An electrode coating liquid composition that contains an electrode active material, a conductive auxiliary, a dispersant, and a binding agent. The dispersant contains cellulose fibers that satisfy (a)-(c). A total amount of the dispersant and the binding agent is 0.5 mass % or more and 15 mass % or less with respect to 100 mass % of the solid content of the electrode coating liquid composition. (a) the number average width of the shortest widths is 2 nm or more and 200 nm or less. (b) the aspect ratio is 7.5 or more and 75 or less. (c) cellulose I crystals are included and the crystallinity thereof is 70% or more and 95% or less.

A battery and supercapacitor system of a vehicle includes a lithium ion battery (LIB) having first and second electrodes, and a supercapacitor having third and fourth electrodes. A first reference electrode is disposed between the first and second electrodes and is configured to measure a first potential at a location between the first and second electrodes. A second reference electrode is disposed between the third and fourth electrodes and is configured to measure a second potential at a location between the third and fourth electrodes. The first electrode may be connected to the third electrode, and the second electrode may be connected to the fourth electrode. The first and second reference electrodes may not be connected to any of the first, second, third, or fourth electrodes.

A battery and supercapacitor system of a vehicle includes a lithium ion battery (LIB) having first and second electrodes, and a supercapacitor having third and fourth electrodes. A first reference electrode is disposed between the first and second electrodes and is configured to measure a first potential at a location between the first and second electrodes. A second reference electrode is disposed between the third and fourth electrodes and is configured to measure a second potential at a location between the third and fourth electrodes. The first electrode may be connected to the third electrode, and the second electrode may be connected to the fourth electrode. The first and second reference electrodes may not be connected to any of the first, second, third, or fourth electrodes.

The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

A separator includes a porous substrate and a first coating located on at least one surface of the porous substrate. The first coating includes a first polymer binder and first inorganic particles, and the first polymer binder comprising core-shell structured particles. 0.3×Dv50 of the first polymer binder≤Dv50 of the first inorganic particles≤0.7×Dv50 of the first polymer binder. Dv50 represents a particle size which reaches 50% of a cumulative volume from a side of small particle size in a granularity distribution on a volume basis The first inorganic particles are used in the first coating, ensuring that the first polymer binder has a bonding function, electrolyte transport is promoted, and the rate performance of the electrochemical device is improved.

A separator includes a porous substrate and a first coating located on at least one surface of the porous substrate. The first coating includes a first polymer binder and first inorganic particles, and the first polymer binder comprising core-shell structured particles. 0.3×Dv50 of the first polymer binder≤Dv50 of the first inorganic particles≤0.7×Dv50 of the first polymer binder. Dv50 represents a particle size which reaches 50% of a cumulative volume from a side of small particle size in a granularity distribution on a volume basis The first inorganic particles are used in the first coating, ensuring that the first polymer binder has a bonding function, electrolyte transport is promoted, and the rate performance of the electrochemical device is improved.

An electrode for power storage devices includes: a conductor plate having a first surface which has at least one first recessed portion and a second surface located opposite to the first surface, the first surface including a first region located outside the first recessed portion; and a first composite film including a first layer which contains an insulative material, a first electrically-conductive layer and a second electrically-conductive layer, the first layer being provided between the first electrically-conductive layer and the second electrically-conductive layer, wherein the first electrically-conductive layer of the first composite film is connected with the conductor plate at the first recessed portion, and the second electrically-conductive layer of the first composite film is connected with the first electrically-conductive layer at a position overlapping the first recessed portion as viewed in a normal direction of the first region of the conductor plate.

A wireless sensor device capable of constant operation without replacement of batteries. The wireless sensor device is equipped with a rechargeable battery and the battery is recharged wirelessly. Radio waves received at an antenna circuit are converted into electrical energy and stored in the battery. A sensor circuit operates with the electrical energy stored in the battery, and acquires information. Then, a signal containing the information acquired is converted into radio waves at the antenna circuit, whereby the information can be read out wirelessly.

The present invention relates to an aqueous electrolyte capable of improving low temperature performance. More specifically, the present invention provides an aqueous electrolyte that is an aqueous solution including lithium trifluoromethanesulfonate at a predetermined concentration range without separate additives, and thus can prevent freezing and realize high performance even at a very low temperature of about −30° C. or less, and an energy storage device including the same.