Anisotropically thermal transfer improvement and shape stabilization of paraffin supported by SiC-coated biomass carbon fiber scaffolds for thermal energy storage

•Biomass-derived porous carbon frameworks as supporting scaffolds to PCM are prepared.•The porous carbon scaffolds with high porosity are consisted of 1D aligned SiC-coated carbon fibers.•The composite PCMs indicate anisotropically enhanced heat transfer and good anti-leakage properties.•The composites indicate high thermal conductivity, high heat storage capability and good cycling stability. Phase change materials (PCMs) play a promising application in the field of heat management and energy storage, which are restricted by the problems of low thermal conductivity and leakage. In this work, 3D porous carbon scaffolds as-consisted of SiC-wrapped biomass carbon fibers were prepared, which were used as the thermal conductive skeleton and shape stabilizer for paraffin PCM. In particular, the porous carbon scaffolds were designed with 1D arranged carbon fibers and hierarchical pore structure, thereby the resulting composite PCMs indicate anisotropically improved heat transfer and good anti-leakage properties. High thermal conductivity values of 0.61 W m−1 k− 1 in the axial direction (> 3 times of paraffin) and 0.48 W m−1 k−1 in the lateral direction were obtained for the composite with a filler ratio of 10.4 wt%. The composite also presented well-behaved thermal cycling stability and high heat storage capacity (186 J g−1). With a high heat storage capability and anisotropically improved heat transfer properties, the biomass carbon supported PCMs indicate enormous potentials in thermal management applications. [Display omitted]