Abstract: Disclosed herein is an efficient and high capacity electrical energy storage device consisting of diaphragm-less anode and cathode cells charging and discharging an electrolyte containing suitable ions that store electrical energy during the charging cycle and release the electrical energy during the discharge cycle. The charge-discharge reactions are reversible so that the efficiency does not reduce with the number of cycles and efficiency is maintained until the last of the charged electrolyte passes through the cells.

Abstract: A redox flow battery including a positive electrode electrolyte and a negative electrode electrolyte, each of which includes a metal-ligand coordination complex, in which a metal of a metal-ligand coordination complex of the positive electrode electrolyte is different from a metal of a metal-ligand coordination complex of the negative electrode electrolyte. Due to use of different metals in the positive and negative electrode electrolytes, the redox flow battery has high energy density and high charge and discharge efficiency.

Abstract: Introducing multiple redox reactions with a suitable voltage range can improve the energy density of redox flow battery (RFB) systems. One example includes RFB systems utilizing multiple redox pairs in the positive half cell, the negative half cell, or in both. Such RFB systems can have a negative electrolyte, a positive electrolyte, and a membrane between the negative electrolyte and the positive electrolyte, in which at least two electrochemically active elements exist in the negative electrolyte, the positive electrolyte, or both.

Abstract: A redox flow battery having a supporting solution that includes Cl? anions is characterized by an anolyte having V2+ and V3+ in the supporting solution, a catholyte having Fe2+ and Fe3+ in the supporting solution, and a membrane separating the anolyte and the catholyte. The anolyte and catholyte can have V cations and Fe cations, respectively, or the anolyte and catholyte can each contain both V and Fe cations in a mixture. Furthermore, the supporting solution can contain a mixture of SO42? and Cl? anions.

Abstract: An organic electrolyte solution for use in a redox flow battery and the redox flow battery including the organic electrolyte solution has a high energy density because re-precipitation is prevented in the organic electrolyte solution or eduction is prevented in an electrode during reduction of a metal ion used as an electrolyte.

Abstract: Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

Abstract: An electrolyte for a flow cell battery is provided. The electrolyte includes a concentration of chromium ions that is greater than the concentration of iron ions.

Abstract: A method for preparing a redox flow battery electrolyte is provided. In some embodiments, the method includes the processing of raw materials containing sources of chromium ions and/or iron ions. The method further comprises the removal of impurities such as metal ions from those raw materials. In some embodiments, a reductant may be used to remove metal impurities from an aqueous electrolyte containing chromium ions and/or nickel ions. In some embodiments, the reductant is an amalgam. In some embodiments, the reductant is a zinc amalgam. Also provided is a method for removing ionic impurities from an aqueous acid solution. Further provided a redox flow battery comprising at least one electrolyte prepared from the above-identified methods.

Abstract: A solid anode composite material for use in thermal batteries that comprises about 65-85% by weight (about 34 to 40 atom percent) particulate iron, about 15-35% by weight (50 to 70 atom percent) lithium, and about 0.1-10% by weight (1.7 to 2.3 atom percent) aluminum. Lithium and Aluminum are only slightly or not alloyed with the particulate iron. The iron and/or the aluminum may be in the form of a powder. The aluminum may be in the form of lithium-aluminum alloy.

Abstract: Batteries including a lithium anode stabilized with a metal-lithium alloy and battery cells comprising such anodes are provided. In one embodiment, an electrochemical cell having an anode and a sulfur electrode including at least one of elemental sulfur, lithium sulfide, and a lithium polysulfide is provided. The anode includes a lithium core and a ternary alloy layer over the lithium core where the ternary alloy comprises lithium and two other metals. The ternary alloy layer is effective to increase cycle life and storageability of the electrochemical cell. In a more particular embodiment, the ternary alloy layer is comprised of lithium, copper and tin.

Abstract: A method suitable for detecting the onset of colloid formation within a solution whose composition is in a state of change, which method makes use of the technique of acoustophoresis and which comprises the step of either (I) applying an oscillating electric field to the solution and monitoring the amplitude of the resultant acoustic signal, the onset of colloid formation being detected by a change in the amplitude of the resultant acoustic signal, or (ii) applying an oscillating acoustic signal to the solution and monitoring the resultant oscillating electric field, the onset of colloid formation being detected by a change in the amplitude of the resultant oscillating electric field, or (iii) applying an oscillating electric field to the solution and monitoring the resultant oscillating electric field, the onset of colloid formation being detected by a change in the amplitude of the resultant oscillating electric field.

Abstract: An electric storage battery comprising an electrically neutral alkaline ionic conductor, an anode and a Fe(VI) salt cathode, and having new Fe(VI) salt cathode formulations. The high +6 valence state of the iron in said salt provides the advantage of a high storage capacity, high voltage, and an environmental advantage. The new formulations improve the lifetime of the salt during storage and during battery discharge. The anode may be any of a large variety of conventional anode materials capable of being oxidized.

