Ball milling synthesis of LixTiP4: Improvement of the electrochemical performances

Abstract

While promising performance as a negative electrode in Li-ion batteries, with flat voltage profiles at about 1 V and large specific capacities, today’s drawback with LixTiP4 materials is the difficulty encountered in preparing single-phase powders. To alleviate this issue, new synthetic routes have been investigated and we present here our results obtained by ball milling (BM) syntheses. Despite the poor crystallinity of the as prepared BM powders demonstrated by both X-rays and electron diffractions, preliminary electrochemical tests have shown a dramatic improvement of the specific capacity and charging-discharging rate confirming the advantages of BM synthesis over the high temperature route. To divert any amorphous phases contamination by amorphous phases contamination, BM samples were annealed at 500 °C and 900 °C. Nicely crystallized samples devoid of any impurities are obtained. We also detail in this paper the improvement in cyclability of these annealed BM LixTiP4 electrode materials.