Abstract:In order to optimize and select the appropriate binder to improve the electrochemical performance of aqueous zinc-manganese batteries, the influences of water-soluble binders and oil-based binders on the zinc storage performance of manganese-based cathode materials were systematically investigated. The results show that the water-soluble binders with large numbers of hydroxyl and carboxyl groups are easily soluble in aqueous electrolytes, leading to poor electrochemical performance. Fortunately, the cathodes with polyvinylidene fluoride- hexafluoropropylene (PVDF-HFP) binder display high specific capacity of 264.9 mA·h/g and good capacity retention of 92% after 90 cycles at 100 mA/g. Meanwhile, PVDF-HFP binder with plenty of hydrophobic groups presents excellent ability in inhibiting cracks on the surface of electrode, reducing voltage polarization and charge transfer resistance, as well as maintaining electrode integrity.

Key words: aqueous zinc-manganese batteries; binders; PVDF-HFP; cycling stability