Chromium Oxides and Lithiated Chromium Oxides. Promising Cathode Materials for Secondary Lithium Batteries

摘要

Chromium oxides and lithiated chromium oxides were synthesized by thermal decomposition of chromium trioxide (CrO_3) at high temperatures and oxygen pressures. Synthesis temperature and pressure markedly affect the performance of these cathode materials. Higher pressures lead to a higher O/Cr ration and fewer impurities in the final product. These materials are stable intercalation hosts for lithium, and exhibit a higher capacity than any of the prominent positive electrodes used in secondary lithium batteries. m-CrO_x has a capacity of 255 mAh/g, while m-LiCrO_x has a capacity of 210 mAh/g, during the first discharge. The average voltage of these cells is 3.0 V vs. Li/Li~+ that gives an average energy density of approximately 650 Wh/Kg.