Aqueous redox flow battery using iron 2,2‐bis(hydroxymethyl)‐2,2′,2′‐nitrilotriethanol complex and ferrocyanide as newly developed redox couple

An all-iron aqueous redox flow battery using iron (Fe) 2,2-bis(hydroxymethyl)-2,2',2'-nitrilotriethanol (BIS-TRIS) complex (Fe(BIS-TRIS)) and Ferrocyanide (Fe[CN](6)) as redox couple is newly suggested. The redox potential of Fe(BIS-TRIS) is -1.11 V (vs Ag/AgCl) and this makes Fe(BIS-TRIS) appropriate as active material for anolyte, while Fe(CN)(6) is proper for catholyte due to its excellent redox reactivity, redox potential, and cheap cost. According to quantitative evaluations, Fe(BIS-TRIS) does not produce any side reactions and is more stable than Fe triethanolamine (TEA) (Fe(TEA)) complex that is conventionally considered for the purpose. This fact is confirmed by computational analysis using density functional theory. In the calculation, energy barrier of Fe(BIS-TR1S) suppressing the occurrence of undesirable side reactions is higher than that of other Fe-ligand complexes, indicating that desirable redox reaction of Fe(BIS-TRIS) occurs more stably. In redox flow battery (RFB) tests, RFBs using Fe(BIS-TRIS) do not show any side reactions even after 250 cycles with excellent performances, such as capacity of 11.7 Ah L-1. and coulombic efficiency and capacity retention rate of 99.8 and 99.9%, respectively. This corroborates that RFBs using Fe(BIS-TRIS) have excellency in both performance and stability, while the cheap cost of BIS-TRIS and Fe(CN)(6) enhances the economic benefit of RFBs.11Nsciescopu

Output Performance Enhanced Triboelectric Nanogenerators Induced by Magnetic Ink Trapping Property Act as Wearable Sensors

The demand for clean-energy collection has gradually increased in recent years, making triboelectric nanogenerators a promising research field, because of their advantages in convenient manufacturing, diversified materials, and diverse synthesis and modification possibilities. However, recent studies indicate that charge decay, a major limiting factor in the triboelectric output, prevents the induced charge from combining with the bottom electrode, leading to charge loss. The use of charge-trapping sites to retain the induced charge generated during the friction process is an important solution in the field of triboelectric nanogenerator research. This study proposes the use of an elastic ink with macroscopic magnetism as trapping sites by coating the ink as dots between the polytetrafluoroethylene (PTFE) dielectric layer and the electrode layer. Nickel particles in the magnetic ink are doped into the system as microcapacitors, which prevent the combination of the friction layer and induced charges on the back electrode. Because the nickel itself can be used as a charge-potential trap to capture the charge introduced by the charge-injection process, the charge can be maintained for a long time and achieve a long-term high-output state. The output voltage was more than 6 times that of the reference group without the magnetic-ink coating after 3 h. The results provide a reference direction for research on preventing charge decay and trapping charges in triboelectric nanogenerators

Output Performance Enhanced Triboelectric Nanogenerators Induced by Magnetic Ink Trapping Property Act as Wearable Sensors

The demand for clean-energy collection has gradually increased in recent years, making triboelectric nanogenerators a promising research field, because of their advantages in convenient manufacturing, diversified materials, and diverse synthesis and modification possibilities. However, recent studies indicate that charge decay, a major limiting factor in the triboelectric output, prevents the induced charge from combining with the bottom electrode, leading to charge loss. The use of charge-trapping sites to retain the induced charge generated during the friction process is an important solution in the field of triboelectric nanogenerator research. This study proposes the use of an elastic ink with macroscopic magnetism as trapping sites by coating the ink as dots between the polytetrafluoroethylene (PTFE) dielectric layer and the electrode layer. Nickel particles in the magnetic ink are doped into the system as microcapacitors, which prevent the combination of the friction layer and induced charges on the back electrode. Because the nickel itself can be used as a charge-potential trap to capture the charge introduced by the charge-injection process, the charge can be maintained for a long time and achieve a long-term high-output state. The output voltage was more than 6 times that of the reference group without the magnetic-ink coating after 3 h. The results provide a reference direction for research on preventing charge decay and trapping charges in triboelectric nanogenerators