Nano-semiconductor material stabilized Zn metal anode for long-life aqueous Zn-ion batteries

The advantages of aqueous Zn-ion batteries lie in the affordability and environmental friendliness. Nonetheless, the use of aqueous Zn-ion batteries is severely hindered by key issues such dendrite formation and side reactions in Zn metal anodes. It is able to works well so as to create a stable interface layer, which controls the development of dendrites and adverse reactions. In this study, it is recommended that the coating formed by nano-semiconductor material graphitic carbon nitride (g-C3N4) should be applied to the surface of Zn metal to evenly disperse the electric field, as well as inhibit the development of tip effect, thus preventing Zn dendrite growth. Zn deposition occurs quickly and steadily as a result of Zn2+ ions being adsorbed and the Zn2+ ion flow being reallocated by the zincophilicity of N atoms in the coating. The Zn symmetrical battery can be stable cycled for 1,000 h at a current density of 0.5 mA cm-2, with its overall areal capacity of 0.5mAh cm-2, which is attributed to these benefits of the coating. It can be stable circulated for 500 h at a high current density of 5 mA cm-2, with its total areal capacity of 1mAh cm-2. The completely constructed Zn-g-C3N4//V2O5 according exhibits exceptional long-term cycle stability. Under the current density of 2 A/g, the initial capacity is 312.3 mAh g-1, which can cycle be stable circulated for 1,000 cycles. Under the high current density of 5 A/g, the whole battery's capacity keeping holding rate is 70% after 2000 cycles, and the coulomb efficiency (CE) is extremely near to 100%.