Refinement of electrodeposition mechanism for fabrication of thin nickel films on n-type silicon (111)

Effect of Mn, N co-doped LiFePO4 on electrochemical and mechanical properties: A DFT study

In this study, the thermodynamic stability, embedding voltage, volume change rate, electronic structure properties, mechanical properties and lithium-ion diffusion characteristics of the Mn, N co-doped LiFePO4 material are investigated using a first-principles approach based on density generalization theory. The results show that the doped system has a low formation energy and the material meets the thermodynamic stability criteria. During the de-lithium process, the volume change rate of the doped material decreases and the cycling performance is improved, but the battery energy density decreases slightly. It is also found that the doping of N led to the transformation of the material from a p-type semiconductor to an N-type semiconductor, while the doping of Mn and N lead to the creation of impurity bands, narrowing of the band gap and an increase in conductivity. At the same time, Mn, N co-doping greatly improve the ductility of the material, suppress the generation of microcracks, and reduce the possibility of shear deformation. In addition, it is noteworthy that the lithium-ion diffusion energy barrier of the doped system is reduced, which predicts an increase in the diffusion rate of lithium ions in the doped system.

Synergistic Effects of 2-Butyne-1,4-Diol and Chloride Ions on the Microstructure and Residual Stress of Electrodeposited Nickel

To assess the individual and synergistic effects of 2-butyne-1,4-diol (BD) and chloride ions on the microstructure and residual stress of electrodeposited nickel, various nickel layers were prepared from sulfamate baths comprising varying concentrations of BD and chloride ions by applying direct-current electrodeposition. And their surface morphologies, microstructure, and residual stress were tested using SEM, XRD, EBSD, TEM, and AFM. While the nickel layers composed of pyramid morphology were prepared from additive-free baths, the surface flattened gradually as the BD concentration of the baths was increased, and the acicular grains in the deposits were replaced with <100> oriented columnar grains or <111> oriented nanograins; additionally, the residual tensile stress of the deposits increased. The addition of chloride ions to the baths containing BD significantly increased the residual stress in the nickel layers, although it only slightly promoted surface flattening and columnar grain coarsening. The effects of BD and chloride ions on the growth mode and residual stress of nickel deposits were explained via analysis of surface morphologies and microstructure. And the results indicate that the reduction of chloride ion concentration is a feasible way to reduce the residual stress of the nickel deposits when BD is included in the baths.

Exploring ionic liquid-laden metal-organic framework composite materials as hybrid electrolytes in metal (ion) batteries

This review focuses on the combination of metal-organic frameworks (MOFs) and ionic liquids (ILs) to obtain composite materials to be used as solid electrolytes in metal-ion battery applications. Benefiting from the controllable chemical composition, tunable pore structure and surface functionality, MOFs offer great opportunities for synthesizing high-performance electrolytes. Moreover, the encapsulation of ILs into porous materials can provide environmentally benign solid-state electrolytes for electrochemical devices. Due to the versatility of MOF-based materials, in this review we also explore their use as anodes and cathodes in Li- and Na-ion batteries. Finally, solid IL@MOF electrolytes and their implementation into Li and Na batteries have been analyzed, as well as the design and advanced manufacturing of solid IL@MOF electrolytes embedded on polymeric matrices.