Abstract:
To increase the volume density or weight density of lithium ions that can be received and released in and from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese composite oxide represented by LixMnyMzOw that includes a region belonging to a space group C2/c and is covered with a carbon-containing layer is used as the positive electrode active material. The element M is an element other than lithium and manganese. The lithium manganese composite oxide has high structural stability and high capacity.
Abstract:
In manufacturing a storage battery electrode, a method for manufacturing a storage battery electrode with high capacity and stability is provided. As a method for preventing a mixture for forming an active material layer from becoming strongly basic, a first aqueous solution is formed by mixing an active material exhibiting basicity with an aqueous solution exhibiting acidity and including an oxidized derivative of a first conductive additive; a first mixture is formed by reducing the oxidized derivative of the first conductive additive by drying the first aqueous solution; a second mixture is formed by mixing a second conductive additive and a binder; a third mixture is formed by mixing the first mixture and the second mixture; and a current collector is coated with the third mixture. The strong basicity of the mixture for forming an active material layer is lowered; thus, the binder can be prevented from becoming gelled.
Abstract:
A graphene oxide used as a raw material of a conductive additive for forming an active material layer with high electron conductivity with a small amount of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery using the graphene oxide as a conductive additive is provided. The graphene oxide is used as a raw material of a conductive additive in a positive electrode for a nonaqueous secondary battery and, in the graphene oxide, the atomic ratio of oxygen to carbon is greater than or equal to 0.405.
Abstract:
To provide a power storage device with a high capacity. To provide a power storage device with a high energy density. To provide a highly reliable power storage device. To provide a long-life power storage device. To provide an electrode with a high capacity. To provide an electrode with a high energy density. To provide a highly reliable electrode. To provide a long-life electrode. The power storage device includes a first electrode and a second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer includes a first active material and a first binder. The first active material is graphite. A separation strength F of the first electrode that is measured when the first active material layer is separated from the first current collector after the first electrode is immersed in a solution at a temperature higher than or equal to 20° C. and lower than or equal to 70° C. for longer than or equal to three hours is higher than or equal to 0.05 N/cm and lower than or equal to 5 N/cm per unit width of a sample that is separated.
Abstract:
The volume density or weight density of lithium ions that can be received and released in and from a positive electrode active material is increased to achieve high capacity and high energy density of a secondary battery. In a lithium manganese composite oxide, each particle includes a first region including a crystal with a layered rock-salt crystal structure and a second region including a crystal with a spinel crystal structure. The second region is in contact with the outside of the first region. The lithium manganese composite oxide has high structural stability and high capacity.
Abstract:
A graphene oxide used as a raw material of a conductive additive for forming an active material layer with high electron conductivity with a small amount of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery using the graphene oxide as a conductive additive is provided. The graphene oxide is used as a raw material of a conductive additive in a positive electrode for a nonaqueous secondary battery and, in the graphene oxide, the weight ratio of oxygen to carbon is greater than or equal to 0.405.
Abstract:
An electrode improved for achieving a storage battery having both a high electrode strength and favorable electrode conductivity is provided. The electrode includes graphene and a modified polymer in an active material layer or includes a layer substantially formed of carbon particles and an active material layer including a modified polymer over a current collector. The modified polymer has a poly(vinylidene fluoride) structure and partly has a polyene structure or an aromatic ring structure. The polyene structure or the aromatic ring structure is sandwiched between poly(vinylidene fluoride) structures.
Abstract:
The cycle performance of a lithium-ion secondary battery or a lithium-ion capacitor can be obtained by minimizing the decomposition reaction of an electrolytic solution, etc. in the repeated charge and discharge cycles of the lithium-ion secondary battery or the lithium-ion capacitor. An electrode includes a current collector and an active material layer over the current collector. The active material layer includes active material particles, a conductive additive, a binder, and a film containing silicon oxide as its main component. The surface of one of the active material particles includes at least one of a region in contact with the surface of another active material particle, a region in contact with the conductive additive, and a region in contact with the binder. The surface of the active material particle except these regions is at least partly in contact with the film containing silicon oxide as its main component.
Abstract:
The volume density or weight density of lithium ions that can be received and released in and from a positive electrode active material is increased to achieve high capacity and high energy density of a secondary battery. In a lithium manganese composite oxide, each particle includes a first region including a crystal with a layered rock-salt crystal structure and a second region including a crystal with a spinel crystal structure. The second region is in contact with the outside of the first region. The lithium manganese composite oxide has high structural stability and high capacity.