Contributed Commentary by Johannes Eschenauer, Hitachi High Technologies
June 8, 2023 | Gigafactories have developed quickly to meet the ever-increasing demand for the lithium-ion batteries needed to power electric vehicles. This rapid expansion has created several challenges, including large-scale battery waste and scrappage.
Poor yield-to-defect ratios mean that manufacturing costs remain high, especially in lithium-ion battery production processes, where material defects lead to product scrappage – an avoidable cost had the defects been detected earlier.
This principle applies across the whole manufacturing process. Identifying areas where production can be improved to minimise waste and reduce costs is critical for Gigafactory operators looking to maintain a competitive advantage and improve production yields.
Cost Implications Of Scrappage
The cost of scrappage can be significant, especially for a Gigafactory reliant on high-volume production to maintain profitability. The ratio between the cost of material consumed and sales volumes in lithium-ion battery cell production is approximately 75%. Cell production losses can be high, and a scrap rate of up to 30% is not uncommon due to poor quality.
The cost to Gigafactory operators is significant. For example, at US$100 per kWh, the loss is about US$22.50. For a Gigafactory with a 10 GWhproduction capacity, this equates to an annual cost of US$225 million. This loss of revenue can have a significant impact on the company’s bottom line and its ability to invest in future research and development.
Additionally, scrapped batteries must be disposed of or recycled. These batteries contain toxic chemicals and heavy metals that can be harmful to the environment if not disposed of properly, and disposal is often expensive. As well as the financial burden, companies face potential damage to their reputation if they are seen as operating in a non-sustainable way. As consumers continue to become more environmentally conscious, non-sustainable behaviour can lead to a significant backlash, which can ultimately impact the company’s ability to sell products and generate revenue.
The cost of recycling lithium-ion batteries in a safe, efficient, and environmentally sustainable way is likewise significant and can often be higher than the value of the materials recovered. There are also safety risks if batteries are improperly handled during recycling.
Investing In Materials Analysis
In the long term, investing in better quality control solutions may outweigh the cost of scrappage and allows companies to reduce their environmental impact, improve their reputation, and potentially generate additional revenue from recycled materials.
Improved quality control, particularly of incoming materials, increases yield and reduces waste, for a more sustainable process and lower costs.
Using materials analysis solutions across the production process, Gigafactory operators can easily determine the root cause of battery defects. An effective solution quickly identifies which process and materials are causing the defect, so that the problem can be corrected rapidly and waste product minimised.
100% incoming inspection is needed to prevent contaminated raw materials entering the production process. This is easily achievable with today’s materials analysers.
Complementary Solutions For Quality Control
The key to overcoming the challenges of battery contamination—and the resulting scrappage—lies in managing the number, size, and nature of the contaminants upstream of the production process. Armed with this information, operators can compare it with the defect ratio to improve the process and introduce rapid countermeasures that allow them to increase yield, lower energy consumption, and reduce scrappage.
Two complementary solutions are recommended for effective contaminant monitoring in a Gigafactory. The first is an X-ray particle contaminant analyser that combines X-ray transmission (XRT) and X-ray fluorescence (XRF) technologies in a single device. This instrument can rapidly detect the number, size, and elemental composition of each contaminant – typically within 5-15 minutes. A single two-stage analysis setup allows the analyser to use both technologies seamlessly, measuring multiple samples in the sample jig, with minimum preparation and unattended operation. The analyser can look at a variety of samples, including powders (such as conductive materials, anode/cathode), solids (for example, electrode plates and separators), and slurries. Together, the two technologies can identify defects due to uneven material distribution, clumps, or gaps in anode active material, and separator damage caused by metallic foreign materials. As the analysis is X-ray based, it is a non-destructive technique that leaves the sampled material undamaged.
The second solution is a scanning electron microscope (SEM) which, working alongside an X-ray contaminant particle analyser, provides a complementary analysis to create a detailed picture of material quality. The SEM can detect very small particles and determine the morphology and composition of metallic and non-metallic particles on any substrate. This type of analysis can be automated so that large datasets can be produced quickly and easily, providing thorough insights into the exact state of particulate contamination in the production process. SEM is also used in combination with broad ion beam milling to produce high quality cross-sections through materials. This helps to identify possible flaws in the formed electrode foil and trace them back to the different steps in the production.
One of the key factors in reducing costs and waste in the Gigafactory is overcoming product defects in lithium-ion battery production. Success can be achieved only by selecting the right materials analysers to support the manufacturing process, increase yield, and drive sustainability.
Unless they use a comprehensive monitoring solution to overcome this challenge, Gigafactories will continue to experience high manufacturing costs and poor yield-to-defect ratios, leaving them facing a competitive disadvantage. However, a combination of offline incoming inspection, inline process monitoring, and dust monitoring helps detect contamination before and during the battery manufacturing process, allowing operators to take early action that can significantly reduce scrappage.
Johannes Eschenauer is the EMEA Business Development Manager for Coating Thickness XRF and Battery Particle Contaminant Analyzer of Hitachi High-Tech Analytical Science (HHA), a wholly owned subsidiary of Hitachi High Technologies Inc., based in Tokyo, Japan. With over 35 years’ global experience in capital equipment sales, service & applications he is specialized in XRF for coating thickness systems as well as for XRF in the field of battery particle analyses in the global EV industry. With his deep technical knowledge, he understands the needs of customers and their analytical requirements to save cost and improve yields in their production using the right quality tools. He can be reached at johannes.eschenauer.je@hitachi-hightech.com.
