The present invention is aimed at providing: a non-aqueous electrolyte solution for a sodium ion secondary battery, with which a sodium ion secondary battery having a low resistance and showing a limited amount of gas generation after a durability test can be provided; and a sodium ion secondary battery obtained by using the same. The non-aqueous electrolyte solution for a sodium ion secondary battery comprises: a non-aqueous solvent; NaPF.sub.6; and a compound represented by the following Formula (1) (wherein, R.sub.1 and R.sub.2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and n represents 0 or 1), and a ratio of the content of the compound represented by Formula (1) with respect to the content of NaPF.sub.6, [compound represented by Formula (1)]/[NaPF.sub.6] (molar ratio), is 0.001 to 1.5: ##STR00001##

An electrolyte and a preparation method thereof and a lithium ion battery, where the electrolyte comprises the following components in percentages by mass: 10-20% of a lithium salt, 0.2-7% of an additive composition and a balance of a solvent; among them, the additive composition comprises a boron-containing lithium salt compound and a sulfur-based compound represented by Formula 1, in which R.sub.1 and R.sub.3 are each independently selected from hydrogen, halogen, or substituted or unsubstituted alkyl; R.sub.2 is selected from a substituted or unsubstituted alkylene, or is a direct bond; the boron-containing lithium salt compound is at least 0.1% by mass of the electrolyte. The electrolyte can significantly improve the performance of an SEI film, thereby facilitating increasing the cycle performance and storage performance of the lithium ion battery.

An electrolyte and a preparation method thereof and a lithium ion battery, where the electrolyte comprises the following components in percentages by mass: 10-20% of a lithium salt, 0.2-7% of an additive composition and a balance of a solvent; among them, the additive composition comprises a boron-containing lithium salt compound and a sulfur-based compound represented by Formula 1, in which R.sub.1 and R.sub.3 are each independently selected from hydrogen, halogen, or substituted or unsubstituted alkyl; R.sub.2 is selected from a substituted or unsubstituted alkylene, or is a direct bond; the boron-containing lithium salt compound is at least 0.1% by mass of the electrolyte. The electrolyte can significantly improve the performance of an SEI film, thereby facilitating increasing the cycle performance and storage performance of the lithium ion battery.

A non-aqueous electrolyte, a secondary battery and an electric device are described. The non-aqueous electrolyte comprises additives; the additives comprise a first additive and a second additive; the first additive is any one or more cyclic sulfate compounds having a structure represented by general formula (I);

##STR00001##

the second additive is an organic base additive; the organic base additive comprises any one or more of groups consisting of 5-12 membered aromatic heterocyclic organic bases or 5-12 membered aliphatic heterocyclic organic bases; ring structures in the 5-12 membered aromatic heterocyclic organic bases and the 5-12 membered aliphatic heterocyclic organic bases contain nitrogen atoms.

A non-aqueous electrolyte, a secondary battery and an electric device are described. The non-aqueous electrolyte comprises additives; the additives comprise a first additive and a second additive; the first additive is any one or more cyclic sulfate compounds having a structure represented by general formula (I);

##STR00001##

the second additive is an organic base additive; the organic base additive comprises any one or more of groups consisting of 5-12 membered aromatic heterocyclic organic bases or 5-12 membered aliphatic heterocyclic organic bases; ring structures in the 5-12 membered aromatic heterocyclic organic bases and the 5-12 membered aliphatic heterocyclic organic bases contain nitrogen atoms.

Provided are a non-aqueous electrolyte, a secondary battery, and an electrical apparatus. The non-aqueous electrolyte comprises an additive, the additive comprising a cyclic sulfate ester compound having the structure shown in general formula (I), wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are each independently selected from any one of: a group having the structure shown in general formula (II), a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C1-C6 alkoxy group, a C1-C6 haloalkoxy group, a C2-C6 alkenyl group, a C2-C6 ester group, a cyano group, and a sulfonic acid group, where n1, n2 and n3 are each independently any integer 0-2.

An organic electrolytic solution includes a first lithium salt; an organic solvent; a bicyclic sulfate-based compound represented by Formula 1 below; and a nitrile group-containing compound, wherein the nitrile group-containing compound includes a plurality of nitrile groups: ##STR00001## 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.

A lithium battery includes a cathode including a cathode active material; an anode including an anode active material; and an organic electrolytic solution between the cathode and the anode, wherein the cathode active material includes a first lithium transition metal oxide and a second lithium transition metal oxide, the first lithium transition metal oxide and the second lithium transition metal oxide have different particle diameters, the second lithium transition metal oxide includes primary particles having a particle diameter of about 1 m or more, and the organic electrolytic solution includes a first lithium salt, an organic solvent, and a bicyclic sulfate-based compound represented by Formula 1 below: ##STR00001##