*3.4. Effect of Different Electrolytes on Thermoelectric Performance of the Novel TEP*

Figure 8 demonstrates the thermal conductivities with temperatures change of the novel TEP under various electrolytes, including the deionized water, seawater, titanium dioxide nanofluid, and polymeric nanofluid composed of titanium dioxide nanoparticles with sodium hydroxide. The thermal conductivity of TiO2 nanofluid was the best among these four solutions. The polymeric nanofluid composed of TiO2 nanoparticles added to NaOH affects the nanoparticle size, resulting in more serious agglomeration between the nanoparticles and the lower thermal conductivity of NaOH, so that its thermal conductivity tended to decrease more than TiO2 nanofluid. The difference of thermal conductivity coefficient between seawater and deionized water was not much different and their thermal conductivity coefficients were relatively poor. Compared with deionized water, the overall increase of thermal conductivity coefficient of the novel TEP containing TiO2 nanofluid was about 11%. The relationships between electric performances and temperatures of the novel TEP at different electrolytes are shown in the Figure 9. However, the effects of different electrolytes on the novel TEP could be seen in that the electric performances of the polymeric nanofluid was the highest among them, and the difference between seawater and the polymeric nanofluid was not much different. Compared with deionized water and TiO2 nanofluid from Figure 9a, the current density was relatively low. The overall increases in current density of TiO2 nanofluid and the polymeric nanofluid were respectively about 45% and 419%. Compared with deionized water and TiO2 nanofluid from Figure 9b, the power density was relatively low. The overall increases in power density of TiO2 nanofluid and the polymeric nanofluid were respectively about 55% and 768%.

**Figure 8.** Relationship between thermal conductivity and temperature of different electrolytes of the novel TEP.

**Figure 9.** Relationship between electric performances and temperatures of different electrolytes of the novel TEP. (**a**) Current, (**b**) power.
