Quinone-based redox molecules are gaining attention as practical alternatives in redox flow battery research. While viologen derivatives are widely regarded as benchmark anolyte because of their well-defined and reversible electrochemistry, they are inherently sensitive to moisture and oxygen. Their reduced radical cation readily reacts with dissolved oxygen, leading to parasitic side reactions, capacity fade, and the need for stringent air-free handling. In contrast, the quinone compound we are developing as a reference standard is commercially available, low-cost, and chemically robust under ambient conditions. Quinones undergo reversible two-electron redox processes, often via proton-coupled electron transfer, and their redox potentials are well established and highly reproducible. Importantly, this particular quinone demonstrates strong intrinsic stability toward oxygen, avoiding the degradation pathways that limit viologen systems. Its affordability and ready availability remove barriers associated with custom synthesis and purification, enabling broader adoption across laboratories. As a stable and economical redox-active benchmark, this quinone offers a practical alternative standard that simplifies experimental design, enhances reproducibility, and supports more reliable cross-comparison of emerging redox flow battery chemistries in non-aqueous systems.
Key words- non-aqueous redox flow batteries (NRFBs), energy storage, quinone, viologen, anolyte