Phosphaviologen‐Based Pyrene‐Carbon Nanotube Composites for Stable Battery Electrodes

Abstract

The adoption of intermittent renewable power sources has placed battery technologies into the limelight, initiating a push to develop sustainable materials for energy storage that do not rely on rare or toxic elements. Organic electrode materials are made from abundant elements that are consumed in the biomass cycle, which can make large‐scale manufacturing and recycling of these materials less detrimental to the environment. Herein, we explore how organic, electroactive phosphoryl‐bridged viologens (phosphaviologens) can be composited with single‐walled carbon nanotubes (SWCNTs) and used as organic electrodes composed of sustainable/abundant materials. To this end, we have functionalized phosphaviologens that exhibit two stable and reversible reductions with pendant pyrene moieties to interface them with carbon nanotubes. The anchoring of the redox active species on the surface of SWCNTs prevents electrode dissolution, and hybrid batteries with a high voltage (1.95–3.5 V) vs. Li/Li+ using phosphaviologens as the cathode remain stable past 500 charge/discharge cycles.

Roadmap of Solid-State Lithium-Organic Batteries toward 500 Wh kg–1

“…The matching of the particle size and morphology between active materials and conductive agents might also improve the particle-to-particle contact of these components. Different electrode engineering techniques were used, such as ball milling, 46 in situ coating, 171 wet impregnation, and direct crystallization onto the surface of the conductive agent, 172 to achieve high active material fraction and high utilization.…”

Emerging trends in sustainable battery chemistries

“…This requires complete elimination of toxic, scarce, or nonbiodegradable components at the entire-cell level. Ideal candidates include batteries using organic electrodes (e.g., naphthalene diimide, phosphaviologens, quinone), which are fully biodegradable and environmentally benign [59,60]. Aqueous based electrolytes should also be adopted to avoid hazardous organic solvent exposure to the environment during disposal [61,62].…”

Highly Soluble Arylene Diimide Derivatives as Anolyte Materials with Two-Electron Storage for Ultrastable Neutral Aqueous Organic Redox Flow Batteries

“…Viologen has been widely used as an electrolyte material for neutral AORFBs. [34][35][36][37][38][39] Viologens are mostly used for one-electron storage due to the lack of stability of highly reduced species. 40 Therefore, improving the effective electron utilization and stability of viologen has become an important challenge in the application of neutral AORFBs.…”