Method for producing a non-aqueous secondary battery
A non-aqueous secondary battery production method is provided. The method comprises constructing a preconditioning cell that comprises a positive electrode comprising a positive electrode active material, a preconditioning electrolyte solution comprising a supporting salt and a fluorine-containing non-ionic compound, and a preconditioning negative electrode (step S 110 ); of carrying out a preconditioning process by charging the preconditioning cell and allowing the fluorine-containing non-ionic compound to be decomposed at the positive electrode to form coatings on surfaces of the positive electrode active material (step S 120 ); and of constructing a non-aqueous secondary battery, using the coated positive electrode active material, a non-aqueous electrolyte solution different from the preconditioning electrolyte solution, and a negative electrode comprising a negative electrode active material (step S 130 ).
1. A method for producing a non-aqueous secondary battery comprising:
constructing a preconditioning cell that comprises a positive electrode comprising a positive electrode active material, a preconditioning electrolyte solution comprising a supporting salt and a fluorine containing non-ionic compound, and a preconditioning negative electrode;
carrying out a preconditioning process by charging the preconditioning cell and allowing the fluorine-containing non-ionic compound to be decomposed at the positive electrode to form coatings on surfaces of the positive electrode active material; and
constructing a non-aqueous secondary battery, using the positive electrode active material having the coatings formed, a non-aqueous electrolyte solution different from the preconditioning electrolyte solution, and a negative electrode comprising a negative electrode active material.
2. The method according to claim 1 wherein the preconditioning electrolyte solution comprises a fluorine-containing carbonate as the fluorine-containing non-ionic compound.
3. The method according to claim 1 wherein the preconditioning electrolyte solution comprises a fluorine-containing cyclic carbonate as the fluorine-containing non-ionic compound.
4. The method according to claim 1 wherein the preconditioning electrolyte solution comprises at least one of transdifluoroethylene carbonate and mono-fluoroethylene carbonate as the fluorine-containing non-ionic compound.
5. The method according to claim 1 wherein the nonaqueous electrolyte solution used for constructing the non-aqueous secondary battery comprises a supporting salt and a non-aqueous solvent, with the non-aqueous solvent consisting essentially of a fluorine-free non-ionic compound.
6. The method according to claim 1 wherein, in the preconditioning process, the fluorine-containing non-ionic compound is allowed to be decomposed with the positive electrode being at a potential above 4.3 V versus lithium metal.
7. The method according to claim 1 wherein the battery is the non-aqueous secondary battery in which the positive electrode operates at a potential above 4.3 V versus lithium metal.
8. The method according to claim 1 wherein the positive electrode active material comprises a spinel lithium nickel manganese oxide.
9. A non-aqueous secondary battery produced by the method according to claim 1 .
10. A power-supply unit comprising
a non-aqueous secondary battery according to claim 9 , and
a control circuit that is electrically connected to the battery and controls at least the upper voltage limit of the battery, wherein
the upper voltage limit is set at a level that allows the positive electrode of the battery to reach a potential above 4.3 V versus lithium metal.