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US-12617696-B2 - Powderous lithium cobalt-based oxide cathode active material powder for rechargeable lithium ion batteries and a method for making thereof

US12617696B2US 12617696 B2US12617696 B2US 12617696B2US-12617696-B2

Abstract

A lithium cobalt-based oxide cathode active material powder having: —a primary phase comprising Li, Co, and O, and—a secondary phase comprising LiNaSO 4 , wherein the content of said LiNaSO 4 secondary phase in said powder is of at least 0.4 wt. % and inferior or equal to 1.1 wt. % with respect to a total weight of the cathode active material powder, said cathode active material powder being characterized in that it has a S/Na atomic ratio superior or equal to 0.80 and inferior or equal to 1.20.

Inventors

  • Jens Paulsen
  • Kyeongse SONG

Assignees

  • UMICORE

Dates

Publication Date
20260505
Application Date
20201201
Priority Date
20191218

Claims (11)

  1. 1 . A lithium-ion secondary battery comprising a lithium cobalt-based oxide cathode active material powder having: a primary phase comprising Li, Co, and O, and a secondary phase comprising LiNaSO 4 , wherein a content of said LiNaSO 4 secondary phase in said lithium cobalt-based oxide cathode active material powder is of at least 0.5 wt. % and inferior or equal to 1 wt. % with respect to a total weight of the lithium cobalt-based oxide cathode active material powder, said lithium cobalt-based oxide cathode active material powder being characterized in that it comprises a S/Na atomic ratio superior to 0.8 and inferior to 1.1.
  2. 2 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , wherein the content of said LiNaSO 4 secondary phase is superior or equal to 0.50 wt. % 0.5 wt. % and of at most 0.65 wt. %.
  3. 3 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , wherein said S/Na atomic ratio is superior or equal to 0.95 and inferior or equal to 1.05.
  4. 4 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , comprising at least one element of the group consisting of Al and Mg.
  5. 5 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , comprising a Li/Co atomic ratio superior or equal to 0.98 and inferior or equal to 1.02.
  6. 6 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , having a first discharge capacity at 4.6V (Li + /Li) of at least 210mAh/g.
  7. 7 . The lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , having a capacity fading rate at 4.6V (Li + /Li) of less than 0.60%/cycle.
  8. 8 . The lithium-ion secondary battery comprising a cathode active material comprising the lithium cobalt-based oxide cathode active material powder of claim 1 .
  9. 9 . A process for manufacturing the lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , comprising the steps of: providing a Co-based precursor powder having a Na content superior to 0.05 wt. % and inferior to 0.30 wt. % with respect to a total weight of said Co-based precursor powder, mixing said Co-based precursor powder with a source of Li, a source of S, and optionally, with a source of M′, so as to prepare a mixture having a Li/Co atomic ratio superior or equal to 0.98 and inferior or equal to 1.02 and a S/Na atomic ratio superior er equal to 0.8 and inferior to 1.1, sintering said mixture at a temperature of at least 850° C. and inferior or equal to 1200° C., during a period of at least 5 hours in an oxygen containing atmosphere, so as to obtain a sintered agglomerated powder, milling said sintered agglomerated powder so as to obtain said lithium cobalt-based oxide cathode active material powder, wherein M′ comprises at least element of the group consisting of: Mg, Al, Ni, Mn, Nb, Ti, W, and Zr.
  10. 10 . A process for manufacturing the lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , comprising the steps of: providing a Co-based precursor powder having a S content superior to 0.05 wt. % and inferior to 0.30 wt. % with respect to a total weight of said Co-based precursor powder and a Na content superior to 0.05 wt. % and inferior to 0.30 wt. % with respect to a total weight of said Co-based precursor powder, mixing said Co-based precursor powder with a source of Li, and optionally, with a source of M′, so as to prepare a mixture having a Li/Co atomic ratio superior or equal to 0.98 and inferior or equal to 1.02 and a S/Na atomic ratio superior to 0.8 and inferior to 1.1, sintering said mixture at a temperature of at least 850° C. and inferior or equal to 1200° C., during a period of at least 5 hours in an oxygen containing atmosphere, so as to obtain a sintered agglomerated powder, milling said sintered agglomerated powder so as to obtain said lithium cobalt-based oxide cathode active material powder, wherein M′ comprises at least element of the group consisting of: Mg, Al, Ni, Mn, Nb, Ti, W, and Zr.
