Hybrid Li/Na Ion Batteries: Temperature-Induced Reactivity of Three-Layered Oxide (P3-Na2/3Ni1/3Mg1/6Mn1/2O2) Toward Lithium Ionic Liquid Electrolytes

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.

Oxygen-Storage Materials to Stabilize the Oxygen Redox Activity of Three-Layered Sodium Transition Metal Oxides

“…After the electrochemical reaction, a new peak at low binding-energy around 682.5–683.0 eV is visible only for C-NNM cycled in Li- and Li,Na-ion cells and also for the NNM sample treated in Li-ion cell (Figure a). It can be attributed to F – anions in alkali fluoride NaF and LiF. ,, This assignment is also supported by the Na 2s and Li 1s peaks measured at 62–63 and 53–53.2 eV characteristic for Na and Li atoms in NaF and LiF, respectively (Figure b). , …”

“…It can be attributed to F − anions in alkali fluoride NaF and LiF. 12,16,25 This assignment is also supported by the Na 2s and Li 1s peaks measured at 62−63 and 53−53.2 eV characteristic for Na and Li atoms in NaF and LiF, respectively (Figure 3b). 26,27 Because Na 2s-and Li 1s-binding energies are located in a close spectral range, the depth of surface analysis will be similar too: in this low binding-energy (high kinetic energy of the photoemitted electrons, respectively) the inelastic mean free path of electrons is about 3 nm, giving an analysis depth of 9 nm.…”

“…The occurrence of overoxidized oxygen destabilizes the layered structure, culminating in oxygen gaseous release at a potential higher than 4.5 V versus Li/Li + . In addition, the overoxidized oxygen interacts easily with organic-based electrolytes leading to worsening of the cycling performance. , Therefore, the enhanced surface reactivity of oxides will devaluate the unique properties of Li 1+ x TM 1– x O 2 and Na x TMO 2 .…”

“…15 In addition, the overoxidized oxygen interacts easily with organic-based electrolytes leading to worsening of the cycling performance. 9,16 Therefore, the enhanced surface reactivity of oxides will devaluate the unique properties of Li 1+x TM 1−x O 2 and Na x TMO 2 .…”

Metal Substitution versus Oxygen-Storage Modifier to Regulate the Oxygen Redox Reactions in Sodium-Deficient Three-Layered Oxides

“…The EPR signals due to the oxide bulk and surface are also observed after of electrodes in lithium-ion cells instead of sodium ones (Figure 10). The bulk EPR signal undergoes more significant broadening during the lithium intercalation than that of sodium (Figure 9) [35,43]. The line broadening reflects the transformation from the P3 structure into the O3 structure, where a partial exchange between Li + from lithium layers with Ni 2+ ions of transition metal layers takes place.…”