Abstract: A method for generating electrical energy includes providing an electrical energy generating element. The electrical energy generating element includes a first porous electrode, an eggshell membrane, and a second porous electrode stacked on each other in that order. The electrical energy generating element has a first side and a second side opposite to the first side. A liquid having positive ions and negative ions is allowed to penetrate the electrical energy generating element from the first side to the second side.

Abstract: An all solid battery includes: a solid electrolyte layer; a first electrode layer that is formed on a first main face of the solid electrolyte layer; a first electric collector layer that is formed on a face of the first electrode layer, the face being opposite to the first main face; a second electrode layer that is formed on a second main face of the solid electrolyte layer; and a second electric collector layer that is formed on a face of the second electrolyte layer, the face being opposite to the second main face, wherein at least one of the first electric collector layer and the second electric collector layer includes Pd and board-shaped graphite carbon, wherein a volume ratio of Pd and the board-shaped graphite carbon in the at least one of the first electric collector layer and the second electric collector layer is 20:80 to 80:20.

Abstract: Provided is a capacitive deionization apparatus and a method for manufacturing the same, which capacitive deionization apparatus is enhanced in the removal efficiency for ionic substances and the fluid throughput, hence applicable to water with high salt concentration such as sea water, etc., and easy to manufacture.

Abstract: A rubber valve body for sealed battery includes a rubber composition containing a resin in an amount of 20% by mass or more and an inorganic substance, wherein the melting point of the resin is in a range of 100 to 165° C.

Abstract: A method for making tungsten-alloy nanoparticles that are useful for fuel cell applications includes a step of combining a solvent system and a surfactant to form a first mixture. A tungsten precursor is introduced into the first mixture to form a tungsten precursor suspension. The tungsten precursor suspension is heated to form tungsten nanoparticles. The tungsten nanoparticles are combined with carbon particles to form carbon-nanoparticle composite particles. The carbon-nanoparticle composite particles are combined with a metal salt to form carbon-nanoparticle composite particles with adhered metal salt, the metal salt including a metal other than tungsten. The third solvent system is then removed. A two-stage heat treatment is applied to the carbon-nanoparticle composite particles with adhered metal salt to form carbon supported tungsten-alloy nanoparticles. A method for making carbon supported tungsten alloys by reducing a tungsten salt and a metal salt is also provided.

Abstract: Provided is a stacked structure for a fuel cell in which the plurality of fuel cells are stacked. Each of the fuel cells includes an electrolyte layer, and a cathode layer and an anode layer disposed on both surfaces of the electrolyte layer. The stacked structure includes at least one interconnector, at least one frame, and at least one complex functional part. The interconnector includes a central area electrically connected to the fuel cell, and edge area outwardly extending with respect to end portions of the fuel cell. The frame supports a side portion of the fuel cell to reinforce strength of the fuel cell supported by the interconnector. The complex functional part is disposed between the interconnector and the frame to constantly maintain an interval therebetween.

Abstract: A fuel cell system and a method for controlling the fuel cell system are provided. The method includes detecting an output characteristic value of the fuel cell system and controlling the fuel cell system to respectively operate in at least two of a first mode, a second mode and a third mode at different time points according to the detected output characteristic value. Accordingly, the fuel cell system is capable of stably generating electric power, and is adapted to different operation environments.

Abstract: Provided are a three electrode type microbial fuel cell and a method of operating the same. The fuel cell includes a sediment electrode acting as an anode and placed in sediment on the bottom of a contaminated water zone, an intermediate electrode acting as an anode or a cathode and placed in water, and an floating electrode acting as a cathode and placed adjacent to a water surface. In the three electrode type microbial fuel cell, the intermediate electrode may be used as an anode or a cathode according to the concentration of organic contaminants in water of the contaminated water zone, so that the fuel cell can continue to generate electricity in any case where the organic contaminants are present in or removed from the water.

