Cell Component Mechanical Tests

Cell component mechanical tests are extensive and required in order that a more detailed understanding of how the cells behave can be established. The battery cell is a complex: chemistry, electrical, thermal and mechanical system. Cycle ageing is seen as a deteriation in the chemistry of the cell, but should also be considered as a mechanical system. Expanding and contracting through charging and discharging that leads to fracturing.

This mechanical testing then extends out to module and pack.

Hence it is really interesting to see the suite of tests available from ZwickRoell at their headquarters in Ulm, Germany.

Battery cell materials and components:

  • Tensile strength of separators, copper and aluminum foils, housing components incl. sample preparation
  • Adhesive strength (Z-Direction tensile, 180°- and 90°-peel) of electrode coatings (anode and cathode active material), incl. sample preparation
  • Bending stiffness of coated electrodes (2-point and 3-point bending)
  • Weld strength of tabs and electrodes (pouch, prismatic and cylindrical formats)
  • Coefficient of friction measurement of electrode coatings
  • Sealed seam strength of pouch cell material
  • Puncture resistance of separator foils incl. sample preparation
  • Shear strength of weld seams, prismatic cell terminals
  • Material properties from -80°C to +250°C

Battery modules and packs:

  • Compressive strength of battery and battery components
  • Adhesive strength of tapes and insulation material
  • Tensile and bending strength of busbar connections
  • Hardness testing of materials (Vickers, Rockwell, Brinell)

Advanced tests:

  • High precision compressibility measurements on electrode coatings
  • Fatigue testing of battery structures up to 250 kN
  • Mechanical characterization in various media
  • Electrical conductivity of electrode coatings under pressure
  • Multiphysical characterization of swelling and breathing on certified battery cells
  • Mechanical property data of battery components for simulations
  • Bi-axial mechanical deformation of complete battery structures
  • High speed crush tests of battery structures up to 20 m/s
zwickroell tensile testing of 6 um thick copper foil
Tensile test on a 6 µm copper foil with the most advanced non-contacting video extensometer without the need of marking (and potentially damaging) the sample.

We posted this to inspire the battery design engineers to think about what they can measure and hence mathematically model. It is insight such as this that can take the battery pack designs to the next level.

zwickroell mechanical testing

ZwickRoell

Some key facts: About 50 testing machines in our applications labs available for:

  • customer demonstrations,
  • comparison tests,
  • feasibility studies,
  • trainings,
  • test method optimization
  • general consulting.

We offer also contract testing services to support our customers.

The battery test lab is part of the main applications test lab where 31 application engineers are managing about 40000 tests per year for various test requirements from different industries like metal, plastics, composites, medical or automotive. The latest battery test lab expansion adds 5 testing systems and complete sets of battery related standard and customized tooling.

Everything in a dedicated testing laboratory and designed for the mechanical characterization of battery materials, components and cells.

The battery test lab and its 2 testing experts support the challenges in research and development as well as quality control. The lab is a temperature and humidity controlled environment and ensu

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