The present disclosure provides a non-aqueous electrolyte for a lithium-ion battery and a lithium-ion battery using the non-aqueous electrolyte. The non-aqueous electrolyte includes (a) a lithium, (b) a non-aqueous organic solvent, and (c) at least one compound represented by formula 1; ##STR00001## where the non-aqueous electrolyte further includes at least one of the following components (d) and (e): (d) a nitrile compound including at least one of 1,3,6-hexane trinitrile, glycerol trinitrile, and 3-methoxypropionitrile, and (e) vinyl sulfate. Through the synergy effect between them, the positive electrode is protected and meanwhile the negative electrode is also be protected to a certain extent, and an impedance of a film is lowered. The battery has an excellent high temperature storage performance, high temperature cycle performance and low temperature charge and discharge performance.

Provided is a battery pack having excellent energy density and durability. A battery pack 100 includes solid-state battery modules 102 each configured such that a plurality of solid-state battery cells containing a solid electrolyte is stacked and electrolytic solution-based battery modules 32 each configured such that a plurality of electrolytic solution-based battery cells containing an electrolytic solution is stacked, the solid-state battery modules 102 and the electrolytic solution-based battery modules 32 being combined and housed in the pack. The solid-state battery modules 102 are arranged to surround the electrolytic solution-based battery modules 32.

An electrolyte solution additive, a non-aqueous electrolyte solution including the same, and a lithium secondary battery including the same are disclosed herein. In some embodiments, an electrolyte solution additive is represented by Formula 1

##STR00001##

wherein, in Formula 1,

R is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms.

The present invention provides a polymer which contains a repeating unit represented by formula (1).

##STR00001##

(In the formula, n represents an integer of 1 or more; R.sup.1 represents an optionally substituted monovalent aliphatic hydrocarbon group having from 1 to 60 carbon atoms, an optionally substituted monovalent aromatic hydrocarbon group having from 6 to 60 carbon atoms or an optionally substituted monovalent heterocyclic ring-containing group having from 2 to 60 carbon atoms; L represents a single bond, an optionally substituted divalent aliphatic hydrocarbon group having from 1 to 60 carbon atoms, an optionally substituted divalent aromatic hydrocarbon group having from 6 to 60 carbon atoms or an optionally substituted divalent heterocyclic ring-containing group having from 2 to 60 carbon atoms; and Ar represents an optionally substituted divalent aromatic hydrocarbon group having from 6 to 60 carbon atoms or an optionally substituted divalent heterocyclic ring-containing group having from 2 to 60 carbon atoms.)

A non-aqueous lithium power storage element that includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, the positive electrode having a positive electrode collector and a positive electrode active material layer that includes active carbon, and the non-aqueous lithium power storage element having configuration (1) and/or (2). (1) The negative electrode includes a negative electrode collector and a negative electrode active material layer (2) The non-aqueous electrolyte contains (A) LiPF.sub.6 and/or LiBF.sub.4, (B) an imide lithium salt, and (C) an oxalate-complex lithium salt, the ratio of the mass of component (C) to the total mass of components (A) and (B) being 1.0-10.0 mass %.

The present disclosure relates to a lithium metal battery that can easily and effectively remove water and hydrofluoric acid, thereby suppressing a decrease in cell performance and lifespan characteristics or an increase in the internal pressure due to the water and hydrofluoric acid, etc., and a method for manufacturing the same.

An electrolyte solution additive for a secondary battery, a non-aqueous electrolyte solution, and a lithium secondary battery including the same are disclosed herein. In some embodiments, an electrolyte solution additive is represented by Formula 1:

##STR00001##

In Formula 1, R is an unsubstituted or substituted alkyl group having 1 to 5 carbon atoms.

An electropositive metal electrode coated by an ion-selective conformable polymer provides the negative electrode and the solid-state electrolyte for a rechargeable bi-electrolyte displacement battery that further includes a molten salt electrolyte having a melting temperature below 140° C. interposed between the conformable polymer coating and a positive electrode. Suitable electropositive metals include lithium, sodium, magnesium, and aluminum and the molten salt incorporates a soluble salt of the metal of the negative electrode. Positive electrodes may incorporate metals including Fe, Ni, Bi, Pb, Zn, Sn, and Cu, and thanks to the ion-selective conformable solid-state electrolyte the molten salt is able to incorporate a soluble salt of the metal of the positive electrode. The conformable polymer-coated electropositive metal electrode may be manufactured by a process involving electroplating electropositive metal through a conformable polymer-coated conductive substrate. The conformable polymer-coated conductive substrate may be prepared by coating the conductive substrate in a conformable polymer solution followed by evaporating the solvent. Alternatively, an electropositive metal electrode may be coated directly with the conformable polymer.

An electrolyte including a dinitrile compound, a trinitrile compound, and propyl propionate. Based on the total weight of the electrolyte, the content X of the nitrile compound and the content Y of the trinitrile compound meet the conditions represented by Formula (1) and Formula (2): {about 2 wt %≤(X+Y)≤about 11 wt % . . . (1), about 0.1≤(X/Y)≤about 8 . . . (2)}. The electrolyte further includes at least one selected from the group consisting of a cyclic carbonate ester having a carbon-carbon double bond, a fluorinated chain carbonate ester, a fluorinated cyclic carbonate ester, and a compound having a sulfur-oxygen double bond. The electrolyte is capable of effectively inhibiting the increase in DC internal resistance of an electrochemical device so that the electrochemical device has excellent cycle and storage performance.

There is provided a method for producing lithium difluorophosphate in which difluorophosphate ester reacts with a lithium salt compound in a nonaqueous organic solvent without using water as a raw material, a method for producing a difluoro phosphate ester including a step of allowing a dihalophosphate ester to react with a fluorinating agent having a concentration of contained hydrogen fluoride of 15 mol % or less in a nonaqueous organic solvent; lithium difluorophosphate in which a value of a relational expression (d90-d10)/MV represented by d90 which is a particle size at which a volume cumulative distribution is 90%, d10 which is a particle size at which a volume cumulative distribution is 10%, and MV which is a volume average particle size is 10 or less; and methods for producing a nonaqueous electrolytic solution and a nonaqueous secondary battery using the production method described above.