| Texto completo | |
| Autor(es): |
Agudelo, Hector D.
;
Vasquez, Ferley A.
;
Calderon, Jorge A.
;
Torresi, Roberto M.
;
Carmine, Eduardo
;
Das, Bikram Kumar
;
Cortes, Henry Andres
;
Bonilla, Mauricio R.
;
Akhmatskaya, Elena
Número total de Autores: 9
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Alloys and Compounds; v. 1039, p. 19-pg., 2025-09-10. |
| Resumo | |
High-voltage spinel cathode material LiMn1.5Ni0.5O4 (LMNO) has attracted great interest due to its large theoretical capacity, energy density and cobalt-free chemistry. However, high voltage cycling leads to accelerated decomposition of organic electrolytes (OEs) and to capacity fading in TFSI-based ionic liquid (IL) electrolytes. To address these challenges, LMNO nanorod particles were synthesized based on alpha-MnOOH nanorod templates, facilitating the co-precipitation of lithium and nickel cations. Several vanadium dopant contents were subsequently explored (LiMn1.5-xNi0.5VxO4, where x = 0.01, 0.03, and 0.05), resulting in spinel structures with enhanced structural and electrochemical stability in both OEs and ILs. Morphological and compositional analyses highlighted the reduction of Mn4 + to Mn3+ to sustain electroneutrality within the lattice, as well as the coexistence of two cubic spinel phases (disordered Fd3 & oline;m and ordered P4332) in contributing to superior electrochemical performance and stability. Moreover, the rod-like particle morphology displayed a high-rate capability comparable to that of the well-known octahedral morphology. Density Functional Theory (DFT) calculations confirmed that increasing V-content promotes the formation of the Fd3 & oline;m spinel phase, while incorporation of V in ordered P4332 is not energetically favourable. In addition, machine learning-based molecular dynamics (MD) simulations showed that increasing V-content tends to decrease Li-ion diffusion barriers, increasing the intrinsic ionic mobility in the cathode. Remarkably, LiMn1.49Ni0.5V0.01O4 demonstrated excellent capacity retention when cycled in an OE (75.11 % in LMNO vs 84.33 % in V-doped LMNO) and in IL electrolyte (30.79 % in LMNO vs 79.33 % for V-doped LMNO), positioning it as a promising and safer candidate high-voltage cathode. (AU) | |
| Processo FAPESP: | 21/00675-4 - Arquitetura de materiais para armazenamento de energia eletroquímica e catálise |
| Beneficiário: | Roberto Manuel Torresi |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |