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arXiv · 2604.21842

Critical role of phase-dependent properties in modeling photothermal sintering of LiCoO2 cathodes

Yang Hu·Benoit Sklénard·Wouter Vels·Yaroslav E. Romanyuk·Vladyslav Turlo
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Abstract

Photothermal (photonic) sintering crystallizes as-deposited amorphous LiCoO2 (LCO) cathodes for solid-state thin-film batteries using millisecond, surface-localized heating. However, process design often relies on 1D models with phase-averaged, temperature-independent properties, which can mispredict peak temperatures and thermal damage margins. Here we develop a multiscale, data-driven framework that provides phase- and grain size-resolved thermophysical inputs for stoichiometric LCO. We train an Allegro neural network potential with near-ab initio accuracy, enabling Green-Kubo calculations of thermal conductivity for crystalline and amorphous phases. The low, weakly density-dependent conductivity of amorphous LCO motivates its use as an effective intergranular phase in a thin-interface model that reproduces observed grain-size-dependent thermal transport. Combined with measured wavelength-resolved optical properties in 1D multiphysics simulations, we show amorphous LCO absorbs more strongly and reaches higher peak temperatures than crystalline LCO; thus crystalline, constant-property models systematically overestimate safe operating windows.

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Yang Hu, Benoit Sklénard, Wouter Vels, Yaroslav E. Romanyuk, Vladyslav Turlo. 2026-04-26. Critical role of phase-dependent properties in modeling photothermal sintering of LiCoO2 cathodes. https://arxiv.org/abs/2604.21842

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