In situ micro-current collector of amorphous manganese dioxide as cathode material for sodium-ion batteries

Amorphous manganese dioxide (a-MnO 2 ) as an ideal cathode in sodium-ion batteries (SIBs) possesses a higher theoretical capacity (308 mAh g −1 ), low cost and high-rate capability due to its smaller particle size (5–50 nm) and the abundant manganese in the earth. However, the low electronic conductivity brings a poor cycle stability. In this work, we have prepared a-MnO 2 material with an in-situ composite polyaniline (PANI) layer as cathode for SIBs. The composite cathode material shows a reversible specific capacity of 175.4 mAh g −1 and keeps at 173.2 mAh g −1 after 200 cycles at 0.1 C in SIBs. The electrochemical impedance (EIS) and galvanostatic intermittent titration technique (GITT) indicate that this material shows a higher electronic conductivity and outstanding Na-ion storage performance.