Improving the cycling stability of three-dimensional nanoporous Ge anode by embedding Ag nanoparticles for high-performance lithium-ion battery

Yonghui Yan; Yang Liu; Yongguang Zhang; Chunling Qin; Zhumabay Bakenov; Zhifeng Wang

doi:10.1016/j.jcis.2021.02.026

Improving the cycling stability of three-dimensional nanoporous Ge anode by embedding Ag nanoparticles for high-performance lithium-ion battery

J Colloid Interface Sci. 2021 Jun 15:592:103-115. doi: 10.1016/j.jcis.2021.02.026. Epub 2021 Feb 13.

Authors

Yonghui Yan¹, Yang Liu¹, Yongguang Zhang², Chunling Qin³, Zhumabay Bakenov⁴, Zhifeng Wang⁵

Affiliations

¹ School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China.
² School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China. Electronic address: yongguangzhang@hebut.edu.cn.
³ School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China. Electronic address: clqin@hebut.edu.cn.
⁴ Institute of Batteries LLC, Department of Chemical and Materials Engineering, National Laboratory Astana, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 010000, Kazakhstan.
⁵ School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China; Key Laboratory for New Type of Functional Materials in Hebei Province, Hebei University of Technology, Tianjin 300401, China; Research Institute of Foundry, Hebei University of Technology, Tianjin 300401, China. Electronic address: wangzf@hebut.edu.cn.

PMID: 33647559
DOI: 10.1016/j.jcis.2021.02.026

Abstract

Due to huge volume expansion and poor electrical conductivity, the commercial application of the promising Germanium (Ge) anode is restrained in lithium ion battery (LIB) field. Generally, conductive metals can improve the electron mobility in Ge. In that way, whether active materials or conductive metals account for a higher proportion in the anode is controversial in this field and needs to be clarified urgently. Herein, three Ge-based anodes with different ratios in conductive Ag are fabricated by a facile melt spinning and one-step dealloying method. It is found that Ag nanoparticles embedded three-dimensional nanoporous Ge (Ag/np-Ge) electrode with high active material ratio exhibits the best cycling stability among tested samples, delivering a high capacity of 953 mAh g^-1 after 100 cycles at a current density of 100 mA g^-1 and an excellent reversible capacity of 522 mAh g^-1 after 200 cycles even at the high current density of 1000 mA g^-1. The enhanced cycling stability can be attributed to the synergistic effect of nanoporous network-like structure and embedded Ag nanoparticles. A dramatical increase in electrical conductivity and activity of Ge by doping of Ag is confirmed by density functional theory (DFT) calculations. The work provides us an idea to rationally design the three-dimensional structure of active materials assisting with a proper ratio of conductive metals, which may promote the development of promising Ge anodes for LIBs with excellent cycling stability.

Keywords: Ag; Anode; Dealloying; Li-ion battery; Nanoporous Ge.