The discharge and charge behavior of the Pb-Birnessite in LiOH aqueous solution

Abstract

The Pb-birnessite was prepared by ion exchange from K-birnessite, which was synthesized by calcination of KMnO4. Measure methods of SEM (scanning electron microscopy), XRD (X-ray diffraction), TGA (thermogravimetric analyse), AAS (atomic absorption spectrometry), slow-scanning cyclic voltammetry and galvanostatic step discharge/charge are applied. Potentiostatic step method is used for the determination of a chemical diffusion coefficientD is Li+. XRD patterns indicate the Pb-birnessite has layered structure. Slow-scanning voltammograms show the occurrence of a single-phase redox reaction. The galvanostatic discharge/charge curves indicate the Pb-birnessite has better rechargeability at a high discharge/charge rate. Li+ can reversibly intercalate into and de-intercalate from the Pb-birnessite during discharge and charge. Pb between the layers stabilized the layered structure and prevented partially the conversion to spinel-like structures. The average value of the chemical diffusion coefficientD of Li+ intercalated into the Pb-birnessite is 8.24×10−11 cm2·s−1.