Abstract: Improved metal-based redox flow batteries (RFBs) can utilize a metal and a divalent cation of the metal (M2+) as an active redox couple for a first electrode and electrolyte, respectively, in a first half-cell. For example, the metal can be Zn. The RFBs can also utilize a second electrolyte having I?, anions of Ix (for x?3), or both in an aqueous solution, wherein the I? and the anions of Ix (for x?3) compose an active redox couple in a second half-cell.

Abstract: The present invention relates to a reversible electrochemical cell, such as an electrolysis cell for water splitting or for conversion of carbon dioxide and water into fuel. The present invention relates also to an electrochemical cell that when operated in reverse performs as a fuel cell. The electrochemical cell comprises gas5 diffusion electrodes and a porous layer made of materials and having a structure adapted to allow for a temperature range of operation between 100-374° C. and in a pressure range between 3-200 bars.

Abstract: An electrochemical flow type battery may include at least one electrode and a separator. The electrode may include carbon fibers and/or carbon particles, and has an internal surface area density of at least 1 m2/g. The separator may separate an anode side and a cathode side of the battery. A flat surface of the electrode directly contacts a surface of the separator.

Abstract: An apparatus for harvesting energy from fresh water and salt water, including a first porous electrode having first pores, a second porous electrode having second pores, a non-conducting permeable separator between the first porous electrode and the second porous electrode, a system for applying an electric potential difference between the first porous electrode, and the second porous electrode, and a system for flowing the fresh water and the salt water through the first porous electrode having first pores, through the non-conducting permeable separator, and through the second porous electrode having second pores thereby harvesting energy from the fresh water and the salt water.

Abstract: A redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, wherein the polyoxometallate is represented by the formula: Xa[ZbMcOd] Wherein X is selected from hydrogen, alkali metals, alkaline earth metals, ammonium and combinations of two or more thereof; Z is selected from B, P, S, As, Si, Ge, Ni, Rh, Sn, Al, Cu, I, Br, F, Fe, Co, Cr, Zn, H2, Te, Mn and Se and combinations of two or more thereof; M comprises W and optionally one or more of

Abstract: Membrane, cell and device suitable for reverse electrodialysis for the purpose of generating electricity, and methods therefor, the membrane comprising a number of channels arranged on at least a first side of the membrane, wherein the channels are suitable for throughfeed of a fluid, wherein the dimensions of the channels are aimed at obtaining a laminar flow of the fluid in the channels.

Abstract: An apparatus comprises: an anode formed of graphene oxide from an acidic pH; a cathode from a pH greater than the acidic pH of the anode; and charge collectors deposited on the anode and the cathode.

Abstract: The invention relates to the use of 1-alkyl-2-alkyl pyridinium halide (e.g., 1-ethyl-2-methyl pyridinium bromide), 1-alkyl-3-alkyl pyridinium halide (e.g., 1-ethyl-3-methyl pyridinium bromide) or 1-alkyl-3-alkyl imidazolium halide (e.g., 1-butyl 3-methyl imidazolium bromide) as additives in an electrolyte used in hydrogen/bromine cells, for complexing the elemental bromine formed in such cells. The invention also provides an electrolyte comprising aqueous hydrogen bromide and said additives, and processes for operating an electrochemical flow cell selected from the group consisting of hydrogen/bromine or vanadium/bromine cells.

Abstract: An aqueous electrolyte battery is provided with a positive electrode, a negative electrolyte, an aqueous electrolyte, and a deposition portion that promotes deposition of discharge product and that is provided at a location that contacts the aqueous electrolyte and that is a location other than at a catalyst included in the positive electrode.

Abstract: An electrolyte solution for a lithium-air battery contains an ionic liquid that has a cation in which ether groups are incorporated in parallel.

