Abstract
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-Na2/3Ni1/3Mg1/6Mn1/2O2, 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-Na2/3Ni1/3Mg1/6Mn1/2O2 are monitored and discussed. Understanding the relevant changes occurring during dual Li+ and Na+ intercalation into P3-Na2/3Ni1/3Mg1/6Mn1/2O2 is of crucial importance to enhance the overall performance of hybrid Li/Na ion batteries at elevated temperatures.