Electrocatalysts for Using Renewably-Sourced, Organic Electrolytes for Redox Flow Batteries

Biomass could be a source of the redox shuttles that have shown promise for operation as high potential, organic electrolytes for redox flow batteries. There is a sufficient quantity of biomass to satisfy the growing demand to buffer the episodic nature of renewably produced electricity. However, despite a century of effort, it is still not evident how to use existing information from organic electrochemistry to design the electrocatalysts or supporting electrolytes that will confer the required activity, selectivity and longevity. In this research, the use of a fiducial reaction to normalize reaction rates is shown to fail.

Overcharge protection of lithium-ion batteries with phenothiazine redox shuttles

Overcharge protection of Li-ion batteries with a variety of phenothiazine derivatives.

Cu(ii/i) redox couples: potential alternatives to traditional electrolytes for dye-sensitized solar cells

DSSCs have reached certified efficiency of 11.9% and device efficiency of 14.3% using I−/I3− or Co(ii/iii) redox shuttles. But, they have many constraints and Cu(i/ii) electrolytes are found to be best alternatives and the efficiency has crossed 30% under low light conditions, potential applications in Internet of things.

Ferrocene Derivatives Functionalized with Donor/Acceptor (Hetero)Aromatic Substituents: Tuning of Redox Properties

A series of functionalized ferrocene derivatives carrying electron-donor and electron-withdrawing (hetero)aromatic substituents has been designed as potential alternative electrolyte redox couples for dye-sensitized solar cells (DSSC). The compounds have been synthesized and fully characterized in their optical and electrochemical properties. A general synthetic approach that implies the use of a microwave assisted Suzuki coupling has been developed to access a significative number of compounds. The presence of different electron-rich and electron-poor substituents provided fine tuning of optical properties and energy levels. HOMO and LUMO energy values showed that the substitution of one or two cyclopentadienyl rings of ferrocene can be successfully exploited to increase the maximum attainable voltage from a standard DSSC device using TiO2 as a semiconductor, opening the way to highly efficient, non-toxic, and cheap redox shuttles to be employed in solar energy technologies.