Review and Perspectives on Advanced Binder Designs Incorporating Multifunctionalities for Lithium–Sulfur Batteries

Abstract

Lithium−sulfur (Li−S) batteries have received paramount attention as a next-generation energy storage device due to their remarkably high specific capacity (1675 mAh g −1 ), energy density (2600 Wh kg −1 ), and cost-effectiveness compared to the forefront lithium-ion batteries. However, certain issues still hamper the smooth working of Li−S batteries, which need to be addressed to fill the gap between fundamental research and commercialization. Polymer binders, as an inevitable part of the cathode structure, play a vital role in upholding the structural robustness and firmness of the electrode. However, conventional binders like PVDF are not capable of effectively accommodating the large volume changes within the electrode, facilitating electronic/ionic conductivity, entrapping the soluble polysulfide intermediates, and enhancing polysulfide redox kinetics. Therefore, novel multifunctional binder designs are adopted in Li−S batteries to tackle the above-mentioned issues. This review summarizes the recent progress in this research area employing advanced multifunctional polymer binders in Li−S batteries. The action of the binder through various mechanisms is discussed in detail. The role of binder is given immense attention in the emerging field of various energy storage devices, including Li−S batteries, and, thus, here discussed as well.

Bridging the gap between academic research and industrial development in advanced all-solid-state lithium–sulfur batteries

“…Polymeric binders play a crucial role in composite electrodes, facilitating intimate particle contacts to maintain structural robustness and electrode firmness, while also controlling slurry properties. 219 Despite their critical role, research on binders has been relatively underexplored in Li–S batteries. The extensive use of carbon as a conductive agent poses a challenge in binder selection owing to its high surface area, which absorbs a significant amount of solvents, making it difficult to form a homogeneous slurry with modest viscosity.…”

Recent advances in rational design for high-performance potassium-ion batteries

“…PVDF exhibits a linear structure terminated by interaction-resistant –C–F groups and does not adhere well to active material particles, with an adhesion strength ranging from 0.1–0.32 N cm −1 . 674–676 Additionally, PVDF is less flexible and has limited mechanical strength. Therefore, using PVDF as a binder is often disastrous for electrodes with large volume expansion, such as conversion-type anodes and alloy-type anodes.…”

Cyclodextrins for Lithium Batteries Applications

“…Binders play a vital role in maintaining strong adhesion to the current collector and cohesion between various electrode components [ 64 , 65 , 66 , 67 ]. Traditional binders, such as sodium carboxymethyl cellulose (CMC), poly(acrylic acid) (PAA), poly(vinyl alcohol) (PVA), poly(ethylene oxide) (PEO), poly(tetrafluoro ethylene) (PTFE), poly(vinylidene fluoride) (PVDF), styrene butadiene rubber (SBR), and poly(vinylidene fluoride) have been used to accommodate the unique properties of the active material [ 68 , 69 , 70 ]. The electrochemical reactions that occur in battery electrodes result in the flow of ions through the electrolyte and electrons through the external circuit.…”