SODIUM NICKEL MANGANESE OXIDE AS A POTENTIAL CATHODE MATERIAL FOR SODIUM-ION BATTERIES
Moses Kodur, Chuze Ma, Shirley Meng.
University of California, San Diego, La Jolla, CA.
Because of the need for low-cost energy-storage devices, sodium-ion batteries are being investigated as potential candidates due to the abundance of sodium and its chemical similarity to lithium. In the many studies conducted on layered cathode materials for sodium-ion batteries, relatively low reversibility and poor rate performance have been exhibited. In this project, a morphology controlled Na0.78Ni0.23Mn0.69O2 is investigated as a potential cathode material. Solid state synthesis is used to make the material. Purity is confirmed through X-ray diffraction. When tested from 2.0 V to 4.5 V, the material exhibits a specific capacity of 135 mAh/g at a current density of 12 mA/g. The capacity can still be maintained as high as 120 mAh/g despite increasing the current by 50 times (600 mA/g). This is, so far, the best performance rate of layered oxide cathodes for sodium-ion batteries. Therefore, a series of material characterizations including X-ray absorption spectroscopy, scanning transmission electron microscopy, and electron energy loss spectroscopy are ongoing in order to reveal the Na intercalation mechanism of the internal redox reaction, as it is yet unknown.