Electrodeposited ε-MnO2 on carbon fibers as an ideal cathode material for aqueous zinc-ion batteries

The aqueous zinc-ion batteries (AZIBs) have drawn widespread attention due to their high safety and low cost. Manganese dioxide (MnO2) is a commonly used cathode material because of its high theoretical capacity and abundant natural reserves. However, Mn2+ dissolution and low electrical conductivity cause poor cycling stability. In this work, ε-MnO2 was electrodeposited on carbon fibers (ε-MnO2/CFs) which was then used as a cathode material for aqueous zinc-ion batteries. In the unique structure, CFs alleviate the dissolution of ε-MnO2 and enhance the electrical conductivity of MnO2. As a result, the ε-MnO2/CFs cathode exhibits high cycling stability (a stable capacity of 256.3 mAh g−1 after 100 cycles at 0.1 C) and excellent rate performance (a high capacity of 118.3 mAh g−1 at 3.0 C). This work provides a feasible strategy to inhibit the dissolution of MnO2 cathode material and design high-performance AZIBs.