method for forming a Li-ion battery cell equipped with a positive electrode comprising a sacrificial salt

The invention relates to a method for forming a Li-ion battery cell comprising a positive electrode material having a porosity rate of 20 to 35% and comprising at least one sacrificial salt, a negative electrode material, a separator and an electrolyte, comprising the following successive steps: (a) heating the cell to a temperature T of from 30 to 45 ° C; (B) charging the cell until a lower or equal potential to 4.8 V, preferably ranging from 4.6 to 4.8 V, more preferably from 4.7 to 4.8V.