VITRONIC has developed a process for the quality inspection of lithium-ion batteries for electric vehicles, to detect particle contamination in battery cells. In rare cases, particles can cause short circuits, as a result of which the battery can ignite during operation. As the production volume of Li-ion batteries will multiply in the coming years, this could result in a relevant safety problem. The new process offers a solution: it enables inexpensive, continuous inline inspection in mass production.

Particle contamination as a cause of battery fires

When electric vehicles catch fire as out of nothing, they could be responsible: production residues just micrometers in size in the cells of lithium-ion batteries. They stem from the electrodes and separator foils being cut to size or from the abrasion of mechanical parts in the production line. Despite cleaning systems, individual particles remain stuck on the foils of the battery cell. 

When particles are 10 micrometers and larger, they can penetrate the 10-40 micrometer thick separators between the anode and cathode. This usually happens only after the batteries have been in use for a while - perhaps during a car trip. The battery shorts, can ignite and set the entire vehicle on fire. 

The problem has been accepted so far

With the usual quality controls in battery production, such particle contamination cannot be detected; at the time of delivery, the battery is still functioning normally. Available inspection systems - industrial microscopes - must be operated manually. They are only suitable for spot checks, but not for mass production. 

Due to the relatively small number of units produced to date, the safety risk could be accepted up to now. However, the current figure of around 20 million e-vehicles worldwide is expected to grow into hundreds of millions in the coming years. The current individual cases could then become a relevant number of incidents. 

Inspection system for mass production is currently being tested

Seamless particle inspection will therefore soon become standard in battery production. The new process from VITRONIC, the specialists for industrial image processing, offers a solution for this. A high-resolution 16k camera sensor simultaneously takes several images of the electrode foils from different angles, with different illumination. This makes it possible to detect tiny particles that have hardly any contrast with the background and are practically invisible. The detected particles are measured and automatically classified. Other flaws can also be detected, such as position deviations, edge and cutting defects, or surface defects of the electrodes caused by transport. 

The inspection is performed directly in the production line, after laser cutting and before stacking the electrode and separator foils. The transport of the foils does not have to be interrupted for this. The inline inspection system is therefore suitable for use in mass production. It supports battery cell manufacturers in further increasing product quality and implementing a zero-defect strategy. 

At the Battery Show in Stuttgart from June 28-30, 2022, VITRONIC will present these and other innovations in quality inspection. Interested parties can find more information here.


VITRONIC is the world's leading innovation driver for machine vision, enabling its customers to master the challenges of tomorrow.  

The family owned group of companies develops forward-looking solutions in the form of specialized products and software for image-based quality inspection, identification and process optimization, ​​which find application in the growth sectors of automation and traffic engineering. 

VITRONIC solutions make an important contribution to helping shape a safe and sustainable world. The existing limits of what is economically feasible are constantly being questioned in order to achieve the highest quality and productivity, for example in the production of automotive and pharmaceutical companies. Worldwide, Auto-ID solutions in logistics centers and at cargo airports, take over the reliable and efficient recording of shipments and thus ensure a transparent flow of goods.  

In the transport sector, VITRONIC offers leading technology for increased safety on the roads, for optimizing traffic flow and for recording road usage.  

Open and honest dealings with our customers form the foundation for jointly exploiting technological and process potential to the full. Joint success forms the basis of long-term cooperation with companies such as B. Braun, BMW, Daimler, DHL, UPS, Toll Collect, Fresenius and Sanofi as well as with public clients. 

Since its foundation in 1984, VITRONIC has been growing continuously for almost 40 years. The current annual turnover (2022) is 208 million EUR and the company is currently represented on five continents in over 80 countries with more than 1,400 employees.  

Development and production of VITRONIC systems are located at the company headquarters in Wiesbaden. VITRONIC subsidiaries in North America, Europe, Asia and Australia, as well as a worldwide network of sales and service partners, provide local support to international customers. 

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