Abstract: An electrolyte for a lithium battery includes a non-aqueous organic solvent, a lithium salt, and an additive comprising a) a compound represented by the following Formula (1), and b) a compound selected from the group consisting of a sulfone-based compound, a poly(ester)(metha)acrylate, a polymer of poly(ester)(metha)acrylate, and a mixture thereof: wherein R1 is a C1 to C10 alkyl, a C1 to C10 alkoxy, or a C6 to C10 aryl, and preferably a methyl, ethyl, or methoxy, X is a halogen, and m and n are integers ranging from 1 to 5, where m+n is less than or equal to 6.

Abstract: The invention related to a liquid electrolyte for a lithium battery comprising a lithium salt dissolved in a mixture of three non-aqueous organic solvents. This mixture consists of: 33% to 49 volume % of propylene carbonate, 33% to 49 volume % of diethyl carbonate, and 2% to 34 volume % of ethyl acetate. The liquid electrolyte is in particular suitable for a lithium battery based on the LiFePO4/Li4Ti5O-12 pair or derivatives thereof, these materials being the respective active materials of the positive and negative electrodes. Such a lithium battery in fact has the advantage of operating in power, over a wide temperature range, while at the same time preserving a low self-discharge capacity.

Abstract: The present technology relates to stabilizing additives and electrolytes containing the same for use in electrochemical devices such as lithium ion batteries and capacitors. The stabilizing additives include triazinane triones and bicyclic compounds comprising succinic anhydride, such as compounds of Formulas I and II described herein.

Abstract: Spiro ammonium salts as an additive for electrolytes in electric current producing cells, in particular electric current producing cells comprising a Li-based anode, are provided. In some embodiments, the electric current producing cell comprises a cathode, a Li-based anode, and at least one electrolyte wherein the electrolyte contains at least one spiro ammonium salt.

Abstract: An organic electrolyte solution includes a lithium salt; an organic solvent including a high permittivity solvent and a low boiling solvent; and a vinyl-based compound represented by Formula 1 below, wherein m and n are each independently integers of 1 to 10; X1, X2, and X3 each independently represent O, S, or NR9; and R1, R2, R3, R4, R5, R6, R7, R8, and R9 are represented in the detailed description. The organic electrolyte solution of the present invention and a lithium battery using the same suppress degradation of an electrolyte, providing improved cycle properties and life span thereof.

Abstract: Electrolytes of lithium ion batteries of the present disclosure comprise: a lithium salt, a non-aqueous solvent, and an additive. The additive further comprises a first and second compound. The first compound is a 4 X1, 5 R1 [1,3]dioxolan-2-one, wherein X1 is selected from the group consisting of: F, Cl, and Br and R1 is selected from the group consisting of hydrogen and linear alkyl compounds having between 1 and 3 carbon atoms. The second compound has a molecular formula of: F(CF2CF2)x—CH2CH2—(CH2CH2O)yH, wherein x is any integer ranging from 1 to 7, and y is any integer ranging from 1 to 15.

Abstract: A nonaqueous electrolyte having maleimide additives and rechargeable cells employing the same are provided. The nonaqueous electrolyte having maleimide additives comprises an alkali metal electrolyte, a nonaqueous solvent, and maleimide additives. Specifically, the maleimide additives comprise maleimide monomer, bismaleimide monomer, bismaleimide oligomer, or mixtures thereof. The maleimide additives comprise functional groups, such as a maleimide double bond, phenyl group carboxyl, or imide, enhancing the charge-discharge efficiency, safety, thermal stability, chemical stability, flame-resistance, and lifespan of the secondary cells of the invention.

Abstract: Disclosed are an electrolyte for a rechargeable lithium battery that includes a lithium salt, a non-aqueous organic solvent, and an additive including a triazine-based compound represented by the following Chemical Formula 1 and fluoroethyl carbonate, and a rechargeable lithium battery including the electrolyte. where R1, R2, and R3 are the same as described in the detailed description.

Abstract: Disclosed is a non-aqueous electrolyte solution for a lithium secondary battery. The non-aqueous electrolyte solution includes a lithium salt, an organic solvent and additives. The additives include: 1 to 10% by weight of a mixture of a particular halogenated cyclic carbonate and a compound containing a vinylene or vinyl group; and 0.1 to 9% by weight of a nitrile compound having a C2-C12 alkoxyalkyl group. A lithium secondary battery including the non-aqueous electrolyte solution is also disclosed. The lithium secondary battery is protected from catching fire when overcharged and is prevented from swelling during storage at high temperature.

