Abstract: A bicyclophosphate-modified ionic liquid compound, the synthesis thereof, an electrochemical electrolyte containing a bicyclophosphate-modified ionic liquid compound, and energy storage device containing the electrolyte are disclosed.

Abstract: A lithium secondary battery is disclosed herein. In some embodiments, a lithium secondary battery including a positive electrode including a lithium-nickel-cobalt-manganese-based oxide as a positive electrode active material, a negative electrode including a carbon-based negative electrode active material, a separator interposed between the negative electrode and the positive electrode, and a non-aqueous electrolyte solution containing a lithium salt, an organic solvent, and an additive. The organic solvent includes fluoroethylene carbonate in amount of 10 wt % or greater and ethylene carbonate in an amount of 20 wt % or less, based on the total weight of the organic solvent. The additive includes propene sultone and lithium fluoromalonato (difluoro) borate. The driving voltage of the lithium secondary battery is 4.35 V or greater.

Abstract: An electrolytic solution for an electrochemical device including a magnesium electrode as a negative electrode is provided. The electrolytic solution includes a linear ether solvent. The linear ether solvent includes a first magnesium salt having a disilazide structure represented by a general formula (R3Si)2N where R represents a hydrocarbon radical with one or more and ten or less carbon atoms and a second magnesium salt without the disilazide structure.

Abstract: Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. Electrolytes have been formulated that provide for extended cycling of cells incorporating a mixture of a silicon-oxide based active material with graphite active material in negative electrodes that can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to cells with unprecedented cycling properties for large capacity cell based on a silicon negative electrode active material.

Abstract: An electrolyte solution containing a compound (1) represented by the formula (1), (wherein R101 and R102 are each individually a substituent such as a C1-C7 alkyl group, and the substituent optionally contains at least one divalent to hexavalent hetero atom in a structure or optionally has a structure obtained by replacing at least one hydrogen atom by a fluorine atom or a C0-C7 functional group) and at least one compound (11) selected from compounds such as a compound represented by formula (11-1) (wherein R111 and R112 are the same as or different from each other and are each a hydrogen atom or the like, and R113 is an alkyl group free from a fluorine atom or the like):

Abstract: An electrochemical device including a negative electrode made of a magnesium-based material includes an electrolyte solution consisting of a solvent composed of linear ether, and magnesium salt dissolved in the solvent, in which the magnesium salt is dissolved in 3 moles or more per liter of the solvent.

Abstract: Fluorinated ionic liquids have been prepared to be used as catholytes in lithium battery cells. Such ionic liquids are immiscible with polyethylene-oxide-based solid polymer electrolytes, which may be used as separators in such cells. Such catholytes can increase the lifetime and boost the performance of lithium battery cells.

Abstract: Improved oxygen reduction reaction catalysts include octahedral nanoparticles of a platinum-copper-nickel alloy contacted by a secondary ionomer. The alloy can have a formula of Pt2CuNi, and the secondary ionomer can include an ionic liquid, 1-methyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,2-a]pyrimidin-9-ium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate ([MTBD][C4F9SO3]). The oxygen reductions catalysts have improved stability, as well as mass area and specific area comparted to competing catalysts.

Abstract: The invention is directed in a first aspect to electrolyte salt of the general formula Li+Z?, wherein Z? has the following chemical formula: wherein R1 is an alkyl group (R?) containing at least one and up to twelve carbon atoms, and R2 and R3 are independently selected from fluorine atom, hydrocarbon groups R, alkoxy groups (—OR), and ester groups —OC(O)R, wherein R2 and R3 can optionally interconnect via R functionalities to form a boron-containing ring. The invention is also directed to electrolyte compositions in which the above electrolyte salt is incorporated. The invention is further directed to lithium-ion batteries containing these electrolytes.

Abstract: Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.

Abstract: The purpose of the present invention is to provide a nonaqueous electrolyte that contains acetonitrile having excellent balance between viscosity and the dielectric constant and a fluorine-containing inorganic lithium salt, wherein the generation of complex cations comprising a transition metal and acetonitrile is suppressed, excellent load characteristics are exhibited, and self-discharge during high-temperature storage is suppressed; a further purpose of the present invention is to provide a nonaqueous secondary battery. The present invention relates to a nonaqueous electrolyte which contains: a nonaqueous solvent comprising 30 to 100 vol % of acetonitrile; a fluorine-containing inorganic lithium salt; and a specific nitrogenous cyclic compound typified by pyridine.

