Suitability of N-propanoic acid spiropyrans and spirooxazines for use as sensitizing dyes in dye-sensitized solar cells.

This work deals with the fabrication and evaluation of color-changing dye-sensitized solar cells (DSSCs) that include N-propanoic acid-functionalized spiropyrans and spirooxazines as sensitizing dyes. We investigated the photophysical properties of these compounds in various solvents and pH conditions using UV-Vis spectroscopy, and their behavior on TiO2 photoanode surfaces using a combination of UV-Vis and FT-IR. Their performance as sensitizing dyes for DSSCs was also analyzed. This study revealed a number of unique properties for this class of compounds that affect their performance as both photochromic compounds and DSSC sensitizers, which allow for future creation of efficient photochromic DSSCs.

Enabling High-Temperature and High-Voltage Lithium-Ion Battery Performance through a Novel Cathode Surface-Targeted Additive.

Lithium-ion batteries (LIBs) are being used in locations and applications never imagined when they were first conceived. To enable this broad range of applications, it has become necessary for LIBs to be stable to an ever broader range of conditions, including temperature and energy. Unfortunately, while negative electrodes have received a great deal of focus in electrolyte development, stabilization of positive electrodes remains an elusive target. Here, we report a novel additive that shows the ability to protect positive electrodes against elevated temperatures and voltages. This additive can be used in small quantities, and its targeted behavior allows it to remain functional in complex electrolyte packages. This can prove an effective approach to targeting specific aspects of cell performance.