An organic electrolytic solution includes a first lithium salt; an organic solvent; a bicyclic sulfate-based compound represented by Formula 1 below; and a monocyclic phosphate-based compound represented by Formula K1 below:

##STR00001## wherein in Formula 1, each of A.sub.1, A.sub.2, A.sub.3, and A.sub.4 is independently a covalent bond, a substituted or unsubstituted C.sub.1-C.sub.5 alkylene group, a carbonyl group, or a sulfinyl group, wherein both A.sub.1 and A.sub.2 are not a covalent bond and both A.sub.3 and A.sub.4 are not a covalent bond, and in Formula K1, each of A.sub.5 and A.sub.6 is independently a substituted or unsubstituted C.sub.1-C.sub.5 alkylene group.

A compound according to an embodiment of the present disclosure is represented by Formula 1. An electrolyte for a lithium secondary battery according to an embodiment of the present disclosure may include the compound, and a lithium secondary battery according to an embodiment of the present disclosure may include the electrolyte.

According to an embodiment of the present inventive concept, an electrolyte additive represented by the compounds of Chemical Formulas 1 to 4 may be provided. In addition, according to another embodiment of the present inventive concept, a method for preparing an electrolyte additive of the compounds of Chemical Formulas 1 to 4 may be provided, wherein the method for preparing the electrolyte additive includes reacting hexafluorophosphate and 2-monofluoromalonic acid, further adding an HF scavenger to the mixed solution produced by the reaction, and concentrating and drying the reaction solution obtained therefrom.

An object of the present invention is to provide a nonaqueous electrolytic solution and a nonaqueous electrolytic solution secondary battery capable of showing high output characteristics at a low temperature even after the battery is used to some extent, and capable of showing good high-rate properties, and further capable of improving safety of batteries. The nonaqueous electrolytic solution includes a nonaqueous solvent, an electrolyte dissolved in the nonaqueous solvent, (I) a difluoro ionic complex (1) represented by the general formula (1), and (II) at least one compound selected from the group consisting of a specific cyclic phosphazene compound, siloxane compound, aromatic compound, cyclohexene compound, phosphoric acid ester compound, fluorinated linear ether compound, fluorinated cyclic ether compound, and boric acid ester compound, and 95 mol % or more of the difluoro ionic complex (1) is a difluoro ionic complex (1-Cis) in a cis configuration represented by the general formula (1-Cis). ##STR00001##

A heat-resistant composition useful as a flame retardant, a flame retardant composition containing the same, and a flame-retardant resin composition are provided. The composition contains 20 to 50 parts by mass of a specific melamine salt as component (A), 50 to 80 parts by mass of a specific piperazine salt as component (B), and 1 to 50 parts by mass of a phosphoric ester compound having a specific structure as component (C), wherein the sum of the components (A) and (B) is 100 parts by mass.

The present disclosure provides an electrolyte and an electrochemical energy storage device, the electrolyte comprises an electrolyte salt and an additive. The additive comprises a sulfonic ester cyclic quaternary ammonium salt and a multinitrile compound. The sulfonic ester cyclic quaternary ammonium salt and the multinitrile compound can form a dense and uniform passive film with high ionic conductivity on a surface of each of the positive electrode film and the negative electrode film, so as to prevent continuous oxidation and reduction reaction from occurring between the electrolyte and the positive electrode film and the negative electrode film and make the electrochemical energy storage device has excellent high temperature cycle performance and high temperature storage performance.

The present specification provides an electrolyte including a phthalate phosphine-type anion, an additive for a secondary battery including the electrolyte, and a secondary battery including the additive.

The present invention relates to a novel electrolyte and a secondary battery including the same. The present invention has an effect of providing a secondary battery having improved charging efficiency and output due to reduced charging resistance and having excellent long-term lifespan and high-temperature capacity retention rate.

An object of the present invention is to provide a nonaqueous electrolytic solution and a nonaqueous electrolytic solution secondary battery capable of showing high output characteristics at a low temperature even after the battery is used to some extent, and capable of showing good high-rate properties, and further capable of improving safety of batteries. The nonaqueous electrolytic solution includes a nonaqueous solvent, an electrolyte dissolved in the nonaqueous solvent, (I) a difluoro ionic complex (1) represented by the general formula (1), and (II) at least one compound selected from the group consisting of a specific cyclic phosphazene compound, siloxane compound, aromatic compound, cyclohexene compound, phosphoric acid ester compound, fluorinated linear ether compound, fluorinated cyclic ether compound, and boric acid ester compound, and 95 mol % or more of the difluoro ionic complex (1) is a difluoro ionic complex (1-Cis) in a cis configuration represented by the general formula (1-Cis).

##STR00001##

The present disclosure provides an electrolyte and an electrochemical energy storage device, the electrolyte comprises an electrolyte salt and an additive. The additive comprises a sulfonic ester cyclic quaternary ammonium salt and a multinitrile compound. The sulfonic ester cyclic quaternary ammonium salt and the multinitrile compound can form a dense and uniform passive film with high ionic conductivity on a surface of each of the positive electrode film and the negative electrode film, so as to prevent continuous oxidation and reduction reaction from occurring between the electrolyte and the positive electrode film and the negative electrode film and make the electrochemical energy storage device has excellent high temperature cycle performance and high temperature storage performance.