  11. 11 . A process for manufacturing the lithium-ion secondary battery comprising the lithium cobalt-based oxide cathode active material powder according to claim 1 , comprising the steps of: providing a Co-based precursor powder, mixing said Co-based precursor powder with a source of Li, a source of S, and a source of Na, and optionally, with a source of M′, so as to prepare a mixture having a Li/Co atomic ratio superior or equal to 0.98 and inferior or equal to 1.02 and a S/Na atomic ratio superior to 0.8 and inferior to 1.1, sintering said mixture at a temperature of at least 850° C. and inferior or equal to 1200° C., during a period of at least 5 hours in an oxygen containing atmosphere, so as to obtain a sintered agglomerated powder, milling said sintered agglomerated powder so as to obtain said lithium cobalt-based oxide cathode active material powder, wherein M′ comprises at least element of the group consisting of: Mg, Al, Ni, Mn, Nb, Ti, W, and Zr.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Stage application of International Patent Application No. PCT/EP2020/084040, filed on Dec. 1, 2020, which claims the benefit of European Patent Application No. 19217373.0, filed on Dec. 18, 2019. TECHNICAL FIELD AND BACKGROUND This invention relates to a lithium cobalt-based oxide (LCO) cathode active material powder for lithium-ion secondary batteries (LIBs) suitable for (portable) electronic device applications, comprising particles having: a primary phase comprising Li, Co, and O, anda secondary phase comprising LiNaSO4. By LCO cathode active material it is understood in the context of the presented invention that such a material has an atomic ratio of Co to transition metals in said powder is of at least 85 mol %. In the framework of the present invention, it must be understood that if the particles of the LCO material have said primary and secondary phases, that means that the LCO powder has these said primary and secondary phases. Such a cathode active material powder is already known, for instance, from the document US 2017/0179479 A1 which discloses a material having a core comprising the primary phase LiCoO2 and a coating layer on top of the core comprising the secondary phase LiNaSO4. The content of this secondary phase in the cathode active material powder varies in a range defined from 0.5 wt. % to 5 wt. % with respect to the total weight of the cathode active material powder. The cathode active material powder of US 2017/0179479 A1 presents a first discharge capacity (DQ1) of 217.6 mAh/g and a capacity fading rate (QF) of 0.79% per cycle obtained by the analytical methods of the present invention. The capacity fading rate (QF) per cycle should be improved. WO2018/162165 also discloses a LCO cathode active material comprising 1.26 wt. % LiNaSO4 and showing DQ1 of 204.6 mAh/g and QF of 0.69%/cycle. WO2018/162165 teaches to wash said LCO cathode active material. Water-washed LCO material according to this document comprises 0.05 wt. % LiNaSO4 and shows poor cycle life. It is therefore an object of the present invention to provide a LCO cathode active material powder for lithium-ion secondary batteries, having subsequently an improved DQ1 of at least 210 mAh/g and an improved QF of at less than 0.60% per cycle obtained by the analytical methods of the present invention. SUMMARY OF THE INVENTION This objective is achieved by providing a lithium cobalt-based oxide cathode active material powder according to claim 1, wherein the particles have a S/Na atomic ratio superior or equal to 0.80 and inferior or equal to 1.20. It is indeed observed that an improved DQ1 of higher than 210 mAh/g and an improved QF of lower than 0.60%/cycle, as illustrated in the results provided in Table 2, are achieved in a LIBs using a LCO cathode active material powder according to EX1.1 having the following features: an amount of a LiNaSO4 compound of 0.54 wt. % with respect to the total weight of the cathode active material powder, anda S/Na atomic ratio of 1.01. In the framework of the present invention, it must be understood that if the particles of the LCO material have the claimed range(s) of (wt. %) amounts of said LiNaSO4 compound and the claimed range(s) of S/Na atomic ratios, that means that the LCO powder has these claimed ranges of (wt. %) amounts of said LiNaSO4 compound and S/Na atomic ratios. The cathode active material powder comprises a LiNaSO4 compound superior or equal to 0.4 wt. % and inferior or equal to 1.1 wt. % with respect to the total weight of the cathode active material powder. If the amount of the LiNaSO4 compound is less than 0.4 wt. % or higher than 1.1 wt. %, DQ1 decreases and the cycle life deteriorates. In the framework of the present invention, the primary phase comprises Li, Co, and O. The primary phase has a first own crystalline structure (monocrystalline or polycrystalline). The secondary phase comprises LiNaSO4. The secondary phase has a second own crystalline structure (monocrystalline or polycrystalline). The second compound is distinct from the first compound. The present invention concerns the following embodiments: Embodiment 1 In a first aspect, the present invention concerns a lithium cobalt-based oxide (LCO) cathode active material powder for lithium-ion secondary batteries (LIBs) suitable for (portable) electronic device applications, comprising: a primary phase comprising Li, Co, and O, anda secondary phase comprising LiNaSO4, wherein preferably said material has an atomic ratio of Co to transition metals in said powder is of at least 85 mol %. The content of said LiNaSO4 secondary phase in said powder is of at least 0.4 wt. % and inferior or equal to 1.1 wt. % with respect to a total weight of the cathode active material powder particles and S/Na atomic ratio superior or equal to 0.80 and inferior or equal to 1.20. Preferably, in the Embodiment 1, the content of the LiNaSO4 secondary phase is superio