Li-O2 Cells Based on Hierarchically Structured Porous α-MnO2 Catalyst and an Imidazolium Based Ionic Liquid Electrolyte
ABSTRACT Highly crystalline α-MnO2 is synthesized by facile reduction of KMnO4 in acidic solution. The obtained α-MnO2 exhibits a high specific surface area of about 156 m2g-1 with a hierarchical bimodal porous structure. The TEM analysis confirmed that the α-MnO2 is highly crystalline and exists in the form of nano-rods agglomerated to form the shape of sphere. It is a promising electro-active material that can act as an oxygen reduction catalyst to improve the recharge ability of lithium-oxygen cells. The cell with α-MnO2 as catalyst and commercially available imidazolium-based room temperature ionic liquid with LiClO4 as electrolyte displayed an initial discharge capacity of 900 mAhg-1 which, after prolonged cycling, reached a stable value of about 600 mAhg-1 with a high recharge efficiency (~ 90%) and good capacity retention. Thus α-MnO2 catalyst along with ionic liquid based electrolyte could be an effective combination to obtain improved capacity and durability in a rechargeable lithium-O2 batteries.
- SourceAvailable from: Marcella Bini[Show abstract] [Hide abstract]
ABSTRACT: The global energy demand calls for more efficient storage systems. In this review, the state of the art of Li/air and Li/O2 batteries is discussed with particular attention on the more recent findings regarding all the battery compartments. Both aqueous and non-aqueous systems are considered, and the most critical issues for better battery design are addressed. Whereas the predicted charge/discharge values for these devices do justify the intense research efforts performed nowadays, great problems are still present which must be overcome in order to make Li/air and Li/O2 a reality for future large-scale applications.Journal of Power Sources 220:253–263. · 5.26 Impact Factor