Vanadyl Phosphates as High Energy Density Cathode Materials

Background:

The invention utilizes the epsilon polymorph of vanadyl phosphate (ε-VOPO4) as a positive electrode material for alkali-ion secondary rechargeable battery, particularly for the lithium or sodium-ion battery. This material adopts a stable 3D tunnel structure for Li ion intercalation with a theoretical specific capacity of ~2*158mAh/g (almost double that of LiFePO4). Compared with LiFePO4, ε-VOPO4 has a much higher conductivity and one higher charge/discharge plateau (around 4.0 V), and one lower (around 2.5 V). As ε-VOPO4 is capable of reversibly intercalating more than one lithium ion into the structure, it stores and delivers more energy than current batteries in the market. Overall, ε-VOPO4 makes a great candidate for next generation of high energy Li-ion batteries.

Advantages:

• Precursors are readily and controllably synthesized with a well-defined stoichiometry with no undesired impurities incorporated into the final product.
• ε-VOPO4 pure phase is synthesized through a short single step heat treatment under moderate temperature without involving complicated and costly high-temperature vacuum environment.
• Low fabrication costs with simple processing procedures, easy to scale up, cheap equipment and earth abundant starting materials.

   

 Intellectual Property Summary:

 

• U.S. 16/291,617