Electrochemical cell for lithium accumulator comprising a specific negative electrode made of metallic lithium and a positive electrode on aluminium collector

Patent metadata

Field	Value
Publication number	US-2020220201-A1
Application number	US-202016732866-A
Country	US
Kind code	A1
Filing date	Jan 2, 2020
Priority date	Jan 3, 2019
Publication date	Jul 9, 2020
Grant date	—

Abstract

An electrochemical cell for a lithium accumulator comprising: a negative electrode comprising metallic lithium as active material; a positive electrode associated with an aluminium current collector; and an electrolyte placed between the negative electrode and the positive electrode, wherein the negative electrode is provided with a layer comprising a compound containing aluminium at its face in contact with the electrolyte, and in that the electrolyte comprises at least one lithium salt chosen from among lithium imidide, lithium triflate, lithium perchlorate salts and mixtures thereof.

First claim

1 . Electrochemical cell for lithium accumulator comprising:
a negative electrode comprising metallic lithium as active material; a positive electrode associated with an aluminium current collector; and a liquid or gel electrolyte placed between said negative electrode and said positive electrode, characterised in that the negative electrode is provided at its face in contact with the electrolyte with a layer comprising a compound containing aluminium, said compound being an aluminium salt, and in that the electrolyte comprises at least one lithium salt chosen from among lithium imidide, lithium triflate, lithium perchlorate salts and mixtures thereof.

2 . Cell according to claim 1 , wherein the positive electrode comprises as active material, an active material chosen from among lithiated phosphates comprising at least one metallic transition element, lithiated oxides comprising at least one metallic element, lithium based metal sulfides, vanadium oxides, disulfides based on at least one metallic transition element, elementary sulfur and mixtures thereof.

3 . Cell according to claim 2 wherein, when the active material is a lithiated phosphate comprising at least one metallic transition element, it corresponds to a lithiated phosphate with formula LiM 1 PO 4 , wherein M 1 is chosen from among Fe, Mn, Ni, Co and mixtures thereof.

4 . Cell according to claim 2 wherein, when the active material is a lithiated oxide comprising at least one metallic transition element, it corresponds to a lithiated oxide comprising nickel, cobalt, manganese and/or aluminium.

5 . Cell according to claim 4 , wherein the lithiated oxide comprising nickel, cobalt, manganese and/or aluminium satisfies the following formula:
Li i+x M 2 O 2 wherein M 2 is an element chosen from among Ni, Co, Mn, Al and mixtures thereof and x is greater than or equal to 0.

6 . Cell according to claim 2 wherein, when the active material is a lithium based metal sulfide, it corresponds to a lithium based metal sulfide of the “rock-salt” type, such as Li 2 TiS 3 or Li 3 NbS 4 .

7 . Cell according to claim 2 wherein, when the active material is a vanadium oxide, it corresponds to vanadium oxide V 2 O 5 .

8 . Cell according to claim 2 wherein, when the active material is a disulfide based on at least one metallic transition element, it corresponds to a crystallising disulfide in a pyrite type crystalline system, such as FeS 2 , TiS 2 .

9 . Cell according to claim 1 , wherein the liquid electrolyte comprises one or several organic solvents in the carbonate solvents family and/or the ether solvents family.

10 . Cell according to claim 1 , wherein the gel electrolyte is a liquid electrolyte impregnating a polymer matrix that gelifies in contact with the liquid electrolyte.

11 . Cell according to claim 10 , wherein the liquid electrolyte impregnating the polymer matrix is a liquid electrolyte as defined in claim 9 .

12 . Cell according to any one of the preceding claims wherein, when the lithium salts are lithium imidide salts, they are chosen from among lithium bis(trifluoromethane)sulfonylimidide with formula Li[N(SO 2 CF 3 ) 2 ), lithium bis(fluorosulfonyl)imidide with formula Li[N(SO 2 F) 2 ] and lithium bis(pentafluoroethane)sulfonylimidide with formula Li[N(SO 2 CF 2 CF 3 ) 2 ].

