Electrode-forming composition

Patent metadata

Field	Value
Publication number	US-2017350015-A1
Application number	US-201515536128-A
Country	US
Kind code	A1
Filing date	Dec 18, 2015
Priority date	Dec 19, 2014
Publication date	Dec 7, 2017
Grant date	—

Abstract

The present invention pertains to an electrode-forming composition comprising: (a) at least one fluoropolymer [polymer (F)]; (b) particles of at least one active electrode material [particles (P)], said particles (P) comprising: —a core comprising at least one active electrode compound [compound (NMC)] of formula (I): Li[Li x (A p B Q C w ) 1-x ]O 2 (I) wherein A, B and C, different from each other, are selected from the group consisting of Fe, Ni, Mn and Co, x is comprised between 0 and 0.3, P is comprised between 0.2 and 0.8, preferably between 0.2 and 0.5, more preferably between 0.2 and 0.4, Q is comprised between 0.1 and 0.4, and W is comprised between 0.1 and 0.4, and —an outer layer consisting of a metal compound [compound (M)] different from Lithium, said outer layer at least partially surrounding said core; and (c) a liquid medium [medium (L)]. The present invention also pertains to a process for manufacturing said electrode-forming composition, to the use of said electrode-forming composition in a process for manufacturing a positive electrode and to the positive electrode obtainable therefrom.

First claim

1 . An electrode-forming composition comprising:
(a) at least one fluoropolymer [polymer (F)]; (b) particles of at least one active electrode material [particles (P)], said particles (P) comprising:
a core comprising at least one active electrode compound (NMC) of formula (I):
Li[Li x (A P B Q C W ) 1-x ]O 2   (I)

wherein A, B and C, different from each other, are selected from the group consisting of Fe, Ni, Mn and Co, x is comprised between 0 and 0.3, P is comprised between 0.2 and 0.8, Q is comprised between 0.1 and 0.4, and W is comprised between 0.1 and 0.4, and
an outer layer consisting of a metal compound (M), said compound (M) consisting of one or more metals selected from the group consisting of Ru, Ti, Cd, Tl, Pb, In, Al, Ti, Cu, Ni, Pd, V, Fe, Cr, Mn, Co, Mo, W, Ag, Au, Pt, Ir, Ru, Pd, Sn and Ga,
said outer layer at least partially surrounding said core; and (c) a liquid medium (L).

2 . The electrode-forming composition according to claim 1 , wherein polymer (F) is a vinylidene fluoride (VDF) polymer [polymer (VDF)] comprising:
(aa) at least 50% by moles of recurring units derived from vinylidene fluoride (VDF); (bb) optionally, from 0.1% to 20% by moles of a fluorinated monomer different from VDF; and (cc) optionally, from 0.1% to 10% by moles, based on the total amount of monomers (aa) and (bb), of at least one hydrogenated monomer.

3 . The electrode-forming composition according to claim 2 , wherein polymer (F) is a polymer (VDF) comprising recurring units derived from vinylidene fluoride (VDF) and from at least one (meth)acrylic monomer (MA) of formula (II):

wherein:
R 1 , R 2 and R 3 , equal to or different from each other, are independently selected from a hydrogen atom and a C 1 -C 3 hydrocarbon group, and
R X is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group.

4 . The electrode-forming composition according to claim 1 , wherein compound (NMC) is of formula (I-A):
Li[Li x′ (Ni P′ Mn Q′ Co W′ ) 1-x′ ]O 2   (I-A)
wherein x′ is comprised between 0 and 0.3, P′ is comprised between 0.2 and 0.8, Q′ is comprised between 0.1 and 0.4, and W′ is comprised between 0.1 and 0.4.

5 . The electrode-forming composition according to claim 4 , wherein compound (NMC) is of formula (I-B):
Li[Li x″ (Ni P″ Mn Q″ Co W″ ) 1-x″ ]O 2   (I-B)

wherein x″ is equal to 0, P″ is comprised between 0.2 and 0.8, Q″ is comprised between 0.1 and 0.4, and W″ is comprised between 0.1 and 0.4, with the proviso that the sum (P″+Q″+W″) is equal to 1.

6 . The electrode-forming composition according to claim 1 , wherein compound (M) consists of one or more metals selected from the group consisting of Ni, Cu, Al, Ag and alloys thereof.

7 . The electrode-forming composition according to claim 1 , said composition further comprising at least one electroconductivity-imparting additive.

8 . The electrode-forming composition according to claim 1 , wherein medium (L) comprises water.

9 . The electrode-forming composition according to claim 1 , wherein medium (L) comprises at least one organic solvent (S).

10 . A process for manufacturing the electrode-forming composition according to claim 1 , said process comprising mixing at least one polymer (F), the particles (P) and, optionally, one or more other ingredients, in a medium (L), wherein the particles (P) are manufactured by electroless plating.

11 . The process according to claim 10 , wherein mixing of at least one polymer (F), particles (P) and, optionally, one or more other ingredients in a medium (L) is carried out by means of a roll kneader, a mixer, a homo mixer, a ball mixer, or a bead mill.

12 . A process for manufacturing a positive electrode, said process comprising:
(i) applying the electrode-forming composition according to claim 1 onto at least one surface of a current collector thereby providing a film; and (ii) drying the film provided in step (i).

13 . The process according to claim 12 , wherein the electrode-forming composition is applied by a conventional wet coating process selected from the group consisting of screen printing, coating using a roll coater, a blade coater, a slit coater, a curtain coater, a wire coater, a sprayer, a foam applicator and a brush coater.

14 . A positive electrode obtainable by the process according to claim 12 .

15 . An electrochemical device comprising the positive electrode according to claim 14 .

16 . The electrode-forming composition according to claim 1 , wherein P is comprised between 0.2 and 0.4.

17 . The electrode-forming composition according to claim 2 , wherein polymer (VDF) comprises:
(aa) at least 80% by moles of recurring units derived from vinylidene fluoride (VDF); (bb) optionally, from 0.1% to 10% by moles of a fluorinated monomer different from VDF; and (cc) optionally, from 0.1% to 3% by moles, based on the total amount of monomers (aa) and (bb), of at least one hydrogenated monomer.

18 . The electrode-forming composition according to claim 2 , wherein the fluorinated monomer different from VDF is a fluorinated monomer selected from the group consisting of vinylfluoride (VF1), chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), tetrafluoroethylene (TFE), perfluoromethylvinylether (MVE), trifluoroethylene (TrFE) and mixtures thereof.

19 . The electrode-forming composition according to claim 4 , wherein P′ is comprised between 0.2 and 0.4.

20 . The electrode-forming composition according to claim 7 , said composition further comprising at least one electroconductivity-imparting additive, preferably selected from the group consisting of carbon black, graphene or carbon nanotubes, powders and fibers of metals, including nickel and aluminium.

Assignees

• Solvay Specialty Polymers It

Inventors

• Cojocaru Paula
• Triulzi Francesco Maria
• Apostolo Marco
• Biso Maurizio

Classifications

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• C23C18/1635

  Composition of the substrate · CPC title

• H01M4/0419

  involving spraying · CPC title

• C23C18/1639

  Substrates other than metallic, e.g. inorganic or organic or non-conductive · CPC title

• C23C18/1875 Primary

  only one step pretreatment · CPC title