Effect of electrode porosity on the charge transfer in vanadium redox flow battery

JOURNAL OF POWER SOURCES

卷:488

Article

Abbas, Aumber¹  Abbas, Saleem²  Bhattarai, Arjun³  Latiff, Naziah Mohamad⁴  Wai, Nyunt⁵  Phan, Anh N.¹  Lim, Tuti Mariana⁶ 

[1] Newcastle Univ, Sch Engn, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England

[2] Hebei Univ Technol, Sch Mat Sci & Engn, Tianjin 300130, Peoples R China

[3] V Flow Tech Pte Ltd, 02-26,1 CleanTech Loop, Singapore 637141, Singapore

[4] Nanyang Technol Univ, Nanyang Environm & Water Res Inst, Singapore 637141, Singapore

[5] Nanyang Technol Univ, Energy Res Inst NTU, Singapore 637141, Singapore

[6] Nanyang Technol Univ, Sch Civil & Environm Engn, Singapore 639798, Singapore

关键词: Electrode porosity;    Charge transfer;    Reaction kinetics;    Electrocatalytic activity;    Vanadium redox flow battery;    Biomass waste;   

DOI  :  10.1016/j.jpowsour.2020.229411

来源: Elsevier

【 摘 要 】

Vanadium redox flow battery (VRB) has attracted enormous attention as a large-scale energy storage system owing to its long life, stable capacity and high safety. The electrode porosity plays a crucial role in the performance of VRB. This work reports the effect of electrode porosity on the electrocatalytic activity and charge transfer in VRB using spent tea derived porous carbon as electrode material. The electrode porous microstructure is systematically modified and specific surface area is enhanced from similar to 10 to similar to 2085 m(2) g(-1), with microporosity up to similar to 1930 m(2) g(-1). The electrochemical performance of modified electrodes is comprehensively investigated by cyclic voltammetry, impedance spectroscopy and galvanostatic charge/discharge studies. The modified electrode with high degree of porosity improves the charge transfer process and exhibits lower charge transfer resistance with higher electrocatalytic activity for vanadium redox reactions. Moreover, the VRB static cell performance demonstrates superior energy, voltage and coulombic efficiencies for modified electrodes than the pristine graphite electrode at all tested current densities. The results suggest that the tailored porosity substantially influences the charge migration and significantly improves the VRB performance.

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