Available Technology

BSA 16-04:Nanostructured Copper Vanadium Oxides as High-Capacity Cathodes for Lithium Ion Batteries

Copper vanadium oxide (CVO) has gained popularity as intercalating cathode for the Li-ion battery due to its wide open channels for Cu-ion and Li-ion transport properties. This invention describes a synthesis method and material composition towards making high energy density and high performing cathodes for lithium ion battery at low cost. A modified CVO synthesis and post synthesis processes produced a unique phase-pure alpha-CVO material (Cu6.90V6O19) that exhibited energy capacity as high as ~350 mAh/g, which is two-fold or higher than any commercial cathodes available. The alpha-CVO structure identified in the process has an unusual cluster structure that allows the compound to exchange large quantities of ions during electrochemical cycling without irreversibly destroying its framework.
Patent Abstract: 
The structure and electrochemical properties of some alpha-CVO cathodes were previously reported in literature. However, the reported activity was only a relatively small fraction (< 50%) of the theoretical capacity of this phase. The new alpha-phase CVO obtained after mechanical ball milling processing showed a discharge potential of about 2.6 V, and fully reversible with specific capacities of ~350 mAh/g in the window of 2.0-3.6 V and partially reversible capacities exceeding 500 mAh/g in the window of 1.0-4.5V. This gives reversible energy densities of about 850 Wh/kg, and partially reversible capacities of more than 1000 Wh/kg. These energy densities are substantially higher than commercially available cathodes. In the traditional cathodes, lithium storage/release goes via an intercalation process and only one electron is transferred per redox center. The high lithium storage capacity in alpha-copper vanadium oxide was achieved via combined displacement and intercalation reactions during which multiple electron transfers occur, which allow this compound to exhibit an extremely high capacity and high energy density.
Benefits 
Potential benefit is a low cost synthesis method for making high performance cathodes for rechargeable Li-ion batteries.
applications 
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