Predictive Modeling of Creep Driven Pore Growth under Cyclic High Temperature Tooling Loads
Predictive creep modeling quantifies elevated temperature pore evolution in solid state cell tooling to establish precise hold times and prevent yield loss.
Pressing Platen Planarity
Meaning
Geometric tolerance specification defining the degree to which the contact surfaces of a compression press remain within two parallel planes during operation. Pressing platen planarity is necessary for ensuring uniform pressure distribution across a battery cell stack during formation or lamination. It prevents localized stress concentrations that could damage delicate separator membranes.
Measurement Method
Laser trackers or precision dial indicators verify the flatness of the surfaces at multiple points across the entire area. Maintaining pressing platen planarity requires regular calibration because thermal expansion and mechanical wear can warp the metal over time. The measurement is recorded in microns per meter.
Operational Impact
Uneven pressure leads to variations in electrode thickness and electrolyte wetting. When pressing platen planarity falls outside the specified limits, the resulting cells may exhibit inconsistent capacity and shortened cycle life. The platen must remain flat even under maximum hydraulic force.
Engineering Correction
Shims or active thermal compensation systems are used to restore the alignment of the pressing assembly. This pressing platen planarity adjustment ensures that the load remains perpendicular to the cell surface throughout the entire stroke. Precise control of the machine frame prevents the tilting that often occurs during the high pressure stages of the manufacturing cycle.
Stiffening the structural members of the press reduces the deflection that would otherwise compromise the uniformity of the finished product.