Prime Planet Energy & Solutions

The battery system 1 includes plural battery modules 10 connected to a load 100 and includes a control device 60. The battery module 10 includes a pre-charge unit 40 having a pre-resistance 41. The control device 60 includes a pre-charge process executing part 67 that executes a pre-charge process on each one battery module 10 of the plural battery modules 10 one by one. The control device 60 further includes a time obtaining part 64 that obtains a cooling time T<C> being an elapsed time since a previous pre-charge process is performed on a previous hierarchy No. 1 battery module on which the pre-charge process is firstly executed when the previous connection to the load 100 is performed, and includes an order deciding part 65 that decides the order to inhibit the pre-charge process from being executed firstly on the previous hierarchy No. 1 battery module when the cooling time T<C> is equal to or less than a reference time T<D>. Accordingly, it is possible to suppress a deviation of the deteriorations of the pre-resistances.

A herein disclosed battery system 1 includes two kinds of contactors, i.e., a first contactor 40 and a second contactor 50. The first contactor 40 includes a first positive electrode terminal 42 connected to a positive electrode 11Ap of a battery unit 10, and includes a first negative electrode terminal 44 connected via a positive electrode output terminal 20 to an external load 100. In addition, the second contactor 50 includes a second positive electrode terminal 52 connected to a negative electrode 11Nn of the battery unit 10, and includes a second negative electrode terminal 54 connected via a negative electrode output terminal 30 to the external load 100. Then, the herein disclosed battery system 1 is configured to preferentially turn OFF the contactor, in which a forward electric current flows,during both of an electrical charge and an electrical discharge. Accordingly, the electric current can be safely and promptly interrupted, and thus it is possible to inhibit an malfunction due to welding of the contactor.

A battery cell (10, 10B, 10C, 10D, 10E, 10F) that forms a secondary battery (ND) includes an electrode body (2), and a battery can (1, 1B, 1C, 1D, 1E, 1F) made of metal and having an extruded can (11, 11B, 11C, 11D, 11E, 11F) in the form of a quadrangular tube which contains the electrode body (2) and is open at opposite ends in an axial direction (Z), and lids (12) that seal the opposite ends of the extruded can (11, 11B, 11C, 11D, 11E, 11F). The extruded can (11, 11B, 11C, 11D, 11E, 11F) includes a pair of long side portions (111) extending in the axial direction, and an upper short side portion (112a) and a lower short side portion (112b) perpendicular to the long side portions (111). The lower short side portion (112b) has a larger thickness than the upper short side portion (112a).

A method for sequentially deciding allowable power or allowable current for charging or discharging of a system (10) including parallel-connected electric storage devices (100) includes: determining allowable power or allowable current for each of the electric storage devices (100) at a present time; estimating a power ratio or current ratio between the electric storage devices (100) at a future time within a predetermined time; and deciding, in accordance with the estimated future power ratio or current ratio, allowable power or allowable current for the system (10) valid until after lapse of the predetermined time such that power or current of each of the electric storage devices (100) is within the allowable power or allowable current for each of the electric storage devices (100) at the present time.

A method of manufacturing a battery case includes: forming a first thin portion (12A) and a second thin portion (12B) in a metal plate (10); cutting the metal plate (10) into a substantially rectangular shape having a pair of first end sides (21A, 21B) and a pair of second end sides (22A, 22B), wherein one of the pair of first end sides (21A, 21B) is formed by cutting the first thin portion (12A), and the other of the pair of first end sides (21A, 21B) is formed by cutting the second thin portion (12B); after the cutting the metal plate (10), bending the metal plate (10) into a tubular shape; and joining one of the pair of second end sides (22A, 22B) and the other of the pair of second end sides (22A, 22B) after the bending the metal plate (10) into the tubular shape.

A battery case for a secondary battery having a gas discharge valve provided on one flat surface, wherein the gas discharge valve comprises a first thin portion having a thickness smaller than that of the flat surface and a second thin portion formed on a surface of the first thin portion, and having a thickness even smaller than that of the first thin portion, and a residual stress at the first thin portion is greater than that at the second thin portion.

A laser welding method includes a preparation step and a welding step. A first member and a second member prepared in the preparation step have end faces that are adjusted to the same level in height when stacked with each other. Each of the first member and the second member has a stepped face higher than the end face at a position away from a boundary between the stacked first and second members. In the welding step, the boundary between the end faces of the first member and the second member is irradiated with a laser beam in a state that hoods are placed on the stepped faces of the first member and the second member, respectively.

A laser welding method includes a preparation step and a welding step. A first member and a second member prepared in the preparation step have end faces that are adjusted to the same level in height in a state that the first and second members are stacked with each other. The first member has a stepped face lower than its end face at a position away from a boundary between the stacked first and second members. The second member has a stepped face lower than or higher than its end face at a position away from the boundary between the stacked first and second members. In the welding step, the boundary between the end faces of the first and second members is irradiated with a laser beam in a state that hoods are placed on the stepped faces of the first and second members, respectively.

An electrode plate (5P) includes a current collecting foil (SPF), a conductive bonding layer (5PY) provided on the electrode foil (5PF), an active material layer (SPA) provided on the bonding layer (5PY) and bonded to the bonding layer (5PY), and an insulating protective layer (SPX) provided along the bonding layer (5PY) and the active material layer (5PA) and between an electrode foil exposed portion (5PC) of the electrode foil (SPF), where the electrode foil (5PF) is exposed, and the bonding layer (5PY). The insulating protective layer (SPX) is thinner than the bonding layer (SPY).

An electricity storage device disclosed herein includes an electrode assembly including a positive electrode and a negative electrode. The negative electrode includes a negative electrode composite material layer containing a graphite-based negative electrode active material particle. A mean circularity of the graphite-based negative electrode active material particle is equal to or more than 0.8. With respect to a particle size distribution on a volume basis of the graphite-based negative electrode active material particle that is obtained by a laser diffraction scattering method, all of following conditions are satisfied when a particle diameter whose cumulative frequency from a small particle side is 10% is treated as d10, a particle diameter whose cumulative frequency is 50% is treated as d50, and a particle diameter whose cumulative frequency is 90% is treated as d90: (1) d90/d10 is equal to or more than 5; and (2) d90/d50 is equal to or less than 2.