Abstract: A cathode for a lithium secondary battery includes a cathode current collector, and a cathode active material layer formed on the cathode current collector. The cathode active material layer includes cathode active material particles. The cathode active material particles include a lithium metal oxide particle containing nickel and having a mole fraction of cobalt of 0.02 or less among all elements except lithium and oxygen.

Abstract: A cylindrical secondary battery, a battery pack, and a vehicle are provided. The cylindrical secondary battery includes an electrode assembly having a first electrode tab at a first end of the electrode assembly a battery can configured to accommodate the electrode assembly through an opening portion formed at one side of the battery can, a current collecting plate including three or more tab coupling portions electrically connected to the first electrode tab, and a can coupling portion extending from ends of the tab coupling portions toward the opening portion of the battery can and having a continuous outer peripheral surface electrically connected to an inner surface of the battery can, and a top cap configured to cover the opening portion of the battery can.

Abstract: The laser welding system including a welding frame for receiving a first steel plate to be welded thereupon, at least one first clamping member to be installed above the welding frame, for fixing the first steel plate received on the welding frame, at least one second clamping member for fixing a second steel plate to be welded in close vicinity to a position at which the first steel plate is to be engaged with and welded with the second steel plate, an anvil on which the second steel plate is received, for moving the second steel plate to the position at which the first steel plate is to be engaged with and welded with the second steel plate, and a laser welding head for welding the first and second steel plates at the position at which the first steel plate is to be welded with the second steel plate. The first and second clamping members and anvil are operated by air bags.