Northvolt has been granted a patent for a cylindrical secondary cell and its assembly method. The cell includes a cylindrical can with a beading groove, a conductive sheet wound into a jelly roll, and an electrode lead plate in direct contact with the conductive sheet. The beading groove bends and presses the flange of the electrode lead plate inwards towards the center of the can. GlobalData’s report on Northvolt gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Northvolt, hydrogen storage alloys was a key innovation area identified from patents. Northvolt's grant share as of June 2023 was 1%. Grant share is based on the ratio of number of grants to total number of patents.
Patent granted for a cylindrical secondary cell assembly
A recently granted patent (Publication Number: US11670815B2) describes a cylindrical secondary cell design that includes a cylindrical can with a beading groove formed in its wall. The cell also includes a first conductive sheet wound into a jelly roll shape and placed inside the can. The first conductive sheet has a portion without electrode coating that protrudes on one end of the jelly roll. An electrode lead plate, which is electrically conductive, is positioned at the end of the jelly roll and in direct contact with the uncoated portion of the first conductive sheet. The electrode lead plate has a flange that extends around a substantial portion of its periphery, with the flange bent and pressed inwards towards the center of the can by the beading groove. The flange is further bent so that its edge portion is positioned closest to the edge of the electrode lead plate and extends towards the center of the can.
The patent also includes several additional claims and methods for assembling the cylindrical secondary cell. These claims include the presence of slits in the flange and edge of the electrode lead plate, the inclusion of through holes in the electrode lead plate for electrolyte filling, direct contact between the electrode lead plate and the cylindrical can, the welding of the flange to the can, the use of an insulating member between the electrode lead plate and the can, and the presence of a lid resting on the beading groove opposite the electrode lead plate.
The method for assembling the cylindrical secondary cell involves arranging the jelly roll and electrode lead plate inside the can, ensuring direct contact between the uncoated portion of the first conductive sheet and the electrode lead plate, and then beading the can to form the beading groove. The method may also include the placement of an insulating member before beading and the welding of the flange to the can. The beading process not only forms the groove but also bends a part of the electrode lead plate closest to the edge towards the jelly roll.
Overall, this patent describes a specific design and assembly method for a cylindrical secondary cell that aims to improve the electrical conductivity and structural integrity of the cell.
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