Vanadium diphosphides as negative electrodes for secondary Li-ion batteries
Language
en
Article de revue
This item was published in
Journal of Power Sources. 2007, vol. 172, n° 2, p. 877-885
Elsevier
English Abstract
We report on the Li electrochemical reactivity of amorphous and crystalline VP2, synthesized by ball-milling and by 600 °C heat treatment of a ball-milled sample, respectively. The amorphous sample can reversibly react ...Read more >
We report on the Li electrochemical reactivity of amorphous and crystalline VP2, synthesized by ball-milling and by 600 °C heat treatment of a ball-milled sample, respectively. The amorphous sample can reversibly react with 3.5 Li per formula unit as compared to solely 2.5 for the crystalline one. However in both cases there is a rapid capacity decay upon cycling that is more pronounced in the case of the crystalline sample. Complementary X-rays, HTREM and NMR tend to show that the Li reactivity mechanism differs from the classical conversion reactions since neither V nanoparticles nor the formation of Li3P were detected, as opposed to some of the other MP2 compounds (M = Ni or Cu). Besides structural phase variations within the 3d metal-based binary phosphide series, the possibility of a change in the nature of the redox centre upon lithiation from cation (M) to anion (P) is evoked.Read less <
English Keywords
Ball-milling
Capacity retention
Lithium ion batteries
Vanadium diphosphides
Origin
Hal imported