Synthesis of Graphene-Supported Nano-Na3MnCO3PO4 for High Rate and High Capacity Sodium Ion Batteries

It has been predicted via ab-initio calculations that Na₃MnCO₃PO₄ possesses a high specific capacity of 191 mAh/g, due to its potential to deliver two-electron transfer redox reactions per formula via Mn²⁺/Mn³⁺ and Mn³⁺/Mn⁴⁺ redox reactions (Hautier, et al. 2011). To improve battery performance for high power applications such as hybrid electric vehicles and electric grid systems, it is necessary to enhance the electronic conductivity. Graphene has been reported to be a suitable conductive substrate to grow active materials for energy storage applications owning to its superior electrical conductivity, chemical stability, high mechanical strength, high surface-to-volume ratio, and light weight. In this study, Na₃MnCO₃PO₄, one of the most promising materials for Na-ion batteries, has been synthesized on a graphene sheet surface via hydrothermal method. The cathode material was characterized by FE-SEM, XRD, and electrochemical tests. It is shown that by having the total graphene content as low as 5.1wt%, specific capacity improves 40%. With this improvement in specific capacity, Na₃MnCO₃PO₄ has a great potential to be a viable cathode material for Na-ion batteries.