have diameters ranging between about 0.05 .mu.m and 0.2 .mu.m, and the electrode is formed by mixing the hairy carbon material with a suitable binder and pressing the admixture into a desired shape. Hairy carbon is particularly useful as an anode material in a rechargeable alkali metal electrochemical cell due to its excellent reversibility for the intercalation and deintercalation of alkali metal ions over extended discharge and recharge cycles.
Abstract:
A chemical pretreatment method for inserting lithium into cathode active material silver vanadium oxide to provide a reduced form of silver vanadium oxide which, when included into a cathode mixture and incorporated into an electrochemical cell, may result in a cell with a lowered initial open circuit voltage, thereby eliminating the need to lower unstably high initial cell voltages through external loads after cell construction.
Abstract:
An anode assembly for a lithium-halogen cell including halogen-containing cathode material, i.e. depolarizer, such as an iodine-organic complex wherein the anode comprises an electrical conductor sandwiched between a pair of lithium plates defining substantially oppositely directed lithium surfaces terminating in a peripheral lithium edge and characterized by a major portion of the length of the peripheral edge being exposed to the cathode material. This greatly increases the available internal volume of the cell for cathode material which, in turn, increases the theoretical ampere-hour rating of the cell. At least one and preferably both oppositely directed lithium surfaces have formations such as ribs or the equivalent which increases the surface area thereof, and the formations terminate a short distance from the edge to form a marginal type, peripheral border and highly effective seal therearound. The inner surfaces of the lithium plates can include co-operating formations near the peripheral edge shaped to expose new surfaces of the lithium plates to each other to form or enhance the bond therebetween. The anode assembly is formed using mold sections of a polyolefin material such as a high density polyethylene or equivalent material and having tapered recesses to provide effective separation of the anode from the mold without any need for parting sheets.
Abstract:
An electrochemical cell incorporating cathode materials comprising at least one metal oxide, at least one metal, or mixture of metals or metal oxides incorporated in the matrix of a host metal oxide. The cathode materials of this invention are constructed by the chemical addition, reaction, or otherwise intimate contact of various metal oxides and/or metal elements during thermal treatment in mixed states. The materials thereby produced contain metals and oxides of the groups IB, IIB, IIIB, IVB, VB, VIB, VIIB, and VIII, which includes the noble metals and/or their oxide compounds.The incorporation of the metal oxides, metals or mixtures thereof substantially increases the discharge capacity and the overall performance of the cathode materials.
Abstract:
A lithium-iodine cell comprising a casing of electrically conducting material, an anode including a lithium element within the casing, an electrical conductor operatively connected to the lithium element and extending out from the casing, and a cathode comprising iodine-containing material in operative contact with both the casing and the lithium element. The anode electrical conductor is completely sealed from the rest of the cell, and the casing serves as the cathode current collector. The anode operative surface is provided with a coating of an organic electron donor material. The anode is enclosed within an insulator element within the casing and a ferrule having one end within the insulator and the other end extending from the casing.