Achieving Stable Zinc-Ion Storage Performance of Manganese Oxides by Synergistic Engineering of the Interlayer Structure and Interface.

Manganese oxide is a promising cathode material for rechargeable aqueous zinc-ion batteries (ZIBs). However, the low electronic conductivity and unstable structure evolution of manganese materials often result in poor rate performance and rapid capacity decay. Herein, we design N-doped Na 2 Mn 3 O 7 (N-NMO) by combining sodium preintercalation and nitridation treatment strategies to stabilize the crystalline structure and reaction interface. Sodium preintercalation not only enlarges the interlayer distance for fast Zn 2+ ion diffusion but also serves as a robust pillar to stabilize the crystalline structure during cycling. Meanwhile, the nitridation layer on the surface of Na 2 Mn 3 O 7 particles is favorable for enhancing the electronic conductivity and inhibiting the cathode dissolution issue during repeated cycling. Consequently, the as-prepared N-NMO exhibits high reversible capacity (300 mAh g -1 at 0.2 A g -1 ), good rate capability (100 mAh g -1 at 10 A g -1 ), and outstanding long-term cycling stability (high capacity retention of 78.9% after 550 cycles at 2 A g -1 ). Considering the facile and simple synthesizing methods, the synergistic engineering of the interlayer structure and interface is expected to provide new opportunities for the development of high-performance Mn-based cathode materials for aqueous ZIBs.