Deformation Stiffness Measurement for Secondary Batteries

The patent combines force measurement and thickness measurement into a single integrated system. The force sensor measures force in the thickness direction while the thickness sensor measures thickness changes, and both measurements are performed simultaneously on the same battery sample during charge/discharge cycles. This merging of multiple measurement functions into one system resolves the contradiction by achieving precise mechanical property measurement without requiring separate complex measurement devices.

The patent introduces a data processor as an intermediary that receives raw data from both sensors, performs differentiation calculations (dF/dh), and outputs the deformation stiffness. This intermediary processing step transforms simple force and thickness measurements into meaningful mechanical property data, resolving the contradiction by adding computational intelligence rather than physical complexity to the measurement system.

The patent replaces traditional mechanical testing methods (which would require physical deformation or destruction of the battery) with a non-contact or minimal-contact sensing system. Force sensors and thickness sensors detect mechanical properties through electrical or optical means rather than through physical stress application, enabling nondestructive evaluation while maintaining the ability to measure mechanical properties during natural volume changes.

The patent enables the battery to serve as its own test subject by measuring its own mechanical properties during normal charge/discharge operations. The battery undergoes natural volume changes during electrochemical reactions, and the sensing system detects these self-generated changes without requiring external mechanical testing equipment, thus achieving nondestructive evaluation while maintaining measurement capability.