Abstract: Disclosed herein is a pouch-type secondary battery and a manufacturing method thereof including. The pouch-type secondary battery includes an electrode assembly; an electrode lead extending from an electrode tab of the electrode assembly; an upper pouch; and a lower pouch. The upper pouch and the lower pouch include a sealed area where the edges are sealed and an unsealed area. An average thickness of the sealed area of the upper pouch and an average thickness of the sealed area of the lower pouch are equal to each other, and the average thickness of the unsealed area of the upper pouch is smaller than the average thickness of the unsealed area of the lower pouch, so that even if the thickness of the lower pouch is reduced during the sealing process of heat-sealing, the sealed area of the upper and lower pouches are formed with little difference in thickness.

Abstract: A sealing device for a pouch-type battery includes an upper sealing block and a lower sealing block. The upper sealing block has a two-stage upper sealing groove, including a first upper step and a second upper step, and the lower sealing block has a two-stage lower sealing groove, including a first lower step and a second lower step. The upper sealing block contacts a first surface of an electrode lead sealing part of the pouch-type battery, and the lower sealing block contacts a second surface of the electrode lead sealing part of the pouch-type battery in a process of performing sealing through heat fusion. A pouch-type battery having an electrode lead sealing part formed by the sealing device is also provided.

Abstract: A precursor for a positive electrode active material and a method of making the same are disclosed herein. In some embodiments a method includes forming precursor seeds for a positive electrode active material by a co-precipitation reaction while supplying a transition metal aqueous solution, an ammonium cationic complexing agent, and a basic compound to a reaction solution, and growing precursor particles for a positive electrode active material by a co-precipitation reaction while supplying a transition metal aqueous solution, an ammonium cationic complexing agent, and a basic compound to the reaction solution containing the precursor seeds, wherein the co-precipitation reaction to grow the precursor particles proceeds while continuously increasing feed rates of the transition metal aqueous solution and the ammonium cationic complexing agent.

Abstract: A secondary battery includes: an electrode assembly; an electrode lead; a battery case with an accommodation portion for the electrode assembly and a sealing portion sealing the accommodation portion; and a lead film. The sealing portion includes a connection-sealing region connected to the accommodation portion, a front end-sealing region, and a reinforcement-sealing region therebetween. The reinforcement-sealing region includes a compressed surface, provided in the sealing portion between the connection-sealing region and the front end-sealing region and recessed into the sealing portion, and raised surfaces, provided in the sealing portion between the connection-sealing region and the compressed surface and between the front end-sealing region and the compressed surface and each of which is formed thicker than the compressed surface. The battery case has a resin layer, a metal layer, and an insulating layer.

Abstract: The present invention is provided with a secondary battery comprising: an electrode assembly to which an electrode lead is bonded; a pouch configured to accommodate the electrode assembly and provided with a sealing part; and a lead film configured to seal a portion between the sealing part and the electrode lead, wherein a pattern means configured to pattern the sealing part and the lead film so as to increase in bonding area between the sealing part and the lead film is provided on a bonding portion between the sealing part and the lead film. Therefore, bonding force and sealing force between the lead film and the sealing part may increase.