Abstract: Systems and methods for the storage of energy that can be easily converted to electrical power are disclosed. A concentration battery includes a stack of alternating cation and anion exchange membranes separated from one another by alternating first and second spaces; a first reservoir containing a concentrated ionic solution; a second reservoir containing a dilute ionic solution; multiple spaced first fluid pathways in fluid communication with the first reservoir and configured to flow concentrated ionic solution flows into the first spaces; and multiple spaced second fluid pathways in fluid communication with the second reservoir and configured to flow dilute ionic solution flows into the second spaces. The fluid pathways may be configured to flow the ionic solutions in a common first direction. Electrodes at either end of the device in fluid communication with the concentrated ionic solution permit electrical energy to be applied or extracted. A related method is included.

Abstract: Provided is an electrolyte equipped with a hydrophilic portion having a cyclic quaternary ammonium salt and a hydrophobic portion bonded to the hydrophilic portion; and a fuel cell, a Li secondary battery, secondary battery and a primary battery using the electrolyte. The electrolyte has preferably a structure represented by the formula (A) or (B), wherein P? represents a hydrophobic portion, R1 and R2 each represents hydrogen, fluorine, a hydroxy group, or a hydrocarbon or fluorinated hydrocarbon group having from 1 to 10 carbon atoms, R3 and R4 each represents a hydrocarbon, fluorinated hydrocarbon, or a fluorocarbon group having from 1 to 10 carbon atoms, r and s each represents an integer of 0 or greater but not greater than 8 and satisfies 1?r+s?8, u represents an integer and satisfies 2?u?9, and X? represents a counter anion.

Abstract: Redox flow battery systems having a supporting solution that contains Cl? ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO42? and Cl? ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V2+ and V3+ in a supporting solution and a catholyte having V4+ and V5+ in a supporting solution. The supporting solution can contain Cl? ions or a mixture of SO42? and Cl? ions.

Abstract: Redox flow battery systems having a supporting solution that contains Cl? ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO42? and Cl? ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V2+ and V3+ in a supporting solution and a catholyte having V4+ and V5+ in a supporting solution. The supporting solution can contain Cl? ions or a mixture of SO42? and Cl? ions.

Abstract: The invention provides a fuel cell comprising an anode in an anode region of the cell and a cathode in a cathode region of the cell, the anode being separated from the cathode by an ion selective polymer electrolyte membrane, the anode region of the cell being supplied in use thereof with an alcoholic fuel, the cathode region of the cell being supplied in use thereof with an oxidant, the cell being provided with means for generating an electrical circuit between the anode and the cathode and with a non-volatile redox couple in solution in flowing fluid communication with the cathode in the cathode region of the cell, the redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the redox couple and/or the concentration of the redox couple in the catholyte solution being selected so that the current density generated by the cell in operation is substantially unaffected by the cross

Abstract: The invention concerns flow batteries comprising: a first aqueous electrolyte comprising a first redox active material; a second aqueous electrolyte comprising a second redox active material; a first electrode in contact with the first aqueous electrolyte; a second electrode in contact with the second aqueous electrolyte and a separator disposed between the first aqueous electrolyte and the second aqueous electrolyte; the flow battery having an open circuit potential of at least 1.4 V, and is capable of operating or is operating at a current density at least about 50 mA/cm2, wherein both of the first and second redox active materials remain soluble in both the charged and discharged states. In certain embodiments, the redox active materials are metal ligand coordination compounds. The disclosure also describes systems comprising these flow batteries and methods of them.

Abstract: This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and ionomer membranes, wherein the charge of the redox active materials is of the same sign as that of the ionomer, so as to confer specific improvements.

Abstract: Stable solutions comprising high concentrations of charged coordination complexes, including iron hexacyanides are described, as are methods of preparing and using same in chemical energy storage systems, including flow battery systems. The use of these compositions allows energy storage densities at levels unavailable by other iron hexacyanide systems.

Abstract: This invention is directed to aqueous redox flow batteries comprising redox-active metal ligand coordination compounds. The compounds and configurations described herein enable flow batteries with performance and cost parameters that represent a significant improvement over that previous known in the art.

