Manganese-based metal-organic-framework derived hydrophilic cathode with carbon nanotubes introduced for long-life and high-performance aqueous zinc-ion battery

Aqueous zinc-ion batteries (ZIBs) have received widespread attention due to their high specific capacity (820 mA h g−1), high safety and low cost. Manganese (Mn)-based oxides show great potential as cathode materials for aqueous ZIBs, but they also face problems of low conductivity and poor rate performance. The introduction of carbon nanotubes (CNTs) can improve the hydrophilicity, enhance the conductivity of Mn-based oxides, and further improve the cycling performances of the ZIBs at high current density. Therefore, in this paper, Mn-based metal-organic-framework (Mn-MOF) is chosen as a template, while carboxylic CNTs are introduced during the synthesis process of Mn-MOF, finally after further calcination, composite material of Mn-based oxides, MOF-derived carbon and CNTs (MnOx@C@CNT) is prepared as the cathode for aqueous ZIBs. After 5000 cycles at a current density of 3 A g−1, the capacity retains 96.7 mA h g−1, while the capacity decay rate is 2% only. This work provides a solution to the challenges of Mn-based oxides for aqueous ZIBs cathode, thus achieve better electrochemical performances.