PVD customized 2D porous amorphous silicon nanoflakes percolated with carbon nanotubes for high areal capacity lithium ion batteries

authored by

Zhouhao Wang, Yan Li, Shaozhuan Huang, Lixiang Liu, Ye Wang, Jun Jin, Dezhi Kong, Lin Zhang, Oliver G. Schmidt

Abstract

Integrating nanostructured Si materials into a freestanding membrane with high mechanical strength and a continuous conductive network is a promising but challenging route to achieve high energy density lithium ion batteries (LIBs). Herein, we demonstrate that physical vapor deposition (PVD) customized two-dimensional (2D) porous amorphous Si nanoflakes, reinforced with ultralong multiwalled carbon nanotubes (MWCNTs), can be integrated into a freestanding film electrode with high volumetric/areal capacity and energy density. Owing to the special 1D/2D nanotube/nanoflake entangled architecture, the freestanding Si-MWCNT film is highly porous, electrically conductive, and mechanically robust. Moreover, the interconnected MWCNT network functions as a spacer to prevent adjacent Si nanoflakes from restacking, and the 2D porous Si nanoflakes provide a large electrode/electrolyte contact area, both of which enable fast Li

⁺ transportation. Due to the existence of abundant pores in both amorphous Si nanoflakes (mesopores) and Si-MWCNT electrodes (macropores), the volume change is significantly suppressed, resulting in stable electrodes with tunable mass loadings from 1.7 to 5.4 mg cm

^-2. When directly used as an anode, the Si-MWCNT film with a mass loading of 2.9 mg cm

^-2 exhibits a high specific capacity of 1556 mA h g

^-1 and an areal capacity of 4.5 mA h cm

^-2. Remarkably, when this freestanding anode is coupled with a commercial LiNi

_1/3Co

_1/3Mn

_1/3O

₂ (NCM) cathode, the full battery delivers a high gravimetric energy density of ∼484.7 W h kg

^-1. This study offers a promising and general route to design freestanding electrodes by percolating CNTs with PVD generated 2D porous nanoflakes and provides significant insights for developing high energy battery systems.

Organisation(s)

Institute of Solid State Physics

External Organisation(s)

South-Central University for Nationalities
Leibniz Institute for Solid State and Materials Research Dresden (IFW)
Zhengzhou University
China University of Geosciences
Chemnitz University of Technology (CUT)

Type

Article

Journal

Journal of Materials Chemistry A

Volume

8

Pages

4836-4843

No. of pages

8

ISSN

2050-7488

Publication date

07.03.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Chemistry, Renewable Energy, Sustainability and the Environment, General Materials Science

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1039/c9ta12923e (Access: Closed)