Engineering a Low-Strain Si@TiSi 2 @NC Composite for High-Performance Lithium-Ion Batteries

作者：Wen Zhang, Wanming Li, Siwei Gui, Xinxin Wang, Zihan Zhang, Qin Chen, Junhong Wei, Shuibin Tu, Xiangrui Duan, Xiancheng Wang, Kai Cheng, Renming Zhan, Yuchen Tan, Feifei Fan, Yun Zhang, Huiqiao Li, Yongming Sun, Huamin Zhou, Hui Yang · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.4c03759 · 被引用次数：7 · 研究领域：Advancements in Battery Materials、Semiconductor materials and interfaces、Advanced Battery Technologies Research

The huge volume expansion/contraction of silicon (Si) during the lithium (Li) insertion/extraction process, which can lead to cracking and pulverization, poses a substantial impediment to its practical implementation in lithium-ion batteries (LIBs). The development of low-strain Si-based composite materials is imperative to address the challenges associated with Si anodes. In this study, we have engineered a TiSi 2 interface on the surface of Si particles via a high-temperature calcination process, followed by the introduction of an outermost carbon (C) shell, leading to the construction of a low-strain and highly stable Si@TiSi 2 @NC composite. The robust TiSi 2 interface not only enhances electrical and ionic transport but also, more critically, significantly mitigates particle cracking by restraining the stress/strain induced by volumetric variations, thus alleviating pulverization during the lithiation/delithiation process. As a result, the as-fabricated Si@TiSi 2 @NC electrode exhibits a high initial reversible capacity (2172.7 mAh g –1 at 0.2 A g –1 ), superior rate performance (1198.4 mAh g –1 at 2.0 A g –1 ), and excellent long-term cycling stability (847.0 mAh g –1 after 1000 cycles at 2.0 A g –1 ). Upon pairing with LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622), the assembled Si@TiSi 2 @NC||NCM622 pouch-type full cell exhibits exceptional cycling stability, retaining 90.1% of its capacity after 160 cycles at 0.5 C.