Stretchable thermogalvanic hydrogel thermocell with record-high specific output power density enabled by ion-induced crystallization

Abstract

Ionic thermocells have relatively high thermopowers based on thermogalvanic effect, but their small electricity output is still insufficient for practical applications. We demonstrated a highly ionic conductive, anti-freezing stretchable thermogalvanic...

Realizing record-high output power in flexible gelatin/GTA-KCl-FeCN4−/3− ionic thermoelectric cells enabled by extending the working temperature range

“…(e) Comparison of the P max /DT 2 with that of the reported liquid-state and quasi-solid-state i-TE cells. 13,17,18,25,[29][30][31][38][39][40][41] Energy & Environmental Science Paper samples undergo an irreversible phase transition at specific temperature points (T M ). T M was significantly enhanced from 30 1C to 40 1C upon introducing 0.8 mM GTA (r v = 3) and then increased to 44 1C upon adjusting r v from 3 to 2.8.…”

“…(d) P max of gelatin-KCl-FeCN 4À/3À (r v = 3) and gelatin/0.8 mM GTA-KCl-FeCN 4À/3À (r v = 2.8) i-TE cells at different T H with a fixed T C,min = 21 1C. (e) Comparison of the P max /DT 2 with that of the reported liquid-state and quasi-solid-state i-TE cells 13,17,18,25,[29][30][31][38][39][40][41].…”

Potential and Challenges of Thermogalvanic Cells for Low-Grade Heat Harvesting

“…In comparison with the conventional electronic thermoelectrics (Taroni et al, 2018;Chae et al, 2020) and ionic thermos capacitors (Al-zubaidi et al, 2017;Wu et al, 2021), thermogalvanic cells based on redox reactions are not only noise-free and environmentally friendly, but also they enable continuous conversion of lowgrade heat to electricity (Gao et al, 2022). Moreover, the thermogalvanic cells hold the potential to enable an efficient, lightweight, continuous flexible power supply for the burgeoning flexible electronics (e.g., flexible screens and wearable medical electronics) (Liu et al, 2022;Peng et al, 2022;Zhang et al, 2022). This imposes the challenge of durably optimizing the performance of thermogalvanic cells in terms of thermopower (Duan et al, 2018), mechanical properties (Lei et al, 2021;Gao et al, 2022;Lei et al, 2022), and anti-freezing (Gao et al, 2021), among others.…”

Thermoelectrochemical Seebeck coefficient and viscosity of Co-complex electrolytes rationalized by the Einstein relation, Jones–Dole B coefficient, and quantum-chemical calculations

“…Thermoelectrochemical conversion (TEC) using redox electrolytes 1-6 has been burgeoning since around 2010 [7][8][9][10] as a green technology because it can generate electric power from abundant low-grade thermal energy without generating carbon dioxide. Nowadays, diverse aspects of this technology are studied, spanning the uses of nanocarbon electrodes, 8,[11][12][13][14][15][16] additives, [17][18][19][20] phase changes, [21][22][23][24] supramolecular concepts, 25,26 and stretchable quasisolid matrices, 24,[27][28][29][30][31][32] in addition to mechanistic studies. [33][34][35][36][37] However, one of the current problems is the serious disjunction between recent efforts on TEC and the fundamental knowledge of solution chemistry that was explored and accumulated in the previous century.…”

“…Thermoelectrochemical conversion (TEC) using redox electrolytes 1–6 has been burgeoning since around 2010 7–10 as a green technology because it can generate electric power from abundant low-grade thermal energy without generating carbon dioxide. Nowadays, diverse aspects of this technology are studied, spanning the uses of nanocarbon electrodes, 8,11–16 additives, 17–20 phase changes, 21–24 supramolecular concepts, 25,26 and stretchable quasi-solid matrices, 24,27–32 in addition to mechanistic studies. 33–37…”