A sodium-ion battery based on a P2-Na0.5Ni0.22Fe0.11Mn0.66O2 cathode and a nanostructured Sb-C anode in a ionic liquid based electrolyte

Na-based storage systems working at room-temperature have recently gained the interest of the research community thanks to the large availability and low cost of sodium.[1,2] The real challenge in the sodium-based battery field is represented by the substitution of the extremely reactive metallic sodium anode that represents a serious issue to face in order to increase the intrinsic safety of the sodium cells. To further improve the safety level of sodium cells, we propose here the substitution of the more common organic-carbonate based electrolytes with an ionic liquid-based electrolyte characterized by higher thermal stability, lower volatility and non flammability.[3] Here we propose the study of a sodium-ion battery based on a P2-type, Na0.5Ni0.22Fe0.11Mn0.66O2 transition metal layered oxide cathode material and a nanostructured Sb-C alloying anode in a 0.2m NaTFSI-Py14TFSI electrolyte. The improved morphology of the electrode materials here investigated ensure an enhanced electrochemical behavior in terms of cycle stability and delivered capacity.