NiO/MnO_2分级纳米片阵列复合材料的制备与超电容性能

Preparation and Supercapacitance Performances of Hierarchical NiO/MnO_2 Nanosheet Array

通过化学浴沉积和水热法在泡沫镍上制备了NiO/MnO_2分级纳米片阵列复合材料,XRD和SEM测试表明NiO纳米片垂直生长在泡沫镍上,交叉形成网状阵列结构;MnO_2纳米介孔泡沫进一步生长在NiO纳米片两侧,与NiO形成了壳核式的复合结构。循环伏安和恒流充放电测试发现,NiO/MnO_2分级纳米片阵列复合材料的电化学性能相比复合前得到明显改善,在1 A·g^(-1)的电流密度下,比电容提高至1 297 F·g^(-1);2 A·g^(-1)下循环1 000次,比电容保持率高达97%,比电容和循环性能的改善是由于分级纳米片阵列复合结构方便了电解液传质,扩大了活性材料与电解液的接触,促进了赝电容反应,提高了NiO和MnO_2的结构稳定性。

Hierarchical NiO/MnO2 nanosheet array were synthesized by chemical bath deposition and hydrothermal method. XRD and SEM show that NiO nanosheets vertically grow on Ni foam and connect with each other to form a net-like array. Then, MnO2 nano mesoporous foam deposites on both sides of NiO nanosheets, constructing NiO/MnO2 core-shell composite structure. Pseudocapacitance performances were examined by cyclic voltammetry and galvanostatic charge-discharge. Compared with single NiO and MnO2, hierarchical NiO/MnO2 nanosheet array shows improved electrochemical performances, exhibiting high specific capacitance of 1 297 F·g^-1 at 1 A·g^-1 and 97% retention at 2 A·g^-1 after 1 000 cycles, which is due to the fact that the hierarchical nanosheet array structure quickens mass transfer of the electrolyte, enlarges contact between active material with the electrolyte, promotes pseudocapacitance reaction and enhances structure stability of NiO and MnO2.