A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an SO group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.

A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an SO group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.

Disclosed is an additive for an electrochemical cell wherein the additive includes an NO 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.

To provide a material suitable for a nonaqueous electrolyte battery having high-temperature durability. An ionic complex of the present invention is represented by any of the following formulae (1) to (3). For example, in the formula (1), A is a metal ion, a proton, or an onium ion; M is any of groups 13 to 15 elements. R.sup.1 represents a C.sub.1 to C.sub.10 hydrocarbon group which may have a ring, a heteroatom, or a halogen atom, or N(R.sup.2). R.sup.2 at this time represents hydrogen atom, alkali metal atom, a C.sub.1 to C.sub.10 hydrocarbon group which may have a ring, a heteroatom, or a halogen atom. R.sup.2 can also have a branched chain or a ring structure when the number of carbon atoms is 3 or more. Y is carbon atom or sulfur atom. a, o, n, p, q, and r are each predetermined integers.

##STR00001##

Disclosed are a non-aqueous electrolytic solution, which can improve cycle characteristics when a power storage device is used at high temperature and high voltage, and a power device using the same. The non-aqueous electrolytic solution according to the present invention comprises, in addition to a non-aqueous solvent and an electrolyte salt dissolved therein, a compound represented by the following formula (I):

##STR00001## wherein n is an integer of 1 or 2; and when n is 1, L represents a straight or branched unsaturated hydrocarbon group of which at least one hydrogen atom is optionally substituted by a halogen atom, a cycloalkyl group of which at least one hydrogen atom is optionally substituted by a halogen atom, or an aryl group of which at least one hydrogen atom is optionally substituted by a halogen atom; and when n is 2, L represents a saturated or unsaturated divalent hydrocarbon group which optionally contains ether bond(s), or an arylene group.

Disclosed is a process for one-step preparing electrolyte used for lithium-iron(II) disulfide batteries. The process includes the following steps of: adding iodine-containing precursors into an organic solvent in an inert atmosphere, homogeneously stirring, then adding lithium-containing precursors, stirring and reacting, separating solids to obtain an electrolyte used for lithium-iron(II) disulfide batteries. The process involves one-step synthesizing electrolyte used for lithium-iron(II) disulfide batteries. The whole procedures do not introduce water and have a lower cost. The lithium-iron(II) disulfide batteries prepared by using the electrolyte prepared by the process of the present invention have better properties.

Cathodes and electrochemical cells are provided, wherein a barium, bismuth, or nickel additive is included to increase the stability of manganese dioxide at high voltage. The metal additives provided herein improve the performance of electrochemical cells.

The present invention relates to an organic electrolyte including at least one cyclic nitrile-based compound; and at least one chain type nitrile-based compound, and a secondary battery including the same.

A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an SO group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.

A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an SO group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.