Novel Rechargeable M(3)V(2)(PO(4))(3)//Zinc (M = Li, Na) Hybrid Aqueous Batteries with Excellent Cycling Performance

A rechargeable hybrid aqueous battery (ReHAB) containing NASICON-type M(3)V(2)(PO(4))(3) (M = Li, Na) as the cathodes and Zinc metal as the anode, working in Li(2)SO(4)-ZnSO(4) aqueous electrolyte, has been studied. Both of Li(3)V(2)(PO(4))(3) and Na(3)V(2)(PO(4))(3) cathodes can be reversibly charge/discharge with the initial discharge capacity of 128 mAh g(−1) and 96 mAh g(−1) at 0.2C, respectively, with high up to 84% of capacity retention ratio after 200 cycles. The electrochemical assisted ex-XRD confirm that Li(3)V(2)(PO(4))(3) and Na(3)V(2)(PO(4))(3) are relative stable in aqueous electrolyte, and Na(3)V(2)(PO(4))(3) showed more complicated electrochemical mechanism due to the co-insertion of Li(+) and Na(+). The effect of pH of aqueous electrolyte and the dendrite of Zn on the cycling performance of as designed MVP/Zn ReHABs were investigated, and weak acidic aqueous electrolyte with pH around 4.0–4.5 was optimized. The float current test confirmed that the designed batteries are stable in aqueous electrolytes. The MVP//Zn ReHABs could be a potential candidate for future rechargeable aqueous battery due to their high safety, fast dynamic speed and adaptable electrochemical window. Moreover, this hybrid battery broadens the scope of battery material research from single-ion-involving to double-ions -involving rechargeable batteries.