Abstract: Methods and articles relating to separation of electrolyte compositions within lithium batteries are provided. Suitable electrolytes for the lithium batteries can comprise a heterogeneous electrolyte including a first electrolyte solvent (e.g., dioxolane (DOL)) that partitions towards the anode and is favorable towards the anode (e.g., as an “anode-side electrolyte solvent”) and a second electrolyte solvent (e.g., 1,2-dimethoxyethane (DME)) that partitions towards the cathode and is favorable towards the cathode (e.g., an “cathode-side electrolyte solvent”). By separating the electrolyte solvents during operation of the battery such that the anode-side electrolyte solvent is present disproportionately at the anode and the cathode-side electrolyte solvent is present disproportionately at the cathode, the battery can benefit from desirable characteristics of both electrolyte solvents (e.g.

Abstract: Articles and methods including layers for protection of electrodes in electrochemical cells are provided. As described herein, a layer, such as a protective layer for an electrode, may comprise a plurality of particles (e.g., crystalline inorganic particles, amorphous inorganic particles). In some embodiments, at least a portion of the plurality of particles (e.g., inorganic particles) are fused to one another. For instance, in some embodiments, the layer may be formed by aerosol deposition or another suitable process that involves subjecting the particles to a relatively high velocity such that fusion of particles occurs during deposition. In some embodiments, the layer (e.g., the layer comprising a plurality of particles) is an ion-conducting layer.

Abstract: Articles and methods including layers for protection of electrodes in electrochemical cells are provided. As described herein, a layer, such as a protective layer for an electrode, may comprise a plurality of particles (e.g., crystalline inorganic particles, amorphous inorganic particles). In some embodiments, at least a portion of the plurality of particles (e.g., inorganic particles) are fused to one another. For instance, in some embodiments, the layer may be formed by aerosol deposition or another suitable process that involves subjecting the particles to a relatively high velocity such that fusion of particles occurs during deposition. In some embodiments, the layer (e.g., the layer comprising a plurality of particles) is an ion-conducting layer.

Abstract: Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.

Abstract: According to one embodiment, an air battery includes a case, a positive electrode, a negative electrode, a first nonaqueous electrolyte, a second nonaqueous electrolyte, a solid electrolyte layer and a hole. The first nonaqueous electrolyte is permeated into the positive electrode and includes an ionic liquid. The second nonaqueous electrolyte is permeated into the negative electrode and includes an organic solvent. The solid electrolyte layer is provided between the positive electrode and the negative electrode and has lithium ion conductivity.

Abstract: A non-aqueous liquid electrolyte for a secondary battery, containing, in an aprotic solvent: an electrolyte; a particular nitrile compound; and a flame retardant composed of a particular phosphate compound or a phosphazene compound, in which the nitrile compound is contained in an amount of 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the flame retardant.

Abstract: Disclosed is a rechargeable lithium battery including a positive electrode; a negative electrode including a negative active material, the negative active material including a silicon-based material; and an electrolyte solution including a lithium salt, a non-aqueous organic solvent, and an additive. The additive includes an ethylene carbonate-based compound represented by Chemical Formula 1 and a pyridine-based compound represented by Chemical Formula 2: R11, R12 and R1 to R5 are each independently hydrogen, a halogen, a substituted or unsubstituted C1 to C20 alkyl group, or a C1 to C20 haloalkyl group; at least one of R11 and R12 is a halogen; and at least one of R1 to R5 is a halogen.

Abstract: An electrolyte contains a non-aqueous solvent, a lithium salt, and a fluorine-containing ether compound represented by the following Formula (I). In the following formula, R1 represents an alkyl group having 3 to 8 carbon atoms; R2 represents an alkyl group having 1 carbon atom; at least 6 carbon atoms among carbon atoms bonded to the alkyl group represented by R1 are substituted with fluorine atoms; and at least one hydrogen atom among hydrogen atoms bonded to the alkyl group represented by R2 is substituted with a fluorine atom.

Abstract: A nonaqueous electrolyte battery is provided. The nonaqueous electrolyte battery includes an anode; a cathode; a separator; an electrolytic solution including a solvent and an electrolyte salt; wherein the solvent includes a fluoro ethylene carbonate, wherein the nonaqueous electrolyte battery has a discharge capacity ratio of a discharge capacity B when discharging at a 5 C rate to a discharge capacity A when discharging at a 0.2 C rate ((B/A)×100%), and wherein the discharge capacity ratio is 80% or more. An electrical apparatus including a nonaqueous electrolyte battery is also provided.

