Small Things Make a Big Difference: Conductive Cross-Linking Sodium Alginate@MXene Binder Enables High-Volumetric-Capacity and High-Mass-Loading Li–S Battery
Lu Cheng, Ruiyuan Tian, Yifan Zhao, Zhixuan Wei, Xin Pu, You‐Liang Zhu, Dong Zhang, Fei Du
Abstract
Binders are crucial for maintaining the integrity of an electrode, and there is a growing need for integrating multiple desirable properties into the binder for high-energy batteries, yet significant challenges remain. Here, we successfully synthesized a new binder by cross-linking sodium alginate (SA) with MXene materials (Ti 3 C 2 T x ). Besides the improved adhesion and mechanical properties, the integrated SA@Ti 3 C 2 T x binder demonstrates much improved electronic conductivity, which enables ruling out the fluffy conductive additive from the electrode component with enhanced volumetric capacity. When SA@Ti 3 C 2 T x is used to fabricate sulfur (S) cathodes, the conductive-additive-free electrode demonstrates extremely high capacity (1422 mAh cm –3 /24.5 mAh cm –2 ) under an S loading of 17.2 mg cm –2 for Li–S batteries. Impressively, the SA@Ti 3 C 2 T x binder shows remarkable feasibility in other battery systems such as Na–S and LiFePO 4 batteries. The proposed strategy of constructing a cross-linking conductive binder opens new possibilities for designing high-mass-loading electrodes with high volumetric capacity.