▎ 摘　　要

Organic phase change materials (PCMs) have low thermal conductivity and poor form stability, which prohibit their usage in high-efficient heat storage and thermal management. This study demonstrated how to efficiently fabricate phase change composites (PCCs) with directional thermal conductivity and good form stability using vertically aligned carbon fibers as supporting scaffolds. Cotton blankets with aligned fibers were firstly impregnated with graphene flake solutions, which were then rolled to columns along the fiber direction and subsequently carbonized to obtain the porous carbon fiber scaffolds. PCCs were prepared by vacuum impreg-nation of paraffin into the scaffolds. The porous scaffolds supported PCCs showed good shape stability and greatly improved thermal transfer properties, which were especially endowed with a directional heat conduc-tivity as a result of the vertically arranged hollow carbon fiber structure. The thermal conductivity of PCCs along the axial direction of the fibers was greater than along the lateral direction, because the arranged fibers provided the majority of the thermal transfer path in PCCs. With a carbon content of 19.46 wt%, the axial thermal con-ductivity was 2.13 W K-1 m-1, which was twice of the lateral one and 8.5 times of the PW. Last but not least, the PCCs also possessed high latent heat capacity, high thermal cycling and chemical stability. These results suggest that the novel carbon scaffolds may enable PCCs with directionally improved thermal transfer properties.