Synthesis, characterization and cycling performance of novel chromium oxide cathode materials for lithium batteries

Chromium oxide (CrOx) cathode material (with chromium oxidation state of +5.3) was synthesized by thermal decomposition of chromium trioxide at high temperature and pressure in oxygen atmosphere. The duration of thermal decomposition had a significant effect on the performance of these materials in terms of lithiation capacity. The detrimental effect of CrO3 and lower oxidation state chromium oxides have been reduced considerably by reducing their amounts in the material. The operating conditions, namely, temperature, pressure and the reaction time were optimized based on synthesizing novel CrOx cathode material with superior properties, such as low irreversible capacity loss, stable capacity and low capacity fade under continuous cycling. These materials are stable intercalation hosts for lithium and were found to be reversible in the entire intercalation range (2.0–4.2 V versus Li/Li+). The average voltage of these cells is 3 V versus Li/Li+. CrOx-B cathodes exhibit higher capacity than any of the prominent cathode materials used for lithium batteries with an initial lithiation capacity of capacity of 322 mAh/g. The material shows very low capacity fade during cycling and retained 93% of its reversible capacity after 100 cycles. © 2003 Elsevier B.V. All rights reserved.