Electrochemical Performance of Manganese Coordinated Polyaniline

Abstract

Manganese (II) coordinated polyaniline (PANI‐Mn) is designed as an energy‐storage electrode to improve electrochemical cycling stability of conductive polymer‐based supercapacitors. A PANI‐Mn electrode is synthesized through electro‐polymerization and hydrothermal coordination processes. A tetrahedron coordination structure is formed between manganese (II) dichloride and neighboring imino nitrogen to enforce the bonding strength of conjoint aniline units, restraining excessive volume expansion of the PANI molecule chain. Specific capacitance is enhanced from 350 F g−1 of PANI to 810 F g−1 of PANI‐Mn at 1 A g−1. Cycling capacitance retention is improved from 61% of PANI to 88% of PANI‐Mn at 5 A g−1 for 1000 cycles. PANI‐Mn shows larger response current than PANI at the same potential. First principle calculations prove that PANIs‐Mn exhibits higher density of state at Fermi level than PANI. The conjugated electron delocalization is strengthened in transitional metal‐coordinated conductive polymer, causing the improved conductivity of PANI‐Mn. Furthermore, an all‐solid‐state symmetric supercapacitor based on a PANI‐Mn electrode exhibits an energy density of 51.38 Wh kg−1 at a power density of 850 W kg−1 and a considerable cycling life of 82% after 1000 cycles at 5 A g−1. PANI‐Mn coordination polymer exhibits enhanced electrochemical stability, thus showing promise for energy storage application.

Enhanced Specific Capacitance and Stability of Polyaniline by Nafion Doping

“…The peaks at 1306, 1242, 1162, and 829 cm À 1 were assigned to the CÀ N stretching of the aromatic secondary amine, CÀ N + stretching of the polarized structure, and in-plane and out-of-plane of CÀ H bending vibration, respectively, which were consistent with previous FTIR spectra of PANI. [25][26][27][28] After adding Nafion, the new peak at 1042 cm À 1 can be assigned to the symmetric stretching of the SO 3 2À group in Nafion (Figure 2a and S5), and the intensity of the CÀ N + peak increases with increasing Nafion content (Figure 2a), indicating that the Nafion was doped into PANI. The inplane CÀ H stretching vibration of PANI at 1162 cm À 1 showed a low wavenumber shift (or red shift) with increasing Nafion content (Table S1), which can be attributed to the electrostatic interactions between the sulfonate group of Nafion and the amino group of PANI.…”

Photoelectrochemical performance of tubewall‐separated titanium dioxide nanotube array photoelectrode

“…The ohm resistance can be obtained by the intercept of the semicircular arc on real axis at the high frequency region. The charge transfer resistance can be estimated by the radius of the first semicircle at the high frequency region 41 . TiO 2 NTA shows similar ohm resistance of 0.74 Ω at different potentials due to stable electrochemical properties of TiO 2 NTA in Na 2 SO 4 electrolyte solution.…”

Electrochemical performance of activated carbon fiber with hydrogen bond-induced high sulfur/nitrogen doping

“…First, the H 2 SO 4 -PVA gel electrolyte was obtained with a solution-casting method that was similar to the papers of our research group. 26 The rectangular S/N-ACF (total area: $1 Â 3 cm 2 , working area: $1 Â 2 cm 2 ) was immersed into the H 2 SO 4 -PVA gel electrolyte three times to make sure that the electrolyte was in full contact with the electrode. Two S/N-ACF electrodes of the same shape were placed face-to-face, and assembled into S/N-ACF FSC.…”