Preparation of PPy-Coated MnO(2) Hybrid Micromaterials and Their Improved Cyclic Performance as Anode for Lithium-Ion Batteries

MnO(2)@PPy core-shell micromaterials are prepared by chemical polymerization of pyrrole on the MnO(2) surface. The polypyrrole (PPy) is formed as a homogeneous organic shell on the MnO(2) surface. The thickness of PPy shell can be adjusted by the usage of pyrrole. The analysis of SEM, FT-IR, X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), and XRD are used to confirm the formation of PPy shell. Galvanostatic cell cycling and electrochemical impedance spectroscopy (EIS) are used to evaluate the electrochemical performance as anode for lithium-ion batteries. The results show that after formation of MnO(2)@PPy core-shell micromaterials, the cyclic performance as anode for lithium-ion batteries is improved. Fifty microliters of PPy-coated caddice-clew-like MnO(2) has the best cyclic performances as has 620 mAh g(−1) discharge specific capacities after 300 cycles. As a comparison, the discharge specific capacity of bare MnO(2) materials falls to below 200 mAh g(−1) after 10 cycles. The improved lithium-storage cyclic stability of the MnO(2)@PPy samples attributes to the core-shell hybrid structure which can buffer the structural expansion and contraction of MnO(2) caused by the repeated embedding and disengagement of Li ions and can prevent the pulverization of MnO(2). This experiment provides an effective way to mitigate the problem of capacity fading of the transition metal oxide materials as anode materials for (lithium-ion batteries) LIBs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-017-2286-3) contains supplementary material, which is available to authorized users.