One of the possible solutions to circumvent the sluggish kinetics, low capacity, and poor integrity of inorganic cathodes commonly used in rechargeable aluminium batteries (RABs) is the use of redox-active polymers as cathodes. They are not only sustainable materials characterised by their structure tunability, but also exhibit a unique ion coordination redox mechanism that makes them versatile ion hosts suitable for voluminous aluminium cation complexes, as demonstrated by the poly(quinoyl) family. Recently, phenazine-based compounds have been found to have high capacity, reversibility and fast redox kinetics in aqueous electrolytes because of the presence of a CN double bond.
View Article and Find Full Text PDFCa- and Mg-based batteries represent a more sustainable alternative to Li-ion batteries. However, multivalent cation technologies suffer from poor cation mass transport. In addition, the development of positive electrodes enabling reversible charge storage currently represents one of the major challenges.
View Article and Find Full Text PDFEnergy-storage materials can be assembled directly on the electrodes of a battery using electrochemical methods, this allowing sequential deposition, high structural control, and low cost. Here, a two-step approach combining electrophoretic deposition (EPD) and cathodic electrodeposition (CED) is demonstrated to fabricate multilayer hierarchical electrodes of reduced graphene oxide (rGO) and mixed transition metal sulfides (NiCoMnS ). The process is performed directly on conductive electrodes applying a small electric bias to electro-deposit rGO and NiCoMnS in alternated cycles, yielding an ideal porous network and a continuous path for transport of ions and electrons.
View Article and Find Full Text PDFAqueous zinc-polymer batteries (AZPBs) comprising abundant Zn metal anode and redox-active polymer (RAP) cathodes can be a promising solution for accomplishing viable, safe and sustainable energy storage systems. Though a limited number of RAPs have been successfully applied as organic cathodes in AZPBs, their macromolecular engineering towards improving electrochemical performance is rarely considered. In this study, we systematically compare performance of AZPB comprising Zn metal anode and either poly(catechol) homopolymer (named P(4VC)) or poly(catechol) copolymer (named P(4VC--SS)) as polymer cathodes.
View Article and Find Full Text PDFRedox-active catechols are bioinspired precursors for ortho-quinones that are characterized by higher discharge potentials than para-quinones, the latter being extensively used as organic cathode materials for lithium ion batteries (LIBs). Here, this study demonstrates that the rational molecular design of copolymers bearing catechol- and Li ion-conducting anionic pendants endow redox-active polymers (RAPs) with ultrarobust electrochemical energy storage features when combined to carbon nanotubes as a flexible, binder-, and metal current collector-free buckypaper electrode. The importance of the structure and functionality of the RAPs on the battery performances in LIBs is discussed.
View Article and Find Full Text PDFThermoresponsive poly(2-(2-methoxyethoxy)ethyl methacrylate) (PMEO2MA) based hybrid nanocomposite hydrogels (NCH) were synthesized by dispersing preformed cadmium sulfide (CdS) quantum dots (QDs) in the reaction mixture followed by polymerization via reversible addition-fragmentation chain transfer (RAFT) technique. High doping capacity and negligible QDs leakage were observed for hydrophilic QDs doped hydrogels (hpl-NCH) due to H-bonding interactions between QDs and pendant groups of hydrogel network. The hpl-NCH networks showed improved structural/orientational order and swelling ratios with increasing doping concentration compared to the organic hydrogel (OH).
View Article and Find Full Text PDFThermodynamically favored polymer-water interactions below the lower critical solution temperature (LCST) caused swelling-induced optical anisotropy (linear retardance) of thermoresponsive hydrogels based on poly(2-(2-methoxyethoxy)ethyl methacrylate). This was exploited to study the macroscopic deswelling kinetics quantitatively by a generalized polarimetry analysis method, based on measurement of the Mueller matrix and its subsequent inverse analysis via the polar decomposition approach. The derived medium polarization parameters, namely, linear retardance (δ), diattenuation (d), and depolarization coefficient (Δ), of the hydrogels showed interesting differences between the gels prepared by conventional free radical polymerization (FRP) and reversible addition-fragmentation chain transfer polymerization (RAFT) and also between dry and swollen state.
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