Abstract: A non-aqueous electrolyte secondary battery which is one example of an embodiment of the present disclosure is a non-aqueous electrolyte secondary battery including a non-aqueous electrolyte which contains a non-aqueous solvent. The non-aqueous solvent contains a fluoroethylene carbonate, a difluorobutylene carbonate, and at least one of a fluorinated chain carbonate and a fluorinated chain carboxylic acid ester, total volumetric contents of which is more than 50 percent with respect to the total volume of the non-aqueous solvent.

Abstract: The invention relates to a separator filled with an electrolyte composition. The separator has a ceramic surface and the electrolyte composition comprises an ionic fluid. Filling with the electrolyte composition can take place, for example, by inserting the separator into a battery, e.g. into a lithium ion battery, which is filled with a corresponding electrolyte composition.

Abstract: The present invention provides a non-aqueous electrolytic solution including a methylenebissulfonate derivative and improving initial irreversible capacity and other characteristics of a battery such as cycle characteristics, electric capacity, and storage characteristics; a method for producing thereof; and a battery using the electrolytic solution. The non-aqueous electrolytic solution includes: (1) a non-aqueous solvent comprising a cyclic carbonate ester, a straight chained carbonate ester, and/or a cyclic carboxylic acid ester, (2) a lithium salt which may be dissolved in the non-aqueous solvent, as an electrolyte salt, and (3) a methylenebissulfonate derivative of formula [I]: The method includes steps of dissolving a lithium salt in a non-aqueous solvent, and then dissolving the methylenebissulfonate derivative. The non-aqueous electrolytic solution battery includes (i) the non-aqueous electrolytic solution above, (ii) a negative electrode, (iii) a positive electrode, and (iv) a separator.

Abstract: The application relates to a gel polymer electrolyte and/or polymer modified electrode materials for lithium batteries.

Abstract: The invention relates to reactive ionic liquids containing organic cations with groups or substituents which are susceptible to electrochemical reduction and anions obtained from fluoroalkyl phosphates, fluoroalkyl phosphinates, fluoroalkyl phosphonates, acetates, triflates, imides, methides, borates, phosphates and/or aluminates, for use in electrochemical cells, such as lithium ion batteries and double-layer capacitors.

Abstract: An improved lithium-sulfur battery containing a surface-functionalized carbonaceous material. The presence of the surface-functionalized carbonaceous material generates weak chemical bonds between the functional groups of the surface-functionalized carbonaceous material and the functional groups of the polysulfides, which prevents the polysulfide migration to the battery anode, thereby providing a battery with relatively high energy density and good partial discharge efficiency.

Abstract: An ionic liquid having high electrochemical stability and a low melting point. An ionic liquid represented by the following general formula (G0) is provided. In the general formula (G0), R0 to R5 are individually any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, a methoxyethyl group, and a hydrogen atom, and A? is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.

Abstract: A nonaqueous solvent that includes an ionic liquid and has at least one of the following characteristics: high lithium ion conductivity, high lithium ion conductivity in a low temperature environment, high heat resistance, a wide available temperature range, a low freezing point (melting point), low viscosity, and the like. The nonaqueous solvent includes an ionic liquid and a fluorinated solvent. The ionic liquid contains an alicyclic quaternary ammonium cation which has a substituent and a counter anion to the alicyclic quaternary ammonium cation which has the substituent.

Abstract: Disclosed is a nonaqueous electrolytic solution which enables formation of a nonaqueous-electrolyte battery having high capacity and excellent storage characteristics at high temperatures, while sufficiently enhancing safety at the time of overcharge. A nonaqueous-electrolyte battery produced by using the nonaqueous electrolytic solution is also disclosed. The nonaqueous electrolytic solution comprises an electrolyte and a nonaqueous solvent, and includes any of specific nonaqueous electrolytic solutions (A) to (D).

Abstract: A rechargeable lithium metal or lithium-ion cell comprising a cathode having a cathode active material and/or a conductive supporting structure, an anode having an anode active material and/or a conductive supporting nano-structure, a porous separator electronically separating the anode and the cathode, a highly concentrated electrolyte in contact with the cathode active material and the anode active material, wherein the electrolyte contains a lithium salt dissolved in an ionic liquid solvent with a concentration greater than 3 M. The cell exhibits an exceptionally high specific energy, a relatively high power density, a long cycle life, and high safety with no flammability.

Abstract: In some embodiments, the present disclosure pertains to energy storage compositions that comprise a clay and an ionic liquid. In some embodiments, the clay is a bentonite clay and the ionic liquid is a room temperature ionic liquid (RTIL). In some embodiments, the clay and the ionic liquid are present in the energy storage compositions of the present disclosure in a weight ratio of 1:1. In some embodiments, the ionic liquid further comprises a lithium-containing salt that is dissolved in the ionic liquid. In some embodiments, the energy storage compositions of the present disclosure further comprise a thermoplastic polymer, such as polyurethane. In some embodiments, the thermoplastic polymer constitutes about 10% by weight of the energy storage composition. In some embodiments, the energy storage compositions of the present disclosure are associated with components of energy storage devices, such as electrodes and separators.

