Working Mechanisms and Structure Engineering of Renewable Biomass‐Derived Materials for Advanced Lithium‐Sulfur Batteries: A Review

Green Production of Biomass-Derived Carbon Materials for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) with a high energy density have been regarded as a promising energy storage device to harness unstable but clean energy from wind, tide, solar cells, and so on. However, LSBs still suffer from the disadvantages of the notorious shuttle effect of polysulfides and low sulfur utilization, which greatly hider their final commercialization. Biomasses represent green, abundant and renewable resources for the production of carbon materials to address the aforementioned issues by taking advantages of their intrinsic hierarchical porous structures and heteroatom-doping sites, which could attribute to the strong physical and chemical adsorptions as well as excellent catalytic performances of LSBs. Therefore, many efforts have been devoted to improving the performances of biomass-derived carbons from the aspects of exploring new biomass resources, optimizing the pyrolysis method, developing effective modification strategies, or achieving further understanding about their working principles in LSBs. This review firstly introduces the structures and working principles of LSBs and then summarizes recent developments in research on carbon materials employed in LSBs. Particularly, this review focuses on recent progresses in the design, preparation and application of biomass-derived carbons as host or interlayer materials in LSBs. Moreover, outlooks on the future research of LSBs based on biomass-derived carbons are discussed.

Biosurfactant promoted enzymatic saccharification of alkali‑pretreated reed straw

The decrease of cellulase activity and unproductive adsorption of lignin are important obstructive factors for inefficient enzymatic hydrolysis. This paper applied five different kinds of biosurfactants including rhamnolipid, sophorolipid, chitin, tea saponin, and sodium lignosulfonate in the enzymatic hydrolysis process of alkali-pretreated reed straw (RS) to enhance the saccharification efficiency. When 8 g/L sophorolipid is added, the efficiency of enzymatic hydrolysis is 91.68 %, which is 30.65 % higher than that without using any biosurfactant. The efficiency of enzymatic hydrolysis can be further increased to 99.56 % when 7.5 g/L sophorolipid and 1.5 g/L tea saponin are added together. This is because the sophorolipid, rhamnolipid, and chitin can synergistically hamper the enzymatic inactivation during enzymatic hydrolysis, while tea saponin and sodium lignosulfonate can inhibit the non-productive adsorption of lignin. This work proposed a very effective method to improve the efficiency of enzymatic hydrolysis and reduce the dosage of the enzyme by adding biosurfactants.