Abstract: This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and separators, wherein the separator is about 100 microns or less and the flow battery is capable of (a) operating with a current efficiency of at least 85% with a current density of at least about 100 mA/cm2; (b) operating with a round trip voltage efficiency of at least 60% with a current density of at least about 100 mA/cm2; and/or (c) giving rise to diffusion rates through the separator for the first active material, the second active material, or both, of about 1×10?7 mol/cm2-sec or less.

Abstract: The invention concerns flow batteries comprising: a first half-cell comprising: (i) a first aqueous electrolyte comprising a first redox active material; and a first carbon electrode in contact with the first aqueous electrolyte; (ii) a second half-cell comprising: a second aqueous electrolyte comprising a second redox active material; and a second carbon electrode in contact with the second aqueous electrolyte; and (iii) a separator disposed between the first half-cell and the second half-cell; the first half-cell having a half-cell potential equal to or more negative than about ?0.3 V with respect to a reversible hydrogen electrode; and the first aqueous electrolyte having a pH in a range of from about 8 to about 13, wherein the flow battery is capable of operating or is operating at a current density at least about 25 mA/cm2.

Abstract: A fuel cell system that includes a control system for regulating the power produced by the fuel cell system. The fuel cell system includes a fuel cell stack adapted to produce electrical power from a feed. In some embodiments, the fuel cell system includes a fuel processing assembly adapted to produce the feed for the fuel cell stack from one or more feedstocks. The control system regulates the power produced by the fuel cell system to prevent damage to, and/or failure of, the system.

Abstract: The present invention uses the principles of electrochemical ion absorption (charging) and ion desorption (discharge), and relates to a continuous flow-electrode system, a high-capacity energy storage system, and a water treatment method using the same, in which high-capacity electric energy is stored as electrode materials of a slurry phase and electrolytes simultaneously flow in a successive manner within a fine flow channel structure formed on an electrode. More specifically, the present invention relates to a continuous flow-electrode system, an energy storage system, and a water treatment method, wherein electrode active materials consecutively flow in a slurry state whereby a high capacity is easily obtained without enlarging or stacking electrodes.

Abstract: An electrochemical cell includes a fuel electrode configured to operate as an anode to oxidize a fuel when connected to a load. An electrode holder includes a cavity for holding the fuel electrode, at least one inlet connected to the cavity on one side of the cavity and configured to supply an ionically conductive medium to the cavity, and at least one outlet connected to the cavity on an opposite side of the cavity and configured to allow the ionically conductive medium to flow out of the cavity. A plurality of spacers extend across the fuel electrode and the cavity in a spaced relation from each other to define a plurality of flow lanes in the cavity.

Abstract: Provided are lithium sulfur battery cells that use water as an electrolyte solvent. In various embodiments the water solvent enhances one or more of the following cell attributes: energy density, power density and cycle life. Significant cost reduction can also be realized by using an aqueous electrolyte in combination with a sulfur cathode. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage.

Abstract: A device or system for operating one or more electrochemical cells, such as a rechargeable fuel cell, is provided. A plurality of subsystems include a humidity level control subsystem, a reagent gas delivery subsystem, and a gas scrubbing subsystem. A method for operating the device or system is also provided.

Abstract: The present invention relates to a hydrogen generation apparatus using chemical hydride. The present invention features an electrolyte including chemical hydride and a catalyst that is inserted between metal electrodes, wherein the hydrogen is generated in a unit cell by hydrolysis of the hydride.

Abstract: The invention concerns the use as a redox a catalyst and/or mediator in a fuel cell catholyte solution of the compound of Formula (I) wherein: X is selected from hydrogen and from various functional groups; R1-8 are independently selected from hydrogen and various functional groups; wherein R1 and X and/or R5 and X may together form an optionally substituted ring structure; wherein R1 and R2 and/or R2 and R3 and/or R3 and R4 and/or R4 and R8 and/or R8 and R7 and/or R7 and R6 and/or R6 and R5 may together form an optionally substituted ring structure; wherein (L) indicates the optional presence of a linking bond or group between the two neighbouring aromatic rings of the structure, and when present may form an optionally substituted ring structure with one or both of R4 and R8; and wherein at least one substituent group of the structure is a charge-modifying substituent.

