Electrochemical Testing of Cathode Active Material in Standard Cell Formats

Supervisors: Dr. Marvin Gernhardt & Dr. Michael Horn

As part of the National Battery Strategy, the Australian Government has planned to invest over $500 million into domestic battery production. The QUT Energy Storage Research Group (ESRG) plays a key role in supporting the emerging Australian battery industry by developing and testing commercially relevant lithium-ion battery materials. This project focuses on building Australian capability to qualify new battery materials for commercial use. This process follows a well-defined series of cell scale-up stages. This VRES project highlights the importance of this development cycle using a case study on a particular Cathode Active Material (CAM), NCM-90, which consists of 90% Nickel as well as Cobalt and Manganese. We aimed to test the CAM in 4 different cell formats, with each subsequent format being closer to a commercial lithium-ion battery. The battery formats range from half-coin cells to multi-layered pouch cells, similar to those in smartphones. By using this case study as an example, I explain how scaling up from coin cells to pouch cells introduces specific factors at each stage crucial for understanding battery performance. These factors cumulatively determine whether a given CAM is relevant for commercial use. The results show that: 1) the electrical capacity (EC) delivered by NCM-90 decreases by approximately 4% in each subsequent cell format due to increasing cell complexity and 2) the NCM-90 did not strictly obey the anticipated positive correlation between Nickle content and EC, as a previous NCM-83 (83% Nickel) delivered more EC on average than the NCM-90. Due to time constraints, the material was not tested in the final cell format. Based on previous data, however, we expect the EC in the multi-layer pouch cells to be similar to other cells. In conclusion, the results highlight the need to individually test CAMs and upscale them through different cell formats to accurately determine their capability in real world batteries.