Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one dicarbonate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl dicarbonate additive.
Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one nitrate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkali metal nitrate, alkaline earth metal nitrate and/or an organic alkyl nitrate additive.
Abstract: Disclosed are electrolyte solvents for ambient-temperature lithium-sulfur batteries. The disclosed solvents include at least one ethoxy repeating unit compound of the general formula R.sub.1 (CH.sub.2 CH.sub.2 O).sub.n R.sub.2, where n ranges between 2 and 10 and R.sub.1 and R.sub.2 are different or identical alkyl or alkoxy groups (including substituted alkyl or alkoxy groups). Alternatively, R.sub.1 and R.sub.2 may together with (CH.sub.2 CH.sub.2 O).sub.n form a closed ring. Examples of linear solvents include the glymes (CH.sub.3 O(CH.sub.2 CH.sub.2).sub.n CH.sub.3). Some electrolyte solvents include a donor or acceptor solvent in addition to an ethoxy compound as described.
Type:
Grant
Filed:
October 10, 1997
Date of Patent:
February 29, 2000
Assignee:
PolyPlus Battery Co., Inc.
Inventors:
May-Ying Chu, Lutgard C. De Jonghe, Steven J. Visco, Bruce D. Katz
Abstract: A primary lithium battery particularly adapted for use in self-contained self-powered devices (SSPD) for mobile communication and computing products, such as radio frequency identification tags, PCMCIA cards, and smart cards. The battery utilizes a solid polymer electrolyte membrane that preferably has a polyacrylonitrile matrix. Performance of the electrolyte membrane is optimized by controlling the amount of aprotic organic solvents within the membrane within a prescribed range of ratios. The battery cathode is encapsulated within a polymeric matrix that eliminates the exposure hazard posed by lithium intercalation compounds used within the cathode. Use of stainless steel foil current collectors gives a high open circuit voltage of 3.8 volts and high cell capacity. A method of determining the optimum cathode thickness in the battery is also described. This provides a means of maximizing volumetric and gravimetric energy densities by using the optimum amount of cathode material.
Type:
Grant
Filed:
August 20, 1997
Date of Patent:
February 29, 2000
Assignee:
International Business Machines Corporation
Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one organic sulfate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and a dialkyl sulfate additive.
Abstract: An organic electrolyte cell comprising an organic electrolyte and an anode and/or a cathode of a carbonaceous material of a heat-treated material of an aromatic condensation polymer having a specific surface area of at least 1,500 m.sup.2 /g measured by BET method, wherein a solvent in the electrolyte is a mixed solvent containing a chain-like carbonate of the formula R.sup.1 OC(.dbd.O)OR.sup.2 (wherein R.sup.1 and R.sup.2 are monovalent organic groups which may be the same or different) and sulfolane or its derivative.