Constructing a Strong-Affinity Elastic Network Binder Enabled by Tannic Acid as the Bifunctional Anchoring Agent for High-Performance Li–S Battery

Abstract

Lithium–sulfur (Li–S) batteries have been limited by their poor electrochemical performance due to the large volume change and severe shuttle effect during cycling. Binders serve as an essential role in sulfur electrodes and can stabilize the mechanical integrity of the electrode. It also has been demonstrated that designing strong-affinity binders is a feasible and facile method to suppress the shuttle effect. Therefore, in this work a strong-affinity elastic network binder is designed for high-performance Li–S battery coupling with tannic acid (TA) and polyurethane (PU). Firstly, the rich hydrogen bonds between TA and PU result in a mechanically robust network to keep the sulfur electrode from cracking in the cycling process. Secondly, the selected TA with abundant phenolic hydroxyl groups possesses strong adsorption capability toward polysulfides, which can efficiently restrain the shuttle effect. Hence, the cycling stability of Li–S batteries using P1T1 binder is significantly improved, maintaining the capacity of 602.5 mAh g–1 after 500 cycles at the current density of 0.5 C.

Achievements, challenges, and perspectives in the design of polymer binders for advanced lithium-ion batteries

“…Both non-conducting organic polymers with polar groups ( e.g. PVP), 278 tannic acid – polyurethane 3D network 217 and polyelectrolyte binder based on poly[ N -bis(2-cyanoethyl)acrylamide- co-N -vinylpyrrolidone- co -2-methoxyethylacrylate 602 ] and conducting polymers with π-conjugated backbone have been considered as sulfur host materials (as an encapsulation layer or conductive matrix) to tackle the shuttling of polysulfides. Hollow and yolk–shell nanostructures encapsulated with conducting polymers (PANi, 70,312 PPy, 603 and PEDOT 312 ) were designed and synthesized to physically confine the dissolution of polysulfides in an electrolyte (Fig.…”

Investigation of the Chemisorption‐Catalysis Behavior of Sulfur Species on the Electrocatalysts Designed by Co‐regulation Strategy of Anions and Cations

“…[15,16] Similarly, polymers with rich polar groups (À OH, À COOH, À NH 2 et al) were also exploited as hosts in Li-S batteries. [17][18][19][20][21] For example, Cui et al elucidated the interactions between sulfur species with various functional groups in macromolecular polymers via ab initio simulations, guiding a rapid discovery of a bifunctional binder for stable Li 2 S cathodes. [18] Compared with such carbon materials and polymers, metal oxides, sulfides, nitrides et al normally possess a stronger polar surface to firmly anchor polysulfides and promote the electrochemical performance of sulfur cathodes.…”

“…Similarly, polymers with rich polar groups (−OH, −COOH, −NH 2 et al.) were also exploited as hosts in Li‐S batteries [17–21] . For example, Cui et al.…”

An interweaving 3D ion-conductive network binder for high-loading and lean-electrolyte lithium–sulfur batteries

“…Several water-soluble functional binders, including polyacrylic acid (PAA), 15 sodium carboxymethyl cellulose (CMC), 16 Na-alginate, 17 gelatin, 18 and others, 19,20 have been extensively developed and have demonstrated improved performance of Li-S batteries. These polymers contain abundant multi-functional polar groups, such as carboxyl, hydroxyl, and amino groups, facilitating the adsorption of LiPSs and enhancing adhesion strength through the formation of hydrogen bonds.…”