Evaluation of Nb-Doping on performance of LiNiO2 in wide temperature range

Surface Stabilization of Cobalt-Free LiNiO2 with Niobium for Lithium-Ion Batteries

“…The differences between our observations on the spatial distribution of Nb 5+ and those reported in the previous studies on Nb incorporation in Ni-rich layered oxides may be a result of the refractory nature of niobium oxide species . The calcination temperatures used to achieve the incorporation of Nb into the bulk layered structure (i.e., bulk doping) in previous studies are typically relatively high (>725 °C), whereas the calcination of LNO and Nb-LNO requires lower temperatures (650–700 °C) to achieve optimal electrochemical performance. ,,− To the best of our knowledge, methods of niobium incorporation, including the niobium source and procedure for distributing it uniformly within the host material, have not yet been comprehensively investigated. This may play a critical role in controlling the niobium distribution and in turn the electrochemical properties of the material.…”

“…To this end, many different strategies have been proposed, among which elemental doping and surface coating are the most widely investigated. − While many different elements have been investigated, niobium appears to yield exceptionally remarkable performance enhancement. Nb incorporation has been investigated in a variety of high-nickel cathode materials, including NMC 532, NMC 811, NMC 85:10:05, NMC 88:02:10, NMC 90:05:05, and LNO, showing notable enhancements in cycle life, rate capability, and thermal stability. − Furthermore, computational screening of various elements suggests that Nb may be the optimal choice among transition-metal dopants . Lithium niobates, of the general formula Li x NbO y , have been widely investigated in the field of solid-state batteries, where they are used as coatings to improve the interfacial stability between the cathode and solid electrolyte. , Generally, they have been found to offer beneficial properties as thin coatings to passivate the surface of layered oxide particles due to their relatively high Li + conductivity, which may be improved further by inclusion of Ni 2+ to form Li + vacancies. , …”

Stabilizing the Interphase in Cobalt‐Free, Ultrahigh‐Nickel Cathodes for Lithium‐Ion Batteries

“…Future work on analyzing other promising dopants, such as Nb, W, and Al, on improving LNO stability should be considered. [75][76][77] In addition to cathode modifications, prospective efforts to mitigate air instability and gas release from Co-free ultrahigh-Ni cathodes will be of great importance for potential commercialization. Future work on studying performance enhancements with the cathodes and advanced electrolytes, such as novel localized-high concentration and saturated electrolytes, will also be paramount to promoting the feasibility of such battery chemistries into the global LIB market.…”

First-Principles Study of the Doping Effect in Half Delithiated LiNiO2 Cathodes

“…Nevertheless, there is a lack of systematic, comprehensive theoretical studies on the properties of various dopants in LiNiO 2 including the preferred occupation site, dopant ion migration, and the mechanism of dopants to suppress oxygen evolution. Candidate dopants, selected based on previous experimental and theoretical investigations, include B, Na, Mg, Al, , Si, Ca, Ti, ,− V, , Cr, , Mn, , Fe, , Co, , Cu, Zn, Ga, , Ge, As, Y, Zr, , Nb, − Mo, , In, Sn, , Sb, ,, La, Ce, Ta, ,, and W. ,, The ion migration from the Ni layer to the Li layer is most thermodynamically favored at x = 0.5 in Li x NiO 2 . − Thus, to study dopant ion migration, we use a 2 × 3 × 2 supercell of Li 0.5 NiO 2 as the base model, which contains 12 Li, 24 Ni, and 48 O. The chemical formula of our model can be approximated as Li 0.5 Ni 0 .…”