Secondary Cell Inspection Using Thermal Pressing and Current Sensing

The patent applies preliminary action by performing the inspection operation before the cell is fully assembled or before aging occurs. The inspection device detects contaminants and defects in the electrode assembly prior to final cell assembly, eliminating the need for time-consuming aging steps later. This allows defect detection to occur at an earlier stage in the manufacturing process, significantly reducing total inspection time while maintaining detection capability.

The patent replaces the chemical/electrochemical aging process with a mechanical inspection system. Instead of relying on electrochemical reactions during aging to reveal defects, the device uses mechanical pressure application combined with optical or electrical detection methods to identify contaminants and defects directly, substituting a fast mechanical process for a slow chemical process.

The patent applies partial action by using a pressure level that is sufficient to detect defects but controlled to avoid excessive force that could damage the cell. The inspection device applies pressure incrementally or at optimized levels that create enough mechanical stress to reveal internal short circuits and contaminants, while staying below the threshold that would cause structural damage to the electrode assembly or cell housing.

The patent uses an intermediary approach by introducing a conductive fluid or gel between the pressure application point and the cell structure. This intermediary medium transmits the pressure uniformly across the cell surface while protecting sensitive internal structures from direct mechanical contact, allowing defect detection through electrical conductivity changes without causing physical damage to the cell components.