Technological Offer

Fast quality characterization method for Lithium ion cells


The life of lithium ion batteries is strongly conditioned by the degradation of the “Solid Electrolyte Interphase” or SEI. SEI is a passive layer that covers the surface of the negative electrode and is formed by degradation of the electrolyte, the decomposition products of which are deposited on the electrode. Over time or after many charge and discharge cycles, SEI tends to detach from the electrode. When this happens, the electrolyte is exposed to the negative electrode and breaks down again, progressively decreasing the amount of Lithium available in the electrolyte and therefore reducing the life of the battery.

To ensure that batteries have a good quality SEI, specific measures are required to assess the quality of the SEI newly formed in the manufacturing process or after a certain period of storage or use.

The invention consists on a new practical methodology to diagnose the presence of failures or micro cracks on the SEI surface.

The new technology developed by IMDEA Energy is aimed at quality control of Lithium – ion batteries and develops a test method faster than existing ones. It can be applied to:

  • The quality control of freshly made batteries in a timeframe of 24 – 48 hours instead of the usual 2 to 3 weeks spent in the tests based on voltage evolution measurements over cell.
  • Assess the SEI layer ageing in a quick manner, without dedicating months or years to perform charge – discharge testing.

Advantages and innovations

Unlike typical and well stablished quality control procedures in Lithium – ion batteries fabrication lines, which usually takes several weeks and are based on voltage evolution measurements over cell just after the fabrication, this concept is a methodology that provides quick information about the Solid Electrolyte Interface (SEI) layer conformation in newly manufactured batteries. It can also be used to assess the SEI layer ageing in a quick manner.

Market applications

Li-ion cells manufacturers with the necessity of a fast quality control procedure that will significantly shorten the stock of freshly produced cells before packaging and shipping to clients.

Li-ion cells integrators with the necessity of a fast quality control procedure to inspect the shipments of cells from their suppliers. Client companies can be:

  • Those involved in second life.
  • Those working in trading of batteries or commercialization of batteries with other type of added values.
  • Manufacturers of cars or devices equipped with batteries.


Félix Marín,