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Electrochemical Performance of Na0.44MnO2 Synthesized bySolid State Reaction and Sol-Gel Using as A Cathode Material ForSodium Ion Batteries

pubblicazioni - Poster

Electrochemical Performance of Na0.44MnO2 Synthesized bySolid State Reaction and Sol-Gel Using as A Cathode Material ForSodium Ion Batteries

Lo scopo dello studio è di confrontare le prestazioni elettrochimiche dei campioni ottenuti dalle due diverse sintesi. Per le analisi strutturali dei campioni sono state eseguite delle misure di diffrazione ai raggi X (XRD) e delle osservazioni al Microscopio Elettronico a Scansione (SEM). per la caratterizzazione elettrochimica sono state eseguite misure di Voltammetria Ciclica (CV) e di carica e scarica a diverse correnti.

Among the several oxide Na-ion battery materials, Na0.44MnO2 (NMO) is regarded as one of the promising cathode materials owing to its high capacity and good cycle life. Recently, we pointed out the possibility of preparing pure Na0.44MnO2 powders by solid-state reaction and sol-gel routs. The aim of this study is to compare electrochemical performance of Na0.44MnO2 synthesized by solid state reaction and sol-gel. For microstructure and purity analysis of synthesized materials Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) were used.

For electrochemical performance, cyclic-voltammetric (CV) and charge/discharge test ere performed on both samples. XRD analysis of both samples proved single phase powder of Na0.44MnO2 for both synthesis routs. The CV curves of both samples are very similar even in the positions of the peaks. In all C-rates, the capacity of sol-gel sample is higher than solid state reaction samples. Moreover, samples prepared by sol-gel method displays about 40 mA.g-1 capacity at C-rate of 5; nonetheless that of solid state sample is almost zero.

The SEM analysis shows rod shape of Na0.44MnO2 crystals for solid state reaction samples and needle like crystals for the sol-gel powder. The reason for the higher capacity of sol-gel samples is its morphology. This morphology provides more available surfaces for intercalation and deintercalation of Na atoms into the structure and charge transfer is more feasible in higher charge/discharge rates.

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