ECS-S Pneumatic Spot Welder for Cylindrical Cells, ESCCPSW

A Pneumatic Spot Welder is a critical piece of equipment in the assembly of cylindrical battery packs (18650, 21700, etc.). It uses compressed air to drive the welding electrodes downward with consistent, adjustable pressure, ensuring a uniform contact between the battery terminal and the nickel connector (tab). 

The welder uses Resistance Spot Welding (RSW). A high-current pulse is passed through the electrodes, creating localized heat at the interface of the nickel tab and the battery cap. (1) Pressure Phase: The pneumatic cylinder lowers the electrodes onto the workpiece with a specific force (e.g., 20 N to 100 N). (2) Current Pulse: The welder releases a millisecond-duration current (often in two pulses: "Pre-weld" to clear oxides and "Main-weld" to fuse). (3) Hold Phase: The electrodes remain down for a fraction of a second to allow the weld nugget to solidify. (4) Retract: The cylinder lifts, ready for the next spot.

References:

N. Phichai, et al., Parametric Effects of Resistance Spot Welding between Li-ion Cylindrical Battery Cell and Nickel Conductor Strip, IOP Conf. Ser.: Mater. Sci. Eng., 2019, 501 012027

V. R. Rikka, et al., Tailoring micro resistance spot welding parameters for joining nickel tab to inner aluminium casing in a cylindrical lithium ion cell and its influence on the electrochemical performance, ournal of Manufacturing Processes, 2020, 49, 463-471.