Mobile storage of electrical energy with high-performance batteries represents one of the key technologies for energy supply in the 21st century. The high power and energy density, good cycle stability and service life make lithium-ion batteries optimal candidates for use in hybrid and electric vehicles.
However, especially in the production process, large-format lithium-ion cells are extremely susceptible to failure even in the event of the smallest defects. Although the process parameters are already precisely documented during production, many faults are only detectable when the battery is in use. Monitoring the battery's inner workings during formation and use is currently not possible, or only possible to a very limited extent, but would be of great advantage. In the Smart-LiB project funded by the Baden-Württemberg Ministry of Economics, lithium-ion cells in PHEV-1 format were equipped with internal sensors (T, V) for the first time and subjected to a load test. The collected sensor data could be transmitted wirelessly to an external receiver via an infrared transmitter and thus the "state of health" of the cell (SOH, State-of-health) could be monitored in real time. This opens up new possibilities for detecting critical battery conditions at an early stage and avoiding failure in the field.