Abstract: A nonaqueous electrolytic solution of an electrolyte salt dissolved in a nonaqueous solvent, containing a hydantoin compound represented by the following general formula (I) in an amount of from 0.01 to 5% by mass of the nonaqueous electrolytic solution, and excellent in battery characteristics such as high-temperature storage property and cycle property. (In the formula, R1 and R2 each represent a methyl group or an ethyl group; R3 and R4 each represent a hydrogen atom, a methyl group or an ethyl group.

Abstract: Disclosed is a nonaqueous electrolytic solution which enables formation of a nonaqueous-electrolyte battery having high capacity and excellent storage characteristics at high temperatures, while sufficiently enhancing safety at the time of overcharge. A nonaqueous-electrolyte battery produced by using the nonaqueous electrolytic solution is also disclosed. The nonaqueous electrolytic solution comprises an electrolyte and a nonaqueous solvent, and includes any of specific nonaqueous electrolytic solutions (A) to (D).

Abstract: Active metal and active metal intercalation electrode structures and battery cells having ionically conductive protective architecture including an active metal (e.g., lithium) conductive impervious layer separated from the electrode (anode) by a porous separator impregnated with a non-aqueous electrolyte (anolyte). This protective architecture prevents the active metal from deleterious reaction with the environment on the other (cathode) side of the impervious layer, which may include aqueous or non-aqueous liquid electrolytes (catholytes) and/or a variety of electrochemically active materials, including liquid, solid and gaseous oxidizers. Safety additives and designs that facilitate manufacture are also provided.

Abstract: A method for making a lithium battery or lithium ion battery having nitrogen silylated compounds as additives in a nonaqueous electrolytic solution. Batteries using this electrolytic solution have long cycle life and high capacity retention.

Abstract: The present invention provides an electrolyte for lithium and/or lithium-ion batteries comprising a lithium salt in a liquid carrier comprising heteroaromatic compound including a five-membered or six-membered heteroaromatic ring moiety selected from the group consisting of a furan, a pyrazine, a triazine, a pyrrole, and a thiophene, the heteroaromatic ring moiety bearing least one carboxylic ester or carboxylic anhydride substituent bound to at least one carbon atom of the heteroaromatic ring. Preferred heteroaromatic ring moieties include pyridine compounds, pyrazine compounds, pyrrole compounds, furan compounds, and thiophene compounds.

Abstract: In one aspect, a rechargeable lithium battery including an electrolyte for the rechargeable lithium battery is provided. The electrolyte for the rechargeable lithium battery includes: a non-aqueous organic solvent; a lithium salt; and a compound represented by Chemical Formula 1.

Abstract: Novel electric battery systems are disclosed utilizing selected ionic liquids as electrolytes and selected metals and metal oxides as electrodes. The ionic liquids utilize a substituted imidazolium cation, which does not have the corrosive safety and environmental concerns associated with corrosive acid and alkali electrolytes.

Abstract: The invention is directed in a first aspect to an ionic liquid of the general formula Y+Z?, wherein Y+ is a positively-charged component of the ionic liquid and Z? is a negatively-charged component of the ionic liquid, wherein Z? is a boron-containing anion of the following formula: The invention is also directed to electrolyte compositions in which the boron-containing ionic liquid Y+Z? is incorporated into a lithium ion battery electrolyte, with or without admixture with another ionic liquid Y+X? and/or non-ionic solvent and/or non-ionic solvent additive.

Abstract: An electrolyte for use in electrochemical cells is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

Abstract: An electrolytic solution capable of improving battery characteristics even at high temperature, and a battery using the electrolytic solution are provided. A separator is impregnated with an electrolytic solution. The electrolytic solution includes a cyclic imide salt such as 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonimide lithium and a light metal salt such as difluoro[oxalato-O,O?] lithium borate or bis[oxalato-O,O?] lithium borate. Thereby, the decomposition reaction of the electrolytic solution can be prevented even at high temperature, and the battery characteristics can be improved.

Abstract: The present application provides a nonaqueous electrolyte secondary battery that includes, a cathode capable of being electrochemically doped/dedoped with lithium, an anode capable of being electrochemically doped/dedoped with lithium, and an electrolyte placed between the cathode and the anode, wherein the electrolyte contains at least one of fluoro ethylene carbonate represented by Chemical Formula (1) and difluoro ethylene carbonate represented by Chemical Formula (2) as a solvent and the ratio of a discharge capacity B during discharging at a 5C rate to a discharge capacity A during discharging at a 0.2C rate ((B/A)×100) is 80% or more.

