Home   >   Product Showcase   >   Battery Technology   >   Manufacturing and Failure Analysis

Manufacturing and Failure Analysis

Materials characterization during and prior to manufacturing is a critical control parameter to ensure the optimal operation of cell components and the final assembled battery.

From raw materials to component manufacture and the assembled battery itself, material characterization plays a vital role in determining the desired electrochemical performance, safety, cell cycling and other important parameters.

Particle size and shape influences packing density which in turn affects electrode thickness and therefore energy density.
It has been shown that the particle size distribution of graphite, as well as particle orientation in the coated foil affects the

electrochemical performance of graphite anodes. Purity is also an important issue and low levels of metallic impurities must be maintained in all powders and additives used in electrode manufacture.

Calendering is the most critical step in the production of high performance electrodes. Porosity and thickness of the electrode film will decrease with increasing calendering. Calendering would also be expected to change the pore structure of the electrode, which would thereby impact the wetting behavior of the film by the electrolyte.

Calendering beyond the optimum level
causes reductions in porosity and average pore diameter which can result in irreversible capacity loss, high rate cycling, and poor longevity in cycle performance.

Solid Fraction is a control parameter used
in roller compaction operations. This control parameter assists in determining the optimal setting for speed, compression and nip angle in the roller compactor.

Using the the solid fraction as a critical quality attribute will ensure consistent product batch to batch, along with the end product having the designed and desired electrochemical performance.

Over the life of a cell, physical and electrochemical occurrences contribute to degradation in performance. This drop in performance is most notably recognized through capacity fade during charge and discharge cycling or by reduced shelf life.

Expansion and contraction may cause interfacial stress that adversely effects the electrode performance, to the point that delamination may occur causing a reduction in contact between the electrode material and the current collector. Pore size changes can occur from this mechanical failure resulting in reduction in electrolyte contact and poor cycling behavior.