Scientific Achievement
Calcium-ion energy storage systems are relatively unexplored mainly due to lack of available active materials. Building on our recent successes with high voltage phosphate materials we have expanded the available Ca-ion cathode materials to the high-capacity layered oxide MoO3.
Significance and Impact
Using a combination of DFT calculations, multiple spectroscopies, and X-Ray diffraction methods available thru JCESR collaborations, we have studied the mechanism of Ca-ion insertion into MoO3 and noted that there appears to be a two-phase reversible region indicating that both endmembers are Cax[MoO3] phases stabilized by MoO3 layer shifts.
Research Details
- Long term stable cycling (200 cycles) of calcium-ions into MoO3 has been achieved with retention of capacity.
- A combination of DFT calculations, XANES spectroscopy, and electrochemical studies has indicated that a phase transition to ≈ Ca0.1[MoO3] stabilizes a more highly conductive phase with higher local symmetry than the parent molybdenum oxide phase.
