Ultrahigh through-plane thermal conductivity of graphite by reducing inter-plane twist

<title>Abstract</title> Graphite is a cornerstone material in heat dissipation due to its exceptionally high in-plane thermal conductivity (~ 2000 W m^{− 1} K^{− 1}). However, its low through-plane thermal conductivity remains a bottleneck for heat dissipation, typically limited to 5–9 W m^{− 1} K^{− 1}. Here we reveal that graphite, when structure is optimized, delivers a record high through-plane thermal conductivity of up to 13.4 W m^{− 1} K^{− 1} at room temperature. This enhancement is achieved by reducing the helical twist within the graphite crystal structure. We demonstrate that while having minimal impact on in-plane conductivity, these twists significantly hinder heat-carrying phonons traveling through-plane. This work establishes a new benchmark for graphite's thermal properties and paves the way for unlocking its full potential in thermal management applications.