Electrochemically deposited sulfur electrode on stainless-steel current collector for lithium-sulfur battery applications

초록

In this study, a binder-and conductive additive-free sulfur electrode was fabricated by electrochemically depositing solid sulfur onto a stainless-steel current collector. Prior to electrode fabrication, the growth process of sulfur as a function of deposition time (5, 15, 30, and 60 min) was systematically investigated. At the initial deposition stage, micro-sized particles with irregular shapes were gradually transformed into spherical ones at 30 min. After 60 min, only spherical sulfur particles with an average diameter of 5.2 mu m completely covered the surface of the current collector. The as-deposited sulfur electrode exhibited unstable discharge behavior due to weak adhesion to the current collector. In contrast, the application of a conductive carbonized PAN (CPAN) interlayer enabled smooth electrochemical reactions during discharge-charge cycling. To further improve cell performance, a glass fiber (GF) separator was employed in combination with CPAN, and its electrochemical properties were compared with those of a commercial PP separator. The GF-cell exhibited superior performance over the PP-cell, delivering higher discharge capacity (1120 vs. 993 mAh/g at 0.1C) and improved capacity retention (86.6% vs. 45.2% at 0.2C after 200 cycles).

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