Electrochemical device for storing electrical energy in rectangular geometric cells, narrow stack geometry, according to the above claims wherein for being built from a sturdy housing (4) in the form of a straight rectangular parallelepiped and where hollow metal rods (5) run on the metal substrate (14) of the base (1) and through the through holes (16) of the base (16) and through the through holes (16) of it run hollow metal rods (5) and on each one of them, the positive electrode is inserted followed by a separating element and so on, while the other hollow metal bar (5) is inserted the negative electrode, followed by a separating element and so on forming a “stack” of electrodes (6) which would fit into the base (1) forming the central structure of the device, with the hollow metal rods (5) serving as current collectors. The rectangular narrow stack geometry electrode (6) allows to carry out the pre-metallisation stage necessary to create the SEI, and the subsequent cycle stage in the same device, without reopening it.

An electrolyte for a lithium-ion battery includes a primary lithium salt and an organic compound composition. In some designs, the organic compound composition includes (1) fluoroethylene carbonate (FEC), (2) vinylene carbonate (VC), (3) at least one ester (ES), and (4) a nitrile additive composition (NAC) which includes at least one nitrile compound. In some designs, a mole fraction of the NAC in the electrolyte is in a range of approximately 0.1 mol. % to approximately 2.0 mol. %. In some designs, a mole fraction of the at least one ES in the electrolyte is at least approximately 35 mol. %.

Provided is a pouch type secondary battery including a jelly roll in which a plurality of unit cells including a structure of a separator interposed between a positive electrode and a negative electrode are laminated, wherein a unit cell positioned in an outermost layer of the jelly roll includes a carbon dioxide adsorbent.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

When a layered rock-salt type cathode active material and a sulfide solid electrolyte are mixed to be a cathode mixture, and an all solid-state battery is obtained using this mixture, oxygen is released from the cathode active material when the battery is charged, and the sulfide solid electrolyte is oxidized, increasing the battery internal resistance. To increase the concentration of cobalt inside the active material, and at the same time to lower the concentration of cobalt of the surface of the cathode active material, to suppress oxygen release in charging, specifically, a cathode mixture includes: a cathode active material; and a sulfide solid electrolyte, wherein the cathode active material has a layered rock-salt crystal phase, and is made of a composite oxide containing Li, Ni, Co, and Mn, and the concentration of cobalt inside the cathode active material is higher than that of a surface of the cathode active material.

Provided are various embodiments of a positive electrode for a secondary battery, which in one embodiment includes a first positive electrode material mixture layer formed on a positive electrode collector, and a second positive electrode material mixture layer formed on the first positive electrode material mixture layer, wherein the first positive electrode material mixture layer has an operating voltage of 4.25 V to 6.0 V and includes an active material for overcharge which generates lithium and gas during charge; a method of preparing such a positive electrode for a secondary battery; and a lithium secondary battery including such a positive electrode.

A positive electrode including a positive electrode current collector, an intermediate layer disposed on the positive electrode current collector and including a conductive agent and inorganic particles, and a positive electrode mixture layer disposed on the intermediate layer and including a positive electrode active material and a hydrogen phosphate salt represented by the general formula MaHbPO4 (wherein a satisfies 1≤a≤2, b satisfies 1≤b≤2, and M includes at least one element selected from alkali metals and alkaline earth metals), the positive electrode satisfying 0.5≤X≤3.0, 1.0≤Y≤7.0, and 0.07≤X/Y≤3.0 wherein X is the mass ratio (mass %) of the hydrogen phosphate salt relative to the total mass of the positive electrode active material and Y is the mass ratio (mass %) of the conductive agent relative to the total mass of the intermediate layer.

A method for modifying an electrode comprising an alkali metal is disclosed, the method comprising casting a salt solution comprising at least one salt comprising an alkaline ion and a solvent on the electrode; casting a fluoropolymer solution comprising at least one fluoropolymer and a solvent on the electrode; and drying the electrode.

Also disclosed is an electrode comprising an alkali metal at least partly covered by a solid electrolyte interphase, said solid electrolyte interphase having atomic ratios of carbon, fluorine and sulfur atoms of 1 C:0.15 to 0.80 F:0.02 to 0.30 S.

Proposed is a current collector for a positive electrode that substitutes for metal foil and includes a polymer film made of a nonmetal, nonconductor material, and an aluminum conductive material configured to define an outermost surface of the current collector for a positive electrode by being formed or applied, with a thickness of 0.25 to 0.6 μm, onto at least one of upper and lower surfaces of the polymer film, in which the conductive material serves as an electrochemical fuse or performs a function of blocking or reducing short-circuit current in the event of an internal short circuit or an external short circuit.

An assembly includes: an electrolytic solution, where the electrolytic solution includes a solvent and an additive, the additive includes fluoroethylene carbonate, and a weight percent of the fluoroethylene carbonate in a total mass of the solvent and the additive is 10% to 30%; and a negative electrode, where the negative electrode contains an active material and a protection layer that covers the active material. The protection layer is located between the electrolytic solution and the active material, the protection layer is in contact with the electrolytic solution, the active material contains lithium metal, and the protection layer contains silicon. The electrode assembly greatly improve the cycle performance of a lithium metal battery.