Lithium-ion batteries are the primary power source for many applications, but none of the current devices can fully satisfy all the projected energy storage needs. Common rechargeable batteries are based on liquid electrolytes, which limit their design and safety. Therefore, the need for all-solid-state micro-batteries arises, showing enhanced safety, volumetric energy/power density and chemical stability. Planar 2D solid-state thin-film batteries exhibit undesirable energy vs. power balance, which can be improved by applying 3D geometries, increasing the internal surface area (Fig. 1).
Fig. 1 – Epitaxial vertically aligned nanocomposite-based solid-state battery configurations: (a) 2D planar, (b) 2D/3D-combined, (c) partial 3D-integrated, and (d) full 3D-interdigitated solid-state batteries. The red arrow indicates the lithium-ion pathway.
Vertically aligned nanocomposite (VAN) thin films have been developed as a new materials' platform for creating self-assembled device architectures and multi functionalities. They show a wide range of attributes arising from the strong interplay among the materials' properties. Epitaxial VANs are self-assembled through pulsed laser deposition (PLD) without controlling the deposition sequence required for planar multilayer films.
To predict the formation of VAN structures and analyze the influence of growth conditions on the morphology evolution of these nanocomposites, a KMCS model is employed. The model allows the study of complex systems and the compatibility of different materials, using activation energies obtained experimentally and with minimum restrictions for hopping directions.
A model to study such a system's formation has already been developed (Figure 2) for the two-material system of a 3D cathode or anode. To obtain a full 3D-interdigitated solid-state battery, a more complex system needs to be implemented. The goal of this project is to:
- Extend the current method to n components;
- Study the relation of energies required to form such structures;
- Analyze the compatibility of different solid-state battery materials with such geometry.
Fig. 2 – KMCS of a VAN layer composed by LiMn2O4 cathode and (Li,La)TiO3 solid-state electrolyte for different deposition conditions.
Daniel Monteiro Cunha (email@example.com)
 Cunha, D.M., Huijben, M. Lithium-based vertically aligned nanocomposites for three-dimensional solid-state batteries. MRS Bulletin 46, 152–158 (2021).
 Cunha, D.M., Vos, C.M., Hendriks, T.A., Singh, D.P., Huijben, M. Morphology Evolution during Lithium-Based Vertically Aligned Nanocomposite Growth. ACS Applied Materials & Interfaces 11 (47), 44444-44450 (2019).