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"Solid-state Lithium-ion batteries for macro- and micro-battery applications"

Lithium ion batteries (LIB) hold more than 75% market share of rechargeable batteries with 3.5 billion LIB cells sold last year, mainly for portable electronics. For the near future an additional demand is expected for batteries in power tools and hybrid electric vehicles (a market currently dominated by NiMH), and for rechargeable microbatteries needed for microsystems such as implants and smart autonomous sensor networks. Most of the production of LIB is located in Asia. In Europe, the main opportunities lie in high tech battery products.
Currently Li-ion batteries use flammable liquid electrolytes which pose safety and health issues. Beside enhancing safety, the transition to a solid state electrolyte would mean significant improvements in the battery performance as well: higher energy density, longer battery lifetime and wider temperature range of operation. The improvements offered by the all-solid-state battery would enable technologies which are currently not economically or technically viable (e.g. fully battery operated vehicles, EV).
Also, solid-state electrolyte enables novel concepts which are not feasible with wet electrolytes (e.g.integration of a microbattery on a chip or microsystem). One such new concept is the 3D thin-film battery, where an anode/solid electrolyte/cathode layer stack is coated onto a 3D structured surface such as pillar arrays. This concept allows direct integration with microsystems or even large-area foil based batteries which could be connected to the back of solar modules.
The goal of this project is to build a functional all solid stated 3D thin film battery. The know how generated in this project on solid electrolytes and engineering of electrode/electrolyte interfaces can be directly transferred to particle-based all solid state batteries which are for example of interest for automotive and small form battery applications.

General project goal and deliverables

The main aim of the SoS-Lion project is to build a functional all solid state 3D thin film microbattery. To this end, both conformal coating processes and solid electrolyte materials need to be developed.

  • Planar thin film battery with focus on conductivity of solid electrolyte
  • 3D thin film battery with focus on conformality and mechanical compliance of solid electrolyte


The 3D thin film approach holds promises for tuning the battery performance through film thickness (power density) and aspect ratio (energy density) of the 3D architectures. In this project, the feasibility of such a scaling approach will be investigated. the current state of the art is limited to half cells, while a full solid state thin film cell as aimed for in the project is not yet demonstrated. Material compatibility, interface control and matching solid electrolyte components are the main hurdles for the integration of a full cell and will therefore take a central role in the project.


The challenges are:

  • Conformal coating of complex materials onto high aspect ratio 3D structured substrates.
  • Development of high conductivity solid electrolyte materials with good chemical , electrochemical and mechanical stability, with a potential for conformal coating.
  • Compatible processes and deposition techniques for complete device fabrication flow.

User Committee

A group of 16 companies and organizations forms the user committee of this project. They closely follow up on the project and provide suggestions for increasing the valorisation potential.
If you are interested in the technology under development, if you see valorisation opportunities for this technology in your company, membership of the user committee is recommended. The user committee is open to all European companies.
Please contact Bart Onsia (see contact section) for further information.