Influence of Lithium Insertion on the Electronic Transport in Electroactive M0Q3 Nanobelts and Classical Powders: Morphological and Particle Size Effects

摘要

Studying the electronic transport in Li_xMoO3 powders is of the utmost interest due to the strong influence of the grain size and morphology on their electrochemical cycling properties. An original straightforward synthesis method permitted the obtaining of nanobelts of α1-MoO3 with a slightly better reversibility of Li insertion-deinsertion and a higher efficiency of the lithium insertion process. The broad-band dielectric spectroscopy technique from 40 to 10~(10) Hz was applied to Li_xMoO3 micronic powder and nanobelts. Dielectric relaxations were found, attributed to polarons and bipolarons motions. The role of the morphology and size effect has been investigated by comparing the electron transport properties of micronic powder and nanobelts. Particle size effect is evidenced giving rise to different thermal behaviors between the two types of powders. This work opens up new prospects for a more fundamental understanding of the electronic transport in relation to the electrochemical properties of α-MoO3.