摘要:
An electrical capacitor is described which comprises a housing, a pair of electrodes in said housing, one of said electrodes being composed of a mixture of carbon particles and an electrolyte and the other electrode being composed of a mixture of lead metal and the same electrolyte, and an ionically conductive separator means between and in contact with said pair of electrodes, electronically separating said electrodes from each other, wherein the electrolyte comprises an acidic solution of soluble sulfate salts.
摘要:
A novel high cycle life, low cost hybrid redox flow battery that has application in the storage of energy generated by solar cells, windmills and other means is described. By combining a solid battery positive electrode with a redox flow negative electrode, the volumetric energy density of the system is maximized and footprint minimized for medium scaled installations of multi kilowatt-hour size as may be envisioned in domestic distributed power systems. The positive electrode is a high cycle life rechargeable nickel hydroxide electrode in alkaline solution. The negative active material is a low cost organic chemical such as a substituted anthroquinone dissolved in an alkaline electrolyte and stored external to the negative plate of the electrochemical device. The material of the negative plate is high surface area and capable of facilitating the oxidation and reduction reactions of the negative active material. The negative and positive electrodes are separated by an electronically insulating but ionically conducting separator material that allows ionic mobility and the generation of electric current when charging or discharging of the battery takes place. Ideally, an ion exchange membrane would separate the positive and negative active material in order to maximize service life and reduce intermingling of active material.
摘要:
The nickel hydroxide particles for a nickel hydroxide electrode may be treated using an alkaline solution of a strong oxidizing agent such as sodium or potassium persulfate to modify the surface nickel hydroxide structure. The resulting modified surface structure has been found to impart various benefits to electrodes formed from the nickel hydroxide. It is believed that the oxidation of cobalt compounds at the surface of the nickel hydroxide particles results in a highly conductive cobalt compound that plays an important role in the high reliability, high stability and high capacity utilization of nickel electrodes as described herein.
摘要:
Active material for a positive electrode of a rechargeable alkaline electrochemical cell is made with nickel hydroxide particles or cobalt-coated nickel hydroxide particles treated with strongly oxidizing reagents such as alkali metal persulfate in alkaline solution. The active material also may be made with cobalt-coated nickel hydroxide particles having a high percentage of cobalt(III) on a surface or an average cobalt oxidation state of about 3 measured across the particles. The treated nickel hydroxide or cobalt-coated nickel hydroxide decreases the cobalt solubility in the alkaline electrolyte and increases the high-rate charge and discharge capability. The lower cobalt solubility decreases cobalt migration that can increase self discharge and lead to premature failure.
摘要:
An improved Ni—Zn cell with a negative electrode substrate plated with tin or tin and zinc during manufacturing has a reduced gassing rate. The copper or brass substrate is electrolytic cleaned, activated, electroplated with a matte surface to a defined thickness range, pasted with zinc oxide electrochemically active material, and baked. The defined plating thickness range of 40-80 μIn maximizes formation of an intermetallic compound Cu3Sn that helps to suppress the copper diffusion from under plating layer to the surface and eliminates formation of an intermetallic compound Cu6Sn5 during baking to provide adequate corrosion resistance during battery operation.
摘要:
Rechargeable nickel zinc cells, and methods of manufacture, of a configuration that utilizes a positive can with a vent cap at the positive pole of the battery are described.
摘要:
A nickel-zinc galvanic cell is provided, having a zinc oxide negative electrode, a nickel oxide positive electrode, and an alkaline electrolyte. Chemical additives are placed in each of the negative and positive electrodes. The positive nickel hydroxide electrode contains a mixture of cobalt oxide contained within a nickel oxide matrix in the range of about 1% to 10%, and cobalt metal in the range of about 1% to 10%, by weight. The negative zinc oxide electrode may contain oxides other than the oxide of zinc, which have redox potentials which are negative of −0.73 volts. Also, the metal oxide additives to the negative zinc oxide electrode are such as to inhibit release of soluble cobalt from the nickel oxide negative electrode prior to a formation charge being applied to the electrochemical cell.
摘要:
A nickel zinc alkaline cell has a zinc oxide negative electrode supported on a conductive substrate, an alkaline electrolyte, and a positive electrode having nickel hydroxide paste supported on a conductive substrate. The negative zinc oxide electrode comprises 85% to 95% zinc oxide powder, 1% to 10% bismuth oxide, 1% to 2% of a binder, and 0.05% to 5% by weight of a fluoride salt chosen from the group consisting of: sodium, potassium, rubidium, caesium, lithium, and mixtures thereof. Typically, the fluoride salt is potassium fluoride, in the amount of 0.5% by weight of the zinc oxide.
摘要:
Methods of manufacturing a rechargeable power cell are described. Methods include providing a slurry, paste, or dry mixture of negative electrode materials having low toxicity and including dispersants to prevent the agglomeration of particles that may adversely affect the performance of power cells. The methods utilize semi-permeable sheets to separate the electrodes and minimize formation of dendrites; and further provide electrode specific electrolyte to achieve efficient electrochemistry and to further discourage dendritic growth in the cell. The negative electrode materials may be comprised of zinc and zinc compounds. Zinc and zinc compounds are notably less toxic than the cadmium used in nickel cadmium batteries. The described methods may utilize some production techniques employed in existing NiCad production lines. Thus, the methods described will find particular use in an already well-defined and mature manufacturing base.
摘要:
A zinc electrode for use in alkaline batteries comprises a mixture of 0.425 to 1.55 volume parts of zinc oxide with a volume part of a metallic oxide chosen from the group consisting of: calcium oxide, barium oxide, and mixtures thereof, together with hydroxy-ethyl cellulose, an oxide dispersant chosen from the group consisting of: soap derivatives, anionic polyelectrolytes, anionic surfactants, and mixtures thereof, and a binder. The electrode is prepared by mixing zinc oxide with the chosen metallic oxide in an aqueous medium such as water or potassium hydroxide, stirring overnight, filtering and drying the mixture, optionally adding a further small amount of zinc oxide, optionally adding other metallic oxides, and adding hydroxy-ethyl cellulose, an oxide dispersant, and a binder. The aqueous paste os slurry thus formed is placed on a conductive substrate, drawn through a sizing gap, cut and dried, to form low cost pasted zinc oxide electrodes.