A novel, game-changing analytical method using a graphene-based magnetic sensor makes the battery mapping process more efficient and accurate.

Li-ion battery designs are constantly evolving, and efforts are being made to speed up charge times and pack more energy storage capacity into more compact spaces. But for battery manufacturers, recyclers and distributors to take advantage of the business opportunities this technology offers, they need access to detailed data on the batteries they develop for their customer base. This will help them differentiate their products, ensure higher levels of quality and reliability, increase yields, and increase sales revenue.

Currently, the technologies available to perform battery analysis are sub-optimal, creating a significant barrier for suppliers. A new, more advanced method is required to be studied in detail, which hopefully can be quick, simple and cost-effective.

Basically what battery manufacturers and recyclers want is:

Manufacture of high-quality products with a competitive advantage.

Continuously high production to meet customer demand with minimal downtime.

Improve operational efficiency by controlling costs and increasing profitability.
Earn a reputation for the best battery performance and quality.graphene battery
How much better battery mapping will make a difference

Detailed battery mapping will serve multiple purposes. Based on battery data that manufacturers integrate into batteries, they will be able to better understand what's going on inside those cells without having to rely on theoretical modeling.

During the initial stages of development, battery manufacturers typically evaluate batteries from different suppliers. They will observe current density data for better understanding of the performance integrated into the battery. This will allow them to see how long these batteries can run while ensuring safe operation (avoiding thermal runaway, etc.). If they experimented with a new design, they hoped to see how the battery in use would be affected. Ultimately, once in full production, end-of-line testing is required to check that the desired quality is achieved.

On top of that, the recycling business has been growing and companies need better battery analysis. When the capacity of those batteries in electric vehicles drops to 75 to 80 percent of their original capacity, then those batteries will be repurposed. These batteries can be used in home solar panel systems or in peak shaving installations such as commercial premises, schools or hospitals. However, before battery recyclers resell these batteries, received batteries must be carefully inspected to assess their suitability for secondary use. This will allow them to identify any barriers to energy storage and identify safety issues that need to be addressed.

Currently, the analysis of Li-ion batteries is derived either by measuring current density indirectly through temperature sensors distributed around the battery, or by measuring the current flowing in and out of the battery through shunt resistors connected to the bus. However, the data obtained from these methods provide an incomplete picture.

Meaningful data from the temperature sensor takes longer because detecting temperature changes requires larger changes in current density. Current measurement through shunt resistors also has disadvantages, as these devices can only be placed at certain points in the battery. This means that overall visibility into battery performance is very limited and it runs slower, increasing downtime when test equipment fails.
High-resolution real-time data

The graphene-based magnetic sensor employs a different approach to cell mapping. This method overcomes the shortcomings of traditional technology and can see the internal dynamics of the battery more precisely. Through the entire supply chain, you can see that battery suppliers, battery manufacturers, and battery recyclers can all benefit. Paragraf is a company dedicated to developing graphene-based magnetic sensors.

Paragraf's Graphene Hall Sensor (GHS) is derived from a proprietary direct deposition process that avoids contamination and structural integrity issues. The sensing element in GHS consists of a graphene monolayer that is only 0.34 nanometers thick. The 2D nature of these sensing elements eliminates the 'Planar Hall Effect' that exists in conventional 3D silicon-based Hall sensors. Therefore, the performance of GHS is not affected by stray in-plane electromagnetic fields. Due to the high magnetic field resolution that can be achieved, even relatively small changes in current density can be detected very quickly. This means that the magnetic field produced at the particle level can be measured to determine any current density fluctuations in real time.

Due to the size or functionality of the shunt resistor and fluxgate devices, which may be limited by mounting, the compactness of the GHS sensor can significantly improve space accuracy (the sensing element occupies only 1.3 mm²). This makes it easier to place these sensors at multiple different points throughout the battery, enabling a more comprehensive assessment of the battery. The GHS approach also provides greater built-in redundancy. If the sensor fails, the rest of the system can continue to work. Only this faulty sensor node needs to be replaced, not all nodes, like a shunt resistor.
BMSGHS is a solution for all key players in the battery supply chain. Battery dealers can map through GHS during the research phase, so they can ensure that the current is distributed evenly across the battery and that there are no hot spots or other anomalies. Once the cells are integrated, battery manufacturers can do a survey. Once the data is integrated, manufacturers can provide valuable information with partner battery distributors. This feedback loop allows manufacturers to collaborate with suppliers to innovate and develop products based on market needs.

Recyclers also benefit by completing the testing process faster. They can use less time to identify batteries they want to reuse. Batteries can be distributed to customers faster, resulting in faster revenue generation. In addition, with better understanding of the parameters, tolerances, etc. of these batteries, a large percentage of the batteries will be reusable. Recyclers are more confident in the quality of the products they sell and open up potential new markets for them.