1 Materials and Methods All reagent

1 Materials and Methods All reagents were of analytical grade and were used as received without further pur「： modified as carboxylaied PU, which is soluble in water. 2 Preparation of Na ion and water molecule intercalated MnO： nanoplate 2.1 Preparation of Mn(OH)： nanoplate precursor Typically, Mn(0H)2 hexagonal nanoplates were prepared by dissolving 4 mmol Mn(Ac)₂ 4H₂O in 40 mL deionized water, and then 3 mL of hydrazine hydrate (N2H4 H2O. 50%) was added into the Mn(Ac)? solution slowly under the stirring condition for 5 min. The mixture was poured into and sealed in a Teflon-lined stainless sled autoclave of 100 mL capacity. The autoclave was heated to and maintained at 180 °C for 12 h and then air-cooled to room temperature. The white product was collected by filtration, washed with distilled water and ethanol several times. The fresh sample now was ready for further processing and characterization. 2.2 Preparation of layered MnCh nanoplates with Na ion and water molecule intercalated 0.2 g of the as-prepared Mn(OH)? nanoplate precursor was first dispersed in 50 mL deionized water, and lhen added 10 mL NaCIO solution (active chlorine>IO%) under stirring, the white suspension turned black immediately. After the suspension was stirred for 24 h at room temperature, the obtained product was tillered. washed with deionized uater and dried under vacuum al 60 °C for several hours, and then the final product was prepared. 3 Preparation of MnO： cathode To prepare the cathode, Na ion and water molecule intercalated MnOi nanoplate, acetylene blacks and PVDF binder were mixed in a weight ratio of 7:2:1 with N-Methyl-2-pyrrolidone (NMP) as the solvent. The mixtures were then stirred for 3 h and coated with a blade on a piece of carbon cloth paper. Finally. the> were dried at 40 °C in a vacuum. The effective mass loading of MnO： is about 2.0-3.0 mg cm'². 4 Preparation of Zn anodeFlexible Zn electrode was prepared by a facile electrochemical deposition method on the Ni/Cualloy cloth substrate. A typical tuo-electrode setup was used for Zn electroplating, in which Ni/Cualloy cloth substrate was used as working electrode, while zinc plate (purity 99.99%. Sigma) was