Lithium-Metal-Free Sulfur Batteries with Biochar and Steam-Activated Biochar-Based Anodes from Spent Common Ivy

Lithium-sulfur batteries are emerging as sustainable replacements for current lithium-ion batteries.The commercial viability of this novel type of battery is still under debate due to the extensive use of highly reactive lithium-metal anodes and the complex electrochemistry of the sulfur cathode.In this research,a novel sulfur-based battery has been proposed that eliminates the need for metallic lithium anodes and other critical raw materials like cobalt and graphite,replacing them with biomass-derived materials.This approach presents numerous benefits,encompassing ample availability,cost-effectiveness,safety,and environmental friendliness.In particular,two types of biochar-based anode electrodes(non-activated and activated biochar)derived from spent common ivy have been investigated as alternatives to metallic lithium.We compared their structural and electrochemical properties,both of which exhibited good compatibility with the typical electrolytes used in sulfur batteries.Surprisingly,while steam activation results in an increased specific surface area,the non-activated ivy biochar demonstrates better performance than the activated biochar,achieving a stable capacity of 400 mA h g^(−1)at 0.1 A g^(−1)and a long lifespan(>400 cycles at 0.5 A g^(−1)).Our results demonstrate that the presence of heteroatoms,such as oxygen and nitrogen positively affects the capacity and cycling performance of the electrodes.This led to increased d-spacing in the graphitic layer,a strong interaction with the solid electrolyte interphase layer,and improved ion transportation.Finally,the non-activated biochar was successfully coupled with a sulfur cathode to fabricate lithium-metal-free sulfur batteries,delivering a specific energy density of~600 Wh kg^(−1).

Morphological peculiarities of the lithium electrode from the perspective of the Marcus-Hush-Chidsey model

This study employs the kinetics framework of Marcus-Hush-Chidsey(MHC)to investigate the charge transfer at the interface of lithium electrode and electrolyte in lithium(ion)-batteries.The chargetransfer rate constant is evaluated for different facets of lithium,namely(100),(110),(101),and(111)as a function of surface charge density with the aid of density functional theory(DFT)calculations.The results highlight and quantify the sensitivity of the rate of lithium plating and stripping to the surface orientation,surface charge density,and charge-transfer over-potential.An intrinsic kinetics competition among the different surface orientations is identified together with an asymmetry between the lithium plating and stripping and showcased to influence the deposit morphology and surface protrusions and indentations.

Bridging the microstructural evolutions from slurry to porous electrode of a lithium-ion battery

1. Introduction The porous electrodes are the crucial components of the modern electrochemical devices including lithium-ion batteries. The detailed configuration of the lithium-insertion, carbon black, and PVDF binder particles in a typical electrode of a lithium-ion cell has a significant impact on its energy and power density. A thinner electrode is desired to decrease the battery volume particularly for portable electronics and mobility applications.