Polymer-Doped Molten Salt Mixtures as a New Concept for Electrolyte Systems in Dye-Sensitized Solar Cells

A conceptually new polymer electrolyte for dye-sensitized solar cells is reported and investigated. The benefits of using this type of electrolyte based on ionic liquid mixtures (ILMs) and room temperature ionic liquids are highlighted. Impedance spectroscopy and transient electron measurements have been used to elucidate the background of the photovoltaic performance. Even though larger recombination losses were noted, the high ion mobility and conductivity induced in the ILMs by the added polymer result in enhanced overall conversion efficiencies.

Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance-electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation.

A first-principles investigation of oxygen reduction reaction catalysis capabilities of As decorated defect graphene

Arsenic adsorbed double vacancy defect graphene systems are found to demonstrate excellent electrocatalytic properties for oxygen reduction reaction via high affinity towards four electron process.

Control of the recombination rate by changing the polarity of the electrolyte in dye-sensitized solar cells

Adding an organic solvent to an ionic liquid modifies the polarity and the reorganization energy, and hence reduces recombination.

Interfacial structure and orientation of confined ionic liquids on charged quartz surfaces

Atomistic molecular dynamics simulations have been performed to study microscopic ionic structures and orientational preferences of absorbed [BMIM] cations and four paired anions ([BF₄], [PF₆], [TFO] and [TF₂N]) on quartz surfaces.

Long-term stability for cobalt-based dye-sensitized solar cells obtained by electrolyte optimization

A significant improvement in the long-term stability for cobalt-based dye-sensitized solar cells (DSCs) under light-soaking conditions has been achieved by optimization of the composition of tris(2,2′-bipyridine) Co(ii)/Co(iii) electrolytes.