A solid-state approach was used to synthesize Li(Ni0.925Co0.03Mn0.045)0.996Nb0.004O1.98F0.02 with double ion doping.
The structure
parameters, micromorphology, and element valence distribution of all
materials were thoroughly investigated by XRD, SEM, EDS, XPS, and
HR-TEM. The results show that the distribution of F and Nb is uniform
both on the surface and inside the particles and that F and Nb ions
have an impact on the valence state of Ni ions on the surface of the
material. In addition, the lattice parameter c is
raised and the (003) crystal plane spacing is widened by the introduction
of both F and Nb ions. The Li(Ni0.925Co0.03Mn0.045)0.996Nb0.004O1.98F0.02 electrode shows a higher discharge specific capacity (169.12
mAh g–1) at 10C and excellent cycling
performance with a capacity retention of 83.60% after 150 cycles.
Comparison of CV, dV/dq, EIS, SEM,
and HR-TEM after cycling for all electrodes reveals that the particles
doped with F and Nb maintained intact morphology and showed varying
degrees of decrease in polarization and impedance.
CoCrCuFeNi high-entropy alloys (HEAs) have high ductility owing to their unique two-phase microstructure. Phase relations and microstructure evolution were investigated by scanning electron microscopy coupled with energy dispersive spectrometry and differential thermal analysis. These results contributed to clarifying the formation mechanism of the HEA microstructures. The effects of Mg addition as an alloying element in HEAs were also studied, with respect to precipitation hardening, thereby aiming to obtain strength-ductility balanced HEAs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.