Abstract: A non-aqueous electrolyte solution for a lithium secondary battery comprises a lithium salt and an organic solvent. The non-aqueous electrolyte solution further comprises a specific siloxane compound and a sulfonate compound. This non-aqueous electrolyte solution solves the capacity degradation phenomenon, which appears in a lithium secondary battery using a non-aqueous electrolyte solution containing only a specific siloxane compound when the lithium secondary battery is used for a long time, so this non-aqueous electrolyte solution is especially useful for high-capacity batteries.

Abstract: A rechargeable lithium battery includes a positive electrode including a positive active material being capable of intercalating and deintercalating lithium ions; a negative electrode including a negative active material being capable of intercalating and deintercalating lithium ions; and an electrolyte including a non-aqueous organic solvent and a lithium salt. The positive electrode has a positive active mass density of 3.65 g/cc or more, and the lithium salt includes lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), and a lithium imide-based compound. The rechargeable lithium battery has high capacity, excellent cycle-life, and reliability at a high temperature.

Abstract: A primary cell having an anode comprising lithium or lithium alloy and a cathode comprising iron disulfide (FeS2), iron sulfide (FeS) and carbon particles. The electrolyte comprises a lithium salt dissolved in a solvent mixture. A cathode slurry is prepared comprising iron disulfide (FeS2) powder, iron sulfide (FeS) powder, carbon, binder, and a liquid solvent. The mixture is coated onto a conductive substrate and solvent evaporated leaving a dry cathode coating on the substrate. The anode and cathode can be spirally wound with separator therebetween and inserted into the cell casing with electrolyte then added.

Abstract: A non-aqueous electrolyte solution is provided that realizes a large capacity, exhibits high storage characteristics and cycle characteristics, and is capable of inhibiting gas generation. The non-aqueous electrolyte solution comprises a lithium salt and a non-aqueous solvent, and further comprises: a cyclic carbonate compound having an unsaturated bond in a concentration of 0.01 weight % or higher and 8 weight % or lower; and a compound expressed by general formula (Ia) in a concentration of 0.01 weight % or higher and 5 weight % or lower. (in the formula (Ia), R11 and R12 represent, independently of each other, an organic group that is composed of one or more carbon atoms and hydrogen atoms and may optionally contain one or more oxygen atoms but excludes unsaturated bonds, provided that at least either R11 or R12 has an ether linkage. The total number of carbon atoms of R11 and R12 is between 3 and 18, and the total number of oxygen atoms contained in R11 and R12 is between 1 and 6.

Abstract: A non-aqueous electrolyte secondary battery has a high initial capacity and excels in cycle characteristics and storage characteristics even when charged until the potential of the positive electrode active material exceeds as high as 4.3V versus lithium. The non-aqueous electrolyte of the secondary battery contains both 1,3-dioxane and a sulfonic acid ester compound.

Abstract: Disclosed are a non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery comprising the same. The non-aqueous electrolyte solution for a lithium secondary battery may include difluorotoluene having a lowest oxidation potential among components of the non-aqueous electrolyte solution. The lithium secondary battery may have improvement in basic performance including high rate charge/discharge characteristics, cycle life characteristics, and the like, and may remarkably reduce swelling caused by decomposition of an electrolyte solution under high voltage conditions such as overcharge.

Abstract: A nonaqueous electrolyte secondary battery of the invention has a positive electrode having a positive electrode active material, a negative electrode, and a nonaqueous electrolyte having electrolyte salt in a nonaqueous solvent. The electric potential of the positive electrode active material is 4.4 to 4.6 V relative to lithium, and the nonaqueous electrolyte contains a compound expressed by structural formula (I) below. The quantity of compound added is preferably 0.1% to 2% by mass. Also, the positive electrode active material preferably comprises a mixture of a lithium-cobalt composite oxide which is LiCoO2 containing at least both zirconium and magnesium and a lithium-manganese-nickel composite oxide that has a layer structure and contains at least both manganese and nickel. Thanks to such structure, a nonaqueous electrolyte secondary battery can be provided that is charged to charging termination potential of 4.4 to 4.6 V relative to lithium and that has enhanced overcharging safety.

