Image: © romaset / Adobe Stock
HSSMI has teamed up with AMTE Power, University College London, and JW Froehlich, in the new Innovate UK funded project AcouBat (Acoustic test for Batteries), which will use novel battery testing processes to progress towards next generation production assurance and ensure the delivery of high-quality and competitive UK products in a high-volume manufacturing environment.
Existing battery testing methods focus on mechanical and electrical in-line testing to qualify the battery joints and connections. This approach is helpful for ensuring quality product delivery, but it is unable to establish the overall electrochemical state of the battery components. At present, these can only be measured offline statistically or in lengthy cycle testing.
Over the past three years, University College London has been developing a novel acoustic test method as part of the Faraday Battery Challenge Round 1 project VALUABLE. The aim of AcouBat is to test this method in a practical setting – on AMTE Power’s cell manufacturing line. This validation is vital in order to commercialise the acoustic testing solution and boost battery production in the UK. Throughout the project, the consortium will also seek to reduce overall lithium-ion cell production time and cost, while maintaining or improving quality.
About the Acoustic Test Method
The speed at which sound travels through a material, and how much it is attenuated, is dependent on the physical properties of that material. The changes occurring to these properties as cells are charged or discharged allows for ultrasonic methods to be used to track cell performance. The acoustic test method provides a cheap, non-invasive and highly sensitive way to monitor the state of charge (SoC) and state of health (SoH) of batteries. It is applicable to a wide range of battery chemistries and can be used to determine if cell damage is occurring under test conditions and potentially to predict cell failure.
This non-destructive testing enables quality assurance processes to be implemented throughout the production line, from initial electrode creation to internal analysis of the completed cell. Inline acoustic testing is able to detect faulty cells or poor electrode coatings before the cells are formed or installed into a battery pack, stopping errors at source and preventing their progress through the entire production line. This early “no faults forward” catchment process also leads to tighter performance tolerances, improved battery pack life and significantly safer cells.
The Role of HSSMI
Alongside the physical validation of the acoustic testing method on the AMTE Power production line, a digital simulation of the testing facility will be created by HSSMI. The simulation will help determine where to implement inline testing on the production line in order to optimise the process, thereby reducing the number of machines and cycle time required. Ultimately, the work of HSSMI in AcouBat will produce a roadmap for the scale up of the test facility, as AMTE Power aims to introduce this testing approach in a Gigafactory in the next few years.
“We are very excited about this new project and work with AMTE Power, JWF and UCL. The AcouBat project will enhance HSSMI’s expertise in battery testing and manufacturing, as well as develop more skills in Anylogic simulation, which is closely related to our scale-up and improved productivity expertise,” says Ibon Terrazas, project manager for AcouBat and HSSMI Engineer for Electric Drives.