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
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
Affiliations
Zhengqiang Hu
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Fengling Zhang
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Huanyu Liang
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Hao Zhang
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Huaizhi Wang
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Tiansheng Wang
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Renbin Liu
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Jie Liu
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Yadong Li
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Xiaotong Dong
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Lianyu Bao
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Zhuan Liang
College of Electrical Engineering and Automation Shandong University of Science and Technology Qingdao Shandong China
Yaqun Wang
College of Electrical Engineering and Automation Shandong University of Science and Technology Qingdao Shandong China
Shishen Yan
State Key Laboratory of Crystal Materials, School of Physics Shandong University Jinan Shandong China
Qiang Li
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
Hongsen Li
Center for Marine Observation and Communications, College of Physics Qingdao University Qingdao Shandong China
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.
