RESUMO
Gel polymer electrolytes are an indispensable part of flexible supercapacitors, since their various characteristics determine the device performance. Here, a composite gel electrolyte (FLPS) mainly consisting of polyvinyl alcohol (PVA), sodium alginate (SA), K3Fe(CN)6/K4Fe(CN)6, and LiCl is rationally designed, in which PVA and SA form a robust three-dimensional network, the redox pair of K3Fe(CN)6/K4Fe(CN)6 serves as a cross-linking agent with SA and even donates the oxidation-reduction reaction from the Fe3+/Fe2+ couple with additional capacitance for the device, and LiCl functions as an ion carrier and a water-retaining salt to improve the long-term stability of FLPS. Thus, the FLPS-based supercapacitor exhibits superior electrochemical characteristics, displaying impressive pseudocapacitance across all current densities and excellent cycling stability (â¼99.07% of capacitance retention after 10,000 cycles). Moreover, the FLPS-based supercapacitor demonstrates great low-temperature working ability and pressure responsiveness, suggesting its freeze-resistance, flexibility, and pressure sensing potential. This work provides a promising strategy for preparing tough gel polymer electrolytes with both ion transfer and charge storage ability.
RESUMO
Transformation of biomass to chemicals and fuels is a long-term goal in both science and industry. However, high cost is one of the major obstacles to the industrialization of this sustainable technology. Thus, developing catalysts with high activity and low-cost is of great importance for biomass conversion. The last two decades have witnessed the increasing achievement of the use of earth-abundant 3d-transition-metals in catalysis due to their low-cost, high efficiency and excellent stability. Here, we aim to review the fast development and recent advances of 3d-metal-based catalysts including Cu, Fe, Co, Ni and Mn in lignocellulosic biomass conversion. Moreover, present research trends and invigorating perspectives on future development are given.
