A Sulfurized Carbon Cathode for High-Capacity and Long-Life Lithium–Sulfur Batteries

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Lithium–sulfur (Li–S) batteries have emerged as promising candidates for next-generation energy storage systems due to their high energy density and low cost. However, challenges such as the low conductivity of sulfur, the notorious "shuttle effect," and substantial volume expansion during charge/discharge cycles have hindered their practical applications. In this study, we introduce sulfurized carbon (SC), a variant of sulfurized poly(acrylonitrile), developed by Zeta Energy, as a cathode material for Li–S batteries, which could mitigate the shuttle effect and enable long cycling life. Remarkably, our SC cathode exhibits a high reversible capacity exceeding 660 mAh/g at a C/3 current rate, maintaining stable retention over 1000 cycles. Moreover, it demonstrates commendable rate capability, sustaining over 92% capacity at a discharge rate of 2C, along with a high area capacity exceeding 3.5 mAh/cm², enabling practical high energy density applications. A series of characterizations, such as Scanning Electronic Microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), have been utilized to investigate the exact molecular structure and its electrochemical reaction mechanism. Additionally, we investigate the effectiveness of incorporating single-wall carbon nanotubes (SWCNTs) as an alternative to the conventional carbon black conductive additive for this SC cathode, and discovered an enhanced electronic conductivity, a significant reduction in charge-transfer resistance and a notable increase in cell capacity. Overall, this work provides insights into sulfur cathodes, paving the way to advance lithium–sulfur battery technology for electric vehicle applications. Acknowledgements The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency – Energy (ARPA-E), U.S. Department of Energy. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. This work was mainly conducted at the Cell Analysis, Modeling, and Prototyping Facility at Argonne National Laboratory. We used resources of the Center for Nanoscale Materials, U.S. Department of Energy (DOE) Office of Science User Facilities operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357.