Abstract: An electrochemical method for providing hydrogen using ammonia, ethanol, or combinations thereof, comprising: forming an anode comprising a layered electrocatalyst, the layered electrocatalyst comprising at least one active metal layer deposited on a carbon support; providing a cathode comprising a conductor; disposing a basic electrolyte between the anode and the cathode; disposing a fuel within the basic electrolyte; and applying a current to the anode causing the oxidation of the fuel, forming hydrogen at the cathode.

Abstract: The present invention provides a fluoropolymer electrolyte material which has improved processability and which is easily produced. The electrolyte emulsion of the present invention comprises an aqueous medium and a fluoropolymer electrolyte dispersed in the aqueous medium. The fluoropolymer electrolyte has a monomer unit having an SO3Z group (Z is an alkali metal, an alkaline-earth metal, hydrogen, or NR1R2R3R4, and R1, R2, R3, and R4 each are individually a C1-C3 alkyl group or hydrogen). The fluoropolymer electrolyte has an equivalent weight (EW) of 250 or more and 700 or less and a proton conductivity at 110° C. and relative humidity 50% RH of 0.10 S/cm or higher. The fluoropolymer electrolyte is a spherical particulate substance having an average particle size of 10 to 500 nm. The fluoropolymer electrolyte has a ratio (the number of SO2F groups)/(the number of SO3Z groups) of 0 to 0.01.

Abstract: A fuel cell capable of operating under a high temperature environment and under a low humidity environment and a method for generating an electric power with use of the fuel cell. The fuel cell comprises an electrolyte membrane, an anode electrode, and an cathode electrode. In each of the anode electrode and the cathode electrode, a catalyst is held on a catalyst support, and an electrolyte covers the catalyst and the catalyst support. The cathode electrolyte is composed of SnO2, NH3, H2O, and H3PO4. A molar ratio X represented by X?NH3/SnO2 is not less than 0.2 and not more than 5, and a molar ratio Y represented by Y?P/Sn is not less than 1.6 and not more than 3.

Abstract: Steam, partial oxidation and pyrolytic fuel reformers (14 or 90) with rotating cylindrical surfaces (18, 24 or 92, 96) that generate Taylor Vortex Flows (28 or 98) and Circular Couette Flows (58, 99) for extracting hydrogen from hydrocarbon fuels such as methane (CH4), methanol (CH3OH), ethanol (C2H5OH), propane (C3H8), butane (C4H10), octane (C8H18), kerosene (C12H26) and gasoline and hydrogen-containing fuels such as ammonia (NH3) and sodium borohydride (NaBH4) are disclosed.

Abstract: A gated electrode structure for altering a potential and electric field in an electrolyte near at least one working electrode is disclosed. The gated electrode structure may comprise a gate electrode biased appropriately with respect to a working electrode. Applying an appropriate static or dynamic (time varying) gate potential relative to the working electrode modifies the electric potential and field in an interfacial region between the working electrode and the electrolyte, and increases electron emission to and from states in the electrolyte, thereby facilitating an electrochemical, electrolytic or electrosynthetic reaction and reducing electrode overvoltage/overpotential.

Abstract: A liquid electrolyte composed of a base A and phosphoric acid B in a molar ratio A:B in a range of 1:3 to 1:50 having a solidification temperature of lower than ?30° C.; and a composite electrolyte membrane comprising a porous body impregnated with such a liquid electrolyte.

Abstract: A battery cell is described that has an anode made of an alkali metal or alkali metal alloy, an alkali metal conductive membrane, and a cathode compartment that houses a hydrogen evolving cathode and a catholyte. The catholyte has dissolved salt comprising cations of the alkali metal. The battery also includes a zone where hydrogen may vent from the catholyte and a zone where water may transport into the catholyte. The zone where water may transport into the catholyte restricts the transport of ions. The battery may be operated (1) in freshwater where there is low ion-conductivity and (2) in seawater where there is a quantity of cations (such as sodium ions) that are incompatible with the alkali metal conductive membrane. The battery is designed such that the alkali metal conductive membrane is protected from cations that operate to foul the alkali metal conductive membrane.