Abstract: A non-aqueous electrolyte solution for a lithium secondary battery includes a lithium salt and an organic solvent and further includes a solvent having a fluoro group and a specific siloxane compound. A lithium secondary battery having the above non-aqueous electrolyte solution exhibits greatly improved capacity recovery characteristics after high temperature storage and also reduces side effects such as swelling.

Abstract: Disclosed is a lithium battery including: a positive electrode including manganese dioxide as a positive electrode active material; a negative electrode including at least one selected from lithium metal and a lithium alloy, as a negative electrode active material; a porous insulating member interposed between the positive electrode and the negative electrode; and an organic electrolyte. The organic electrolyte contains 0.0008 to 1.2% by weight of an alkyl ester of an aliphatic hydroxycarboxylic acid. The alkyl ester may be a C1-6 alkyl ester of an aliphatic hydroxycarboxylic acid having 2 to 7 carbon atoms, such as a C1-4 alkyl 4-hydroxybutyrate.

Abstract: A non-aqueous electrolyte includes (i) an inhibitor against a reaction between an anode and a linear ester; (ii) a mixed organic solvent containing cyclic carbonate and the linear ester; and (iii) an electrolyte salt, wherein the inhibitor is any one compound or a mixture of at least two compounds selected from the group consisting of cyclic carbonate with a vinyl group, fluorinated ethylene carbonate, vinylene carbonate, cyclic acid anhydride, a compound having a cyclic S?O group and an acrylate-based compound. Also, an electrochemical device includes a cathode, an anode and the above non-aqueous electrolyte.

Abstract: A primary electrochemical cell and electrolyte incorporating a linear asymmetric ether is disclosed. The ether may include EME, used in combination with DIOX and DME, or have the general structural formula R1—O—CH2—CH2—O—R2 or R1—O—CH2—CH(CH3)—O—R2, where a total of at least 7 carbon atoms must be present in the compound, and R1 and R2 consist alkyl, cyclic, aromatic or halogenated groups but cannot be the same group (i.e., R1?R2).

Abstract: It is aimed at providing: a negative electrode material for a nonaqueous secondary battery, which has a higher capacity, is low in irreversible capacity upon initial charge and discharge, and has excellent cycle characteristics; and a nonaqueous secondary battery adopting the negative electrode material. The object is achieved by: a multi-layer structured carbonaceous material obtained by mixing graphitic carbon particles with an organic compound and by thermally treating the mixture, wherein loop structures are present at an edge portion of each of the graphitic carbon particles, and wherein the graphitic carbon particles have carbonized products of the organic compound affixed to surfaces of the particles, respectively, while maintaining the loop structures; and a nonaqueous secondary battery adopting the multi-layer structured carbonaceous material.

Abstract: A non-aqueous electrolyte for a lithium battery includes a non-aqueous organic solvent, the organic solvent including one or more of a carbonate-based solvent, an ester-based solvent, an ether-based solvent, and/or a ketone-based solvent, a lithium salt, and a hexafluoroacetylacetone in an amount of about 0.02 parts by weight to about 10 parts by weight, based on 100 parts by weight of the non-aqueous organic solvent.

Abstract: Provided is a non-aqueous electrolyte capable of favorably suppressing the gas generation during storage in a high temperature environment and during charge/discharge cycling of a non-aqueous electrolyte secondary battery. The non-aqueous electrolyte includes a non-aqueous solvent and a solute dissolved in the non-aqueous solvent, wherein: the non-aqueous solvent includes ethylene carbonate, propylene carbonate, diethyl carbonate, and an additive; the additive includes a sultone compound and a cyclic carbonate having a C?C unsaturated bond; a weight percentage WPC of the propylene carbonate relative to a total of the ethylene carbonate, propylene carbonate, and diethyl carbonate is 30 to 60% by weight; a ratio WPC/WEC of the weight percentage WPC of the propylene carbonate to a weight percentage WEC of the ethylene carbonate relative to the total satisfies 2.

