A lithium-ion secondary battery is provided, where an electrolyte solution of the lithium-ion secondary battery comprises a highly heat-stable salt (M.sup.y+).sub.x/yR.sub.1(SO.sub.2N.sup.−).sub.xSO.sub.2R.sub.2, where the M.sup.y+ is a metal ion, R.sub.1 and R.sub.2 are each independently a fluorine atom, an alkyl with 1-20 carbon atoms, a fluoroalkyl with 1-20 carbon atoms, or a fluoroalkoxy with 1-20 carton atoms, x is 1, 2, or 3, and y is 1, 2, or 3. A mass percent of the salt in the electrolyte solution is set as k2%; a temperature rise coefficient k1 of the positive electrode sheet satisfies 2.5≤k1≤32, where k1=Cw/Mc, Cw is a positive electrode material load per unit area (mg/cm.sup.2) on the surface of any side of the positive electrode current collector on which a positive electrode material layer is loaded, and Mc is a carbon content (%) of the positive electrode material layer; and the lithium-ion secondary battery satisfies 0.34≤k2/k1≤8.

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.

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 lithium battery includes a cathode; an anode; and an organic electrolytic solution between the cathode and the anode, wherein the anode includes an anode current collector and an anode active material layer on the anode current collector, the anode active material layer includes carbonaceous and silicon-containing composite anode active materials, the anode active material layer includes first and second anode active material layers, and the first anode active material layer is between the anode current collector and the second anode active material layer, a content of silicon in the first anode active material layer is higher than the second anode active material layer, 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##

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 μm 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##

The invention pertains to a process for the manufacture of a fluoropolymer film, to the fluoropolymer film obtainable therefrom and to use of said fluoropolymer film in electrochemical and photo-electrochemical devices.

To provide a non-aqueous electrolyte solution, a non-aqueous secondary battery, a cell pack, and a hybrid power system, capable of improving desired battery performance in an acetonitrile electrolyte solution, the non-aqueous electrolyte solution contains a non-aqueous solvent, PO.sub.2F.sub.2 anions, and cyclic acid anhydride.

The invention provides a method of recovering a lithium electrolyte salt from a used electrolyte, the method comprising: contacting a used electrolyte comprising a lithium electrolyte salt and electrolyte solvent with a polar aprotic solvent to produce a solution comprising the lithium electrolyte salt, the electrolyte solvent and the polar aprotic solvent, wherein at least one of the electrolyte solvent and the polar aprotic solvent comprises carbonate solvent, combining the solution with a precipitation solvent in which the lithium electrolyte salt is poorly soluble; precipitating a precipitated composition comprising the lithium electrolyte salt solvated by the carbonate solvent from a solvent mixture comprising the polar aprotic solvent, the precipitation solvent and the electrolyte solvent, wherein the precipitated composition precipitates as a solid or as a liquid; and separating the precipitated composition from the solvent mixture.

A non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery including the same are disclosed herein. In some embodiments, a non-aqueous electrolyte solution for a lithium secondary battery includes a lithium salt, an organic solvent containing a carbonate compound and a propionate compound, a first additive containing a compound represented by the following Formula 1, and a second additive containing 1,3,6-hexanetricarbonitrile, wherein the first additive and the second additive are present in a weight ratio of 1:1.1 to 1:5.5,

NC—R—CH═CH—R—CN  [Formula 1] wherein, in Formula 1, R is an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms.

A lithium battery including: a cathode; an anode; and an electrolyte between the cathode and the anode, wherein the cathode includes a cathode active material represented by Formula 1,
Li.sub.xNi.sub.yM.sub.1−yO.sub.2-zA.sub.z  Formula 1 wherein 0.95≤x≤1.2, 0.75≤y≤0.98, and 0≤z<0.2, M is Al, Mg, Mn, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Bi, or a combination thereof, and A is an element having an oxidation number of −1, −2, or −3, wherein each element of M is independently present in an amount of 0.02≤y≤0.3, wherein a total content of M is 0.02≤y≤0.3;
and wherein the electrolyte includes a lithium salt, a non-aqueous solvent, and a diallyl compound represented by Formula 2, ##STR00001## wherein L.sub.1 and L.sub.2 are each independently a single bond, a C.sub.1-C.sub.20 alkylene group, or a substituted or unsubstituted C.sub.2-C.sub.20 alkenylene group.