Abstract: Provided is an electrolyte equipped with a hydrophilic portion having a cyclic quaternary ammonium salt and a hydrophobic portion bonded to the hydrophilic portion; and a fuel cell, a Li secondary battery, secondary battery and a primary battery using the electrolyte. The electrolyte has preferably a structure represented by the formula (A) or (B), wherein P? represents a hydrophobic portion, R1 and R2 each represents hydrogen, fluorine, a hydroxy group, or a hydrocarbon or fluorinated hydrocarbon group having from 1 to 10 carbon atoms, R3 and R4 each represents a hydrocarbon, fluorinated hydrocarbon, or a fluorocarbon group having from 1 to 10 carbon atoms, r and s each represents an integer of 0 or greater but not greater than 8 and satisfies 1?r+s?8, u represents an integer and satisfies 2?u?9, and X? represents a counter anion.

Abstract: Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.

Abstract: A metal halogen electrochemical energy cell system that generates an electrical potential. One embodiment of the system includes at least one cell including at least one positive electrode and at least one negative electrode, at least one electrolyte, a mixing venturi that mixes the electrolyte with a halogen reactant, and a circulation pump that conveys the electrolyte mixed with the halogen reactant through the positive electrode and across the metal electrode. Preferably, the positive electrode comprises porous carbonaceous material, the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. Also, variations of the system and a method of operation for the systems.

Abstract: A fluid handling device with an anisotropic wetting surface including a substrate with a multiplicity of asymmetric substantially uniformly shaped asperities thereon. Each asperity has a first asperity rise angle and a second asperity rise angle relative to the substrate. The asperities are structured to present a desired retentive force ratio (f1/f2) greater or less than unity caused by asymmetry between the first asperity rise angle and the second asperity rise angle according to the formula: f3/f2=sin(?3+½??0)/sin(?2+½??0).

Abstract: An electrolyte membrane assembly for use in a fuel cell or other electrochemical device includes an ion exchange membrane, a base electrolyte reservoir configured and operable to maintain a volume of a basic electrolyte solution in contact with at least some of the first face of the membrane, and an acid electrolyte reservoir configured and operable to maintain a volume of an acidic electrolyte in contact with at least a portion of the second face of the membrane. The membrane may be a cation exchange membrane or an anion exchange membrane. Also disclosed are fuel cells which incorporate the electrolyte membrane assembly.

Abstract: A fuel cell with which in the case where an enzyme is immobilized to at least one of a cathode and an anode, sufficient buffer ability is able to be obtained even at the time of high output operation, ability inherent in the enzyme is able to be sufficiently demonstrated, and which has superior performance is provided. In a bio-fuel cell which has a structure in which a cathode and an anode are opposed to each other with an electrolyte layer containing a buffer substance in between, and in which an enzyme is immobilized to at least one of the cathode and the anode, a compound containing an imidazole ring is contained in the electrolyte layer as a buffer substance, and one or more acids selected from the group consisting of acetic acid, phosphoric acid, and sulfuric acid are further added.

Abstract: An object of the present invention is to provide a fuel cell that operates in a temperature range of not lower than 100° C., and a method for manufacturing such a fuel cell. The fuel cell of the present invention has a proton conductive gel, an anode electrode, and a cathode electrode, the proton conductor being sandwiched between the anode electrode and the cathode electrode, in which the proton conductive gel is composed of SnO2, NH3, H2O, and H3PO4, and provided that the molar ratio represented by NH3/SnO2 is X, and the molar ratio represented by P/Sn is Y, X is not less than 0.2 and not greater than 5, and Y is not less than 1.6 and not greater than 3.