Dual-modification of manganese oxide by heterostructure and cation pre-intercalation for high-rate and stable zinc-ion storage

Abstract Zinc-ion batteries (ZIBs) possess great advantages in terms of high safety and low cost, and are regarded as promising alternatives to lithium-ion batteries (LIBs). However, limited by the electrochemical kinetics and structural stability of the typical cathode materials, it is still difficult to simultaneously achieve high rates and high cycling stability for ZIBs. Herein, we present a manganese oxide (SnxMnO2/SnO2) material that is dual-modified by SnO2/MnO2 heterostructures and pre-intercalated Sn4+ cations as the cathode material for ZIBs. Such modification provides sufficient hetero-interfaces and expanded interlayer spacing in the material, which greatly facilitates the insertion/extraction of Zn2+. Meanwhile, the “structural pillars” of Sn4+ cations and the “pinning effect” of SnO2 also structurally stabilizes the MnO2 species during the repeated Zn2+ insertion/extraction, leading to ultra-high cycling stability. Due to these merits, the SnxMnO2/SnO2 cathode exhibits a high reversible capacity of 316.1 mAh g−1 at 0.3 A g−1, superior rate capability of 179.4 mAh g−1 at 2 A g−1, and 92.4% capacity retention after 2000 cycles. Consequently, this work would provide a promising yet efficient strategy by combining heterostructures and cations pre-intercalation to obtain high-performance cathodes for ZIBs.