Issue 10, 2024

The acupuncture effect of carbon nanotubes induced by the volume expansion of silicon-based anodes

Abstract

The cyclic instability of Si-based anodes can be effectively alleviated by adding carbon nanotube (CNT) networks. However, the ion diffusion and electrochemical performance vary significantly depending on the type of CNTs added, particularly single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs), and the intrinsic mechanism remains unknown. Herein, we revealed that the large volume expansion of Si-based anodes leads to the acupuncture effect of short CNTs, with the compressive stress on the CNTs and the Li-ion (Li+) diffusion energy barriers in the solid electrolyte interphase (SEI) exhibiting a linear correlation. Both the SEI and carbon-coating are penetrated by short, thick CNTs with gigapascal (GPa)-scale compressive stress, thereby accelerating electrolyte decomposition and leading to a LiF-rich SEI and an increased Li+ diffusion barrier. In contrast, long, slender CNTs exhibit limited compressive stress, thus minimizing the acupuncture effect, and the formed SEI possesses a low energy barrier for smooth Li+ diffusion. Thus, long, slender CNTs are ideal for Si-based anodes. This work reveals the structure–property relationships among compressive stress, SEI components and Li+ diffusion energy barriers, providing a novel perspective on the development of high-performance electrodes.

Graphical abstract: The acupuncture effect of carbon nanotubes induced by the volume expansion of silicon-based anodes

Supplementary files

Article information

Article type
Paper
Submitted
15 Feb 2024
Accepted
01 Mar 2024
First published
15 Mar 2024

Energy Environ. Sci., 2024,17, 3358-3364

The acupuncture effect of carbon nanotubes induced by the volume expansion of silicon-based anodes

Z. He, C. Zhang, Y. Zhu and F. Wei, Energy Environ. Sci., 2024, 17, 3358 DOI: 10.1039/D4EE00710G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements