The Electrochemical Performance and Heat Generation Analysis of Na0.7MnO2 as Cathode Material in Coin Cells

摘要

The abundantly available precursors, the environmental friendlyness and the inherent safety are always a driver for new energy storage applications and also much interest in Na-ion batteries is generated because of the lower material cost compared to Li-ion batteries. Therefore, a sodium ion battery was developed by using Na0.7MnO2 as a cathode material and pure Sodium metal as anode in 1 M NaClO4 electrolyte. The P2-layered structural materials have attracted tremendous attention because of their promising electrochemical characteristics. This battery system could be operated within the voltage range of 2.0 V to 4.0 V. Cyclic voltammetry, galvanostatic charge-discharge, self-discharge measurements, Electrochemical Impedance Spectroscopy and Heat generation analysis were thoroughly conducted at different charge-discharge rates. This battery exhibited a discharge capacity of 95 mAh/g at a discharge rate of C/20. It also delivered a good rate capability with 55 mAh/g at 2C. The good capacity retention, couloumbic efficiency (99.5%), reproducible and reversible Na-ion intercalation revealed a satisfactory performance of the coin cell. In addition, a safety-relevant analysis of these coin cells will be carried out by means of Accelerating Rate Calorimetry (ARC).