Lithium-ion batteries must be completely free of water (concentration of H2O < 20 mg/kg), because water reacts with the conducting salt, e.g., LiPF6, to form hydrofluoric acid.
The water content of several materials used in lithium ion batteries can be determined reliably and precisely by coulometric Karl-Fischer titration. In this Application Bulletin the determination for the following materials is described:
- raw materials for the manufacture of lithium-ion batteries (e.g., solvents for electrolytes, carbon black/graphite)
- electrode coating preparations (slurry) for anode and cathode coating
- the coated anode and cathode foils as well as in separator foil and in the combined material
- electrolytes for lithium-ion batteries