Mechanistic understanding of the charge storage processes in FeF2 aggregates assembled with cylindrical nanoparticles as a cathode material for lithium‐ion batteries by in situ magnetometry

Autor: Zhengqiang Hu, Fengling Zhang, Huanyu Liang, Hao Zhang, Huaizhi Wang, Tiansheng Wang, Renbin Liu, Jie Liu, Yadong Li, Xiaotong Dong, Lianyu Bao, Zhuan Liang, Yaqun Wang, Shishen Yan, Qiang Li, Hongsen Li
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Carbon Energy, Vol 4, Iss 6, Pp 1011-1020 (2022)
Druh dokumentu: article
ISSN: 2637-9368
DOI: 10.1002/cey2.201
Popis: Abstract Transition metal fluorides (TMFs) cathode materials have shown extraordinary promises for electrochemical energy storage, but the understanding of their electrochemical reaction mechanisms is still a matter of debate due to the complicated and continuous changing in the battery internal environment. Here, we design a novel iron fluoride (FeF2) aggregate assembled with cylindrical nanoparticles as cathode material to build FeF2 lithium‐ion batteries (LIBs) and employ advanced in situ magnetometry to detect their intrinsic electronic structure during cycling in real time. The results show that FeF2 cannot be involved in complete conversion reactions when the FeF2 LIBs operate between the conventional voltage range of 1.0–4.0 V, and that the corresponding conversion ratio of FeF2 can be further estimated. Importantly, we first demonstrate that the spin‐polarized surface capacitance exists in the FeF2 cathode by monitoring the magnetic responses over various voltage ranges. The research presents an original and insightful method to examine the conversion mechanism of TMFs and significantly provides an important reference for the future artificial design of energy systems based on spin‐polarized surface capacitance.
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