Abstract: Representative embodiments provide a liquid or gel separator utilized to separate and space apart first and second conductors or electrodes of an energy storage device, such as a battery or a supercapacitor. A representative liquid or gel separator comprises a plurality of particles, typically having a size (in any dimension) between about 0.5 to about 50 microns; a first, ionic liquid electrolyte; and a polymer. In another representative embodiment, the plurality of particles comprise diatoms, diatomaceous frustules, and/or diatomaceous fragments or remains. Another representative embodiment further comprises a second electrolyte different from the first electrolyte; the plurality of particles are comprised of silicate glass; the first and second electrolytes comprise zinc tetrafluoroborate salt in 1-ethyl-3-methylimidalzolium tetrafluoroborate ionic liquid; and the polymer comprises polyvinyl alcohol (“PVA”) or polyvinylidene fluoride (“PVFD”).

Abstract: A secondary battery capable of improving battery characteristics is provided. The secondary battery includes a cathode 21 containing a cathode active material capable of inserting and extracting an electrode reactant, an anode 22 containing an anode active material capable of inserting and extracting the electrode reactant, and an electrolyte containing a solvent and an electrolyte salt. At least one of the cathode 21, the anode 22, and the electrolyte contains a radical scavenger compound. The radical scavenger compound is a compound in which a group having a radical scavenger function exists as a matrix, to which one or more carboxylic metal bases or one or more sulfonic metal bases are introduced. Chemical stability of the cathode 21, the anode 22, or the electrolyte containing the radical scavenger compound is improved. Thus, at the time of charge and discharge, decomposition reaction of the electrolytic solution is easily inhibited.

Abstract: A non-aqueous electrolyte in which the proportion of diethyl carbonate is reduced, and a nonaqueous electrolyte secondary battery using the same that has high safety are provided. The non-aqueous electrolyte of the invention for use in secondary batteries includes ethylene carbonate, propylene carbonate, diethyl carbonate, and an additive, as a non-aqueous solvent. The additive is at least one of a fluorinated aromatic compound having a molecular weight of 90 to 200 and a fatty acid alkyl ester having a molecular weight of 80 to 240. A weight ratio WEC ethylene carbonate, a weight ratio WPC of propylene carbonate, a weight ratio W DEC of diethyl carbonate, and a weight ratio WLV of the additive are 5 to 30 wt %, 15 to 60 wt %, 10 to 50 wt %, and 5 to 35 wt %, respectively, to the total of the non-aqueous electrolyte.

Abstract: Novel electric battery systems are disclosed utilizing selected ionic liquids as electrolytes and selected metals and metal oxides as electrodes. The ionic liquids utilize a substituted imidazolium cation, which does not have the corrosive safety and environmental concerns associated with corrosive acid and alkali electrolytes.

Abstract: The present invention provides a lithium-ion electrochemical cell comprising an ionic liquid electrolyte solution and a positive electrode having a carbon sheet current collector.

Abstract: A non-aqueous electro-chemical battery and a method of preparation thereof, wherein the electro-chemical battery comprises an anode current collector, a cathode, electrolyte solution and a separator, wherein the anode current collector contains anode coating and the anode current collector as a whole acts as an anode; both the anode current collector and the cathode are provided with tabs; the cathode is made of lithium metal or lithium-aluminum alloy; ratio of capacity of the anode per unit area to capacity of the cathode per unit area is less than 1.0; ratio of theoretical total capacity of the anode to the theoretical total capacity of the cathode is greater than 1.0. According to the method of preparing the battery, when the anode, the cathode and the separator are placed one over another, a front end of the anode and a front end of the cathode is placed in staggered positions.

Abstract: Disclosed are an additive for improving charge/discharge characteristics of a lithium-ion cell, a nonaqueous electrolytic solution containing the additive, and a lithium-ion cell using the additive and/or the nonaqueous electrolytic solution. The additive serves as a solvent for a fluorine resin, such as poly(vinylidene fluoride), which is incorporated as an adhesive in a positive electrode containing a lithium-transition metal oxide capable of absorbing and releasing lithium and a negative electrode containing a carbon material capable of absorbing and releasing lithium. The additive comprises three compounds selected, respectively, from a 2-pyrrolidinone compound group, a cyclic alkyl compound group, and a cyclic pentanone compound group.

Abstract: A rechargable magnesium battery having an non-aqueous electrolyte is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.