Electrolyte/Structure-Dependent Cocktail Mediation Enabling High-Rate/Low-Plateau Metal Sulfide Anodes for Sodium Storage

Nano-Micro Letters

Jieshan Qiu¹  Chunyi Zhi²  Anthony F. Hollenkamp³  Aaron Seeber³  Tao Jin³  Mustafa Musameh³  Xiaojuan Hao³  Yongchao Tang⁴  Yanan Hou⁴  Xin Pan⁴  Zongbin Zhao⁴  Han Zhang⁴  Yue Wei⁵ 

[1] College of Chemical Engineering, Beijing University of Chemical Technology;Department of Materials Science and Engineering, City University of Hong Kong;Manufacturing, Commonwealth Scientific and Industrial Research Organization (CSIRO);State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology;State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology;

关键词: Metal sulfide anode;    Rate capability;    Voltage plateau;    Cocktail mediation effect;    Sodium-ion batteries;   

DOI  :  10.1007/s40820-021-00686-4

来源: DOAJ

【 摘 要 】

Abstract As promising anodes for sodium-ion batteries, metal sulfides ubiquitously suffer from low-rate and high-plateau issues, greatly hindering their application in full-cells. Herein, exemplifying carbon nanotubes (CNTs)-stringed metal sulfides superstructure (CSC) assembled by nano-dispersed SnS2 and CoS2 phases, cocktail mediation effect similar to that of high-entropy materials is initially studied in ether-based electrolyte to solve the challenges. The high nano-dispersity of metal sulfides in CSC anode underlies the cocktail-like mediation effect, enabling the circumvention of intrinsic drawbacks of different metal sulfides. By utilizing ether-based electrolyte, the reversibility of metal sulfides is greatly improved, sustaining a long-life effectivity of cocktail-like mediation. As such, CSC effectively overcomes low-rate flaw of SnS2 and high-plateau demerit of CoS2, simultaneously realizes a high rate and a low plateau. In half-cells, CSC delivers an ultrahigh-rate capability of 327.6 mAh g−1 anode at 20 A g−1, far outperforming those of monometallic sulfides (SnS2, CoS2) and their mixtures. Compared with CoS2 phase and SnS2/CoS2 mixture, CSC shows remarkably lowered average charge voltage up to ca. 0.62 V. As-assembled CSC//Na1.5VPO4.8F0.7 full-cell shows a good rate capability (0.05 ~ 1.0 A g−1, 120.3 mAh g−1 electrode at 0.05 A g−1) and a high average discharge voltage up to 2.57 V, comparable to full-cells with alloy-type anodes. Kinetics analysis verifies that the cocktail-like mediation effect largely boosts the charge transfer and ionic diffusion in CSC, compared with single phase and mixed phases. Further mechanism study reveals that alternative and complementary electrochemical processes between nano-dispersed SnS2 and CoS2 phases are responsible for the lowered charge voltage of CSC. This electrolyte/structure-dependent cocktail-like mediation effect effectively enhances the practicability of metal sulfide anodes, which will boost the development of high-rate/-voltage sodium-ion full batteries.

【 授权许可】

Unknown