An aqueous electrolyte solution, a power storage device filled with the aqueous electrolyte solution, and a manufacturing method of the power storage device are illustrated. The aqueous electrolyte solution comprises alkali metal cations of different types. With the hydration enthalpy of the alkali metal cations of the different types, a simulated boiling point of the aqueous electrolyte solution is higher than the 105° C. of the conventional aqueous electrolyte solution. After processed by the reflow furnace at 250° C., the power storage device has no cracks found on its appearance, which meets the electrical requirements, and overcomes the problem of bursting of the power storage device filled with conventional aqueous electrolyte solution. The housing of the power storage device adopts liquid crystal polymer, and/or the power storage device is firstly vacuumed and then packaged, therefore increasing coulombic efficiency of electrical testing of the power storage device.

An aqueous electrolyte solution, a power storage device filled with the aqueous electrolyte solution, and a manufacturing method of the power storage device are illustrated. The aqueous electrolyte solution comprises alkali metal cations of different types. With the hydration enthalpy of the alkali metal cations of the different types, a simulated boiling point of the aqueous electrolyte solution is higher than the 105° C. of the conventional aqueous electrolyte solution. After processed by the reflow furnace at 250° C., the power storage device has no cracks found on its appearance, which meets the electrical requirements, and overcomes the problem of bursting of the power storage device filled with conventional aqueous electrolyte solution. The housing of the power storage device adopts liquid crystal polymer, and/or the power storage device is firstly vacuumed and then packaged, therefore increasing coulombic efficiency of electrical testing of the power storage device.

The electrolyte additive includes a neutral compound represented by formula (1) and having, in the molecule, a trialkyl silyl group. It can improve the withstand voltage of the electrolyte and be applied to electrolyte for lithium-ion rechargeable batteries. In formula (1), R.sup.1 each represent independent C1-8 alkyl groups, R.sup.2 each represent independent C1-8 alkyl groups, A represents a C1-10 alkylene group, X represents either a single bond, a methylene group or one of the linking groups represented by formulas (2) to (4), m represents an integer from 1 to 3, n represents an integer from 0 to 2, where m+n is 2 if X is a single bond, a methylene group, a linking group represented by formula (2) or a linking group represented by formula (3), and m+n is 3 if X is a linking group represented by formula (4). In formula (3), R.sup.3 represents a C1-8 alkyl group.

##STR00001##

The electrolyte additive includes a neutral compound represented by formula (1) and having, in the molecule, a trialkyl silyl group. It can improve the withstand voltage of the electrolyte and be applied to electrolyte for lithium-ion rechargeable batteries. In formula (1), R.sup.1 each represent independent C1-8 alkyl groups, R.sup.2 each represent independent C1-8 alkyl groups, A represents a C1-10 alkylene group, X represents either a single bond, a methylene group or one of the linking groups represented by formulas (2) to (4), m represents an integer from 1 to 3, n represents an integer from 0 to 2, where m+n is 2 if X is a single bond, a methylene group, a linking group represented by formula (2) or a linking group represented by formula (3), and m+n is 3 if X is a linking group represented by formula (4). In formula (3), R.sup.3 represents a C1-8 alkyl group.

##STR00001##

Methods, systems, and apparatuses are described for implementing electrochemical energy storage devices using a liquefied gas electrolyte. The mechanical designs of an electrochemical device to house a liquefied gas electrolyte as well as methods of filling and sealing said device are presented.

Methods, systems, and apparatuses are described for implementing electrochemical energy storage devices using a liquefied gas electrolyte. The mechanical designs of an electrochemical device to house a liquefied gas electrolyte as well as methods of filling and sealing said device are presented.

A method for producing a compound of formula (1) R.sup.11X.sup.11—SO.sub.3M.sup.11, which includes reacting a compound of formula (3) R.sup.31O—SO.sub.2—OR.sup.32 and a metal alkoxide, wherein R.sup.11, X.sup.11 and M.sup.11 are as defined herein.

A method for producing a compound of formula (1) R.sup.11X.sup.11—SO.sub.3M.sup.11, which includes reacting a compound of formula (3) R.sup.31O—SO.sub.2—OR.sup.32 and a metal alkoxide, wherein R.sup.11, X.sup.11 and M.sup.11 are as defined herein.

According to the present invention, an electrolyte is composed of one or more lithium salts of asymmetric imides each having a perfluoroalkyl group, or a mixed salt of a lithium salt of an asymmetric imide having a perfluoroalkyl group and a lithium salt of a symmetric imide having a perfluoroalkyl group. The composition ratio of the one or more lithium salts and the mixed salt is expressed by (lithium salt of asymmetric imide).sub.x(lithium salt of symmetric imide).sub.1-x (wherein x is from 0.1 to 1.0) in terms of the molar ratio; the asymmetric imide lithium salt is (C.sub.2F.sub.5SO.sub.2) (CF.sub.3SO.sub.2)NLi or (C.sub.3F.sub.7SO.sub.2) (CF.sub.3SO.sub.2)NLi; the symmetric imide lithium salt is (CF.sub.3SO.sub.2).sub.2NLi; and the composition of an electrolyte solution according to the present invention contains 1.0 mole or more but less than 2 moles of a solvent per 1 mole of the one or more lithium salts or the lithium salts of the mixed salt.

A porous carbon material includes a hierarchical porous structure including a primary microporous structure and at least one of a secondary mesoporous structure and a secondary macroporous structure. The porous carbon material is formed by combining a halogenated-hydrocarbon, an aprotic hydrocarbon solvent, and a reductant to initiate a reaction that forms intermediate particles having a microporous framework; and subjecting the intermediate particles to a heat treatment at a heat treatment temperature ranging from about 300° C. to less than 1,500° C. for a heat treatment time period ranging from about 20 minutes to about 10 hours to thereby form the porous carbon material. The aprotic hydrocarbon solvent is selected from the group consisting of toluene, hexane, cyclohexane, and combinations thereof.