Du Meng, Shi Jiakang, Shi Yuxiao, Zhang Guangxun, Yan Yan, Geng Pengbiao, Tian Ziqi, Pang Huan
School of Chemistry and Chemical Engineering, Yangzhou University Yangzhou 225009 P. R. China
School of Materials Science and Engineering, Suzhou University of Science and Technology Suzhou 215009 P. R. China.
Chem Sci. 2024 May 28;15(25):9775-9783. doi: 10.1039/d4sc01628a. eCollection 2024 Jun 26.
Transition-metal compounds (TMCs) have recently become promising candidates as lithium-sulfur (Li-S) battery cathode materials because they have unique adsorption and catalytic properties. However, the relationship between the anionic species and performance has not been sufficiently revealed. Herein, using FeCoNiX (X = O, S, and P) compounds as examples, we systematically studied the effects of the anion composition of FeCoNiX compounds on the adsorption and catalytic abilities of sulfur cathodes in Li-S batteries. Adsorption tests and density functional theory calculations showed that the adsorption ability toward lithium polysulfides follows the order: FeCoNiP > FeCoNiO > FeCoNiS, while ultraviolet-visible spectroscopy and cyclic voltammetry revealed that the catalytic ability for lithium polysulfide conversion follows the order: FeCoNiP > FeCoNiS > FeCoNiO. These results indicate that FeCoNiP is an excellent polysulfide immobilizer and catalyst that restricts shuttling and improves reaction kinetics. Electrochemical tests further demonstrated that the FeCoNiP cathode delivered superior cycling performance to FeCoNiO or FeCoNiS. In addition, the battery performance order is consistent with that of catalytic ability, which suggests that catalytic ability plays a key influencing role in batteries. This study provides new insight into the use of O-, S-, and P-doped TMCs as functional sulfur carriers.
过渡金属化合物（TMCs）因其具有独特的吸附和催化性能，近来成为锂硫（Li-S）电池阴极材料的有力候选者。然而，阴离子种类与性能之间的关系尚未得到充分揭示。在此，以FeCoNiX（X = O、S和P）化合物为例，我们系统地研究了FeCoNiX化合物的阴离子组成对Li-S电池中硫阴极吸附和催化能力的影响。吸附测试和密度泛函理论计算表明，对多硫化锂的吸附能力顺序为：FeCoNiP > FeCoNiO > FeCoNiS，而紫外可见光谱和循环伏安法显示，对多硫化锂转化的催化能力顺序为：FeCoNiP > FeCoNiS > FeCoNiO。这些结果表明，FeCoNiP是一种优异的多硫化物固定剂和催化剂，可限制穿梭效应并改善反应动力学。电化学测试进一步表明，FeCoNiP阴极的循环性能优于FeCoNiO或FeCoNiS。此外，电池性能顺序与催化能力顺序一致，这表明催化能力在电池中起着关键影响作用。本研究为使用O、S和P掺杂的TMCs作为功能性硫载体提供了新的见解。
