Repurposing paper by-product lignosulfonate as a sulfur donor/acceptor for high performance lithium–sulfur batteries

The recovery and repurposing of biomass are critically important and make a significant contribution to environmental preservation. Lignosulfonate, a by-product of the paper manufacturing industry, is an abundant low cost material with unique potential as a sulfur precursor for high performance cathode materials. In this work, we develop a practical green method of using lignosulfonate as both the donor (decomposition of sulfonic groups (–SO3H)) of sulfur and the sulfur acceptor in lignosulfonate derived activated carbon. Through a circulatory pyrolysis process with carbon activation and sulfur capture, a high surface area carbon/sulfur composite was obtained. This material was successfully developed into a cathode for a lithium–sulfur battery, which demonstrates outstanding cycling stability with a capacity decay rate as low as 0.1% per cycle over 200 cycles. When the sulfur loading was further increased to 68 wt%, the capacity still reaches as high as 1100 mA h g−1, suggesting its promising potential for applications in the field of high energy storage devices.