Biowaste-based hierarchical porous carbon/sulfur composite derived from sustainable fabrication technique as cathode material for Li–S batteries

A potential energy storage device with high energy density, capacity, and low cost is lithium-sulfur batteries (LSBs). However, the commercial implementation is constrained by the discrepancy between the theoretical expectations and actual performance. Herein, a hierarchical porous carbon obtained from shea butter waste is used as a sulfur host for LSB. A straightforward mixing strategy was employed to prepare the carbon–sulfur composite, offering a simpler alternative to the conventional melt-diffusion method and enabling significant reductions in both energy consumption and processing time. The confined sulfur particles in the shea butter waste-derived carbon exhibit enhanced electrochemical performance, suppressing the shuttle effect and volume change during LSB cycling. The porous carbon with 60 wt.% S (SAC@S60) delivers a stable reversible specific discharge capacity of 1340 mAh/g_sulfur at 0.1C. In addition, the SAC@S60-based cathode cell retained 97% of the initial recorded discharge capacity with an impressive 99.4% Coulombic efficiency, illustrating excellent reversibility after 200 cycles. Furthermore, the practical application of the cell was tested by lighting a flameless candle for more than 10 h, even after cycling. Therefore, this work opens a new opportunity for a simple and sustainable carbon-based sulfur composite cathode fabrication technique for high-performance LSBs.

Graphical abstract