Mechanistic Insights into Triple‐Hybrid K⁺ Storage and Binder‐Enabled Stabilization in Polymerized Zn–Mn Perovskite Fluorides@Reduced Graphene Oxides Anodes

Harnessing the synergistic effects of multiple K⁺ storage mechanisms is pivotal yet challenging for constructing high-performance anodes of potassium-ion batteries (KIBs). Herein, a binary perovskite fluoride-reduced graphene oxides composite (K_1.06Zn_0.4Mn_0.6F_4.11@rGO, denoted KZMF@rGO) anode is designed by integrating the advantages of three storage mechanism (conversion, alloying and intercalation). Benefiting from the 3-dimensional framework structure and ultrafast K ion diffusion kinetics, the KZMF@rGO (11) electrode exhibits excellent electrochemical performance, especially at the optimal Zn/Mn ratio. Furthermore, replacing the polyvinylidene fluoride (PVDF) binder with carboxymethyl cellulose (CMC) significantly improves the initial coulombic efficiency by 12.47% (from 33.01% to 45.48%), rate performance (50.9 mAh g^-1 at 500 mA g^-1), and cycling stability (66.77% capacity retention over 1000 cycles at 200 mA g^-1) of the electrode. This enhancement is due to the ability of CMC to stabilize the solid electrolyte interface and maintain electrochemical integrity during repeated volume changes, thereby enhancing charge transfer kinetics. This study offers insights into anode design and highlights the critical impact of binder selection.