13 . Cell according to claim 1 , wherein:
when the lithium salt is lithium bis(trifluoromethane)sulfonylimidide, the positive electrode comprises, as active material, a lithiated phosphate comprising at least one metallic transition element, such as LiFePO 4 and/or a disulfide based on at least one metallic transition element, such as TiS 2 or FeS 2 and/or a vanadium oxide, such as V 2 O 5 and/or a metal sulfide based on lithium of the “rock-salt” type, such as Li 2 TiS 3 or Li 3 NbS 4 ; when the lithium salt is lithium perchlorate, the positive electrode comprises, as active material, elementary sulfur; when the lithium salt is lithium bis(fluorosulfonyl)imidide, the positive electrode comprises, as active material, a lithiated phosphate comprising at least one metallic transition element, such as LiFePO 4 and/or a disulfide based on at least one metallic transition element, such as TiS 2 or FeS 2 and/or a vanadium oxide, such as V 2 O 5 and/or a metal sulfide based on lithium of the “rock-salt” type, such as Li 2 TiS 3 or Li 3 NbS 4 and/or a lithiated oxide comprising at least one metal element such as Li(Mn,Ni,Co)O 2 ; when the lithium salt is lithium triflate, the positive electrode comprises, as active material, elementary sulfur and/or a disulfide based on at least one metallic transition element, such as TiS 2 or FeS 2 and/or a metal sulfide based on lithium of the “rock-salt” type, such as Li 2 TiS 3 or Li 3 NbS 4 ; * when the lithium salt is LiBETI, the positive electrode comprises, as active material, a lithiated phosphate comprising at least one metallic transition element, such as LiFePO 4 or LiMnPO 4 and/or elementary sulfur and/or a disulfide based on at least one metallic transition element, such as TiS 2 or FeS 2 and/or a vanadium oxide such as V 2 O 5 and/or a metal sulfide based on lithium of the “rock-salt” type, such as Li 2 TiS 3 or Li 3 NbS 4 and/or a lithiated oxide comprising at least one metallic element such as LiCoO 2 , Li(Mn,Ni,Co)O 2 , Li(Ni,Co,Al)O 2 , LiMn 2 O 4 or an overlithiated oxide comprising manganese, nickel and possibly cobalt.

14 . Cell according to claim 1 , wherein the aluminium salt comprises, as anions, anions comprising one or more several halogen atoms, such as fluorine and/or chlorine.

15 . Method of preparing or regenerating a cell as defined in claim 1 , comprising a step consisting of subjecting:
a cell comprising a negative electrode comprising metallic lithium as active material; a positive electrode associated with an aluminium current collector; and an electrolyte located between said negative electrode and said positive electrode comprising at least one lithium salt chosen from among lithium imidide, lithium triflate, lithium perchlorate salts and mixtures thereof; to a corrosion potential of aluminium for a sufficiently long time to obtain partial corrosion of the aluminium collector and the concomitant formation of a layer comprising a compound containing aluminium on the face of the negative electrode in contact with the electrolyte.

16 . Use of a layer comprising a compound containing aluminium, which is an aluminium salt, on a metallic lithium electrode, contained in a cell, in order to improve its cyclability, said cell comprising a positive electrode associated with an aluminium current collector and a liquid or gel electrolyte arranged between the positive electrode and the negative electrode and containing at least one lithium salt chosen from among lithium imidide, lithium triflate, lithium perchlorate salts and mixtures thereof, said layer comprising a compound containing aluminium being deposited on the face of the negative electrode in contact with the electrolyte.

Assignees

• Commissariat Energie Atomique

Inventors

• Reynier Yvan
• Barchasz Céline

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M4/5815

  Sulfides · CPC title

• H01M4/0442

  Anodisation, Oxidation (electrolytic coating by anodisation C25D9/00) · CPC title