TY - JOUR
T1 - Carbon microspheres with embedded FeP nanoparticles as a cathode electrocatalyst in Li-S batteries
AU - Xia, Guang
AU - Zheng, Zhiqiang
AU - Ye, Jiajia
AU - Li, Xuting
AU - Biggs, Mark James
AU - Hu, Cheng
N1 - Funding Information:
C.H. acknowledges the support from the Natural Science Foundation of Shandong Province (Grant No. ZR2019QEM001), the Guangdong Basic and Applied Basic Research Foundation (2019A1515111089), and the Fundamental Research Funds of Shandong University (Grant No. 2018JC038).
Funding Information:
C.H. acknowledges the support from the Natural Science Foundation of Shandong Province (Grant No. ZR2019QEM001 ), the Guangdong Basic and Applied Basic Research Foundation ( 2019A1515111089 ), and the Fundamental Research Funds of Shandong University (Grant No. 2018JC038 ).
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/2/15
Y1 - 2021/2/15
N2 - This study reports a composite of FeP nanoparticles embedded in gradient-porous carbon microspheres (PCM) as a high-efficiency cathode electrocatalyst with simultaneous sulfur immobilization and redox promotion for improved high-rate capability and cycling stability in Li-S batteries. The PCM possesses micro-, meso- and macropores that provide effective adsorption of polysulfides and accommodation of volume-expanded Li2S as indicated by post-discharge SEM examinations. The embedment of FeP nanoparticles within the PCM ensures maximized exposure of catalytic sites and their improved interactions with sulfur redox species under the confinement effect of carbon nanopores. Compared with Fe3O4, which shows a stronger polysulfide binding strength, FeP offers a balance between effective polysulfide trapping and elevated conversion kinetics for the subsequent liquid-solid transitions. Significantly improved sulfur utilizations and confinement are obtained for Li2S deposition and decomposition, which are regarded as the rate- and capacity-limiting steps during charge/discharge. Detailed working mechanisms are revealed by electrochemical measurements and density functional theory calculations. PCM/FeP enables outstanding high-rate capability up to 4 C and Li-S pouch cells with high areal (8.6 mAh cm−2) and total (414 mAh) capacities are also demonstrated. This study provides new opportunities for the design of high-performance Li-S electrocatalysts.
AB - This study reports a composite of FeP nanoparticles embedded in gradient-porous carbon microspheres (PCM) as a high-efficiency cathode electrocatalyst with simultaneous sulfur immobilization and redox promotion for improved high-rate capability and cycling stability in Li-S batteries. The PCM possesses micro-, meso- and macropores that provide effective adsorption of polysulfides and accommodation of volume-expanded Li2S as indicated by post-discharge SEM examinations. The embedment of FeP nanoparticles within the PCM ensures maximized exposure of catalytic sites and their improved interactions with sulfur redox species under the confinement effect of carbon nanopores. Compared with Fe3O4, which shows a stronger polysulfide binding strength, FeP offers a balance between effective polysulfide trapping and elevated conversion kinetics for the subsequent liquid-solid transitions. Significantly improved sulfur utilizations and confinement are obtained for Li2S deposition and decomposition, which are regarded as the rate- and capacity-limiting steps during charge/discharge. Detailed working mechanisms are revealed by electrochemical measurements and density functional theory calculations. PCM/FeP enables outstanding high-rate capability up to 4 C and Li-S pouch cells with high areal (8.6 mAh cm−2) and total (414 mAh) capacities are also demonstrated. This study provides new opportunities for the design of high-performance Li-S electrocatalysts.
KW - High-rate capabilities
KW - Lithium-sulfur batteries
KW - PCM/FeP microspheres
KW - Sulfur redox catalysis
UR - http://www.scopus.com/inward/record.url?scp=85090134579&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2020.126823
DO - 10.1016/j.cej.2020.126823
M3 - Article
AN - SCOPUS:85090134579
SN - 1385-8947
VL - 406
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 126823
ER -