不同质量比PANI/α-MnO_2超级电容器材料的制备及表征

Syntheses and Electrochemical Properties of PANI/α-MnO_2 Composites with Different Mass Ratios of Starting Aniline to α-MnO_2 for Supercapacitors

在酸性条件下采用液相共沉淀法合成球状和海胆状的α-MnO2,并以α-MnO2为氧化剂,H2SO4溶液为介质,引发苯胺聚合制备得到不同质量比的聚苯胺(PANI)/α-MnO2复合物。采用XRD、FTIR、SEM等法对材料的形貌和物相进行表征,同时采用循环伏安、计时电位法考察了PANI/α-MnO2复合物在1 mol/L Na2SO4水系电解液中的电化学性能。结果表明,起始原料m(苯胺)∶m(α-MnO2)=1∶3制备的PANI/α-MnO2复合物,在制备电极过程中其质量未到α-MnO2质量一半的条件下,PANI/α-MnO2复合物的比电容达到64.58 F/g,是所合成的α-MnO2比电容(43.49 F/g)的1.48倍,且经过600次循环,其比电容保持率在85%以上,而α-MnO2只有57%的比电容保持率。

Chrysanthemum-like and spherical α-MnO2 particles were synthesized via a chemical co-precipitation route under acidic condition.With the as-prepared α-MnO2 as the oxidant,polyaniline（PANI）/α-MnO2 composites with different mass ratios of starting aniline to α-MnO2 have been successfully synthesized by the oxidative polymerization of aniline in H2SO4 medium.The as-synthesized PANI/α-MnO2 products were characterized by means of XRD,FTIR and SEM.Their electrochemical properties as electrode materials for supercapacitors were investigated via cyclic voltammetry and chronopotentiometry in 1 mol/L Na2SO4 aqueous electrolyte solution.The results show that the maximum specific capacitance of the PANI/α-MnO2 composite prepared with a mass ratio of starting aniline to α-MnO2 of 1∶3 is 64.58 F/g,which is 1.48 times higher than that of pure α-MnO2 when the amount of PANI/α-MnO2 in the electrode is less half that of α-MnO2.Furthermore,over 85% of the initial specific capacitance for the PANI/α-MnO2 composite can be maintained after 600 cycles,while only 57% is obtained for α-MnO2.