Investigation into the Surface Chemistry of Li4Ti5O12 Nanoparticles for Lithium Ion Batteries

Yongqing Wang; Jing Zhao; Jin Qu; Fangfang Wei; Weiguo Song; Yu-Guo Guo; Baomin Xu

doi:10.1021/acsami.6b07902

Investigation into the Surface Chemistry of Li₄Ti₅O₁₂ Nanoparticles for Lithium Ion Batteries

ACS Appl Mater Interfaces. 2016 Oct 5;8(39):26008-26012. doi: 10.1021/acsami.6b07902. Epub 2016 Sep 23.

Authors

Yongqing Wang^{1

2}, Jing Zhao³, Jin Qu⁴, Fangfang Wei⁵, Weiguo Song⁶, Yu-Guo Guo⁶, Baomin Xu²

Affiliations

¹ Department of Chemical Engineering, School of Chemistry & Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, China.
² Department of Materials Science and Engineering, South University of Science and Technology of China , Shenzhen, 518055, China.
³ Center for Gene and Cell Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.
⁴ State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
⁵ Anshun University , 25 Xue Yuan Road, Anshun Economic Development Zone, Guizhou 561000, China.
⁶ CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing, 100190, China.

PMID: 27618283
DOI: 10.1021/acsami.6b07902

Abstract

Elucidating surface chemistry of Li₄Ti₅O₁₂ anode material plays a critical role in solving gas evolution in Li₄Ti₅O₁₂-based lithium ion batteries. Herein, we propose a CO₂ cycloaddition reaction to study the surface chemistry of Li₄Ti₅O₁₂ nanoparticles. Through the reaction, bare Li₄Ti₅O₁₂ nanoparticles were demonstrated to have extensive Lewis-acid sites, that is, dangling Ti bonds or hydroxyl groups. Lewis-acid site is considered to be able to initiate the decomposition of electrolyte solvents and may also serve as one of the main reasons for gas evolution. TiN_x coating layer is used to cover up the Lewis-acid site and is able to decrease yield of the cycloaddition reaction to some extent. These findings may provide a simple yet very effective way to evaluate surface chemistry and gas evolution in other lithium ion batteries, not limited to Li₄Ti₅O₁₂-based batteries.

Keywords: Lewis acid; Li4Ti5O12; carbon dioxide; lithium-ion battery; swelling.