Abstract: A nonaqueous electrolyte for a lithium secondary battery and a lithium secondary battery including the same are provided. In particular, the nonaqueous electrolyte comprises a compound of chemical formula 1 as an electrolyte additive: NC—(R1)n-A-(R2)m—CN??1 wherein, R1 and R2 represent, respectively, alkylene groups, n and m represent integers of 1 to 10, and A is an aromatic hydrocarbon in which the number of carbons is 5 to 9 or O. When the lithium secondary battery is kept at high voltage and temperature, the electrolyte additive reduces gas generation, thereby reducing battery swelling. Therefore, it is possible to reduce a battery thickness increment rate and to increase discharge capacity at a high temperature.

Abstract: A non-aqueous electrolyte for a lithium battery includes a non-aqueous organic solvent, the organic solvent including one or more of a carbonate-based solvent, an ester-based solvent, an ether-based solvent, and/or a ketone-based solvent, a lithium salt, and a hexafluoroacetylacetone in an amount of about 0.02 parts by weight to about 10 parts by weight, based on 100 parts by weight of the non-aqueous organic solvent.

Abstract: The invention provides a lithium secondary battery which is excellent in long-term cycle property and in battery characteristics, such as electric capacity and storage property, and a nonaqueous electrolytic solution usable for such a lithium secondary battery. The present invention relates to a lithium secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolytic solution containing an electrolyte salt dissolved in a nonaqueous solvent, characterized in that the positive electrode is made of a material including a lithium compound oxide, in that the negative electrode is made of a material including graphite, and in that the nonaqueous electrolytic solution contains dialkyl oxalate and further contains vinylene carbonate and/or 1,3-propanesultone, and a nonaqueous electrolytic solution for use in such a battery.

Abstract: Disclosed is a lithium secondary battery which is excellent in battery characteristics such as long-term cycle characteristics, capacity and shelf life characteristics. Also disclosed is a nonaqueous electrolyte solution which can be used for such a lithium secondary battery. Specifically disclosed is a nonaqueous electrolyte solution for lithium secondary batteries obtained by dissolving an electrolyte salt in a nonaqueous solvent which is characterized by containing 0.01-10% by weight of a carboxylate compound represented by the general formula (I) below and 0.01-10% by weight or 0.01-10% by volume of a vinylene carbonate and/or 1,3-propane sultone. Also disclosed is a lithium secondary battery using such a nonaqueous electrolyte solution. (In the formula, R2 represents a hydrogen atom or COOR3 group, R1 and R3 respectively represent an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group or a phenyl group, and X represents an alkynylene group or an alkenylene group.

Abstract: The present invention is concerned with novel polar solvents and novel electrolytic compositions comprising such solvents, and having a high range of stability, as required for applications in the field of electrochemistry. The present solvents have a highly polar amide function, and preferably combine with a salt soluble in the solvent and having an anion with a delocalized charge, and at least one polymer, to form an electrolytic composition.

Abstract: The present invention relates to a nonaqueous electrolyte for a battery, and more particularly to a novel nonaqueous electrolyte for a battery in which a furanone based derivative is added to a conventional nonaqueous electrolyte for the lithium battery to inhibit decomposition of the electrolyte, and thereby the rate of increase of the battery thickness when it is allowed to stand at a high temperature is significantly decreased and capacity storage characteristics at high temperature are improved.

Abstract: The invention is a 1.5 volt primary electrochemical battery cell with an alkali metal lithium negative electrode (such as lithium), a positive electrode (comprising iron disulfide for example) and a nonaqueous electrolyte. The electrolyte has a solute including lithium iodide dissolved in an ether-containing solvent including a 1,2-dimethoxypropane based solvent component and no more than 30 volume percent 1,2-dimethoxyethane. When 1,2-dimethoxypropane is used to replace at least most 1,2-dimethoxyethane in the solvent, the cell provides good discharge capacity at low temperature while maintaining excellent discharge capacity at room temperature.

Abstract: Disclosed is an additive for an electrochemical cell wherein the additive includes an N—O bond. The additive is most preferably included in a nonaqueous electrolyte of the cell. Also disclosed are cells and batteries including the additive, and methods of charging the batteries and cells. An electrochemical cell including the additive preferably has an anode that includes lithium and a cathode including an electroactive sulfur-containing material.

