Hybrid Li/Na Ion Batteries: Temperature-Induced Reactivity of Three-Layered Oxide (P3-Na(2/3)Ni(1/3)Mg(1/6)Mn(1/2)O(2)) Toward Lithium Ionic Liquid Electrolytes

Hybrid metal ion batteries are perceived as competitive alternatives to lithium ion batteries because they provide better balance between energy/power density, battery cost, and environmental requirements. However, their cycling stability and high-temperature storage performance are still far from the desired. Herein, we first examine the temperature-induced reactivity of three-layered oxide, P3-Na(2/3)Ni(1/3)Mg(1/6)Mn(1/2)O(2), toward lithium ionic liquid electrolyte upon cycling in hybrid Li/Na ion cells. Through ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses, the structural and surface changes in P3-Na(2/3)Ni(1/3)Mg(1/6)Mn(1/2)O(2) are monitored and discussed. Understanding the relevant changes occurring during dual Li(+) and Na(+) intercalation into P3-Na(2/3)Ni(1/3)Mg(1/6)Mn(1/2)O(2) is of crucial importance to enhance the overall performance of hybrid Li/Na ion batteries at elevated temperatures.