Method for forming a Li-ion battery cell comprising an LNMO cathode material
A process forms a Li-ion battery cell including an LNMO-based cathode material, an anode material, a separator and an electrolyte. The process successively includes charging the cell until the cell reaches a state of charge of 100%, storing the cell in the state of charge of 100% in an open circuit for a period of time of at least 48 hours, and removing gas generated during the charging and the storage.
1. A process for forming a Li-ion battery cell comprising an LNMO-based cathode material comprising an active material of formula LiNi x Mn 2-x O 4 in which 0<x≤0.5, an anode material, a separator and an electrolyte, the process comprising the following successive steps:
charging a Li-ion battery cell having a charge of less than 100% until the Li-ion battery cell reaches a state of charge of 100%;
storing the Li-ion battery cell in the state of charge of 100% in an open circuit for a period of time of at least 48 hours; and
removing gas generated during the charging and the storing,
wherein, when a volume of the gas generated is below a threshold, the removing of the gas is followed by charging the Li-ion battery cell until the Li-ion battery cell reaches the state of charge of 100%, and then the Li-ion battery cell is discharged until it reaches a state of charge of between 20% and 50%.
2. The process as claimed in claim 1 , wherein the storing is carried out at room temperature.
3. The process as claimed in claim 1 , further comprising:
discharging the Li-ion battery cell until the Li-ion battery cell reaches a state of charge of between 10% and 0%; and
storing, after the discharging, the Li-ion battery cell in the state of charge of between 10% and 0% in an open circuit at room temperature.
4. The process as claimed in claim 1 , wherein the charging, the storing, and the removing are repeated at least a second time.
5. The process as claimed in claim 1 , wherein the period of time for the storing is at least equal to one week.
6. The process as claimed in claim 1 , wherein the period of time for the storing is at least equal to two weeks.
7. The process as claimed in claim 1 , wherein the period of time for the storing is at least equal to four weeks.
8. The process as claimed in claim 1 , further comprising:
measuring a volume of the gas generated during the storing.
9. The process as claimed in claim 1 , further comprising, prior to the charging:
activating the Li-ion battery cell by injecting the electrolyte into the Li-ion battery cell; and
impregnating the electrolyte in an open circuit for 48 hours at room temperature.
10. The process as claimed in claim 1 , wherein:
the storing is carried out at a temperature of between 15 and 45° C.; and
the period of time for the storing is less than or equal to two weeks.