High-performance hydrogel electrolytes play a crucial role in flexible supercapacitors (SCs). However, the unsatisfactory mechanical properties of widely used polyvinyl alcohol-based electrolytes greatly limit their use in the flexible SCs. Here, a novel LiSO-containing agarose/polyacrylamide double-network (Li-AG/PAM DN) hydrogel electrolyte was synthesized by a heating-cooling and subsequent radiation-induced polymerization and cross-linking process. The Li-AG/PAM DN hydrogel electrolyte possesses extremely excellent mechanical properties with a compression strength of 150 MPa, a fracture compression strain of above 99.9%, a tensile strength of 1103 kPa, and an elongation at break of 2780%, greatly superior to those have been reported. It also achieves a high ionic conductivity of 41 mS cm originating from its interconnected three-dimensional porous network structure that provides a three-dimensional channel for ionic migration. Compared to the SC applying LiSO aqueous solution electrolyte, the corresponding flexible Li-AG/PAM DN hydrogel electrolyte-SC presents lower charge-transfer resistance, better ionic diffusion, being closer to ideal capacitive behaviors, superior rate capability, and better cycling stability, owing to the improved ionic transport in the Li-AG/PAM DN hydrogel electrolyte and electrode interfaces. Moreover, after testing with overcharge, short circuit, and high temperature, the capacitance of the Li-AG/PAM DN hydrogel electrolyte-SC can still be well maintained. Furthermore, the electrochemical properties of the Li-AG/PAM DN hydrogel electrolyte-SC remain almost intact under different compression strains/bending angles and even after 1000 compression/bending cycles. It is expected that the Li-AG/PAM DN hydrogel electrolyte may have broad applications in modern flexible and wearable electronics.

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An experimental survey of the electrochemical reactivity of five common fuel species was made employing a solid oxide electrolyte galvanic cell with porous Au and Pt electrodes in the temperature range 700~176The electrolyte used was Sc203-stabilized ZrO2 (SSZ). The fuel species electro-oxidized at the anode were: H2, CO, CH4, CH3OH, and C2H5OH. Rates of reaction were determined coulometrically, SO that species other than H2 could have undergone an undetermined amount of thermal dissociation during electro-oxidation. The concomitant reactivity of 02, which is reduced at the cathode, was also investigated. The current-overpotential behavior at both the cathode and anode was found to be similar whether Au or Pt was used to form the porous electrodes. In the low overpotential range, the rate of charge transfer is found to be rate determining for both the cathodic and anodic reactions. Activation enthalpies obtained from an analysis of the data in this low overpotential range are also found to be similarly independent of the electrode materials. Reduction of the electrolyte by current blackening leads to two to three orders of magnitude increase in both the cathodic and anodic current density at a given overpotential. Again, the current overpotential characteristics obtained with Au and Pt electrodes are very similar. Activation enthalpies obtained with the electrolyte in the blackened state do not deviate significantly from those obtained with an unblackened electrolyte. These experimental observations are consistent with a reaction mechanism in which the major electrochemical steps occur at active sites on the electrolyte surface rather than on the metal electrodes. The electrochemical reaction sites are hypothesized to be oxygen vacancies with electrons migrating along the electrolyte surface to or away from these active sites. Thus, an effective localized electronic conductivity of the electrolyte surface is postulated.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 142.58.129.109 Downloaded on 2015-06-03 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 142.58.129.109 Downloaded on 2015-06-03 to IP Vol. 133, No. 9 ZIRCONIA ELECTROLYTE SURFACE ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 142.58.129.109 Downloaded on 2015-06-03 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 142.58.129.109 Downloaded on 2015-06-03 to IP