Power supply module and method for its assembling

The invention refers to a solution for the integration of lithium batteries in cylindrical format, which allows to realize battery packs (battery packs) consisting of a large number of cells (eg between 1,000 and 10,000) usable in both the automotive and industrial sectors.

Title of the patent Modulo di alimentazione elettrica e metodo per assemblarlo
Thematic area Electrical, electronic and information engineering; Mechanical, civil and environmental engineering
Ownership Alma Mater Studiorum – Università di Bologna
Inventors Claudio Rossi, Matteo Marano, Alessio Pilati
Protection International
Licensing status Available for licensing agreements
Keywords batteries, lithium batteries, cylindrical cells, cell connections, cell support, temperature measurements
Filed on Jun 25, 2018

In the last few years, in the lithium battery sector, the global production capacity has increased, the quality of the products has improved and prices have continuously decreased. These factors make lithium batteries the central element of the mobility electrification process, which will have a massive impact on the production system linked to both the automotive and industrial sectors.

The package integration solutions mainly used in Europe for vehicular applications are based on large format cells in a 'pouch' or prismatic configuration. There is no significant experience in using small-format cylindrical cells. On the other hand, the cylindrical cells represent the constructive solution that offers the best energy density performance and the best quality/cost ratio. The cylindrical cells are currently used on a large scale with excellent results mainly in small applications, for example: e-bike, powertools.

The main technical obstacles to the construction of large battery packs (BP) with cylindrical cells for automotive applications are in particular:

  • difficulty in integrating electrically and mechanically a very high number of cells;
  • difficulty in thermally managing BP under extreme environmental or usage conditions;
  • difficulty in monitoring a large number of physical quantities to guarantee the state of integrity of the BP;
  • difficulty in processing the information acquired and synthesising information capable of describing the status of the BP.

The research activity carried out by the University of Bologna was aimed at developing a solution for integrating lithium batteries in cylindrical format, creating battery packs (BP), consisting of a large number of cells (eg between 1,000 and 10,000), targeted to both the automotive and industrial sectors.

In particular, the proposed solution, compared to existing alternatives, allows to maximize the energy density, the life of the cells and in general the active and passive safety of the package and therefore of the vehicle on which it is installed. The developed solution is also particularly suitable to be assembled with a highly automated process, thus reducing the risks for the operators, the assembly time and therefore the production costs, while offering very high quality and reliability standards.

The invention aims to extending the use of cylindrical to large-sized applications, overcoming the problems of integration and safety currently existing, so as to extend the field of application of this technology to new areas.

The range of possible applications of the technology is very broad and covers primarily the electric cars (BEV) and hybrid (HEV), from compact cars to high-end cars. The basic solution, the package design methodology and the automatic assembly process can be extended to other application sectors, such as light and heavy commercial vehicles, public transport vehicles and industrial and agricultural vehicles.

The main advantages offered by the patented solution concern the increase of the safety, the life of the pack and the reusability of the cells, even in applications other than the automotive. These characteristics are strongly distinctive compared to existing solutions and will increase the competitiveness, and therefore the profitability, of the BP producers who will use the proposed solution.The patented idea presents a process and product solution for the BP that overcomes the problems of integration of existing cylindrical cells.

The main technical solutions that allow to obtain this result are related to:

  • Safety: measurement of temperatures on the two cell terminals, and a guarantee of monitoring the cells, overcoming all current solutions that include sample monitoring;
  • Reliability and cost: modular structure, where electrical and mechanical elements collaborate with each other in the mechanical structuring, avoiding the use of electric yarn connections. Overcoming current solutions where yarn cabling is a central element of integration.