Efficient synthesis of high-sulfur-content cathodes for high-performance Li�VS batteries based on solvothermal polysulfide chemistry
Journal
Journal of Power Sources
Journal Volume
450
Date Issued
2020
Author(s)
Weng, Y.-T.
Wang, H.
Lee, R.-C.
Huang, C.-Y.
Huang, S.-S.
Abdollahifar, M.
Kuo, L.-M.
Hwang, B.-J.
Kuo, C.-L.
Cui, Y.
Wu, N.-L.
Abstract
A novel solvothermal polysulfide (PS) chemistry enables a facile and highly efficient process for synthesizing sulfur-carbon (S–C) composite powders containing up to 90 wt% S for high-performance Li–S batteries. Molecular dynamics calculations and experimental analyses reveal the formation of PSs upon dissolution of elemental S in N-methyl-2-pyrrolidone (NMP) at elevated temperatures and efficient infiltration of the PSs into the carbon host driven by the strong coupling with the C surfaces. The coupling enables extensive contact between S and C in the composite, leading to promising electrochemical properties for Li–S battery applications. In the power-type configuration, the composite cathodes having medium-to-high S contents (55 and 75%) demonstrate stable capacity at high current densities up to 100C (1C = 1670 mA g−1-S) and no capacity fade up to 1000 cycles at 2C. In the energy-type configuration, a high-S-content and high-loading (90%-S, 4.2 mAh cm−2) cathode shows a specific capacity of 1440 mAh g−1 (86% S utilization) and 90% capacity retention after 300 cycles. This synthesis method enables significant advancement in realizing large-scale applications of Li–S batteries.
SDGs
Type
journal article