Battery cell expansion measurement

• Long-term observation of expansion during charging and discharging cycles
• Measurement of forces that occur, with monitoring of temperatures
• Optimization of pressure distribution and service life

Description

Battery cells expand due to their charging and discharging cycles and resulting temperature changes. This places a high load on the housing and cell surroundings. Stresses vary depending on the design and on the formulation of the chemical compounds.

Specific requirements

• Precise measurement of the forces – i.e. expansion with temperature – during cell charging and discharging
• Accurate assessment of long-term behavior and the aging process

A critical look at the details is necessary for exact reproducible recording. Precisely defined pretensioning forces can be applied by the fine pitch of the mounting screws. Uniformly applied tightening torques, if possible, generate an even distribution of forces. The stability and deflection of the plane-parallel intermediate plates, as well as the frictional influences of the guide bushings, also affect the measurement result.

Solution

A precise investigation of the temperature/force curve during various charging and discharging cycles provides key insights into the relationship between the chemical constituents and structural variants. This question is becoming more urgent with ever-increasing packing densities, which are usually achieved by cascading many cells. The results enable an optimum adaptation of the battery. Knowledge of the maximum thermal and mechanical loads under extreme conditions also helps to define precisely specified requirements for the battery environment to guarantee protection and safety.

Video Application