| Texto completo | |
| Autor(es): |
Ferreira, M. J.
;
Schneider, J. F.
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS; v. 211, p. 14-pg., 2026-04-01. |
| Resumo | |
Planetary ball milling (PBM) is a common method used to produce electrode materials for solid-state Li-ion batteries. The transformations of Li-phosphate precursors induced by mechanical energy delivered during PBM were analyzed in the model compound LiCa(PO3)(3). Starting from a crystalline phase, PBM produced a new glass state through a solid-state process at room temperature. The material was analyzed as a function of milling time using XRD, P-31 and Li-7-NMR, and DSC. This glass is produced in an excited structural state, releasing an excess of enthalpy Delta H-rel below T-g, akin to hyperquenched glasses. However, P-31 NMR reveals that the crystal-to-amorphous transition does not occur by discontinuous melt-quench events, but progresses continuously through defect accumulation and bond distortions during the early stages of milling (<5 h), when the amorphized material exhibits a progressive increase in the degree of local disorder around Q(2) groups. DSC shows a correlated rise in Delta H-rel without a well-defined glass transition, even though 80 % of phosphates transitioned to distorted states. After 5 h of milling, structural and thermal parameters reach a stable regime and a glass transition is observed, indicating the amorphous structure has achieved its final configuration. The PBM-produced glass is less stable against devitrification than the melt-quenched counterpart, showing lower T-g, T-c, T-c -T-g, and crystallization enthalpy, and a higher Q(n)-disproportionation, indicating differences in middle-range order. Li-7-NMR demonstrates that Li+ mobility is similar in the crystal and in both melt-quenched and PBM-produced glasses. (AU) | |
| Processo FAPESP: | 19/12885-3 - EMU concedido no processo 2013/07793-6: espectrômetro de ressonância magnética nuclear em estado sólido |
| Beneficiário: | José Fabián Schneider |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa Equipamentos Multiusuários |
| Processo FAPESP: | 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros |
| Beneficiário: | Edgar Dutra Zanotto |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |
| Processo FAPESP: | 24/09884-3 - Amorfização de fosfatos de Li e Al através de métodos mecânicos |
| Beneficiário: | Matheus José Ferreira |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |