Immobilization of phosphotungstate through doping in polypyrrole for supercapacitors

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 48; no. 2; pp. 6812 - 6816
• Main Authors: Chang, Zhihan, Sang, Xiaoguang, Song, Yu, Sun, Xiaoqi, Liu, Xiao-Xia
• Format: Journal Article
• Language: English
• Published: England 21.05.2019
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c9dt00925f

Immobilization of phosphotungstate is achieved through doping in polypyrrole via the electrochemical deposition of polypyrrole (PPy) in the presence of the phosphotungstate anions (PW 12 ) on carbon nanotube film. Electrochemical stability in neutral solution is realized for PW 12 in the prepared ECNT-PPy/5PW 12 , owing to the proton sponge provided by PPy. ECNT-PPy/5PW 12 shows a high areal capacitance of 1300.0 mF cm −2 in LiCl solution at 1 mA cm −2 . ECNT-PPy/5PW 12 also displays high rate capability and good cyclic stability due to the interaction of incorporated PW 12 and the polymer matrix. ECNT-PPy/5PW 12 can retain 78.6% and 92.0% of its capacitance with 40-fold current increase and after 10 000 galvanostatic charge/discharge cycles, respectively. An asymmetric supercapacitor with the ECNT-PPy/5PW 12 anode and CNT-MnO 2 cathode demonstrates high volumetric energy density (4.71 mW h cm −3 at 13.85 mW cm −3 ) and long cycle life (90.0% capacitance retention after 10 000 charge/discharge cycles). Immobilization of phosphotungstate is achieved through doping in polypyrrole. Owing to the proton sponge provided by polypyrrole, electrochemical stability in neutral solution is realized for phosphotungstate.