VEHICLE ENERGY JAPAN INC.

A battery pack capable of suppressing heat generation from current flowing through a bus bar and suppressing cell deterioration includes first to fourth stacked cells, each cell including positive electrode terminal and a negative electrode terminal having higher conductivity, and a bus bar electrically connecting the positive electrode terminal of the second cell and the negative electrode terminal of the third cell, the second and third cells being disposed side-by-side. The bus bar includes a first conductive part connected to the positive electrode terminal of the second cell, a second conductive part connected to the negative electrode terminal of the third cell and having higher conductivity and higher specific gravity, and a connecting part that connects the first conductive part and the second conductive part. The connecting part is disposed in a first region facing the second cell or in a second region facing the third cell.

An electrode (positive electrode ( 100 )) includes a current collector layer (positive electrode current collector layer ( 110 )), an active material layer (positive electrode active material layer ( 120 )) that is stacked on and joined to the current collector layer and contains an active material (positive electrode active material ( 121 )), and an end portion insulating layer ( 130 ) that extends from the side of an end portion ( 110 b ) of the current collector layer to a side portion ( 120 a ) of the active material layer (positive electrode active material layer ( 120 )) and is stacked on the current collector layer to be joined to the current collector layer and the active material layer, the end portion insulating layer ( 130 ) containing particles ( 131 ) and a binder ( 132 ). The occupancy percentage of the particles ( 131 ) in the end portion insulating layer ( 130 ) is at least 55% and at most 99.5%. The occupancy percentage of the particles ( 131 ) and the binder ( 132 ) in the end portion insulating layer ( 130 ) is at least 55.5% and at most 99%. The thickness of the end portion insulating layer ( 130 ) along a stacking direction Z is at least 1/20 and at most ½ of the thickness of the active material layer (positive electrode active material layer ( 120 )) along the stacking direction Z.

An electrode (positive electrode 100 ) has a collector layer (positive electrode collector layer 110 ), an active material layer (positive electrode active material layer 120 ), and an intermediate layer ( 130 ). The active material layer (positive electrode active material layer 120 ) is stacked on and joined with the collector layer (positive electrode collector layer 110 ), and contains an active material (positive electrode active material 121 ). The intermediate layer ( 130 ) is disposed intermediate along a stacking direction (Z) between a side of an end portion ( 110 b ) of the collector layer (positive electrode collector layer 110 ) and an end portion ( 120 b ) of the active material layer (positive electrode active material layer 120 ), and joined with the collector layer (positive electrode collector layer 110 ) and the active material layer (positive electrode active material layer 120 ).

Provided is an electrode (positive electrode 100 ) that includes a current collecting layer (positive electrode current collecting layer 110 ), an active material layer (positive electrode active material layer 120 ), and an insulating layer ( 130 ). The active material layer (positive electrode active material layer 120 ) contains an active material (positive electrode active material 121 ) and is stacked on and bonded to the current collecting layer (positive electrode current collecting layer 110 ). The insulating layer ( 130 ) contains an insulating material ( 131 ) having insulating properties, and is stacked on and bonded to the active material layer (positive electrode active material layer 120 ). The average particle diameter (D50) of the insulating material ( 131 ) is 0.5 μm or more to 5.0 μm. The insulating layer ( 130 ) has a porosity of 25% or more but 70% or less. The insulating layer ( 130 ) and the active material layer (positive electrode active material layer 120 ) overlap with each other by 0.001% or more but 30% or less in a stacking direction Z.

A battery control device which obtains a state of charge of a secondary battery from characteristics representing a relationship of a state of charge and a voltage of the secondary battery comprises a calling unit which calls a first characteristic among a plurality of the characteristics stored in advance based on use history information of the secondary battery, a correction limit width designation unit which designates a correction limit width for prescribing a tolerance level of correcting the first characteristic, and a direct detection correction unit which creates a second characteristic in which the first characteristic has been corrected according to the correction limit width based on a current value and a voltage value of the secondary battery, wherein the state of charge of the secondary battery is obtained using the second characteristic.

A battery including a gas discharge mechanism that discharges when a gas pressure in a battery container reaches a predetermined value. The gas discharge mechanism includes a first gas discharge passage connected to an inner portion side of the battery container, a second gas discharge passage connected to the first gas discharge passage and connected to an outer portion side of the battery container, and a gas discharge valve as part of a gas discharge passage comprising the first and second gas discharge passages and opens so that the inner and outer portion sides of the battery container are connected to each other when gas pressure reaches a predetermined value. A cross-sectional shape of the second gas discharge passage is formed in a shape that does not hinder the flow of a streamline of the gas that flows out of the first gas discharge passage.

A square secondary battery, including: a conductive container which is formed in a rectangular parallelepiped shape opened on one surface side; a lid which seals the one surface side of the container; a charge/discharge body which is housed in the container and which has electrodes respectively formed on both sides in a width direction; and an insulating member which coats the charge/discharge body and which insulates the charge/discharge body and the container from each other, wherein the insulating member is formed in a rectangular parallelepiped shape opened on one surface side and at least one side surface among a pair of side surfaces respectively opposing the electrodes of the charge/discharge body is folded in a direction of separation from the charge/discharge body along a height direction.

A lithium ion secondary battery is provided which has a sufficient discharge capacity and has a low internal resistance in a low SOC range. The lithium ion secondary battery includes: a positive electrode including a positive electrode mixture containing a positive electrode active material represented by the following formula: Li 1+x M A O 2 ; (where X satisfies −0.15≤X≤0.15, M A represents a group of elements including at least one selected from the group consisting of Mn and Al, Ni, and Co.); and a negative electrode including a negative electrode mixture containing a negative electrode active material containing a carbon-based material, a negative electrode additive containing a copper oxide, and a binder, in which the negative electrode mixture contains the copper oxide in an amount of 0.5 wt % or more and 15 wt % or less based on the total weight of the negative electrode active material and the negative electrode additive.

An assembled battery includes: a plurality of batteries, each with a container that contains an electric charger/discharger and an electrolytic solution and a gas discharge unit on its one surface, wherein the plurality of batteries are stacked so that the one surface of each battery is aligned to be flush with the one surface of the other batteries; a metal first flow path member is placed opposite the surface with the gas discharge unit, and configures a first flow path unit for gas discharged from the gas discharge units of the batteries; a second flow path member that forms a second flow path unit with a smaller flow path cross-sectional area; a connector that couples the first and the second flow path unit via an opening in the first flow path member; and a guide member that partitions a space inside the connector. This configuration allows for efficient gas discharge.

It is an object to provide a lithium ion secondary battery that ensures a replaceability of an electrolyte in a proximity of an active material and is excellent in output and responsiveness. The lithium ion secondary battery includes an electrode that includes a negative electrode foil, a negative electrode mixture layer disposed on a surface of the negative electrode foil, and an insulating layer disposed on a surface of the negative electrode mixture layer. The insulating layer contains ceramic particles. On the surface of the negative electrode mixture layer facing a border between the insulating layer and the negative electrode mixture layer, a plurality of holes (puddles) having diameters of 2.5 μm or more are provided.