A method for joining busbars includes reshaping a raw laser beam to obtain a reshaped laser beam. The reshaped laser beam comprises a core focus portion and at least one ring focus portion. The core focus portion and the ring focus portion are coaxial with respect to one another. The ring focus portion surrounds the core focus portion. The method further includes directing the reshaped laser beam to a plurality of busbars to weld the plurality of busbars to one another along at least one weld seam.

A method for joining together metal workpiece (12,14 or 12,150, 14) includes forming a laser weld joint (66) in a workpiece stack-up (10) that fusion welds two or more overlapping metal workpiece (12,14 or 12,150 or 14) together. The laser weld joint (66) has an initial top surface (76). Once the laser weld joint (66) is formed, the method calls for impinging the laser weld joint (66) with a laser beam (24) and moving the laser beam (24) along the initial joint (66) including the initial top surface (76). The laser beam (24) is eventually removed from the laser weld joint (66) to allow the melted upper portion (78) of the joint (66) to resolidify and provide the laser weld joint (66) with a modified top surface (84) that is smoother than the initial top surface (76). By providing the laser weld joint with a smoother modified top surface, residual stress concentration points are removed and the laser weld joint is less liable to damage seal strips.

A method for joining together metal workpiece (12,14 or 12,150, 14) includes forming a laser weld joint (66) in a workpiece stack-up (10) that fusion welds two or more overlapping metal workpiece (12,14 or 12,150 or 14) together. The laser weld joint (66) has an initial top surface (76). Once the laser weld joint (66) is formed, the method calls for impinging the laser weld joint (66) with a laser beam (24) and moving the laser beam (24) along the initial joint (66) including the initial top surface (76). The laser beam (24) is eventually removed from the laser weld joint (66) to allow the melted upper portion (78) of the joint (66) to resolidify and provide the laser weld joint (66) with a modified top surface (84) that is smoother than the initial top surface (76). By providing the laser weld joint with a smoother modified top surface, residual stress concentration points are removed and the laser weld joint is less liable to damage seal strips.

A laser processing device includes: a first laser oscillator that emits a first laser beam having a peak wavelength of a first wavelength; a second laser oscillator that emits a second laser beam having a peak wavelength of a second wavelength different than the first wavelength; a drive controller that drives each of the first laser oscillator and the second laser oscillator; and an analyzer that obtains signal light from a workpiece and adjusts one or more processing conditions for the workpiece based on the obtained signal light. The drive controller drives the first laser oscillator and the second laser oscillator according to the one or more processing conditions to change an intensity of at least one of the first laser beam or the second laser beam and irradiate the workpiece with at least one of the first laser beam or the second laser beam.

A laser welding apparatus generates laser by a laser oscillator, converges the laser by a condenser lens, and applies the laser to an upper sheet and a lower sheet superposed together so as to weld the upper sheet and the lower sheet to each other. According to this apparatus, by laser irradiation, a melt pool Y is formed in the upper sheet and the lower sheet superposed together. Furthermore, by laser irradiation, the melt pool Y is caused to flow, and the upper sheet and the lower sheet are welded together.

A laser welding apparatus generates laser by a laser oscillator, converges the laser by a condenser lens, and applies the laser to an upper sheet and a lower sheet superposed together so as to weld the upper sheet and the lower sheet to each other. According to this apparatus, by laser irradiation, a melt pool Y is formed in the upper sheet and the lower sheet superposed together. Furthermore, by laser irradiation, the melt pool Y is caused to flow, and the upper sheet and the lower sheet are welded together.

A method is provided for interconnecting the batteries in a battery pack in a manner that is designed to minimize damage and contamination of the contact surfaces of the interconnect and the battery terminal, thereby minimizing connection resistance and increasing interconnect reliability.

A rechargeable battery and a manufacturing method of the same are provided, which can aid in preventing an electric short from occurring between electrode plates by forming a cutting portion of each on the electrode plates in the shape of a curved surface or a bead having a uniform thickness and/or a diameter sufficient to prevent or substantially prevent the cutting portion from piercing a separator separating the electrode plates from each other. In a present embodiment, the electrode assembly includes an electrode plate having a current collector plate, a coating portion having an electrically active material coated on the current collector plate, a non-coating portion formed at an edge of the current collector plate and not coated with the electrically active material, a cutting portion inwardly formed from the non-coating portion, and a curved portion formed along the cutting portion in a thickness direction of the non-coating portion.

A rechargeable battery and a manufacturing method of the same are provided, which can aid in preventing an electric short from occurring between electrode plates by forming a cutting portion of each on the electrode plates in the shape of a curved surface or a bead having a uniform thickness and/or a diameter sufficient to prevent or substantially prevent the cutting portion from piercing a separator separating the electrode plates from each other. In a present embodiment, the electrode assembly includes an electrode plate having a current collector plate, a coating portion having an electrically active material coated on the current collector plate, a non-coating portion formed at an edge of the current collector plate and not coated with the electrically active material, a cutting portion inwardly formed from the non-coating portion, and a curved portion formed along the cutting portion in a thickness direction of the non-coating portion.

A new ultrasonic aided laser joining method (UAL) for bonding dissimilar materials has been developed. The method is capable of eliminating the laser-induced bubbles at the bonding faces and to improve the joint strength over that of the conventional laser-assisted metal and plastic joining method (LAMP). Some experiments on joining titanium to polyethylene terephthalate have been conducted to show the superiority of UAL over LAMP. The results showed that the joint strength, measured in terms of failure load, was significantly increased when ultrasonic vibration was employed during laser joining. For the LAMP joined specimens, fracture normally occurred at the metal-plastic interface, whereas for the UAL joined specimens, fracture normally occurred in the parent plastic part. The improvement in joint strength is mainly due to the elimination of pores in the resolidified plastic. In addition, ultrasound vibration promotes chemical bonding between the plastic and metal parts, and this is supported by the XPS results.