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Efficient heat dissipation in batteries is important for thermal management against thermal runaway and chemical instability at elevated temperatures. Nevertheless, thermal transport processes in battery materials have not been well understood especially considering their complicated microstructures. In this study, lattice thermal transport in lithium cobalt oxide (LiCoO 2 ), a popular cathode material for lithium ion batteries, is investigated via molecular dynamics-based approaches and thermal resistance models. A LiCoO 2 single-crystal is shown to have thermal conductivities in the order of 100 W m −1 K −1 with strong anisotropy, temperature dependence, and size effects. By comparison, polycrystalline LiCoO 2 is more isotropic with much lower thermal conductivities. This difference is caused by random grain orientations, the thermal resistance of grain boundaries, and size-dependent intra-grain thermal conductivities that are unique to polycrystals. The grain boundary thermal conductance is calculated to be in the range of 7.16–25.21 GW m −2 K −1 . The size effects of the intra-grain thermal conductivities are described by two empirical equations. Considering all of these effects, two thermal resistance models are developed to predict the thermal conductivity of polycrystalline LiCoO 2 . The two models predict a consistent thermal conductivity–grain size relationship that agrees well with molecular dynamics simulation results. The insights revealed by this study may facilitate future efforts on battery materials design for improved thermal management.
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This content will become publicly available on September 1, 2026
Glass-like thermal conductivity in higher manganese silicides with grain boundary nanostructures
Higher manganese silicides (HMSs) have emerged as promising candidates for environmentally friendly thermoelectric (TE) materials due to their earth-abundant and non-toxic composition. We report grain boundary engineering in ruthenium-doped HMSs via a melt-quenching followed by annealing method. This approach promotes the formation of MnSi nanoprecipitates and nanopores, preferentially near grain boundaries. The presence of these nanostructures results in a weak temperature-dependent thermal conductivity, resembling glass-like thermal transport behavior. A two-channel model incorporating propagons and diffusons describes this glass-like thermal conductivity, with diffusons contributing about 60 % of the lattice thermal conductivity at 300 K. Furthermore, the quench-annealing process enhances electrical conductivity while preserving a large Seebeck coefficient, which is attributed to a high density-of-states effective mass. As a result of improved power factor and reduced thermal conductivity, the figure of merit zT value increases by 33 % at 300 K compared to undoped HMS synthesized via solid-state reaction. These findings present a promising strategy for manipulating phonon dynamics in functional materials and designing efficient TE systems.
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- Award ID(s):
- 2329107
- PAR ID:
- 10630080
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Materials Today Electronics
- Volume:
- 13
- Issue:
- C
- ISSN:
- 2772-9494
- Page Range / eLocation ID:
- 100169
- Subject(s) / Keyword(s):
- Thermoelectrics, Higher manganese silicides, Melt-quenching, Nanopores, Thermal transport
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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