Polyaniline nanoarrays/carbon cloth as binder-free and flexible cathode for magnesium ion batteries

Magnesium ion batteries (MIBs) attracted much attention in recently years due to the advantages of high theoretical capacity and low cost. However, the strong polarization effect of Mg2+ cause slow diffusion rate, hindering the development of MIBs. Herein, we designed and synthesized a binder-free polyaniline array/carbon cloth (PANI/CC) as cathode for MIBs. Given the benefit of improved electrical conductivity and alleviated agglomeration, the cathode exhibits enhanced electrochemical performance compared with the pure polyaniline cathode in MIBs. The PANI/CC cathode displays the highest specific capacity of 219 mA h g(-1) at 200 mA g(-1) and the capacity retention of 97.25% after over 1500 cycles at 1 A g(-1). Then, the reversible redox transformation between quinone rings and benzene rings during charging and discharging process was demonstrated by the ex situ X-ray photoelectron spectroscopy (XPS) and ex-situ Raman spectra. In addition, PANI/CC shows an initial capacity of 75 mA h g(-1) at 50 mA g(-1) in PANI/CC //Mg(TFSI)(2)// MNTO full cell. Our work demonstrates that PANI/CC is a promising cathode for MIBs, which may offer new insight for the development for high-performance MIBs.