fig5

Figure 5. (A) Schematic of TGCs containing only I^-/I₃^- (n-type) and pNIPAm/(I^-/I₃^-) (p-type). (B) The phase change of pNIPAm nanogels and the redox reaction of I^-/I₃^-. (C) Concentration change ratio of I^- and I₃^- at different temperatures. (D) V_oc as a function of temperature difference with and without pNIPAm nanogels in the I^-/I₃^- electrolyte. (E) I-V curves and corresponding power at ΔT = 10 K. (F and G) Schematic of TGCs containing MC/(I^-/I₃^-) at different temperatures, switching from n-type (T_hot < T_transition) to p-type (T_hot > T_transition). (H) Schematic of a TGC containing MC/(I^-/I₃^-)/KCl at T_hot > T_transition. (I) V_oc as a function of hot electrode temperature for various MC/(I^-/I₃^-) electrolytes with different MC amounts. The temperature of the cold electrode was 24 °C. (J) V_oc as a function of hot electrode temperature for 2 wt % MC/(I^-/I₃^-)/KCl with varying KCl amounts. The temperature of the cold electrode was 24 °C. (K) Salt-induced complexation, K⁺ and I₃^- ions interacted with MC via O sites and methyl groups. (L) V_oc and maximum power for I^-/I₃^-, MC/(I^-/I₃^-), and MC/(I^-/I₃^-)/KCl TGCs. (A-D) Reprinted with permission from Ref.^[52]. Copyright 2019 Elsevier. (E-K) Reprinted with permission from Ref.^[53]. Copyright 2020 American Association for the Advancement of Science.