Abstract: A non-aqueous mixture solvent for a non-aqueous electrolytic solution to be used for electrochemical energy devices, which contains an aprotic solvent, and a fluorinated ketone of the formula: (wherein Rf1 and Rf2 each independently represents a fluorinated aliphatic group, or Rf1 and Rf2 together form a cyclic group, Q represents a fluorinated or non-fluorinated alkylene group or a bond, and n represents 0 or 1), and an electrolytic solution containing the mixture solvent.

Abstract: A nonaqueous electrolyte having maleimide additives and rechargeable cells employing the same are provided. The nonaqueous electrolyte having maleimide additives comprises an alkali metal electrolyte, a nonaqueous solvent, and maleimide additives. Specifically, the maleimide additives comprise maleimide monomer, bismaleimide monomer, bismaleimide oligomer, or mixtures thereof. The maleimide additives comprise functional groups, such as a maleimide double bond, phenyl group carboxyl, or imide, enhancing the charge-discharge efficiency, safety, thermal stability, chemical stability, flame-resistance, and lifespan of the secondary cells of the invention.

Abstract: A non-aqueous electrolyte for a lithium battery includes a non-aqueous organic solvent, the organic solvent including one or more of a carbonate-based solvent, an ester-based solvent, an ether-based solvent, and/or a ketone-based solvent, a lithium salt, and a hexafluoroacetylacetone in an amount of about 0.02 parts by weight to about 10 parts by weight, based on 100 parts by weight of the non-aqueous organic solvent.

Abstract: A non-aqueous electrolyte battery of the present invention includes a non-aqueous electrolyte containing a lithium salt, a cyclic sultone derivative, and an acid anhydride, wherein the non-aqueous electrolyte contains the cyclic sultone derivative in an amount of 0.3 to 3% by mass and the non-aqueous electrolyte contains the acid anhydride in an amount of 0.3 to 3% by mass. Furthermore, the non-aqueous electrolyte battery includes at least one selected from a cyclic sultone derivative and an acid anhydride, and an electrolyte salt. The electrolyte salt contains lithium salt A and lithium salt B. The lithium salt A is at least one selected from LiBF4, LiPF6, LiAsF6, and LiSbF6, and the lithium salt B is a lithium salt other than the lithium salt A. The electrolyte contains the lithium salt A in an amount of 2 mol % or more.

Abstract: Electrolytes containing lithium-bis(oxalato)borate, a cyclic carbonate, one or more compounds selected from acrylic carbonates, aliphatic esters, alicyclic ethers and aliphatic, difunctional ethers, one or more compounds selected from lactones, dinitriles, compounds that contain at least one carboxylic acid ester group and an ether group, compounds that contain at least one carbonic acid group and an ether group, compounds that contain at least one nitrile group and an ether group, trialkyl phosphoric acid esters and trialkyl boric acids.

Abstract: An electrolyte for a lithium battery includes a non-aqueous organic solvent, a lithium salt, and an additive comprising a) a compound represented by the following Formula (1), and b) a compound selected from the group consisting of a sulfone-based compound, a poly(ester)(metha)acrylate, a polymer of poly(ester)(metha)acrylate, and a mixture thereof: wherein R1 is a C1 to C10 alkyl, a C1 to C10 alkoxy, or a C6 to C10 aryl, and preferably a methyl, ethyl, or methoxy, X is a halogen, and m and n are integers ranging from 1 to 5, where m+n is less than or equal to 6.

Abstract: Disclosed is a nonaqueous electrolyte secondary battery, comprising a nonaqueous electrolyte containing ethylene carbonate and ?-butyrolactone, wherein, when a charge-discharge cycle test satisfying conditions (A) to (D) given below is performed under an environment of 45° C., the capacity retention rate at 100-th charge-discharge cycle is at least 85% based on the discharge capacity in the first charge-discharge cycle, (A) for the charging, the constant current-constant voltage charging to 4.2V is performed for 3 hours under a current of 1C, (B) the discharging is performed to 3V under a current of 1C, (C) after the charging, the secondary battery is left to stand for 10 minutes, followed by performing the discharging, and (D) after the discharging, the secondary battery is left to stand for 10 minutes, followed by performing the charging.

Abstract: A lithium secondary battery comprising a negative electrode, a positive electrode, a separator and a non-aqueous liquid electrolyte, the non-aqueous liquid electrolyte having an electrical conductivity of 0.05 mS/cm or more and no such a flash point as specified by JIS-K2265 flash point test and comprising an ion nonconductive solvent and a lithium ion conductive solvent, is non-flammable and safe even at high temperatures.

