Process for realizing an electrode based on vanadium oxide and battery comprising such an electrode
AssigneeSTMicroelectronics S.r.l.
InventorSami Oukassi
Life of this patent
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Abstract
A process for realizing a positive electrode of a lithium-ion battery utilizes deposition by cathode sputtering in several steps. Two successive deposition steps are separated by a cooling of the electrode during its realization, a first intermediate step of sputtering the target without introducing oxygen, and a second intermediate step of sputtering the target while introducing oxygen. The electrode obtained is of amorphous vanadium oxide and exhibits good capacity and reversibility.
Claims23
A process for realizing an electrode based on vanadium oxide, comprising:
- performing at least three deposition steps (D), each deposition step accomplished by cathode sputtering of a vanadium-based metal target by means of a plasma containing argon and oxygen, and powered by a discharge of alternating current;
- and
- wherein two successive deposition steps (D) are separated by:
- (A) cooling of the electrode being realized to a temperature of less than 50° C.;
- (B) first intermediate sputtering of the target without introducing oxygen into the plasma, for a first duration of more than 2 minutes;
- and
- (C) second intermediate sputtering of the target in the presence of oxygen, for a second duration of more than 2 minutes;
- wherein steps (B) and (C) are realized while the electrode is isolated from atoms originating from the target.
A lithium-ion battery comprising:
- a positive electrode formed of a thin film based on amorphous vanadium oxide;
- a negative electrode;
- and
- an electrolyte placed between said positive and negative electrodes;
- wherein said battery has a discharge capacity greater than 45 microampere.hours per square centimeter of positive electrode surface area and per micrometer of positive electrode thickness, for a discharge current substantially equal to 10 microamperes per square centimeter of positive electrode surface area and after 25 first charge and discharge cycles of the battery, with each cycle realized by varying an output voltage of said battery over a 2.3 Volt interval.
A process for realizing a positive electrode of a lithium-ion battery, comprising:
- deposition by cathode sputtering in several steps;
- wherein two successive deposition steps are separated by:
- cooling of the electrode;
- a first intermediate sputtering without introducing oxygen;
- and
- a second intermediate sputtering while introducing oxygen.
Dependencies are inferred from the claim text.