Germanium Nanowires via Molten-Salt Electrolysis for Lithium Battery Anode

Huan Liu; Tianhao Wu; Liqiang Zhang; Xin Wang; Haifeng Li; Shiqi Liu; Qi Zhang; Xu Zhang; Haijun Yu

doi:10.1021/acsnano.2c04748

Germanium Nanowires via Molten-Salt Electrolysis for Lithium Battery Anode

ACS Nano. 2022 Sep 27;16(9):14402-14411. doi: 10.1021/acsnano.2c04748. Epub 2022 Sep 2.

Authors

Huan Liu^{1

2}, Tianhao Wu^{1

2}, Liqiang Zhang³, Xin Wang⁴, Haifeng Li^{1

2}, Shiqi Liu^{1

2}, Qi Zhang^{1

2}, Xu Zhang^{1

2}, Haijun Yu^{1

2}

Affiliations

¹ Institute of Advanced Battery Materials and Devices, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, People's Republic of China.
² Key Laboratory of Advanced Functional Materials, Ministry of Education, Beijing University of Technology, Beijing, 100124, People's Republic of China.
³ Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, People's Republic of China.
⁴ Department of Materials Science and Engineering, China University of Petroleum, Beijing Changping, 102249, People's Republic of China.

PMID: 36053270
DOI: 10.1021/acsnano.2c04748

Abstract

Germanium (Ge)-based materials can serve as promising anode candidates for high-energy lithium-ion batteries (LIBs). However, the rapid capacity decay caused by huge volume expansion severely retards their application. Herein, we report a facile and controllable synthesis of Ge nanowire anode materials through molten-salt electrolysis. The optimal Ge nanowires can deliver a capacity of 1058.9 mAh g^-1 at 300 mA g^-1 and a capacity above 602.5 mAh g^-1 at 3000 mA g^-1 for 900 cycles. By in situ transmission electron microscopy and in situ X-ray diffraction, the multiple-step phase transformation and good structural reversibility of the Ge nanowires during charge/discharge are elucidated. When coupled with a lithium-rich Li_1.2Mn_0.567Ni_0.167Co_0.067O₂ cathode in a full battery, the Ge nanowire anode leads to a relatively stable capacity with a retention of 84.5% over 100 cycles. This research highlights the significance of molten-salt electrolysis for the synthesis of alloy-type anode materials toward high-energy LIBs.

Keywords: Ge nanowires; Li-ion battery; anode materials; in situ TEM; molten-salt electrolysis.