High power generation from a new semi-solid thermo-electrochemical cell

Here, we introduce a semi-solid thermo-electrochemical cell based on Bi0.4Sb1.6Te3/[Fe(CN)63-/Fe(CN)64-] electrolyte. The Bi0.4Sb1.6Te3 can not only reduce the circulating distance of electrolytes since the Bi0.4Sb1.6Te3 act as reaction sites (i.e., microelectrodes), but also accelerate redox reactions owing to the decrease of the contact potential between electrode and electrolyte. Thus, the Bi0.4Sb1.6Te3/[Fe(CN)63-/Fe(CN)64-] semi-solid electrolyte enables us to achieve an optimized potential temperature coefficient (Se) of − 4.11 mV and a maximum output power density (Pmax) of 0.99 W/m2. In addition, we designed and prepared a prototype consisting of 16 cells, which generated an open-circuit voltage (Voc) of 1.83 V and a Pmax of 0.90 W/m2 at a temperature difference of 30.7 K. This work provides a reliable way to improve the Se and output power density of thermo-electrochemical cells, so that they can be better used in low grade heat energy recovery.