Lignosulfonate, a sulfonated carbon waste material, is a major by-product in the papermaking industry. Researchers at Rensselaer Polytechnic Institute (RPI) have now developed a method to use this cheap and abundant waste byproduct to build a components for lithium-sulfur batteries.

Reported in an open-access paper published in the RSC journal Sustainable Energy & Fuels, the method uses lignosulfonate as both the donor (decomposition of sulfonic groups (–SO₃H)) of sulfur and the sulfur acceptor in lignosulfonate-derived activated carbon.

Using a circulatory pyrolysis process with carbon activation and sulfur capture, the RPI team obtains a high surface area carbon/sulfur composite. Through this circulatory pyrolysis process, sulfur is effectively trapped in the highly porous structure of activated pyrolyzed lignosulfonate. The micropores provide sufficient space to capture substantial amounts of sulfur and accommodate the large volume change of sulfur during cycling.

This material was successfully developed into a cathode for a lithium–sulfur battery, demonstrating 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.

Schematic illustration of the circulatory synthesis procedure of the Act PyLs-Cap S composite. Li et al. Click to enlarge.

Our research demonstrates the potential of using industrial paper-mill byproducts to design sustainable, low-cost electrode materials for lithium-sulfur batteries.

—Trevor Simmons, a Rensselaer research scientist

Simmons has patented the process with former graduate student Rahul Mukherjee.

Initial funding for the research came from the New York State Pollution Prevention Institute (NYSP2I). The research team then secured a Bench to Prototype grant from the New York State Energy Research and Development Authority, administered through NY-BEST (New York Battery and Energy Storage Technology), to more fully develop the technology.

Resources

• Lu Li, Liping Huang, Robert J. Linhardt, Nikhil Koratkar and Trevor Simmons (2018) “Repurposing paper by-product lignosulfonate as a sulfur donor/acceptor for high performance lithium–sulfur batteries” Sustainable Energy & Fuels2, 422-429 doi: 10.1039/C7SE00394C