利用水热合成法制备了直径为50~80 nm、长度为2~3 μm的α-MnO₂纳米线；在α-MnO₂纳米线表面接枝聚苯乙烯磺酸钠（PSSNa）；以MnO₂-g-PSSNa为模板，利用原位氧化聚合在MnO₂纳米线表面沉积聚（3，4-二氧乙烯基）噻吩（PEDOT）。MnO₂-g-PSSNa与EDOT的质量比对MnO₂@PEDOT的形貌有决定性的影响，当m（MnO₂-g-PSSNa）：m（EDOT） ≤ 1：1时，得到中空的PEDOT纳米管。循环伏安和充放电试验表明，所制备的MnO₂@PEDOT有良好的电容性能，当m（MnO₂-g-PSSNa）：m（EDOT）=1：1时，MnO₂@PEDOT的比电容高达62.9 F/g（MnO₂的比电容为18.5 F/g）。

α-MnO₂ nanowires with a length of 2-3 μm and a thickness of 50-80 nm are prepared by hydrothermal synthesis process.Poly(sodium styrene sulfonate) (PSSNa) chains are grafted onto the surface of α-MnO₂ nanowires to obtain MnO₂-g-PSSNa.Core-shell structured MnO₂ composite (MnO₂@PEDOT) are finally fabricated by in-situ chemical oxidative polymerization through depositing poly(3,4-dioxyvinyl) thiophene (PEDOT) on the surface of α-MnO₂ nanowires with MnO₂-g-PSSNa as template.As the mass ratio of MnO₂-g-PSSNa to EDOT is not more than 1:1,hollow PEDOT nanotubes can be produced.Cyclic voltammetry analysis and charge-discharge test show that the composite exhibits good capacitor properties.The specific capacitance of MnO₂@PEDOT reaches as high as 62.9 F·g^-1 when the mass ratio of MnO₂-g-PSSNa to EDOT equals to 1:1,compared with the 18.5 F·g^-1 of pure MnO₂.