Zinc ion thermal charging cell for low-grade heat conversion and energy storage

Abstract

Converting low-grade heat from environment into electricity shows great sustainability for mitigating the energy crisis and adjusting energy configurations. However, thermally rechargeable devices typically suffer from poor conversion efficiency when a semiconductor is employed. Breaking the convention of thermoelectric systems, we propose and demonstrate a new zinc ion thermal charging cell to generate electricity from low-grade heat via the thermo-extraction/insertion and thermodiffusion processes of insertion-type cathode (VO2-PC) and stripping/plating behaviour of Zn anode. Based on this strategy, an impressively high thermopower of ~12.5 mV K−1 and an excellent output power of 1.2 mW can be obtained. In addition, a high heat-to-current conversion efficiency of 0.95% (7.25% of Carnot efficiency) is achieved with a temperature difference of 45 K. This work, which demonstrates extraordinary energy conversion efficiency and adequate energy storage, will pave the way towards the construction of thermoelectric setups with attractive properties for high value-added utilization of low-grade heat.

Semi‐Immobilized Ionic Liquid Regulator with Fast Kinetics toward Highly Stable Zinc Anode under −35 to 60 °C

“…[5,6] However, some key issues including metal corrosion, complex side reaction, and uncontrollable Zn dendrite caused by Zn metal anode redox chemistry still hinder the practical application of ZIBs. [7][8][9][10] Metallic Zn exhibits relatively poor thermodynamic and electrochemical stability in aqueous electrolytes, leading to the inevitable chemical corrosion in the presence of H 2 O and dissolved O 2 molecules. [11,12] Simultaneously, the unpredicted side reactions, especially for hydrogen evolution reaction (HER), inevitably cause pH increase and continuous consumption of electrolytes [13,14] (Figure 1a), which are more obvious at extreme temperatures.…”

Thermo-electrochemical cells for heat to electricity conversion: from mechanisms, materials, strategies to applications

“…5G, a thermally charging zinc ion cell with a themopower of 12.5 mV K À1 has been proposed by heating the VO 2 -porous carbon cathode. 99…”

“…In addition, the soluble amide derivatives such as urea is also introduced to and thermopower (ii) of this assembled cell. 99 Reproduced with permission. 99 Copyright 2022, Nature Publishing Group.…”

“…Copyright 2019, Nature Publishing Group. (G) Zinc ion thermal charging cell assembled by Li et al: schematic diagram (i) and thermopower (ii) of this assembled cell 99. Reproduced with permission 99.…”

Thermally Chargeable Ammonium‐Ion Capacitor for Energy Storage and Low‐Grade Heat Harvesting

“…Environmental issues caused by the continuous consumption of traditional fossil energy sources become more serious, so the implementation of the global carbon neutrality strategy is no time to delay. [1][2][3][4][5] Consequently, it is especially important to develop and use green and sustainable energy. The survey results show that 72 % of the global primary energy is lost during use, of which 63 % is accounted for low-grade waste heat energy below 100 °C.…”