Crystallography as Forensic Tool for Understanding Electrolyte Degradation in Dye–sensitized Solar Cells

Abstract

The precipitation of solid compounds from model electrolytes for liquid dye‐sensitized solar cells has a story to tell regarding decomposition processes to be expected in such systems. Of course, the crystal lattice energy for a specific crystalline compounds plays a role in what compound that will eventually precipitate, but the compounds nevertheless serve as indicators for what type of processes that take place in the solar cell electrolytes upon ageing. From the compounds isolated in this study we learn that both ligand exchange processes, double‐salt precipitation and oxidation are degradation processes that should not be overlooked when formulating efficient and stable electrolytes for this type of electrochemical system.

Light-induced electrolyte improvement in cobalt tris(bipyridine)-mediated dye-sensitized solar cells

“…Redox reaction products of TBP or bpy are unlikely to explain the spectral changes, but more likely reaction with some unintentional electrolyte component, such as water. 57 A possible reaction is proposed in eqn (3). The production of protons binding to the base TBP could be inferred by the gradual downeld shi of the TBP peak a and water peak in Fig.…”

Electrochemical impedance and X-ray absorption spectroscopy analyses of degradation in dye-sensitized solar cells containing cobalt tris(bipyridine) redox shuttles

“…It is thus plausible to suggest that new Co complexes formed during the ageing may be involved, and possibly in the form of oligomers contributing to the high C new characterizing the new process. 21 X-ray absorption spectroscopy gives some insights into the Co species formed upon electrolyte ageing.…”