Portal de Periódicos da CAPES

Hydrothermal synthesis of α-MnO2 and β-MnO2 nanorods as high capacity cathode materials for sodium ion batteries

2013; Royal Society of Chemistry; Volume: 1; Issue: 15 Linguagem: Inglês

10.1039/c3ta00031a

2050-7488

Dawei Su, Hyo‐Jun Ahn, Guoxiu Wang,

Multiferroics and related materials

Two types of MnO2 polymorphs, α-MnO2 and β-MnO2 nanorods, have been synthesized by a hydrothermal method. Their crystallographic phases, morphologies, and crystal structures were characterized by XRD, FESEM and TEM analysis. Different exposed crystal planes have been identified by TEM. The electrochemical properties of α-MnO2 and β-MnO2 nanorods as cathode materials in Na-ion batteries were evaluated by galvanostatic charge/discharge testing. Both α-MnO2 and β-MnO2 nanorods achieved high initial sodium ion storage capacities of 278 mA h g−1 and 298 mA h g−1, respectively. β-MnO2 nanorods exhibited a better electrochemical performance such as good rate capability and cyclability than that of α-MnO2 nanorods, which could be ascribed to a more compact tunnel structure of β-MnO2 nanorods. Furthermore, the one-dimensional architecture of nanorods could also contribute to facile sodium ion diffusion in the charge and discharge process.