Carbon-free Polymer Air Electrode based on Highly ConductivePEDOT Micro-Particles for Li-O2 Batteries

Abstract

This study introduced a carbon-free electrode for Li-O 2 cells with the aim of suppressing the side reactions activated by carbon material. Micro-particles of poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer, were used as the base material for the air electrode of Li-O 2 cells. The PEDOT micro-particles were treated with H 2 SO 4 to improve their electronic conductivity, and LiBr and CsBr were used as the redox mediators to facilitate the dissociation of there action products in the electrode and reduce the over-potential of the Li-O 2 cells. The capacity of the electrode employing PEDOT micro-particles was significantly enhanced via H 2 SO 4 treatment, which is attributed to the increased electronic conductivity. The considerable capacity enhancement and relatively low over-potential of the electrode employing H 2 SO 4-treated PEDOT micro-particles indicate that the treated PEDOT micro-particles can act as reaction sites and provide storage space for the reaction products. The cyclic performance of the electrode employing H 2 SO 4-treated PEDOT micro-particles was superior to that of a carbon electrode. The results of the Fourier-transform infrared spectroscopic analysis showed that the accumulation of residual reaction products during cycling was significantly reduced by introducing the carbon-free electrode based on H 2 SO 4-treated PEDOT micro-particles, compared with that of the carbon electrode. The cycle life was improved owing to the effect of the redox mediators. The refore, the use of the carbon-free electrode combined with redox mediators could realize excellent cyclic performance and low over-potential simultaneously.

Constructing Resilient Cross‐Linked Network Toward Stable All‐Solid‐State Lithium‐Sulfur Batteries

“…An absorption band at 3440 cm −1 , corresponds to O─H stretching vibration possibly originating from the hydroxyl groups on the surface of carbon materials. [ 12 ] After SC materials are mixed with the EVA polymer (SC‐EVA), the peak at 1736.2 cm −1 corresponding to the C≐O stretching vibration of EVA polymers is observed in the SC‐EVA materials. The O─H peak shifts to lower wavenumbers at 3429 cm −1 , which is due to the electron density change of hydroxyl groups caused by the formation of hydrogen bonds between SC materials and EVA elastomers.…”