Method for forming a Li-ion battery cell
A Li-ion battery cell includes cathode and anode materials, a separator, and an electrolyte including a mixture of a polyethylene oxide and an oxide of formula LivLasZnOn. A method of forming the cell includes the following successive cycling steps: (a) at least two successive charge and discharge cycles of the cell at a first cycling rate C/x, the charge/discharge steps being limited in time to x/2; (b) at least two successive charge and discharge cycles of the cell at a second charging rate C/y, different from the first cycling rate, where y is lower than x, the charge/discharge steps being limited in time to y/2; and (c) at least two successive charge and discharge cycles of the cell at a third cycling rate C/z different from the first and second charging rates, where z is lower than x and y, the charge/discharge steps being limited in time to z/2.
1. A method for forming a lithium-ion battery cell comprising a cathode material, an anode material, and a solid electrolyte, the electrolyte comprising a mixture of a polyethylene oxide and an oxide of formula Li 7 La 3 Zr 2 O 12 , the method comprising the following successive cycling steps:
(a) at least two successive charge/discharge cycles of the cell at a first cycling rate C/x, the charge/discharge steps being limited in time to x/2;
(b) at least two successive charge/discharge cycles of the cell at a second charge rate C/y, different from the first cycling rate, where y is lower than x, the charge/discharge steps being limited in time to y/2; and
(c) at least two successive charge/discharge cycles of the cell at a third cycling rate C/z different from the first and second charge rates, where z is lower than x and y, the charge/discharge steps being limited in time to z/2.
2. The method of formation as claimed in claim 1 , wherein the first cycling rate is of C/40 applied for 20 h of charge/discharge.
3. The method of formation as claimed in claim 1 , wherein the second cycling rate is of C/20 applied for 10 h of charge/discharge.
4. The method of formation as claimed in claim 1 , wherein the third cycling rate is of C/10 applied for 5 h of charge/discharge.
5. The method of formation as claimed in claim 1 , further comprising the following cycling step:
(d) at least two successive charge/discharge cycles of the cell at a fourth cycling rate different from the first, second and third charge rates.
6. The method of formation as claimed in claim 5 , wherein the fourth cycling rate is of C/5 applied for 2.5 h of charge/discharge.
7. The method of formation as claimed in claim 5 , further comprising the following cycling step:
(e) at least two successive charge/discharge cycles of the cell at a fifth cycling rate different from the first, second, third and fourth charge rates.
8. The method of formation as claimed in claim 7 , wherein the fifth cycling rate is of C/2 applied for 1 h of charge/discharge.
9. The method of formation as claimed in claim 7 , wherein one or more of the cycling steps (a), (b), (c), (d) and (e) comprise at least five successive charge/discharge cycles of the cell.
10. The method of formation as claimed in claim 1 , wherein the successive cycling steps are carried out at an increasing cycling rate.
11. The method of formation as claimed in claim 1 , wherein the electrolyte comprises lithium bis(trifluoromethanesulfonyl)imide LiTFSI.
12. The method of formation as claimed in claim 1 , wherein the cathode comprises a catholyte comprising a mixture of polyethylene oxide and oxide Li 7 La 3 Zr 2 O 12 .
13. The method of formation as claimed in claim 12 , wherein the catholyte comprises lithium bis(trifluoromethanesulfonyl)imide LiTFSI.
14. The method of formation as claimed in claim 1 , further comprising a cathode comprising a mixture of nickel-manganese-cobalt active material, of carbon black and of catholyte comprising a mixture of polyethylene oxide and of Li 7 La 3 Zr 2 O 12 .