The water-soluble PPGA is widely employed in industries as a cathodic corrosion inhibitor, effectively halting scale formation at substoichiometric level by intervening in one or more steps of the scale formation processes, such as aggregation, nucleation, crystal growth, and agglomeration33,34,35,36.
suffers from zinc dendrite growth and parasitic HER during the charging process, both of which lead to low coulombic efficiency and poor cycling stability47,48,49. To evaluate the capability of PPGA for flow battery applications, we assembled a Zn|PZS|V2O5 flow battery with a flow rate of 20 mL min−1 and a capacity of 20 mAh. As shown in Fig. 6a, the flow battery exhibited a high initial CE of 96.5% at 20 mA cm−2, 20 mAh, which gradually increased to 99.5% after 20 cycles. In contrast, the flow battery with BZS as the catholyte experienced a low initial CE of 88.2% and quickly dropped to 70.2% after 20 cycles. The coulombic efficiency of the flow battery with PZS was maintained at a high level during the following 100 cycles at 20 mA cm−2, 20 mAh (Fig. 6b). The flow battery with BZS as the catholyte encountered a fast capacity decay and finally short-circuited after 50 cycles at 20 mA cm−2, 20 mAh (Fig. 6c). Notably, the flow battery with PZS as the catholyte exhibited a stable capacity of 18.5 mAh at 20 mA cm−2, 20 mAh for 200 cycles without any capacity loss or short circuit. The voltage efficiency of the flow battery with PZS as the catholyte was maintained at a high level during the 200 cycles at 20 mA cm−2, 20 mAh (Fig. 6d). Instead, the voltage efficiency of the flow battery with BZS as the catholyte quickly dropped to 60% after 50 cycles at 20 mA cm−2, 20 mAh. The flow battery with PZS as the catholyte exhibited a high energy efficiency of 96% at 20 mA cm−2, 20 mAh, which gradually increased to 99% after 20 cycles (Fig. 6e). In contrast, the flow battery with BZS as the catholyte showed a low initial energy efficiency of 84% and quickly dropped to 66% after 20 cycles. The energy efficiency of the flow battery with PZS was maintained at a high level during the following 100 cycles at 20 mA cm−2, 20 mAh (Fig. 6f). The flow battery with BZS as the catholyte encountered a fast energy efficiency decay and finally short-circuited after 50 cycles at 20 mA cm−2, 20 mAh (Fig. 6g). Notably, the flow battery with PZS as the catholyte exhibited a stable energy efficiency of 96% at 20 mA cm−2, 20 mAh for 200 cycles without any capacity loss or short circuit.
suffers from zinc dendrite growth and parasitic HER during the charging process, both of which lead to low coulombic efficiency and poor cycling stability47,48,49. To evaluate the capability of PPGA for flow battery applications, we assembled a Zn|PZS|V2O5 flow battery with a flow rate of 20 mL min−1 and a capacity of 20 mAh. As shown in Fig. 6a, the flow battery exhibited a high initial CE of 96.5% at 20 mA cm−2, 20 mAh, which gradually increased to 99.5% after 20 cycles. In contrast, the flow battery with BZS as the catholyte experienced a low initial CE of 88.2% and quickly dropped to 70.2% after 20 cycles. The coulombic efficiency of the flow battery with PZS was maintained at a high level during the following 100 cycles at 20 mA cm−2, 20 mAh (Fig. 6b). The flow battery with BZS as the catholyte encountered a fast capacity decay and finally short-circuited after 50 cycles at 20 mA cm−2, 20 mAh (Fig. 6c). Notably, the flow battery with PZS as the catholyte exhibited a stable capacity of 18.5 mAh at 20 mA cm−2, 20 mAh for 200 cycles without any capacity loss or short circuit. The voltage efficiency of the flow battery with PZS as the catholyte was maintained at a high level during the 200 cycles at 20 mA cm−2, 20 mAh (Fig. 6d). Instead, the voltage efficiency of the flow battery with BZS as the catholyte quickly dropped to 60% after 50 cycles at 20 mA cm−2, 20 mAh. The flow battery with PZS as the catholyte exhibited a high energy efficiency of 96% at 20 mA cm−2, 20 mAh, which gradually increased to 99% after 20 cycles (Fig. 6e). In contrast, the flow battery with BZS as the catholyte showed a low initial energy efficiency of 84% and quickly dropped to 66% after 20 cycles. The energy efficiency of the flow battery with PZS was maintained at a high level during the following 100 cycles at 20 mA cm−2, 20 mAh (Fig. 6f). The flow battery with BZS as the catholyte encountered a fast energy efficiency decay and finally short-circuited after 50 cycles at 20 mA cm−2, 20 mAh (Fig. 6g). Notably, the flow battery with PZS as the catholyte exhibited a stable energy efficiency of 96% at 20 mA cm−2, 20 mAh for 200 cycles without any capacity loss or short circuit.
a Initial coulombic efficiency, b coulombic efficiency, c capacity, d voltage efficiency, e initial energy efficiency, f energy efficiency, and g capacity of Zn|PZS|V2O5 flow batteries at 20 mA cm−2, 20 mAh. All tests were performed at around 25 oC. The positive electrode mass loading is around 20 mg cm−2.output
