Multi‐Redox Active Carbons and Hydrocarbons: Control of their Redox Properties and Potential Applications
Hiroyuki Ueda, Soichiro Yoshimoto
Abstract
Abstract Precise control over redox properties is essential for high‐performance organic electronic devices such as organic batteries, electrochromic devices, and information storage devices. In this context, multi‐redox active carbons and hydrocarbons, represented as C x H y molecules ( x ≥1, y ≥0), are highly sought after, because they can switch between multiple redox states. Herein, we outline the redox properties of C x H y molecules as solutes and adsorbed species. Furthermore, the limitations of evaluating their redox properties and the possible solutions are summarized. Additionally, the theoretical capacity (mAh/g) and gravimetric energy density (Wh/kg) of secondary batteries were estimated based on the redox properties of 185 C x H y molecules, which have primarily been reported in the last decade. Among them, seven C x H y molecules were found to have the potential to surpass the energy density of LiNi 0.6 Mn 0.2 Co 0.2 O 2 /graphite batteries. The use of C x H y molecules in multielectrochromic devices and multi‐bit memory is also explained. We believe that this review will encourage further utilization of C x H y molecules thereby promoting its applications in organic electronic devices.