Abstract: A non-aqueous electrolyte battery of the present invention includes a non-aqueous electrolyte containing a lithium salt, a cyclic sultone derivative, and an acid anhydride, wherein the non-aqueous electrolyte contains the cyclic sultone derivative in an amount of 0.3 to 3% by mass and the non-aqueous electrolyte contains the acid anhydride in an amount of 0.3 to 3% by mass. Furthermore, the non-aqueous electrolyte battery includes at least one selected from a cyclic sultone derivative and an acid anhydride, and an electrolyte salt. The electrolyte salt contains lithium salt A and lithium salt B. The lithium salt A is at least one selected from LiBF4, LiPF6, LiAsF6, and LiSbF6, and the lithium salt B is a lithium salt other than the lithium salt A. The electrolyte contains the lithium salt A in an amount of 2 mol % or more.

Abstract: A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one carbonate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture including ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate. The preferred additive is either a linear or cyclic carbonate containing covalent O—X and O—Y bonds on opposite sides of a carbonyl group wherein at least one of the O—X and the O—Y bonds has a dissociation energy less than about 80 kcal/mole.

Abstract: Multi-component organic solvent systems, electrolytes and electrochemical cells characterized by good low temperature performance are provided. In one embodiment, an improved organic solvent system contains a ternary mixture of ethylene carbonate, dimethyl carbonate and diethyl carbonate. In other embodiments, quaternary systems include a fourth component, i.e, an aliphatic ester, an asymmetric alkyl carbonate or a compound of the formula LiOX, where X is R, COOR, or COR, where R is alkyl or fluoroalkyl. Electrolytes based on such organic solvent systems are also provided and contain therein a lithium salt of high ionic mobility, such as LiPF6. Reversible electrochemical cells, particularly lithium ion cells, are constructed with the improved electrolytes, and preferably include a carbonaceous anode, an insertion type cathode, and an electrolyte interspersed therebetween.

Abstract: The present invention provides a rechargeable lithium electrochemical cell comprising an electrolyte containing a lithium salt dissolved in a non-aqueous solvent, at least one positive electrode, and at least one negative electrode of the paste type containing an electrochemically active material which is a carbon compound suitable for inserting lithium ions and a binder, the cell being characterized in that said solvent contains at least one saturated cyclic carbonate and at least one linear ester of a saturated aliphatic monocarboxylic acid, and in that said binder is a polymer having no fluorine.

Abstract: A lithium-sulfur battery includes a negative electrode, a positive electrode, and an electrolyte. The negative electrode includes a negative active material selected from materials in which lithium intercalation reversibly occur, lithium alloy or lithium metal. The positive electrode includes at least one of elemental sulfur and organosulfur compounds for a positive active material, and an electrically conductive material. The electrolyte includes at least two groups selected from a weak polar solvent group, a strong polar solvent group, and a lithium protection solvent group, where the electrolyte includes at least one or more solvents selected from the same group. The electrolyte may optionally include one or more electrolyte salts.

Abstract: An alkali metal, solid cathode, non-aqueous 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, 1,2-dimethoxyethane and a sulfate additive having at least one unsaturated hydrocarbon containing a C(sp or sp2)-C(sp3) bond unit having the C(sp3) carbon directly connected to the —OSO3— functional group.

Abstract: A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one carbonate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate and an equilibrated mixture of dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is either a linear or cyclic carbonate containing covalent O—X and O—Y bonds on opposite sides of a carbonyl group wherein at least one of the O—X and the O—Y bonds has a dissociation energy less than about 80 kcal/mole.

Abstract: A lithium secondary battery comprising a negative electrode, a positive electrode, a separator and a non-aqueous liquid electrolyte, the non-aqueous liquid electrolyte having an electrical conductivity of 0.05 mS/cm or more and no such a flash point as specified by JIS-K2265 flash point test and comprising an ion nonconductive solvent and a lithium ion conductive solvent, is non-flammable and safe even at high temperatures.

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 hydrogen fluoride to the nonaqueous 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 hydrogen fluoride having LiAsF.sub.6 or LiPF.sub.6 dissolved therein.

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 phosphate 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 phosphate 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 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.