published at 23/10/2014

MELIES: the microbattery, a new solution for electricity storage

Formation :

The Méliès project was initiated in 2007 by STMicroelectronics and approved by the S2E2 competitive cluster. It has been supported financially by the State and the local authorities (the Centre’s Regional Council, the Departmental Councils of Indre et Loire and Le Loiret, and by the greater administrative district council of Tour(s) Plus). It also received a grant within the context of the 6th call for projects by the Single Inter-ministerial Fund (FUI).

Objectives of the Méliès project

The main challenge of the MELIES project has been to bring into existence microsystems capable of storing electricity, whilst addressing the challenges of miniaturisation.

Its aims were to:

  • identify processes and tools to manufacture microbatteries and in this way prepare for their industrialisation;
  • develop the technologies necessary for making microbatteries with the help of processes and equipment similar to those used in microelectronics. The idea is to envisage their industrial manufacturing over the medium term, or around 3 to 5 years;
  • integrate these microbatteries in the standard boxes used by microelectronics; the microbattery then becoming an electronic component like any other;
  • position the microbatteries as close as possible to the applications by linking them to active electronic chips: (electronics boards, printed circuits and at the core of the same box). 

Promising results

  • Two families of microbatteries have been defined enabling their use in various applications.
  • The processes of microbattery fabrication  have been outlined. Some pre-industrial equipment has been installed on the CEA-Liten site. It is the first equipment of its generation to be able to manufacture microbatteries industrially.
  • Three generations of chips integrating a microbattery have been developed within the context of the project.
  • The coupling, inside the same box, of a microbattery with, for example, a microprocessor, a microcontroller and the direct integration of the microbatteries into the printed circuits has been carried out.
  • The implementation of an automated bump test on the battery bank to place the micro-battery technology under temperature, moisture, mechanical and/or electrical constraints and thus assess their performance. 

The possible applications of this work in the shorter or longer term

The surveillance of the infrastructures

In the building, notably, numerous sensors are used for the surveillance of vibrations, heat and constraints. Today, these sensors work with batteries, which need to be recharged on a regular basis. Often access is difficult, on bridges or facades, and this maintenance operation is extensive and costly. The microbatteries may be associated with a vibratory, thermal or solar recharge. They enable energy-autonomous systems with ‘perpetual’ operation, no longer requiring any manual recharging.

Internet security

The reinforcing of commercial transactions requires use of credit cards with authentication that has been stepped up. These new credit cards will be equipped with a power consumption screen. In order to make such credit cards, an energy source could be embedded in the thickness of the card. Slim and flexible, the microbatteries will then be fully integrated into the format of the credit card.

Medical assistance

The batteries in medical devices like hearing aid applications are not currently rechargeable as well as being costly and polluting and will be able to be replaced by microbatteries.    

In the longer term, one could envisage telephones or tablets with integrated microbatteries. The latter would be placed in the telephone or tablet’s printed circuit.

The prospects 

The project has demonstrated that the fabrication of microbatteries is industrially conceivable with the help of equipment and processes similar to those of microelectronics. MELIES will continue with the development of this technology on an industrial scale. The pilot plant shall soon be installed on the STMicroelectronics site in Tours. It will enable microbattery technologies to be improved and hence enhance performance. The industrialisation of these technologies is then envisaged in Tours, so as to begin production in 2014-2015.

At the same time, the principles of microbatteries integrated in printed circuits are in the development phase. Commercial canvassing has been started by STMicroelectronics and Ciretec. If the marketing takes shape, a production line could see the light of day at Ciretec. The tools for testing reliability and characterisation are enabling an extension of the services provided by the Alpha Test company. As a result, a set of new business opportunities is expected. Finally, this project is subject to an extension via the Stressbat and Tours 2015 programmes. Stressbat II involves the optimisation of microbattery structures through thermo-mechanical simulation, whilst one of the main lines of the Tours 2015 programme relates to the continuation of experimental research and the industrial development of microbatteries.

  

Partners to the project

The project developer is STMicroelectronics
The CEA-Liten
Ciretec (SME)
Alpha Test (SME)

Patents: 11

Scientific publications: 15

STMicroelectronics has registered the "EnFilmTM" brand

Alpha Test can develop a 'test bank' service provision for any other manufacturer involved, independently of the R&D project.