Precision for battery production

battery production

Australia’s battery industry contributes to approximately $1.3 billion of annual GDP.

Bestech Australia tells Manufacturers’ Monthly about how optimising battery production requires the best sensors to monitor measurement tasks.

There are a growing number of activities to support the development and commercialisation of green, zero emission energy technologies such as solar, wind, carbon capture and storage (CCS) and hydrogen. Renewable energy technology has potential as clean alternatives to fossil fuel because it has the capability to generate energy with reduced total emissions of greenhouse gases. The major challenge in using renewables as a main energy source is to keep the electricity running reliably when the source is unavailable.

Energy storage systems such as lithium-ion batteries have been developed for more flexible utilisation of alternative energy. When used for home energy storage, this allows the consumers to have a greater control and full advantage of the solar energy that they generate from their solar panels. They have also been used for electric vehicles and other battery-powered applications.

Locally, the Australian battery industry contributes to approximately $1.3 billion of annual GDP and supports 6000 jobs. We are one of the highest producers of battery materials like lithium and other key metals. However, these raw materials have been processed overseas to produce battery-grade materials which were then exported back to Australia, surging the price of locally-made batteries. It is more economically feasible to outsource manufacturing to countries with cheaper workforces that already specialise in battery technology.

Australia has seen uptakes in the manufacturing of large-scale batteries and household batteries to accelerate the deployment of renewable energy future. This behaviour has seen more interest to bring the manufacturing of battery technology locally. Bringing the manufacturing home also provides more opportunities for local employment and supports the local economy, but the feasibility of local manufacturing relies on our capability to reduce costs while maximising the energy storage density and its operating life.

With fully-automated, precision manufacturing system to streamline production, it will bring down the manufacturing cost and make the technology market-competitive. Optimising battery production requires sensors to monitor measurement tasks during production like electrode manufacturing, assembly and forming processes.

The key control parameter in battery manufacturing is the thickness of film, wet layers and coatings on the electrodes. It is crucial for manufacturers to meet these specifications as per their customer’s requests while optimising production yield and minimising waste. Still, there are measurement challenges for manufacturers to ensure that they can reliably meet these standards.

In-line measurement system is an effective approach used for continuous measurement. It allows the control system to alter the processing parameters to bring the thickness back to the acceptable range if it deviates from the specification limit.

Factors to consider in thickness measurement

A key factor to consider with inline thickness measurement is to select the systems based on accuracy. The performance of the measurement systems can be affected by various factors like environmental influences and sensors accuracy, which altogether create significant combined error.

The sensors must also be perfectly aligned and installed at the direct opposite end of one another. This configuration is to ensure the same measuring spots at all times as a slight degree of misalignment in the sensor position can contribute to measurement errors. This error will be further amplified if the target moves in the measurement field.

After both sensors are perfectly aligned, it is also crucial to synchronise them so that they perform the measurement at the same time and exactly opposite each other. If synchronisation does not occur, it will definitely produce erroneous results as the measurements are taken at different positions of the products which can be prone to error due to micro-vibration or the sensors itself. This is because each sensor has slightly different linearity which varies by percentage of its measuring range.

Once the measurement systems are addressed, manufacturers still need to consider the best technique to mount the sensors as the mounting frame must be isolated from any source of vibration to achieve stable and reliable measurement. The mounting frame must be made from materials with minimum thermal expansion to minimise the movement of sensors due to the variation in temperature.

The above-mentioned challenges can be addressed by using a smart, integrated algorithm to address the source of errors. An integrated automated thermal compensation is implemented to eliminate errors due to the expansion of materials. Regular calibration of sensors can be performed to minimise the non-linearity errors.

Non-contact displacement measurement sensors such as single point laser sensors and confocal sensors provides high resolution and precision measurements that can measure the slightest deviations down to nanometer resolution. The ultra-high precision confocal systems can also provide high speed measurement suitable for inline production environment.

Measurement of other parameters in battery applications

Combining more than 40 years of industrial experiences, engineers at Bestech Australia provide rich expertise in high precision testing applications.  Not only thickness measurement, but technologies that enable reliable measurement of other geometric parameters: edge, gaps, profile as well as physical parameters such as temperature and many more. These operating parameters should be precisely controlled and monitored to optimise the manufacturing process.

For example, optical laser profile scanners can be used to measure the edge curvature and deformations that occurs during cutting of the coating film. They can also be used to inspect the quality and uniformity of the coating process to detect undulations or defects.

Continuous thermal monitoring during initial charging and discharging of batteries is crucial to understand the temperature distribution inside the cell to identify faults such as short circuiting. Non-contact sensors such as thermal imaging cameras or pyrometers are best used for temperature measurement tasks in production environment as the measurement do not interfere with the process, leading to ease of control and integration. Thermal imagers can also provide multiple measuring fields simultaneously and can be integrated with the control system to activate control response if the measurement exceeds the set limit values.

Choose partners, not products

The drive for advanced renewable energy technology is expected to trend upwards to scale-back our emission of greenhouse gases. Commercialisation of these new technologies will require approval from the regulatory board and passing complex testing procedures to ensure that the products are fit for market.

Measurement technology has tremendously advanced in the last few years, with sensors available for all types of measurement applications. As a user, the challenge is to know what types of systems are suitable for the intended applications. It is difficult to find the ideal systems for all available products and it is easier to consult measurement specialists for assistance.

Bestech Australia have established successful partnership with researchers and local manufacturers to support all their testing and measurement needs. The company supplies not only products, but also provides full local technical support from system design, testing and commissioning.

The supplied high precision sensors, measurement and inspection systems from Micro-Epsilon for testing applications in the manufacturing are for the modern battery. They offer the largest range of precision industrial sensors for automation and R&D applications.

Not just Micro-Epsilon, but Bestech has also established long-standing collaborative relationship with all our suppliers and combine this partnership with its local expertise to back local manufacturing and testing capability.