A molten carbonate fuel cell assembly includes a cathode electrode; an anode electrode; an electrolyte matrix disposed between the cathode electrode and the anode electrode; a cathode current collector abutting the cathode electrode; and a first electrolyte composition stored in the cathode electrode, the first electrolyte composition comprising a first mixture of a eutectic Li/Na carbonate electrolyte doped with one or more additive materials, wherein the one or more additive materials comprise one or more of SrO, BaCO.sub.3, BaO, SrCO.sub.3, and combinations thereof.

The present invention relates to an electrochemical device comprising a) a positive electrode, b) a negative electrode, c) a separator, and d) a liquid electrolyte, wherein at least one of said positive electrode and said negative electrode is a gelled electrode comprising an electronic conductive substrate and directly adhered onto the electronic conductive substrate, at least one layer of a gelled electrode-forming composition, and wherein the d) liquid electrolyte comprises at least one organic carbonate and/or at least one ionic liquid, and at least one metal salt. The present invention also relates to a process for manufacturing an electrochemical device comprising at least one gelled electrode.

An electrochemical apparatus, including a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode current collector and a positive electrode mixture layer formed on the positive electrode current collector, where the electrolyte contains a specific proportion of lithium difluorophosphate, and the positive electrode mixture layer has a relatively small thickness change rate.

An electrolyte, an electrochemical device containing same, and an electronic device. Specifically, an electrolyte, including dimethyl carbonate, ethyl methyl carbonate, and lithium bis(oxalato)borate. The ethyl methyl carbonate and the lithium bis(oxalato)borate each account for a specified weight percent in the electrolyte, and the weight percent of the dimethyl carbonate and the weight percent of the ethyl methyl carbonate in the electrolyte meet a specified relationship. The electrolyte provides with balanced rate performance, the low-temperature discharge performance, and the high-temperature storage and cycle performance of the electrochemical device, and helps to achieve excellent comprehensive performance of the electrochemical device.

An electrolyte for a lithium secondary battery according to embodiments of the present invention includes an organic solvent, a lithium salt, and an additive including a succinic anhydride-based compound substituted with a trialkoxysilyl alkyl group. A lithium secondary battery including the electrolyte provides enhanced cycle property and high temperature stability.

An electrolyte solution capable of constituting a secondary battery in which a volume change due to charge and discharge is small and cycle characteristics are excellent is provided. The present example embodiment relates to an electrolyte solution for a lithium ion secondary battery comprising a fluorinated ether and a cyclic dicarboxylic acid ester.

To provide a composition containing a sulfonylimide salt, which has excellent storage stability even at a high temperature and can be used for an electrolytic solution material or an electrolytic solution. The composition contains an electrolyte, a solvent, and an anion component. The electrolyte contains a sulfonylimide salt, the anion component contains an acid component having an acid-dissociation constant pKa (an acid-dissociation constant pKa1 in a first stage for a plurality of ionized acids) of 0 or more and 6.5 or less at a concentration of 50 ppm or more and 10000 ppm or less relative to the electrolyte, a concentration of fluoride ion is 100 ppm or less relative to the electrolyte, and a concentration of sulfate ion is 100 ppm or less relative to the electrolyte.

Embodiments described herein relate to electrochemical cells with multiple separators, and methods of producing the same. A method of producing an electrochemical cell can include disposing an anode material onto an anode current collector, disposing a first separator on the anode material, disposing a cathode material onto a cathode current collector, disposing a second separator onto the cathode material, and disposing the first separator on the second separator to form the electrochemical cell. The anode material and/or the cathode material can be a semi-solid electrode material including an active material, a conductive material, and a volume of liquid electrolyte. In some embodiments, less than about 10% by volume of the liquid electrolyte evaporates during the forming of the electrochemical cell. In some embodiments, the method can further include wetting the first separator and/or the second separator with an electrolyte solution prior to coupling the first separator to the second separator.

Electrolytes are described that involve lithium salt blends and compatible nonaqueous solvents that provide to high rate performance, charging and discharging, of lithium ion cells using silicon-based active materials, such as silicon suboxide composites, for example, silicon oxide/silicon/carbon composites. The lithium salts generally were a blend of LiPF.sub.6, and LiFSI or LiTFSI. The solvents generally comprised fluoroethylene carbonate and dimethyl carbonate with optional cosolvents and/or other additives.

A negative electrode, a method for manufacturing the negative electrode, a secondary battery, and a method for manufacturing the secondary battery, wherein the negative electrode includes a negative electrode current collector, and a negative electrode active material layer. The negative electrode active material layer includes a first negative electrode active material layer on at least one surface of the negative electrode current collector and a second negative electrode active material layer on the first negative electrode active material layer. The first negative electrode active material layer includes ethylene carbonate.