RT Journal Article
T1 Influence of MnO2-Birnessite Microstructure on the Electrochemical Performance of Aqueous Zinc Ion Batteries
A1 López García, María Luisa
A1 Álvarez Serrano, Inmaculada
A1 Giraldo, David Agustin
A1 Almodóvar, Paloma
A1 Rodríguez Aguado, Elena
A1 Rodríguez Castellón, Enrique
AB KxMnO2 materials with birnessite-type structure are synthetized by two different methods which make it possible to obtain manganese oxides with different degrees of crystallinity. The XPS results indicate that the sample obtained at high temperature (KMn8) exhibits a lower oxidation state for manganese ions as well as a denser morphology. Both characteristics could explain the lower capacity value obtained for this electrode. In contrast, the sample obtained at low temperature (KMn4) or by hydrothermal method presents a manganese oxidation state close to 4 and a more porous morphology. Indeed, in this case higher capacity values are obtained. At current density of 30 mA g−1, the KMn8, KMn4, and HKMn samples display a capacity retention of 88, 82, and 68%, respectively. The higher capacity loss obtained for the HKMn compound could be explained considering that the incorporation of Zn2+ in the structure gives rise to the stabilization of a ZnMn2O4 spinel-type phase. This compound is obtained in the discharge process but remains in the charge stage. Thus, when this spinel-type phase is obtained the capacity loss increases. Moreover, the stabilization of this phase is more favorable at low current rates where 100% of retention for all samples, before 50 cycles, was observed.
PB MPDI
SN 2076-3417
YR 2022
FD 2022-01-23
LK https://hdl.handle.net/20.500.14352/72081
UL https://hdl.handle.net/20.500.14352/72081
LA eng
NO Ministerio de Economía y Competitividad (MINECO)
NO Ministerio de Ciencia e Innovación (MICINN)
DS Docta Complutense
RD 6 abr 2025