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

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.