In situ polymerization preparation of K0.5Mn2O4·1.5H2O/PDA composite with excellent zinc storage performance

Abstract

In this study, the K0.5Mn2O4·1.5H2O/polydopamine composite (KMO/PDA) with a core-shell configuration has been synthesized through a straightforward in-situ polymerization process at room temperature. In KMO/PDA, KMO is uniformly coated by PDA, which can suppress the volume expansion and dissolution of KMO efficiently. As a result, the KMO/PDA composite demonstrates high reversible zinc storage performance, and a remarkable high capacity of 479.7 mAh g−1 can be achieved at 0.1 A g−1 during the rate performance test. Importantly, the galvanostatic intermittent titration technique (GITT) test suggests that the improved ion diffusion ability is contributed to enhancing the electrochemical performance of KMO/PDA. Moreover, KMO/PDA also displays good cyclic performance, and a capacity retention of 79.8 % can be reserved after 500 cycles at a high current density of 1 A g−1.