Structural design and interfacial characteristics endow NaTi2(PO4)3 coated zinc anode with high capacity and better cycling stability

Abstract Metal zinc is used as anode in aqueous zinc-ion batteries due to its environmental protection, abundant storage, and high theoretical capacity. However, zinc anode has many challenges such as side reactions and zinc dendrites, which impede the further development of aqueous zinc-ion batteries. A facile strategy of constructing Sn doped NaTi2(PO4)3 (NTP/Sn) protective layer on surface of zinc anode (Zn@NTP/Sn) was adopted to enhance the cycling stability of zinc anode in this work. Sn doped NaTi2(PO4)3 was used to realize high-performance zinc anode via the structure design and interfacial characteristics, which are beneficial to accelerating transfer of Zn2+ and improving interface performance. The average voltage hysteresis of Zn@NTP/Sn symmetric cell is only 17.4 mV at the current density of 0.4 mA cm−2, which is much lower than that of bare Zn (75.8 mV) and Zn@NTP (43.7 mV) symmetric cells. Furthermore, Zn-MnO2 full cell using Zn@NTP/Sn anode also shows good cycling performance. After 500 cycles at a current density of 1.2 A g−1, Zn@NTP/Sn-MnO2 full cell has the highest capacity of 124.2 mAh g−1. While the bare Zn-MnO2 and Zn@NTP-MnO2 full cells only have 39.3 mAh g−1 and 74.2 mAh g−1. The excellent electrochemical performance is related to improvement of wettability, increase of cell volume, and reduction of side reactions. In general, this work realizes a synergistic strategy combining structural design and interfacial modification by doping Sn for NTP as a protective coating layer for zinc anode, which provides a simple strategy for high-performance rechargeable aqueous zinc-ion batteries.