TY - JOUR
T1 - Elucidating the mechanism of discharge performance improvement in zinc-air flow batteries
T2 - A combination of experimental and modeling investigations
AU - Yu, Wentao
AU - Shang, Wenxu
AU - Xiao, Xu
AU - Ma, Yanyi
AU - Chen, Ziqi
AU - Chen, Bin
AU - Xu, Haoran
AU - Ni, Meng
AU - Tan, Peng
N1 - Funding Information:
P. Tan thanks the funding support from Anhui Provincial Natural Science Foundation ( 2008085ME155 ), USTC Research Funds of the Double First-Class Initiative (YD2090002006), Joint Laboratory for USTC and Yanchang Petroleum (ES2090130110), and USTC Tang Scholar (KY2090000065). M. Ni thanks the funding support (Project Number: PolyU 152214/17E and PolyU 152064/18E) from Research Grant Council, University Grants Committee, Hong Kong SAR.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/8
Y1 - 2021/8
N2 - The zinc-air flow battery demonstrates a bright prospect as the next-generation large-scale energy storage devices. Compared with conventional static zinc-air batteries, the electrochemical performance can be significantly improved, whereas the intrinsic mechanism is still unclear. Herein, the mechanism of the discharge performance improvement from the flowing electrolyte is systematically investigated by combining experimental and modeling methods. The experimental results demonstrate that the flowing electrolyte has an apparent effect on the discharge polarization performance, especially on the concentration polarization region. Compared with the static condition, the peak power density is improved by ~10% to 136 mW cm−2 at a flow rate of 5 mL min−1. Further numerical calculations reveal that this enhancement mainly comes from the transfer enhancement of hydroxide ions caused by the flowing electrolyte. Besides, the specific discharge capacity is improved from 623 to 767 mAh gZn−1 due to the alleviation of zinc oxide passivation in the presence of flowing electrolyte. Therefore, the performance improvement in zinc-air flow batteries is attributed to the enhanced transport of hydroxide and zincate ions rather than oxygen. The revealed mechanism can serve as the basis to design proper flow field and battery structure, and promote zinc-air flow batteries toward practical applications.
AB - The zinc-air flow battery demonstrates a bright prospect as the next-generation large-scale energy storage devices. Compared with conventional static zinc-air batteries, the electrochemical performance can be significantly improved, whereas the intrinsic mechanism is still unclear. Herein, the mechanism of the discharge performance improvement from the flowing electrolyte is systematically investigated by combining experimental and modeling methods. The experimental results demonstrate that the flowing electrolyte has an apparent effect on the discharge polarization performance, especially on the concentration polarization region. Compared with the static condition, the peak power density is improved by ~10% to 136 mW cm−2 at a flow rate of 5 mL min−1. Further numerical calculations reveal that this enhancement mainly comes from the transfer enhancement of hydroxide ions caused by the flowing electrolyte. Besides, the specific discharge capacity is improved from 623 to 767 mAh gZn−1 due to the alleviation of zinc oxide passivation in the presence of flowing electrolyte. Therefore, the performance improvement in zinc-air flow batteries is attributed to the enhanced transport of hydroxide and zincate ions rather than oxygen. The revealed mechanism can serve as the basis to design proper flow field and battery structure, and promote zinc-air flow batteries toward practical applications.
KW - Polarization
KW - Power density
KW - Specific discharge capacity
KW - Zinc-air flow battery
UR - http://www.scopus.com/inward/record.url?scp=85108181420&partnerID=8YFLogxK
U2 - 10.1016/j.est.2021.102779
DO - 10.1016/j.est.2021.102779
M3 - Journal article
AN - SCOPUS:85108181420
SN - 2352-152X
VL - 40
JO - Journal of Energy Storage
JF - Journal of Energy Storage
M1 - 102779
ER -
