Boosting Conversion of the Si-O Bond by Introducing Fe2+ in Carbon-Coated SiO x for Superior Lithium Storage

被引：3

作者：

Zhou, Xiaozhong ^{[1
]}

An, Xiaona ^{[1
]}

Ma, Lihua ^{[1
]}

Zhang, Yan ^{[1
]}

Yan, Nuoqian ^{[1
]}

Deng, Jiangwei ^{[1
]}

Peng, Hezong ^{[1
]}

Li, Xiangyuan ^{[1
]}

Lei, Ziqiang ^{[1
]}

机构：

[1] Northwest Normal Univ, Coll Chem & Chem Engn, Key Lab Ecofunct Polymer Mat, Minist Educ, Lanzhou 730070, Gansu, Peoples R China

来源：

ACS APPLIED MATERIALS & INTERFACES | 2024年 / 16卷 / 30期

基金：

中国国家自然科学基金;

关键词：

lithium-ion batteries; anode; SiO x; Si-O bond; electrochemicalperformance; ANODES; PERFORMANCE; GRAPHENE; SILICON; COMPOSITE; CAPACITY; NANOPARTICLES; REDUCTION; MECHANISM; ELECTRODE;

D O I：

10.1021/acsami.4c08687

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

SiOx -based anodes are of great promise for lithium-ion batteries due to their low working potential and high specific capacity. However, several issues involving large volume expansion during the lithiation process, low intrinsic conductivity, and unsatisfactory initial Coulombic efficiency (ICE) hinder their practical application. Here, an Fe-SiOx @C composite with significantly improved lithium-storage performance was successfully synthesized by combining Fe2+ modification with a carbon coating strategy. The results of both experiments and density functional theory calculations confirm that the Fe2+ modification not only effectively achieves uniform carbon coating but also weakens the bonding energy of the Si-O bond and boosts reversible lithiation/delithiation reactions, resulting in great improvement in the electrical conductivity, ICE, and reversible specific capacity of the as-obtained Fe-SiOx @C. Together with the coated carbon, the in situ-generated conductive Fe-based intermediates also ensure the electrical contact of active components, relieve the volume expansion, and maintain the structural integrity of the electrode during cycling. And the Fe-SiOx @C (x approximate to 1.5) electrode can deliver a high-rate capacity of 354 mA h g(-1) at 2.0 A g(-1) and long-term cycling stability (552.4 mA h g(-1) at 0.5 A g(-1) even after 500 cycles). The findings here provide a facile modification strategy to improve the electrochemical lithium-storage performance of SiOx -based anodes.

引用

页码：39482 / 39494

页数：13