Carbon Felt Decorated with Carbon Derived from Spent Asphalt as a Low‐cost and High‐performance Electrode for Vanadium Redox Flow Batteries

Abstract

Vanadium redox flow batteries (VRFBs) have attracted much attention in the field of energy storage systems owing to their safety, long-cycle life, and feasible scalability. However, the market penetration of VRFBs is still hindered by the poor performance of current carbon-based electrodes. Herein, spent asphalt is employed as an efficient and low-cost precursor to generate carbon decorating carbon felt for VRFB applications. By thermal decomposition treatment, the spent asphalt is converted into highly active pyrolytic carbon and deposited on surfaces of carbon felt. The as-prepared carbon felt with increased active sites and improved hydrophility displays superior performance towards redox reactions of VO 2 + /VO 2 + in terms of better electrochemical reversibility and faster reaction kinetics. Therefore, the VRFB cell with the carbon felt decorated with carbon derived from spent asphalt as cathode shows 85% energy efficiency which is higher than the pristine carbon felt cathode by 9%. Meanwhile, the energy efficiency and voltage efficiency are both stable during the cell cycling. This strategy can raise the value of the spent asphalt and improve the performance of VRFBs with the decorated carbon felt electrode shedding light on their commercial applications for large-scale energy storage.

The Role of Proton in High Power Density Vanadium Redox Flow Batteries

“…In comparison to limited proton-incorporated WO 3 , H 0.5 WO 3 exhibits a smaller charge transfer resistance, demonstrating an accelerated electron transfer process. To exclude the effect of specific surface area on the electrochemical performance, the pore structure and the corresponding specific surface area of the samples were measured by the Brunauer–Emmett–Teller (BET) method. , As shown in Figure S13, H 0.5 WO 3 and WO 3 exhibit similar specific surface area. The electrochemically active surface area (ECSA) was further measured to identify the exposure of the active sites.…”

Passivation of Cu nanosheet dissolution with Cu2+-containing electrolytes for selective electroreduction of CO2to CH4

“…[14][15][16] Many methods have been applied to minimize the Cu dissolution and afford a highly stable Cu-based catalyst. [17][18][19] For instance, graphene oxide was used to decrease Cu dissolution, but its CO 2 reduction reaction (CO 2 RR) selectivity was weakened due to internal structural variations. 20,21 An AgCu alloy was developed to mitigate the dissolution of Cu with the reaction sites shifting from Cu to AgCu, while its CH 4 production was severely suppressed.…”

Sponge‐Like Microfiber Electrodes for High‐Performance Redox Flow Batteries

“…[18][19][20] However, RFBs with pristine carbon electrodes always exhibit poor battery performance due to the intrinsic low electrochemical activity and specific surface area. [21] Therefore, catalyst deposition, [22][23][24][25][26][27][28][29] surface etching, [30][31][32][33] and heteroatom doping [34][35][36] are widely adopted to modify electrodes, among which constructing porous fiber electrode through various etching methods are considered one of the most efficient methods to increase the specific surface area while decoupling the influence on the transport properties. [37] For example, Liu and Zhang et al etched the carbon paper electrodes with CO 2 and achieved an energy efficiency (EE) of nearly 80% at 140 mA cm −2 in a vanadium redox flow battery (VRFB).…”