Impact of P-Doped in Spinel LiNi_0.5Mn_1.5O₄ on Degree of Disorder, Grain Morphology, and Electrochemical Performance

Abstract

LiNi 0.5-x P 2x Mn 1.5-x O 4 (x = 0, 0.005, 0.01, and 0.02) submicrograins in regular octahedral shape with merely {111} surface facets and truncated octahedral shape with both {111} and {100} surface planes were obtained by the solid-state reaction method. The effect of doping P on ions arrangement, grain morphology, and the electrochemical performance of lithium nickel manganese oxide was investigated. The characterizations of X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), and selected area electron diffraction (SAED) confirm more Mn 3+ ions in the structure to enhance the cationic disorder degree of LiNi 0.5 Mn 1.5 O 4 after Pdoping. Comparing the LiNi 0.5 Mn 1.5 O 4 and LiNi 0.495 P 0.01 Mn 1.495 O 4 samples both with regular octahedral morpology, their electrochemical performance could be remarkably improved by more disordered transition metal ions arrangement leading to higher conductivity of Li-ions and electrons. However, when the amount of P-doping further increased, the rate and cycle ability of the LiNi 0.480 P 0.04 Mn 1.480 O 4 sample in truncated octahedral shape worsen dramatically even with a higher degree of cationic disorder. This could be on account of the crystal planes starting to dominate the electrochemical performance instead of ions arrangement under high voltage and large rate: the {111} facet is more favorable to the lithium ion transport than the {100} crystal plane for LiNi 0.5 Mn 1.5 O 4 submicrograins during charge and discharge.

F-doped O3-NaNi1/3Fe1/3Mn1/3O2 as high-performance cathode materials for sodium-ion batteries

“…1c, the lattice parameter is first observed to decrease as a function of increased F-doping as the radius of F − (1.33 Å) is smaller than that of O 2− (1.40 Å) [22] when the doping amount is less than 1%. However, further increasing the F-doping levels above 1% results in a lattice parameter increase, which is attributed to an elevated proportion of Mn 3+ /Mn 4+ and the larger ion radius of Mn 3+ (0.645 Å) than Mn 4+ (0.53 Å) [23]. To observe the crystal structure, HRTEM and SAED measurements were performed.…”

Synthesis and Electrochemical Properties of LiNi0.5Mn1.5O4 Cathode Materials with Cr3+ and F− Composite Doping for Lithium-Ion Batteries

“…Cation doping ( Na [13], Ru [14], Rh [15], Co [16], Al [17], Cr [18], Zn [19], Nd [20], Mg [21], Mo [22], Sm [23], Cu [24], etc.) and anion doping (S [25], P [26], and F [27]) have been applied to modify LiNi 0.5 Mn 1.5 O 4. For instance, compared to pure LiNi 0.5 Mn 1.5 O 4 , Al-doped LiNi 0.5 Mn 1.5 O 4 can effectively improve the discharge capacity (up to 140 mAh g −1 ) and cycling stability (70% capacity retention after 200 cycles) [28].…”

Experimental and Simulation Investigations of Porosity Graded Cathodes in Mitigating Battery Degradation of High Voltage Lithium-Ion Batteries

“…Furthermore, we adopted Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II) to demonstrate the porosity-grading as a strategy for mitigating battery degradation. As one promising candidate for high-voltage lithium-ion batteries (LIBs), [1][2][3][4][5][6] 9 However, severe performance degradation, especially at the electrode/electrolyte interface, hinders the implementation of the LNMO. 7,10,11 Besides developing new electrolytes, 8,10 more attention needs to be focused on understanding as well as mitigating the LNMO cathode degradation within most common battery systems (e.g., graphite/LNMO), 7,12,13 which is the focus of this paper.…”