Hierarchical Wood-Derived Carbon Scaffold with Layer-Pillar Structure Enabling Thermomechanical Stability and Bidirectional Thermal Conductivity in Phase Change Materials

As advanced electronics evolve toward integration and miniaturization, phase change materials (PCMs) with efficient encapsulation and thermal management properties become critically imperative. Inspired by architectural frameworks, this work utilized the wood-derived carbon skeleton (CW) as the “layers” and the in situ grown carbon nanotubes (CNTs) as the “pillars”, successfully constructing a layer-pillar structured scaffold, denoted as CW@Ni-CNTs. This architecture enabled highly efficient encapsulation of polyethylene glycol (PEG). The resulting composite PCMs (CW@Ni-CNTs/P) exhibited exceptional thermomechanical stability, maintaining a shape retention ratio of 94.3% under 10 N load with less than 3% leakage after multiple thermal cycles. The interpenetrating network enhanced the thermal conductivity by 160.87% axially and 143.48% radially, while providing an electromagnetic interference (EMI) shielding effectiveness of 39.62 dB to PEG. Combined with high latent heat, the composite PCMs show stable thermal management in electronic devices. This hierarchically layer-pillar structural design offers an effective strategy for fabricating composite PCMs with integrated structural and functional properties.