In this article, we break down tier 1 of The ACE Protocol, Cell Teardowns. Learn more about how this process can tell us how battery cell are constructed and may perform before any type of electrical testing.
In the ACE Protocol, teardown is the first stage of cell characterization in the battery lab. Before any electrical testing, we disassemble the cell to capture the physical data that every downstream step depends on — the dimensions and masses needed to parameterize physics-based models, and the samples needed for advanced material analysis.
Electrical testing tells us how a cell behaves. Teardown tells us how it is built, and provides the inputs that simulations and diagnostics cannot infer on their own.
Physical Dimensions for Model Parameterization
Physics-based models (P2D, electrochemical-thermal, equivalent-circuit with physical grounding) require geometric and mass inputs that cannot be extracted from cycling data. During teardown, we measure and record:
– Electrode geometry: Lengths, widths, and thicknesses of anode and cathode, plus current collector foil thicknesses.
– Overhang: Anode-to-cathode alignment along each edge — a direct input to plating models and a known failure driver.
Separator: Thickness, footprint, and any ceramic or functional coating.
– Jelly roll / stack geometry: Winding diameter and layer count for cylindricals; stack count and footprint for pouches and prismatics.
– Component masses: Housing, current collectors, tabs, electrodes, separator, and the jelly roll itself.
Free Electrolyte Estimation
We estimate the quantity of free (non-absorbed) electrolyte in the cell via mass balance — comparing as-received cell mass, drained mass, and dried component masses. Where possible, we recover a sample of the electrolyte for compositional analysis. This estimate feeds directly into wetting and transport assumptions in the models and helps explain differences in rate capability, aging, and safety between otherwise similar cells.
Acculon Labs’ ACE Protocol can rapidly help you identify the right cell for your application in a matter of weeks, not months.
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Internal Construction & Weld Notes
We document the mechanical and assembly details of the cell:
– Tab welds: Weld type (ultrasonic, laser), geometry, placement, and visual condition at the tab-to-collector and tab-to-terminal joints.
– Can, header, and seal: Crimp/case weld geometry, gasket condition, CID and vent mechanisms.
– Internal layout: Tab routing, insulating tapes, mandrel or center pin, and any structural adhesives.
– Coating condition: Uniformity of the active material, edge effects, and defects such as streaks, craters, agglomerates, or thin spots.
– Contamination: Any particulates or debris observed during disassembly.
All of the above is captured with high-resolution photography at each disassembly step so that findings are auditable.
Sample Preparation for Advanced Characterization
Teardown also produces the samples required for the advanced material level characterization if needed. Materials are handled, labeled, and stored under an inert atmosphere when required by the chemistry. Prepared samples typically feed into:
– SEM / FIB-SEM for surface morphology, cross-sections, and composite electrode structure.
– Porosimetry (mercury intrusion or gas adsorption) for porosity and pore size distribution.
– Elemental analysis (ICP-OES, EDS, XRF) for electrode stoichiometry and trace contaminants.
– XRD for crystal structure and phase identification.
– GC/LC on recovered electrolyte for solvent, salt, and additive composition.
Observations vs. Industry Practice
Every measurement and observation is recorded against known benchmarks for the cell’s chemistry and format: typical overhang values, expected coating uniformity, standard weld geometries, and reasonable mass ratios. Deviations are flagged in the report — whether they reflect cost-cutting, a manufacturing issue, or a deliberate design choice worth understanding.
The Output
The teardown deliverable is a structured dataset: dimensions, masses, free electrolyte estimate, photographic record of internal construction and welds, prepared samples, and observations benchmarked against industry practice.
Are you working from supplier datasheets alone, or do you have measured inputs for the cells you are actually using?