Topotactic Transformation Synthesis of 2D Ultrathin GeS2 Nanosheets toward High-Rate and High-Energy-Density Sodium-Ion Half/Full Batteries

Cheng Chao Li; Bo Wang; Dong Chen; Li-Yong Gan; Yuezhan Feng; Yufei Zhang; Yang Yang; Hongbo Geng; Xianhong Rui; Yan Yu

doi:10.1021/acsnano.9b06855

Topotactic Transformation Synthesis of 2D Ultrathin GeS₂ Nanosheets toward High-Rate and High-Energy-Density Sodium-Ion Half/Full Batteries

ACS Nano. 2020 Jan 28;14(1):531-540. doi: 10.1021/acsnano.9b06855. Epub 2019 Dec 20.

Authors

Cheng Chao Li¹, Bo Wang¹, Dong Chen², Li-Yong Gan³, Yuezhan Feng⁴, Yufei Zhang¹, Yang Yang¹, Hongbo Geng¹, Xianhong Rui², Yan Yu^{5

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Affiliations

¹ School of Chemical Engineering and Light Industry , Guangdong University of Technology , Guangzhou 510006 , China.
² Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage Devices, Collaborative Innovation Center of Advanced Energy Materials, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China.
³ Institute for Structure and Function and Department of Physics , Chongqing University , Chongqing 400030 , China.
⁴ Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education , Zhengzhou University , Zhengzhou 450002 , China.
⁵ Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering , University of Science and Technology of China, Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences (CAS) , Hefei , Anhui 230026 , China.
⁶ State Key Laboratory of Fire Science , University of Science and Technology of China , Hefei , Anhui 230026 , China.
⁷ Dalian National Laboratory for Clean Energy (DNL) , Chinese Academy of Sciences (CAS) , Dalian 116023 , China.

PMID: 31846288
DOI: 10.1021/acsnano.9b06855

Abstract

Currently, development of metal sulfide anodes for sodium-ion batteries (SIBs) with high capacity, fast charging/discharging, and good cycling performance continues to present a great challenge. Hence, a topochemical conversion strategy is reported to fabricate 2D ultrathin GeS₂ nanosheets (thickness: ∼1.2 nm) as the potential anodes for sodium storage. The 2D ultrathin nanostructure can mitigate the electrode-electrolyte contact issue faced by bulk material and provide shorter transport/diffusion pathways for Na ions and electrons, resulting in excellent rate performance. Impressively, ultrathin GeS₂ nanosheets can bring a large capacity of 515 mAh g^-1 even after 2000 cycles under 10 A g^-1. Additionally, as revealed by calculations and in situ/ex situ technique analysis, a favorable mechanism of Na⁺ intercalation/deintercalation into/from the GeS₂ interlayer region (GeS₂ ↔ Na_xGeS₂) is demonstrated. Furthermore, when coupled with the advanced cathode of Na₃V₂(PO₄)₂O₂F, the sodium-ion full cell shows a stable high energy density (213 Wh kg^-1), which makes our ultrathin GeS₂ nanosheets a promising candidate for SIBs.

Keywords: anode; high energy density; sodium-ion batteries; topotactic transformation; ultrathin GeS2 nanosheets.