Fabrication and Study of All-Solid-State Li-Ion Batteries Based on Self-Organized Titania Nanotubes

The electrochemical storage performances of devices are seriously compromised when decreasing the size of the components down to the micrometer scale. This is particularly true for the development of microbatteries which are rapidly reaching their performance limit in terms of energy density and power density because of its two-dimensional geometry thin film technology impeding fast electron/ion transport in the electrodes and higher interfacial charge transfer resistances. To overcome these issues, all-solid-state 3D microbatteries have attracted interest while remaining a technological challenge since they require the marriage between materials science, electrochemistry, and microfabrication processes. In this context, titania nanotubes (TiO₂NTs) have been extensively studied as a 3D negative electrode for lithium-ion batteries (LIBs). These self-supported nanostructured electrode show a suitable nanotubular morphology to fabricate microbatteries with high energy and power densities (1-4).

In this work, the Li⁺ insertion into anatase TiO₂nts using PEO-based polymer as electrolyte has been studied by cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemical characterizations reveal that that the Li⁺ storage is dominated by the bulk diffusion (into the lattice) with the contribution of the pseudo-capacitive effect at the surface. Beside the mechanistic investigations, we report the fabrication of the first all-solid-state Li-ion batteries based on titania nanotubes as negative electrode, PMMA-(PEO)₅  as polymer electrolyte and LiNi0.5Mn1.5O4 as positive electrode (Fig. 1). The electrochemical performance of this new thin film microbattery will be presented and discussed (Fig. 2).

References

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