Details

Autor(en) / Beteiligte

• Zhang, Xicheng
• Wang, Chao
• Yang, Peng
• Zhang, Xu
• Chen, Wei
• Liu, Jianqing
• Cui, Yixiu
• Liu, Xiaojiang
• Li, Xinlu

Titel

Mechanism and kinetics characteristic of self-discharge of FeS cathodes for thermal batteries

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2021-01, Vol.23 (1), p.196-23

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The service life of FeS 2 thermal batteries is significantly affected by self-discharge of the cathode. Herein, SEM, XRD and XPS were employed to characterize the mechanism of self-discharge of the FeS 2 cathode. A novel combined-discharge method, in which a tiny current (5 mA cm −2 ) was applied to minimize the effect of polarization on discharge capacity, was conducted to study the kinetics characteristic of self-discharge of FeS 2 cathode upon discharge. Then, the self-discharge kinetics parameters which are related to the current density (20, 50 and 200 mA cm −2 ) and temperature (400, 450, 500 and 550 °C) were determined by the Serin-Ellickson model. Characterizations of the cells standing at 500 °C confirm that the decomposition product of the FeS 2 cathode is FeS. The quantitative analysis of self-discharge rate constants (SRC) demonstrates that the reaction is a diffusion-controlling process. The kinetics process can conform to the Serin-Ellickson model. Specifically, the values of SRC increase when the cell is carried by a heavier load, since more breakage would form in FeS 2 particles at the larger current density. Besides, the SRC increase at a higher temperature, and the relationship of SRC and temperature can be fitted by the Arrhenius equation. Consequently, the apparent activation energy decreases with the increase of current density. The self-discharge kinetics of FeS 2 cathodes can be exactly quantified by the combined-discharge method.