Fig. 1. Schematic of the one-dimensional composite thermal rectifier model with variable cross section area and thermal conductivity: (a) Forward heat flows from left to right; (b) reverse heat flows from right to left.

Fig. 2. Finite element model of the thermal rectifier.

Fig. 3. Comparisons of temperature distribution of the thermal rectifier (Reverse and Forward denote the case of that LaCoO₃ and La_0.7Sr_0.3CoO₃ materials locate in high-temperature side respectively).

Fig. 4. Response of the thermal rectifier with different temperature differences: (a) Heat flux; (b) thermal rectification ratio.

Fig. 5. Relationship between cross-section area and cross-section radius change rate.

Fig. 6. Temperature distribution of the thermal rectifier with different length ratios: (a) Length ratio is 0.5; (b) length ratio is 0.2.

Fig. 7. Variations of thermal rectification coefficient with length ratio under different contact thermal resistance: (a) ; (b) –0.03

Fig. 8. Variations of thermal rectification coefficient with length ratio at different boundary temperature differences: (a) ; (b)

Fig. 9. Variations of thermal rectification coefficient with length ratio at different length variation ratio.