An ultrafast chargeable polymer electrode based on the combination of nitroxide radical and aqueous electrolyte

Abstract

A film of poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) coated on a current collector displayed a rapid and reversible electrochemical response in aqueous electrolytes, and allowed an ultrafast full charging of 3 mC cm(-2) in as short as 3 seconds by virtue of the combination of the hydrophilic radical polymer and the aqueous electrolyte possessing a high electrical conductivity.

A rechargeable battery based on hydrophilic radical polymer electrode and its green assessment

“…In addition, considering the combination of the electrolyte solution, PTVE was the lowest risk potential of ignition and explosion due to the combination of a low exothermic electrode and aqueous electrolyte solutions. The polymers demonstrated a quantitative coulombic efficiency and high rechargeability (18,22). These results suggested that the redox reaction of TEMPO has no side reactions and both polymers in the charging state and discharging state have a low reactivity toward the electrolyte salts and solutions.…”

“…Synthetic procedures poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) (PTVE) 2,2,6,6-tetramethylpiperidne-N-oxyl-4-vinyl, synthesizedas the monomer, was prepared using the coupling reaction of 4-hydroxy-2,2,6,6-tetramethylpiperidne-4-oxyl and vinyl acetate with catalyst of bis(1,5-cyclooctadiene) diiridium(I) dichloride and 3-chloroperbenzoic acid, according to a previous paper (21,22,29,30). The vinyl monomer was polymerized via cationic polymerization in dichloromethane with boron trifluoride diethyl etherate as the initiator at Á258C.…”

“…(The rate of 1 C is defined as the current density at which the charging or discharging of the cell takes in 1 h. Most conventional batteries function during the charging or discharging at 1Á2 C.) An important issue described in this report is that a combination of hydrophilic radical polymer and aqueous electrolyte allowed an organic electrolytefree battery design and a rapid chargingÁdischarging performance at the same time. Previous papers (21,22) have discussed only the electrode performance, without evaluating the safety of the radical polymer electrode. One could assume that such a battery configuration has inherent advantages in terms of many aspect of green chemistry.…”

“…Recently, we designed a hydrophilic radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) (PTVE), which sufficiently functioned even in an aqueous electrolyte, and reported the following electrode performance (21,22): (i) high charging and discharging capacity of 131 mAh g (1 ascribed to the stoichiometric redox of the radical moieties; (ii) long cycle life, often exceeding 1000 cycles, derived from the chemical stability of the radicals and from the amorphous electrode structure; and (iii) high chargingÁdischarging rate performance (1200 C) resulting from the rapid electron-transfer process of the radical moiety and the high equivalent electrical conductivity of the aqueous electrolyte on the order of 10 Á2 to 10 Á3 m 2 S mol Á1 , which is 10 times higher than that of organic electrolytes (23). (The rate of 1 C is defined as the current density at which the charging or discharging of the cell takes in 1 h. Most conventional batteries function during the charging or discharging at 1Á2 C.) An important issue described in this report is that a combination of hydrophilic radical polymer and aqueous electrolyte allowed an organic electrolytefree battery design and a rapid chargingÁdischarging performance at the same time.…”

Hydroalkoxylation of alkynes by a nitroxyl containing alcohol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl: synthesis of spin-labeled enol ethers

“…In recent years a number of works (mainly patents) describing applications of 4-vinyloxy-TEMPO have appeared. For instance, polymers and copolymers based on this vinyl ether have been proposed as efficient cathode materials for greener organic radical batteries, [25][26][27][28][29][30][31][32][33][34][35] and a nano-scale memory device was constructed by nanolithographic patterning of oxidized poly(4-vinyloxy-TEMPO). 36 The first synthesis of 4-vinyloxy-TEMPO, which goes back to 1986, comprised the hydroalkoxylation of acetylene with 4-hydroxy-2,2,6,6-tetramethylpiperidine in KOH/DMSO followed by oxidation (Na 2 WO 4 as catalyst).…”