Mesoscopic combinatorial design of anisotropic graphitic carbon with ordered porous frameworks for thermoelectric conversion

The incorporation of carbon materials can effectively enhance the performance of thermoelectric materials . By optimizing the thermoelectric properties of the carbon scaffold, it is possible to further improve the thermoelectric performance of the prepared carbon-based composites. To elevate the thermoelectric performance of the carbon scaffold, this work introduces a novel mesoscopic design strategy, utilizing natural flake graphite to create a three-dimensional ordered porous framework. Highly controllable anisotropic conductivity and thermal conductivity of the porous graphite skeleton were achieved, by combining sizable sodium chlorine templates (37.5–250 μm) with a natural flake graphite matrix (50–150 μm). A porous graphite with high electrical conductivity and low thermal conductivity along the vertical axis was obtained by carefully regulating the parameters. The sample demonstrated exceptional thermoelectric conversion performance, achieving a thermoelectric power factor of 12.2 μW m −1  K −2 and a figure of merit value of 28.3 × 10 −4 . Furthermore, the thermoelectric property of the samples could be greatly improved by adding a small amount of ferric chloride, with a thermoelectric power factor reaching 41.9 × 10 −4 and a thermoelectric figure of merit reaching 81.4 μW m −1  K −2 . This work provides an effective scheme for the mesoscopic regulation of porous graphite carbon structures and offers a new strategy for enhancing the performance of thermoelectric generators .