Nowadays Lithium Ion battery cells and pack manufacturing lines allow to collect a huge quantity of data.
Manufacturing automated machines, vision systems, welding tools are able to collect all parameters, process and quality data and allow the manufacturing and process engineers to improve the productivity and quality of Mega and Gifactory in Lithium battery business.
Unfortunately, even if gigabyte of data are collected daily in lithium battery manufacturing line, the data analysis is not so deep and is limited to check the production data and make downtime reason pareto analysis.
But there is much more behind, the data analysis in lithium battery manufacturing can provide you much more detailed information about machines and process technology and give you very precise input to improve your manufacturing process.
With a team of people expert in data analysis and lithium battery cell and battery pack manufacturing we are working on this kind of projects.
If you want to get more details reach us at info@bonsaitechnology.it
Real example what we are doing!
How deep is the data analysis even using very simple techniques but the entity of benefits given.
We are going to consider in this example a Lamination machine.
The lamination machine is mostly a roll to stack machine where unwinding module, unwind anode, cathode and separators.
Then the material pass through a lamination tool where the temperature and pressure applied activate the PVDF binder on separator material. Binder activation allows the anode and cathode sheet to adhere to the two separators web. The strip of laminated material pass through a separator cut unit, and the output are monocells. A stack of monocells represent the final stack (prismatic cell).
Below you can find a basic process flow and layout:
During the ramp up of production line, we started to analyze the machine data, taking multiple megabyte of file from vision systems installed into the machine.
The purpose of the analysis was to find the main reason of scrap. Make a RCA directly from data to improve the productivity of lithium battery cell production line.
First, we started checking the monocells quality through different production day. We didn’t get any information from there, so we started to look the data of one day of production trying to go deeper.
The standard deviation of the measurement Tab to Tab Distance (TTD) was good compared to Upper Tolerance Limit and Lower Tolerance Limit. But was very clear during the beginning of each sub production run there was something wrong. Indeed in the beginning of each sub production run the standard deviation of TTD was many times higher than for steady condition.
In a pilot production run for lithium battery cell is common to have frequent start and stop, but this shouldn’t affect the overall quality of final monocells or lithium prismatic cells.
We decided to isolate each sub production run to find some kind of common pattern and understand deeply was going wrong with the process.
Every time the machine stop for more than 5 minutes, the monocells between the pre-heaters in lamination unit were out of tolerance for TTD. Indeed, the vision system, was installed exactly 22 monocells from the lamination rollers. The distance between heated lamination rollers and start of pre-heating area was equivalent to 4-5 monocells.
Data showed everytime machine stopped for more than 5 minutes, the monocells between 22th and 27th were out of spec.
So we found why 4-5 monocells for each sub production run were not good. But the analysis didn’t stop there!
We modified the machine PLC code to achieve a target condition. Everytime machine stops for more than 3 minutes, the pre-heaters switch off and the upper side moves up to decrease the heavily the amount of heat trasmit to the material.
This simple data analysis, allows the lithium battery cell maker to decrease the daily scrap rate about 1,2%.
This kind of service could be provided to all lithium battery cell and pack manufacturing company where our experts can easily improve the production performance even by remote.
We are developing tool to collect data and anlyze them automatically reducing the analysis time.
For more information, contact us at info@bonsaitechnology.it