A rational proton compensation strategy of polyaniline-MnO2 hybrid structure for promoting dual ion storage of Zn-ion battery

Manganese dioxide is the most potential cathode material for aqueous zinc-ion batteries (ZIBs). Unfortunately, the terrible structure stability and slow kinetic response of manganese dioxide limit their further application. Here, polyaniline (PANI) and manganese dioxide (MnO2) composites are devised as high-performance cathodes for ZIBs. It is demonstrated that the composite exhibits the characteristics of high conductivity, long discharge platform and stable circulation. At the same time, according to the ex-situ X-ray diffraction and X-ray photoelectron spectroscopy, polyaniline can provide additional H+ ions to participate in the reaction, thus increasing the specific capacity. Due to these attractive merits, the PANI-MnO2(1 h)@CC cathode acquires high discharge capacity of 479.9 and 121.2 mAh g–1 at 0.2 and 4 A g–1, respectively. This study supplies a new view to improve the specific capacity of MnO2 cathodes.