This simulator is a bounded numerical abuse fixture built around four cylindrical lithium-ion cells (3 Ah nominal, teaching parameters) in an insulating carrier. It is designed to separate three distinct thermal effects that are easy to conflate in real hardware: an externally applied heat trigger, an internal exothermic reaction that can outrun cooling, and conduction of heat from one cell into its neighbors.
• A real-time 3D four-cell thermal propagation chamber — cell module with vented cans, an insulating cell cradle, an intercell mica-like thermal barrier, an instrumented external heater fixture on cell 1, an infrared inspection head that colors cell surfaces by modeled temperature, and a vented test enclosure — with toggleable enclosure, auto-rotate, exploded view and selectable, labeled components. • Four controls: cell 1 external heater power (0–100 W), intercell thermal conductance (0.02–1 W/K), ambient heat rejection (0.05–0.6 W/K per cell) and ambient temperature (−10 to 45°C). • Live readouts for hottest cell temperature, total chemical heat rate, maximum reaction progress, count of cells with more than 5% reaction progress, and individual temperatures for cell 1 and cell 4. • Time controls: pause/run, advance 1 s, advance 60 s, and a playback selector from real time up to 1 hour per second, plus start/stop/remove-heater actions for the heater fixture. • An Operating sequence readout, a switch-state panel and a per-cell readings table. • An Analysis tab with temperature/reaction charts, the underlying four-node lumped thermal model equations, and snapshot measurements. • A Tests tab with four guided experiments (observe onset, higher coupling, thermal barrier, remove the trigger), a Verification bench of automated model checks, and a timestamped event log with report export. • A Learn tab with four lessons (external heat is a trigger, positive thermal feedback, heat propagation, opening is not extinguishing), a knowledge-check quiz and a written model-scope statement with references.
Each cell's temperature is governed by C·dT/dt = heater input + reaction heat release − conduction to neighbors − heat rejection to ambient, with a finite-reactant kinetic term dα/dt = k(T)·(1−α) that only accelerates once the cell crosses a teaching activation range. Reaction heat (12 kJ per cell) is capped, so a cell cannot generate unlimited heat — the model is bounded and always resolves to either quenching or full reactant consumption.
Raising intercell conductance moves more energy into neighboring cells, which can either help (by distributing and radiating heat faster) or hurt (by pushing neighbors into their own activation range) depending on how much ambient heat rejection is available. Lowering conductance thermally isolates the source cell, keeping it hotter for longer but reducing what reaches its neighbors — the classic barrier-versus-containment tradeoff the experiments are built to demonstrate.
The external heater is a separately powered numerical fixture, wired independently of the cells' own chemistry. Removing it (or opening the fixture's contactor) stops the external trigger immediately, but any reaction already underway inside a cell continues on its own stored chemical energy until reactants are consumed or the cell cools below the activation threshold. The simulator's "Remove heater" experiment is built specifically to let you verify this: heat the pack until reaction is active, then remove the heater and watch internal heat persist.
This is a teaching model, not a validated calorimetry or safety-certification test. It excludes flame, pressure, gas evolution, ejecta, radiative heat transfer, electrical internal-short mechanisms and any chemistry-specific failure thresholds — the kinetics and thermal parameters are illustrative and uncalibrated, and the model does not predict any specific product's failure behavior.
It is an instrumented, separately powered numerical heater applied to cell 1 to trigger the experiment, distinct from the cells' own electrical or chemical heat paths. It lets you isolate an external heating trigger from the internal exothermic reaction it can start.
No. The simulator specifically demonstrates that stored chemical energy already reacting inside a cell is internal — removing the external heater or opening an external contactor stops the external trigger but does not repair the cell or remove heat already being generated by an active reaction.
It sets the modeled W/K coupling between neighboring cells through the intercell barrier and cradle. Higher conductance spreads heat faster to neighbors (which can trigger their own reaction or help dissipate heat, depending on ambient rejection); lower conductance keeps the source cell more thermally isolated at the cost of it staying hotter longer.
This is an illustrative, uncalibrated four-node finite-reactant thermal model. It does not include flame, pressure buildup, vented gas composition, ejecta, radiative heat transfer, electrical internal-short initiation, or any chemistry-specific or product-specific failure thresholds, and it is not a validated calorimetry or safety-certification test.