An additive for a non-aqueous electrolyte solution that can suppress the initial gas generation amount when used in a non-aqueous electrolyte solution battery. The additive for a non-aqueous electrolyte solution is represented by any one of formulae [1] to [4]: ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, X.sup.1, X.sup.2 and Y are as defined in the specification.

Separators, materials, and processes for producing electrochemical cells, for example, lithium (Li) metal batteries, and electrochemical cells produced therefrom. Such a separator includes a permeable membrane formed of a first polymer that is hydrophobic and has oppositely-disposed first and second surfaces, a second polymer that is hydrophilic and is incorporated into the first surface of the first polymer so that the first surface of the first polymer is a hydrophilic surface, and a conductive composite layer on the hydrophilic surface. The composite layer contains at least one layer of a carbonaceous material and an aqueous binder that binds the carbonaceous material together and to the hydrophilic.

A metal battery, such as a lithium battery, includes an anode, an anode current collector in electrical contact with the anode, a cathode, a cathode current collector in electrical contact with the cathode, a separator disposed between the anode and cathode, a liquid electrolyte, and an anode protection structure. The anode protection structure includes an anode protection layer disposed between the anode and the separator. The anode protection layer includes a matrix and domains within the matrix. One of the matrix and domains contains a first material and the other of the matrix and domains contains a second material. The first material is less permeable by the electrolyte than the second material.

A non-aqueous electrolyte secondary battery including a positive electrode, a separator, a negative electrode facing the positive electrode, with the separator interposed; and a liquid electrolyte. The positive electrode includes a composite oxide containing lithium as a first metal, and a second metal other than lithium. In the composite oxide, the second metal contains Ni, a content of Ni in the second metal is 90 at % or more, and a content of Co in the second metal is 10 at % or less. The liquid electrolyte contains at least one cation X selected from the group consisting of Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Fe, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, and Al.sup.3+, and an oxalate complex anion Y.

A positive electrode material of the present disclosure includes: a positive electrode active material; and a first solid electrolyte material coating at least partially a surface of the positive electrode active material, wherein the first solid electrolyte material includes Li, Ti, M1, and F, and the M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr.

Disclosed are an electrolyte for a lithium secondary battery and a lithium secondary battery comprising the same. The electrolyte for a lithium secondary battery, according to an embodiment, can comprise: a nonaqueous organic solvent; a lithium salt; a first additive comprising a compound represented by a specific chemical formula; and a second additive including at least one of lithium difluorophosphate (LiPO.sub.2F.sub.2), a cyclic carbonate including a fluorine atom, and a dinitrile compound.

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.

This invention provides nonaqueous electrolyte solutions for lithium batteries which contain one or more brominated flame retardants. The nonaqueous electrolyte solutions comprise a) a liquid electrolyte medium; b) a lithium-containing salt; and c) at least one brominated flame retardant. The brominated flame retardant is present in the electrolyte solution in a flame retardant amount.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein lithium metal deposits on the negative electrode during charging, and the lithium metal dissolves in the nonaqueous electrolyte from the negative electrode during discharging. The positive electrode includes a positive electrode mixture comprising a positive electrode active material and an additive. The positive electrode active material includes a composite oxide including lithium and a transition metal. The additive includes a particulate base material, and an organic compound group fixed to a surface of the base material by a covalent bond. The covalent bond includes a X—O-A bond. The element X is bonded to the organic compound group, and is at least one selected from the group consisting of Si and Ti. The element A is an element constituting the base material. The organic compound group has 2 or more carbon atoms.

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.