Disclosed are a positive active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same.

The positive active material includes a first positive active material in a form of secondary particles including a plurality of primary particles that are aggregated together, and a second positive active material having a single crystal form, wherein both of the first positive active material and the second positive active material are nickel-based positive active materials, each of the first positive active material and the second positive active material is coated with cobalt, and a maximum roughness of a surface of the second positive active material is greater than or equal to about 15 nm.

A negative electrode for an alkaline storage battery that achieves both an improvement in cycle life and an improvement in low temperature discharge characteristics, and an alkaline storage battery including the negative electrode are disclosed. The negative electrode for an alkaline storage battery includes a negative electrode core body formed of metal, and a negative electrode mixture layer which contains at least a hydrogen storage alloy and yttrium fluoride, and is carried on the negative electrode core body. Particles of the yttrium fluoride are formed so that the average particle size thereof is equal to 1 μm or more and 7 μm or less.

The present disclosure provides an electroactive material for an electrochemical cell that cycles lithium ions. The electroactive material includes a plurality of electroactive particles having an average diameter greater than or equal to about 100 nm to less than or equal to about 50 μm. Each electroactive particle includes a layered anode material defined by a two-dimensional allotrope. The two-dimensional allotrope includes a plurality of atomic layers that include a negative electroactive material selected from the group consisting of: silicon (Si), germanium (Ge), boron (B), and combinations thereof. In certain variations, the layered anode material may be prelithiated. For example, lithium ions may be dispersed between the atomic layers of the two-dimensional allotrope to pre-lithiate the layered anode material.

A lithium-ion secondary battery including positive and negative electrodes, a separator element, an electrical conductor element and a binder, wherein the positive electrode includes a lithium-containing metal phosphate compound coated with a carbon material having at least one phase selected from a graphene phase and an amorphous phase, and further includes carbon black and a fibrous carbon material and wherein the negative-electrode material includes a graphite carbon material having at least one carbon phase selected from a graphene phase and an amorphous phase, and further includes carbon black and a fibrous carbon material, and wherein the binder includes a water-soluble synthetic resin or a water-dispersible synthetic resin. The most preferred positive electrode includes LiFePO.sub.4, The most preferred negative electrode includes artificial graphite or graphitazable powder. The most preferred binder is carboxyl methyl cellulose further including a surface active agent. A method of making the lithium-ion secondary battery.

A positive electrode for a nonaqueous secondary battery including an active material layer which has sufficient electron conductivity with a low ratio of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery including an active material layer which is highly filled with an active material, id est, including the active material and a low ratio of a conductive additive. The active material layer includes a plurality of particles of an active material with a layered rock salt structure, graphene that is in surface contact with the plurality of particles of the active material, and a binder.

Disclosed is a method for producing polymer-encapsulated Li.sub.2S.sub.x (where 1≤x≤2) nanoparticles. The method comprises the step of forming a mixture of a polymer and sulfur. The method further comprises vulcanizing the mixture at a vulcanization temperature attained at a heating rate, in a vulcanization atmosphere, and electrochemically reducing a vulcanized product at a reduction potential. Also disclosed is a method for producing a battery component, the component comprising a cathode and a separator.

The present invention relates to a negative active material for a lithium secondary battery, a preparation method therefor, and a lithium secondary battery including the same. The negative electrode active material is a negative electrode material for a secondary battery, the negative electrode active material comprising a silicon-carbon composite comprising: a core comprising crystalline carbon and silicon particles; and an amorphous carbon-containing coating layer disposed on a surface of the core, wherein the negative electrode active material comprises: silicon oxide formed on a surface of the silicon particles; and an oxide of crystalline carbon, formed on a surface of the crystalline carbon, the average particle diameter (D50) of the silicon particles having a nanometer size, the proportion of O relative to Si in the silicon oxide is 30%-50%, and the proportion of O relative to C in the oxide of the crystalline carbon is 4%-10%.

A nanocomposite includes one or more graphene-based materials (GMs), a nitrogen-containing polymer (an N-polymer), and elemental sulfur (S). The nanocomposite is suitable for use as a stable, high capacity electrode for rechargeable batteries such as lithium-sulfur (Li—S) batteries. Example methods of fabricating a nanocomposite include the addition of an N-polymer to a dispersion (e.g., an aqueous dispersion) or slurry of GMs mixed with a sulfur sol. The N-polymer can interact strongly with the GMs to form a cross-linked network. In one embodiment, hydrothermal treatment of the aqueous dispersion or slurry is used to melt the sulfur such that it becomes distributed within the network formed by the GMs and the N-polymer. The resulting nanocomposite material can then be processed through the addition of one or more other binders and/or solvents, and formed into a final electrode.

A positive electrode active material for a secondary battery includes a first positive electrode active material and a second positive electrode active material, wherein an average particle diameter (D.sub.50) of the first positive electrode active material is twice or more than an average particle diameter (D.sub.50) of the second positive electrode active material, and the second positive electrode active material has a crystallite size of 200 nm or more.

A method for manufacturing a lithium secondary battery, including the steps: (S1) forming a preliminary negative electrode by coating a negative electrode slurry including a negative electrode active material, conductive material, binder and a solvent onto at least one surface of a current collector, followed by drying and pressing the negative electrode slurry coated current collector, to form a negative electrode active material layer surface on the current collector; (S2) coating lithium metal foil onto the negative electrode active material layer surface of the preliminary negative electrode in the shape of a pattern in which pattern units are arranged; (S3) cutting the preliminary negative electrode on which the lithium metal foil is pattern-coated to obtain negative electrode units; (S4) impregnating the negative electrode units with an electrolyte to obtain a pre-lithiated negative electrode; and (S5) assembling the negative electrode obtained from step (S4) with a positive electrode and a separator.