There is a liquid electrolyte composition comprising: i) a magnesium salt comprising a trifluoromethane sulfonate anion; ii) an additive comprising an organic halide salt, an inorganic halide salt or a mixture thereof; and iii) a solvent comprising one or more ethers, wherein the organic halide salt comprises a halide anion and a cation selected from an optionally substituted quaternary ammonium or a three to nine membered N-heterocyclic cation, and the cation comprises at least one protonated nitrogen capable of dissociating the trifluoromethane sulfonate anion from the magnesium salt, and wherein the total concentration of cations of the inorganic halide salt and magnesium ions of the magnesium salt divided by the concentration of anions of the inorganic halide salt is greater than 1 in the electrolyte composition. There is further provided an electrochemical cell comprising a) a positive electrode; b) a magnesium negative electrode; and c) the electrolyte composition as described herein, wherein the positive electrode and the magnesium negative electrode are in fluid communication with the electrolyte.

An electrolytic solution comprising N-(fluorosulfonyl)-N-(fluoroalkylsulfonyl)imide or di(fluorosulfonyl)imide, from which a residual solvent that affects the properties of the electrolyte solution material is reduced, is provided. A method for producing an electrolyte solution material containing fluorosulfonyl imide salt represented by the following general formula (1) and an electrolyte solution preparation solvent comprises decompressing and/or heating a solution containing the fluorosulfonyl imide salt and the electrolyte solution preparation solvent to volatilize a production solvent for the fluorosulfonyl imide salt. ##STR00001## In general formula (1), R.sub.1 represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms, R.sub.2 represents an alkali metal ion.

An electrolyte for a lithium secondary battery and a lithium secondary battery including the same, and more specifically, an electrolyte for a lithium secondary battery that can uniformly maintain a lithium ion concentration on the surface of a lithium metal negative electrode to inhibit the growth of lithium dendrites, even if a small amount of an additive comprising a functional group forming a bond with lithium metal and a polyethylene oxide chain interacting with lithium ion is contained.

An electrochemical energy storage device is described. The electrochemical energy storage device comprises: a first electrode comprising a transition metal fluoride; a second electrode; and an electrolyte comprising an ionic liquid. An electrode for the electrochemical energy storage device and a method of preparing the electrode are also described.

A gel-type electrolyte comprising a matrix which is a poly(vinylidene fluoride-co-hexafluoropropylene) polymer in which is embedded a liquid mixture comprising at least one lithium salt and a solvent comprising at least one linear carbonate, the poly(vinylidene fluoride-co-hexafluoropropylene) polymer matrix representing 5 to 95% by weight in relation to the weight of the gel-type electrolyte and the liquid mixture representing 95 to 5% by weight in relation to the weight of the gel-type electrolyte. This electrolyte exhibits increased stability with respect to oxidation and reduction.

An electrolyte solution includes an electrolyte salt and an organic solvent, wherein the electrolyte salt includes lithium bis(fluorosulfonyl)imide (LiFSI), and the percentage mass content of the lithium bis(fluorosulfonyl)imide (LiFSI) in the electrolyte solution is 4.5%-11%; the organic solvent includes ethylene carbonate, and the percentage mass contents of the ethylene carbonate and the lithium bis(fluorosulfonyl)imide satisfy: 0.9≤W.sub.LiFSI/(16.77%−W.sub.EC)≤2.9. The electrolyte solution of the present disclosure can make the battery take lower cell internal resistance, excellent high temperature storage performance and high temperature cycling performance into account at the same time.

Provided is an electrolyte for a secondary battery including: a sulfone solvent represented by the following Chemical Formula 1; and a bis(fluorosulfonyl)imide alkali metal salt (MFSI):

R.sub.1R.sub.2SO.sub.2  [Chemical Formula 1] wherein R.sub.1 and R.sub.2 are independently of each other alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, aryl having 6 to 12 carbon atoms, or a combination thereof, and the alkyl, alkoxy, and aryl of R.sub.1 and R.sub.2 are independently of one another unsubstituted or substituted with halogen, amino, or nitro.

Some embodiments of the present disclosure relate to a battery comprising a housing. In some embodiments, the housing comprises an opening. In some embodiments, the battery comprises at least one fluoropolymer membrane. In some embodiments, the at least one fluoropolymer membrane covers the opening of the housing. In some embodiments, the at least one fluoropolymer membrane has a crystallinity of 85% to 100%. In some embodiments, the at least one fluoropolymer membrane has a density of 2.0 g/cm.sup.3 to 2.2 g/cm.sup.3. In some embodiments, the at least one fluoropolymer membrane has a CO.sub.2 permeability to moisture permeability ratio of more than 0.5. A polytetrafluoroethylene film for electronic components, characterized in that the polytetrafluoroethylene film can have a density of 1.40 g/cm.sup.3 or higher and an air impermeability of 3,000 seconds or higher.

The purpose of the present disclosure is to provide a non-aqueous electrolyte secondary battery that can suppress reductions in rapid charge cycle characteristics. The non-aqueous electrolyte secondary battery according to one embodiment of the present disclosure has a positive electrode, a negative electrode, and a non-aqueous electrolyte. The negative electrode has a negative electrode collector and a negative electrode active material layer that is provided on the negative electrode collector. The negative electrode active material layer includes graphite particles A and graphite particles B as negative electrode active materials. The internal porosity of graphite particles A is no more than 5%, and the internal porosity of graphite particles B is 8%-20%. When the negative electrode active material layer is bisected in the thickness direction, there is a greater amount of graphite particles A in the outer surface-side half than in the negative electrode collector-side half.

A sulfur-carbon composite including a porous carbon material; and sulfur present in at least a part of pores of the porous carbon material and on an outer surface of the porous carbon material, wherein an inner surface and the outer surface of the porous carbon material are doped with a carbonate compound. Also, a positive electrode and a secondary battery including the same. Further, a method of preparing a sulfur-carbon composite and a method of preparing a positive electrode.