The electrochemical reactivity of ball-milled MoO3 powders was investigated in Li rechargeable cells. High-energy ball-milling converts highly-crystalline MoO3 bulk powders into partially reduced low-crystalline MoO3-y materials with a reduced particle size. Both bulk and ball-milled MoO3 exhibit a first discharge capacity beyond 1100 mAh g-1 when tested in the 0-3 V (vs. Li/Li+) range, which is indicative of a complete conversion reaction. It is found that partial reduction caused by ball-milling results in a reduction in the conversion reaction. Additionally, incomplete re-oxidation during subsequent charge results in the formation of MoO2 instead of MoO3, which in turn affects the reactivity in subsequent cycles. As compared to bulk MoO3, ball-milled MoO3-y showed significantly enhanced cycle performance (bulk: 27.6% charge capacity retention at the 10th cycle vs. ball-milled for 8 h: 64.4% at the 35th cycle), which can be attributed to the nano-texture wherein nanometer-sized particles aggregate to form secondary ones.
Bibliographical noteFunding Information:
This work was funded by the U.S. Department of Energy under subcontract number DE-AC36-99-GO10337 through the Office of Energy Efficiency and Renewable Energy Office of the Vehicle Technologies Program. Dr. Yoon S. Jung acknowledges the Korea Research Foundation Grant funded by the Korean Government [KRF-2008-357-D00066]. Sangkyoo Lee acknowledges the Korea South-East Power Generation Co.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering