A method for manufacturing an electrode having a porosity of between 20% and 60% by volume and pores with an average diameter of less than 50 nm. In the method, provision is made of a substrate and a colloidal suspension of aggregates or agglomerates of monodisperse primary nanoparticles of an active electrode material, having an average primary diameter D.sub.50 of between 2 and 100 nm, the aggregates or agglomerates having an average diameter D.sub.50 of between 50 nm and 300 nm. A layer is deposited from said colloidal suspension on the substrate. The deposited layer is then dried and consolidated to obtain a mesoporous layer. A coating of an electronically conductive material is then deposited on and inside the pores of the porous layer. Such a porous electrode can be used in lithium-ion microbatteries.

A method for processing a negative electrode plate, a sodium-metal negative electrode plate and related devices. In a vacuum environment, the metal vapor reacts with oxygen, and the metal oxide formed by the reaction is plated on the surface of the sodium-metal negative electrode plate to form a metal oxide protective layer with high mechanical strength and stable chemical properties. The metal oxide protective layer can greatly reduce the phenomenon of low yield and performance deterioration caused by the reaction of sodium metal with air and water during the processing of the sodium-metal negative electrode plate. Since the metal oxide has a nanoscale thickness, it can form a corresponding sodium salt with sodium metal under electrochemical conditions, thereby improving the sodium ion transport rate on the surface of the sodium-metal negative electrode plate and improving the battery’s kinetic performance.

Various implementations of a method of forming an electrochemical cell include providing a first electrode, a second electrode, a separator between the first and second electrodes, and an electrolyte in a cell container. The first electrode can include silicon-dominant electrochemically active material. The silicon-dominant electrochemically active material can include greater than 50% silicon by weight. The method can also include exposing at least a part of the electrochemical cell to CO.sub.2, and forming a solid electrolyte interphase (SEI) layer on the first electrode using the CO.sub.2.

A method for fabricating an electrode for an energy storage device is provided. The method includes heating a mixture of solvent and materials for use as energy storage media; adding active material to the mixture; adding dispersant to the mixture to provide a slurry; coating a current collector with the slurry; and calendering the coating of slurry on the current collector to provide the electrode.

A method of making a positive electrode includes forming a slurry of particles using an electrode formulation, a diluent, and oxalic acid, coating the slurry on a collector and drying the coating on the collector to form the positive electrode. The electrode formulation includes an electrode active material, a conductive carbon source, an organic polymeric binder, and a water soluble polymer. The diluent consists essentially of water.

A method of making a positive electrode includes forming a slurry of particles using an electrode formulation, a diluent, and oxalic acid, coating the slurry on a collector and drying the coating on the collector to form the positive electrode. The electrode formulation includes an electrode active material, a conductive carbon source, an organic polymeric binder, and a water soluble polymer. The diluent consists essentially of water.

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.

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 material for a lithium secondary battery is provided. The material includes a lithium oxide compound or a complex oxide as reactive substance. The material also includes at least one type of carbon material, and optionally a binder. A first type of carbon material is provided as a coating on the reactive substance particles surface. A second type of carbon material is carbon black. And a third type of carbon material is a fibrous carbon material provided as a mixture of at least two types of fibrous carbon material different in fiber diameter and/or fiber length. Also, a method for preparing the material as well as lithium secondary batteries including the material is provided.