Abstract: An alkaline gel electrolyte for an electrochemical cell is based on a polymeric binder of polyvinyl alcohol or polyvinyl acetate. Potassium hydroxide and/or sodium hydroxide is blended into the polymeric binder or matrix, and the resulting solution is used to cast a film that is useful as a gel electrolyte. The hydroxide in the solution is between about 1% to 25% by weight, and the polymer concentration is between about 0.5% to 10% by weight. The resulting gel electrolyte film contains between 10 to 90% water by weight. A nickel or iron porphine modifier may be added in an amount between about 1 to 1000 parts per million. The alkaline gel electrolyte is useful in combination with asymmetric inorganic electrodes to make electrochemical cells, and can also function as a separator. Improved power density and higher cycle life is achieved with the gel electrolyte.

Abstract: The premature capacity failure of Ni/NiCl.sub.2 secondary cells due to agglomeration of nickel particles on the surface of the NiCl.sub.2 cathode is prevented by addition of a minor amount, such as 10 percent by weight of a transition metal such as Co, Fe or Mn to the cathode. The chlorides of the transition metals have lower potentials than nickel chloride and chlorinate during charge. A uniform dispersion of the transition metals in the cathodes prevents agglomeration of nickel, maintains morphology of the electrode, maintains the electrochemical area of the electrode and thus maintains capacity of the electrode. The additives do not effect sintering. The addition of sulfur to the liquid catholyte is expected to further reduce agglomeration of nickel in the cathode.

Abstract: A novel battery cell is disclosed which is characterized by a metal-organosulfur positive electrode which has one or more metal-sulfur bonds wherein when the positive electrode is charged and discharged, the formal oxidation state of the metal is changed. The positive electrode has the general formula(M'.sup.z.spsp.+.sub.(c/z) [M.sub.q (RS.sub.y).sub.x.sup.c- ]).sub.nwhereinz=1 or 2; y=1 to 20; x=1 to 10; c=0 to 10; n.gtoreq.

Abstract: An electrochemical apparatus for energy storage and power generation comprises a single cell or an array of unit cells (10), each cell comprising a +.sup.ve electrode (12) and a -.sup.ve electrode (14) with a dual membrane in each cell dividing it into +.sup.ve chambers (22C and 24C) for posilyte and anolyte solutions (22, 24) which are recirculated through separate pumps (26, 28) and storage tanks (32, 34) and back to the chambers. The dual membranes in each cell provide a third chamber (23C) between the +.sup.ve chamber (22C) and the -.sup.ve chamber (24C), through which an idler electrolyte is circulated.During the operation of the cell, any ionic species which cross the cation exchange membranes, which in an ideal system would remain in either the +.sup.ve chamber or the -.sup.ve chamber of the cell, will collect in the buffer chamber or chambers.

Abstract: The invention provides a rebalance cell for a Cr/Fe redox storage system. The rebalance cell has a catalyst for the reduction of Fe.sup.3+ ions by means of hydrogen. The catalyst separates a gas chamber of the rebalance cell (holding hydrogen) and a liquid chamber of the rebalance cell (holding Fe.sup.3+ electrolyte). The catalyst is in the form of an activated charcoal made hydrophobic and coated with a platinum metal, gold or silver. The catalyst can also be in the form of tungsten carbide made hydrophobic.

Abstract: The combination of gold, thallium, lead and bismuth is used as a catalyst in a battery comprised of at least one "redox" cell to accelerate the oxidation of chromous ions to chromic ions and the reduction of chromic ions to chromous ions. The gold, thallium, lead and bismuth catalyst is coated on an electronically conductive, inert electrode which is in the anode fluid of the "redox" cell.

Abstract: A redox battery electrolyte is prepared from a chromium and/or iron base raw material containing nickel as impurities by dissolving the raw material in a hydrochloric acid-containing aqueous liquid to form a solution containing chromium ions and/or iron ions and nickel ions, the resulting solution being subjected to a cathodic reduction in the presence of lead ions until the electric potential thereof becomes lower than -0.6 V vs. saturated calomel electrode, thereby to remove the nickel ions therefrom.

Abstract: The invention provides a method of protecting an electrochemical cell which has a molten sodium anode, a chloride-ion containing sodium aluminum halide molten salt electrolyte, an iron-containing cathode in contact with the electrolyte and a solid conductor of sodium ions which separates the anode from the electrolyte, from the adverse effects of overcharging. The method comprises operating the cell, to prevent oxidation of iron to FeCl.sub.3 in the cathode, by connecting it in parallel with a protective cell having an open circuit charging plateau at a voltage less than the open circuit voltage of the Fe/FeCl.sub.3 //Na plateau of the cell being protected, and greater than the open circuit voltage, in its fully charged state, of the cell being protected. The invention also provides a cell of this type protected in this fashion, a battery including one or more such protected cells, and a cathode for such cells.

Abstract: For batteries containing strong oxidizing electrolyte and a membrane separating two electrolyte solutions, e.g., a zinc ferricyanide battery, an improved membrane is provided comprising an oxidative resistant, conductive, ion-selective membrane fabricated from a catenated aromatic polymer having an absence of tertiary hydrogens, e.g., a sulfonated polysulfone.

