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• The capacities achieved 0.08 mAh/cm2 for thin-film electrolytic MnO 2 -Zn batteries. • Over 200 cycles were demonstrated for batteries with electrolyte of 25 µL/cm2. • The shuttle reactions caused by iodide mediators were revealed experimentally. Whilst electrolytic MnO 2 with a high capacity draws great attention recently, the shuttle reactions between the mediator additives in the electrolytes with zinc and MnO 2 are often overlooked. In this work, neutral acetate electrolytes with iodide mediator are tested for electrolytic MnO 2 -Zn system on thin-film batteries. With a limited amount of electrolyte, the shuttle reactions caused by iodide mediator becomes more obvious, which results in low Coulombic efficiencies and shortens shelf-life. [ABSTRACT FROM AUTHOR]

We report on the improvement of power conversion efficiency (PCE) of PTB7/PC70BM solar cells by the addition of small quantities (0.02%-0.04%) of pristine single-walled carbon nanotubes (SWNTs) in the active-layer. SWNTs and purified semiconducting SWNTs (S-SWNTs) were added in quantities, which is 2 orders of magnitude lower than previously reported value and resulted in a reduction in the series resistance of the solar cell with minor changes on the shunt resistance. On addition of purified S-SWNT, the PCE of air measured devices enhanced by 29% from 4.9% to 6.3%, with short-circuit current density (JSC) improving from 12.1mA/cm² to 14.4 mA/cm² and a fill factor improvement from 54% to 61%. In addition, the role of processing additive N-Methyl-2-pyrrolidone, which acts as a SWNT dispersant, is also investigated. A single diode model of a solar cell is used to extract the cell parameters and understand the effect of SWNTs. Based on experimental data and it's fitting to the single diode model, we propose that S-SWNT improve the transport and extraction of photogenerated charges within the solar cell device. [ABSTRACT FROM AUTHOR]

Linear wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from linear wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of wave energy converters. Hardware systems have been constructed to control the linear wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based wave energy emulators. [ABSTRACT FROM AUTHOR]