Integrated CFD modeling for energy performance evaluation and optimization of NCM cathode calcination

초록

Industrial-scale calcination of nickel–cobalt-manganese (NCM) cathode materials in roller hearth kiln is among the most energy-intensive unit operations in lithium-ion battery manufacturing, yet equipment-level thermal-engineering frameworks linking operating conditions to energy performance remain scarce. We present an integrated computational fluid dynamics (CFD) framework that addresses this gap for a multi-zone industrial roller hearth kiln. The framework simultaneously resolves four coupled phenomena—transient heater control, multi-zone material transport, lithium-hydroxide dehydration kinetics, and volumetric radiative heat transfer—within a single CFD platform validated against full-scale industrial measurements. Two performance metrics, the specific energy consumption (SEC) and the transition-zone mean temperature uniformity factor (TUFmean), are adopted to quantify the energy-uniformity tradeoff. Parametric studies on calcination time (16–24 h) and cathode material weight per saggar (1–8 kg) reveal opposing sensitivities of the two metrics, establishing a fundamental SEC-TUF tradeoff. Reduced-order models are constructed from an eighteen-case training set comprising the original one-at-a-time screening cases and eight additional CFD simulations arranged according to a Face-Centered Central Composite Design, with interaction terms, validated by leave-one-out cross-validation and two held-out CFD cases. Constrained optimization along the temperature uniformity target boundary identifies an operationally robust feasible band (w = 5.55–8.00 kg/saggar, t = 17.71–23.42 h) that simultaneously satisfies both targets, across which the specific energy consumption decreases from 1.50 to 1.29 kWh/kg (31–41% reduction from the baseline of 2.18 kWh/kg) while maintaining TUFmean at or above the 90% target.

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