Abstract: A rebalance cell is provided for a REDOX electrochemical system of the type having anode and cathode fluids which are aqueous HCl solutions with two metal species in each. The rebalance cell has a cathode compartment and a chlorine compartment separated by an ion permeable membrane. By applying an electrical potential to the rebalance cell while circulating cathode fluid through the cathode compartment and while circulating an identical fluid through the chlorine compartment, any significant imbalance of the REDOX system is prevented.

Abstract: An electrode for an flowcell comprising electrode material made of carbon fiber having average <002> spacing of quasi-graphite crystalline structure of not more than 3.70 .ANG., and the average C-axis size of crystallite of not less than 9.0 .ANG. and at least 3 % by mole of oxygen atom bound to the fiber surface based on carbon atom, whereby the electrode has remarkable high electrical conductivity, current efficiency handling characteristics and hydrodynamic characteristics, and is adapted to flowcell.

Abstract: Zirconium carbide is used as a catalyst in a REDOX cell for the oxidation of chromous ions to chromic ions and for the reduction of chromic ions to chromous ions. The zirconium carbide is coated on an inert electronically conductive electrode which is present in the anode fluid of the cell.

Abstract: A fuel cell using hydrogen sulfide as the fuel therefor, wherein the electrolytic cell is divided by a diaphragm into a positive electrode chamber and a negative electrode chamber, which fuel cell is operated by feeding a redox solution as the negative electrolyte to the negative electrode chamber, withdrawing from the electrolytic cell the redox solution which has been oxidized by reaction with the negative electrode, removing from the negative electrode chamber the sulfur produced by contact with hydrogen sulfide, and circulating to the negative electrode chamber only the redox solution which has been reduced by contact with hydrogen sulfide.

Abstract: Electrical cells are provided including a plurality of hydrogen-oxygen fuel cells imbedded in a porous mass of iron-ferrous oxide, which can be present as porous particles. The fuel cells are formed of tubes including an inner anode wall, an outer cathode wall adjacent the particles and a solid electrolyte that permits oxygen ion transfer positioned between the cathode and anode. During cell charging, the particles are reduced and during cell discharging, the particles are oxidized.

Abstract: There is disclosed an electricity producing cell of the reduction-oxidation (REDOX) type divided into two compartments by a membrane, each compartment containing a solid inert electrode. A ferrous/ferric couple in a chloride solution serves as a cathode fluid which is circulated through one of the compartments to produce a positive electric potential disposed therein. A chromic/chromous couple in a chloride solution serves as an anode fluid which is circulated through the second compartment to produce a negative potential on an electrode disposed therein. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which has been added to the anode fluid.

Abstract: An electrically rechargeable battery comprising an inert cathode, a zinc anode and an aqueous alkaline electrolyte, for example, NaOH, in which said anode and cathode are immersed. The alkaline electrolyte in the vicinity of the cathode contains an alkali metal ferricyanide salt, such as K.sub.3 Fe(CN).sub.6 or Na.sub.3 Fe(CN).sub.6. Optionally, a mechanical separator is utilized between the anode and cathode to prevent gross mixing of the saturated electrolyte at the cathode with the electrolyte in the vicinity of the anode. Preferably, the separator is of the ion exchange type. During electrical discharge, at the anode and cathode, the battery produces soluble reaction products which are transported in the electrolyte to respective external storage tanks which increase battery capacity. During the charge cycle, the reverse conditions occur.

Abstract: Secondary batteries with aqueous acid solutions of lead salts as electrolytes and inert electrode base plates also contain redox systems in solution. These systems have a standard potential of from -0.1 to +1.4 V relative to a standard hydrogen reference electrode, do not form insoluble compounds with the electrolytes and are not oxidized or reduced irreversibly by the active compositions applied to the electrode base plates, within their range of operating potentials.

Abstract: Gels are formed from silica powders and hydrochloric acid. The gels can then be impregnated into a polymeric foam and the resultant sheet material can then be used in applications where the transport of chloride ions is desired. Specifically disclosed is the utilization of the sheet in electrically rechargable redox flow cells which find application in bulk power storage systems.

Abstract: The addition of cathode materials comprising Cu.sup.++, Fe.sup.+++, Cr.sup.+++ or Au.sup.+++, in the form of salts such as the nitrate or halide, e.g. Fe(NO.sub.3).sub.3 or CuCl.sub.2, to low melting nitrate electrolyte cells increases cell potential. Other ions such as Co.sup.++, Eu.sup.+++, La.sup.+++, Ni.sup.++, Mn.sup.++, Ce.sup.+++, Pr.sup.+++, Nd.sup.+++, Gd.sup.+++, Sm.sup.+++ and Tb.sup.+++, in the form of salts thereof, can also be used, but yield smaller cell potentials. Such cathodic materials in the form of a suitable salt, such as a nitrate or halide, e.g. Fe(NO.sub.3).sub.3 or CuCl.sub.2, are added to low melting fused nitrate electrolytes, e.g. a LiNO.sub.3, KNO.sub.3 mixture, in a concentration sufficient to increase cell potential, using Li or Ca anodes. A suitable metal current collector such as a Ni screen can be used as a cathode. The above cathodic materials can be used in conjunction with other cathodic materials such as AgNO.sub.3, which undergoes reduction to the free metal.