Tuning Inactive Phases in Si-Ti-B Ternary Alloy Anodes to Achieve Stable Cycling for High-Energy-Density Lithium-Ion Batteries

Hui Liu; Yuegang Long; Yun Chen; Zhiguo Wang; Chun Zhang; Renzong Hu; Xiong Zhang; Peng Yu

doi:10.1021/acsami.1c18150

Tuning Inactive Phases in Si-Ti-B Ternary Alloy Anodes to Achieve Stable Cycling for High-Energy-Density Lithium-Ion Batteries

ACS Appl Mater Interfaces. 2021 Dec 8;13(48):57317-57325. doi: 10.1021/acsami.1c18150. Epub 2021 Nov 24.

Authors

Hui Liu^{1

2}, Yuegang Long¹, Yun Chen¹, Zhiguo Wang¹, Chun Zhang¹, Renzong Hu², Xiong Zhang³, Peng Yu¹

Affiliations

¹ School of Chemistry and Material Science, Hunan Agricultural University, Changsha 410128, China.
² Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
³ Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China.

PMID: 34817991
DOI: 10.1021/acsami.1c18150

Abstract

Cycle stability improvement of a high-capacity Si anode is a challenge for its wide application in high-energy-density lithium-ion batteries. Active amorphous/nanosized Si embedded in an inactive matrix is a strategy to improve the cycle stability of Si anodes. Ternary Si_100-x-yTi_xB_y (5 ≤ y ≤ x ≤ 20) alloys are designed and prepared by ball milling using elemental Si, Ti, and B as starting materials. The formation sequence of inactive phases during mechanical alloying is predicted by an effective heat-of-formation model and verified by microstructural characterization. The local-fine distribution of free amorphous and nanocrystalline Si in the Si_100-x-yTi_xB_y is analyzed by confocal μ-Raman spectroscopy. When used as lithium-ion anodes, the capacity and voltage affected by Si and inactive compounds in the Si_100-x-yTi_xB_y are concerned to assess their high energy density. Furthermore, the impact of free active Si, the inactive phase, and amorphous Si on the cyclability of Si_100-x-yTi_xB_y is studied. The results show that the Si_100-x-yTi_xB_y material is a potential anode for high-energy-density Li-ion batteries and could be used to guide the design of multi-component Si-alloy anodes.

Keywords: Si-alloy; capacity retention; energy density; heat of formation; lithium-ion battery.