No abstract

Aqueous organic redox flowb atteries (AORFBs) are ap romising electrochemical technology for large-scale energy storage.W er eport ab iomimetic,u ltra-stable AORFB utilizing an amino acid functionalizedp henazine (AFP). A series of AFPs with various commercial amino acids at different substituted positions were synthesized and studied. 1,6-AFPs displaym uchh igher stability during cycling when compared to 2,7-and 1,8-AFPs.M echanism investigations reveal that the reduced 2,7-and 1,8-AFPs tend to tautomerize and lose their reversible redox activities,w hile 1,6-AFPs possess ultra-high stability both in their oxidized and reduced states.B yp airing 3,3'-(phenazine-1,6-diylbis(azanediyl))dipropionic acid (1,6-DPAP)w ith ferrocyanide at pH 8w ith 1.0 Melectron concentration, this flowbattery exhibits an OCV of 1.15 Vand an extremely lowcapacity fade rate of 0.5 %per year.These results show the importance of molecular engineering of redox-active organics for robust redox-flowb atteries.

Utilization of hemicelluloses from biomass energy is an important approach to explore renewable resources. A convenient, quick, and inexpensive method for the preparation of blended films from quaternized hemicelluloses (QH) and carboxymethyl cellulose (CMC) was introduced into this study. QH and CMC solution were first mixed to form homogeneous suspension, and then were dried under vacuum to fabricate the blended films. The FT-IR and XRD results indicated that the linkage between QH and CMC was due to the hydrogen bonding and electrostatic interaction. From the results of mechanical properties and water vapor permeability (WVP), the tensile strength of the blended films increased with the QH/CMC content ratio increasing in appropriate range, and the WVP of the blended films decreased. The maximum value of tensile strength of blend film achieved was 27.4 MPa. In addition, the transmittances of the blended films increased with the decreasing of QH/CMC content ratio. When the weight ratio (QH: CMC) was 1:1.5, the blend film showed the best light transmittance (45%). All the results suggested that the blended films could be used in areas of application in the coating and packaging fields from the good tensile strength, transmittance, and low WVP.

Modern power systems are equipped with comprehensive protective devices to remove the fault section, and the fault diagnosis problem is to interpret the alarms of the protective devices and estimate the fault section. To deal with the uncertainty and temporal constraint of the alarms, a novel fault diagnosis model based on the temporal constrained fuzzy Petri nets (TCFPNs) is proposed in this paper. The truth degree and the timing contribute of the alarms are introduced into the graphic model of the TCFPNs, and the matrix algorithm, considering both the fuzzy reasoning and temporal reasoning, is carried out to obtain the fault probability as well as the time point constraint of each candidate section. The developed approach is performed on different test systems for case studies, and the results demonstrate the feasibility, efficiency, and fault tolerance of the method.

Aqueous organic redox flowb atteries (AORFBs) are ap romising electrochemical technology for large-scale energy storage.W er eport ab iomimetic,u ltra-stable AORFB utilizing an amino acid functionalizedp henazine (AFP). A series of AFPs with various commercial amino acids at different substituted positions were synthesized and studied. 1,6-AFPs displaym uchh igher stability during cycling when compared to 2,7-and 1,8-AFPs.M echanism investigations reveal that the reduced 2,7-and 1,8-AFPs tend to tautomerize and lose their reversible redox activities,w hile 1,6-AFPs possess ultra-high stability both in their oxidized and reduced states.B yp airing 3,3'-(phenazine-1,6-diylbis(azanediyl))dipropionic acid (1,6-DPAP)w ith ferrocyanide at pH 8w ith 1.0 Melectron concentration, this flowbattery exhibits an OCV of 1.15 Vand an extremely lowcapacity fade rate of 0.5 %per year.These results show the importance of molecular engineering of redox-active organics for robust redox-flowb atteries.