A lithium-ion battery cell consists of various components and materials that are subject to a number of load applications based on their different functions.Variousmaterials are used.In the production process, materials are subjected to mechanical loads throughout the various manufacturing stages and must be adapted to such loads.During battery operation, the materials used are subjected to electrochemical, thermal and mechanical loads.ZwickRoell offers testing solutions for every requirement.
- A lithium-ion battery cell consists of various components and materials that are subject to a number of load applications based on their different functions.
- Various materials are used: including electrode material made of aluminum and copper film, polymer separators (PE oder PP), graphite or titanate electrode coatings, lithium metal oxide coatings, aluminum-based housing (solid housings or laminated foils), etc.
- In the production process, materials are subjected to mechanical loads throughout the various manufacturing stages and must be adapted to such loads.During battery operation, the materials used are subjected to electrochemical, thermal and mechanical loads.
- Therefore, tensile stresses, buckling resistance, crack strength, shear strength, sealed seam strength, bond strength, puncture resistance, elasticity, temperature stress or compressive strength have to be determined.In addition, some components also have to pass function tests such as shear forces at terminals or puncture resistance of safety valves for prismatic cells, or simple verification of the strength of welded seams of current collectors.The performance cycle of a lithium-ion cell must also be understood, and for this, acquisition of the mechanical cell deformation caused by swelling during the charging process plays an important role in the design of the battery cell environment.Additional challenges include:Temperature resistance over a wide temperature range (-40 up to +120°C), vibration resistance, cyclical loads and aging processes due to electrochemical influences.
- Based on the requirement, tests are performed with universal testing machines in a force range of 1 to 10 kN.
- Important material characteristics, especially in tensile testing, can be determined with repeatability due to easy alignment and adapted pneumatic grips.This also allows for very thin metallic and plastic films (<50µm) to be held without crushing or kinking.
- Very precise force and deformation sensors are used for the measurement of highly accurate material properties, which are mainly used in simulation processes.For the determination of strain values on very thin electrode films it is particularly important that there is no influence on the specimen from contact extensometers.Non-contact video- or laser-based extensometersof the videoXtens or laserXtens series are ideal for this purpose.
- Thermal influences can be freely simulated with a temperature chamber in a wide temperature range of -80°C to +250°C.