Lithium-Ion

Pinning Effects of Heavy Elements for the Structural Stability of Ni-Based Layered Oxides Pinning effect: Nb5 and Ta5 exhibit the same oxidation state identical ionic radii but differ in atomic weight, exhibiting reduced atomic displacement, reinforced Ni−O bond strength, and expanded Li slab spacing to improve electrochemical performance Performance improvement: The specific capacity was observed to increase in the order of Ref-NMC Nb-NMC Ta-NMC over the voltage range of 2.84.3 V, further supported by the differential capacity (dQ/dV) curves. Such a tendency remains over subsequent cycles.

PINNING EFFECT The stabilizing effects were more pronounced for Ta-doped NMC, highlighting the role of atomic mass in modulating the structural and thermal

PERFORMANCE IMPROVEMENT In situ XRD and dQ/dV analyses indicate the H3 phase is stabilized through the pinning effect of Nb and Ta, resulting in a prolonged voltage plateau and enhanced electrochemical stability at high voltage

stability of the material The synergistic effects of heavy element doping includes enhanced structural stability, smoother phase transitions, suppressed lattice collapse, and delayed thermal decomposition

Source: W. Lee et al. ACS Energy Lett. 2025.

Extracted from the PDF; charts and images may read imperfectly.