Synthesis and Charge–Discharge Studies of Poly(ethynylphenyl)galvinoxyles and Their Use in Organic Radical Batteries with Aqueous Electrolytes

Abstract

The synthesis and electrochemical characterization of polymers that bear galvinoxyles in the side chains is described. The monomers are synthesized employing C-C coupling reactions, polymerized with Rh(nbd)BPh 4 as a catalyst, and subsequently oxidized. These galvinoxylcontaining polymers represent interesting anode materials for organic radical batteries and employ stable organic radicals, which are bound to polymers; hereby, metals and metal oxides, as active compounds, can be replaced. With the use of ethynylphenyl-galvinoxyles as anode-active material and poly(2,2,6,6-tetramethylpiperidine-N -oxyl)methacrylate (PTMA) as cathode-active material, metal-free batteries with an aqueous and environment-friendly electrolyte are built. These cells are tested for their charge and discharge capacities.SECs for the radical polymers were measured with a Shimadzu SCL-10A VP controller, a LC-10AD pump, a RID-10A refractive index detector, a SPD-10AD VP UV-detector, and a PSS SDV pre/ lin M (THF-N) column; temperature: 40 °C, eluent: THF; fl ow rate: 1 mL min −1 , calibration: polystyrene.

Polymers with n-type nitroxide side groups: Synthesis and electrochemical characterization

“…After oxidation PDI values of the polymer increased to 1.24, but its molar mass, obtained by SEC, decreased to 6500 g/mol. This may be due to the different hydrodynamic volume of the oxidized polymer compared to its predecessor or side-reactions caused by the radical [21]. Polymer [7] again revealed the expected behavior.…”

“…Molar masses of 16,800 g/mol (M n ) could be achieved for polymer [3] with a polydispersity index (PDI value) of 1.16 (Table 1). After oxidation the molar mass of the polymer increased slightly accompanied with an increase of the PDI value to 1.67 due to sidereactions caused by the formed radicals [21,22]. Methacrylamide polymer [4] was obtained with a molar mass of 9.700 g/mol (M n ) and a PDI value of 1.65.…”

Assorted Phenoxyl-Radical Polymers and Their Application in Lithium-Organic Batteries

“…The most common anode‐active polymer is poly[( p ‐vinylphenyl)galvinoxyl] . Based on the extremely stable galvinoxyl‐radical, several polymeric architectures including polyacetylene, poly(phenyleneethynylene), and poly­thiophene‐based compounds have been synthesized and were tested as active materials for ORBs . These cells usually show good cycling‐stability, even in aqueous electrolytes, and are stable in air .…”

“…Based on the extremely stable galvinoxyl‐radical, several polymeric architectures including polyacetylene, poly(phenyleneethynylene), and poly­thiophene‐based compounds have been synthesized and were tested as active materials for ORBs . These cells usually show good cycling‐stability, even in aqueous electrolytes, and are stable in air . Other attempts to replace metals in the anode of ORBs and to gain the possibility to achieve higher possible charge‐ and discharge‐rates compared to inorganic materials include the use of poly(viologene) and phenoxyl‐radicals .…”

Poly(exTTF): A Novel Redox‐Active Polymer as Active Material for Li‐Organic Batteries

“…The second generation of organic batteries eluded this problem by utilization of polymers with pendant nonconjugated redox‐active groups. In particular organic radicals such as nitroxides, galvinoxyls, nitronylnitroxides, and arylnitroxides have been studied intensively, but also other redox‐active compounds such as triarylamines, carbazoles, or ferrocene were utilized. Most of these compounds possess an ordinary one‐electron redox reaction, leading to a single charge/discharge plateau with a constant cell potential.…”