SAFT

The invention relates to an electrochemical cell comprising: —at least one anode comprising metallic lithium or a lithium alloy or at least one anode comprising a current collector at least partially covered with metallic lithium deposited after at least one charge of the cell, the cell not containing metallic lithium at the time of its manufacture, —at least one cathode, —a liquid or gelled electrolyte composition comprising: a) a solvent comprising: i) either a mixture of 1,1,1,3,3,3-hexafluoro-2-methoxypropane (HFMP) and/or 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (HFMFP), ethylene monofluorocarbonate (F1EC) and 2,2,2-trifluoroethyl methyl carbonate (F3EMC), ii) or a mixture of 1,1,1,3,3,3-hexafluoro-2-methoxypropane (HFMP) and/or 1,1,1,3,3,3-hexafluo-ro-2-(fluoromethoxy)propane (HFMFP), ethylene monofluorocarbonate (F1EC) and 2,2,2-trifluoroethyl acetate (F3EA), b) at least one salt whose cation is the lithium cation, c) lithium difluorophosphate LiPO 2 F 2 in an amount representing from 0.05 to 5% of the mass of the combination made up of the solvent and said at least one dissolved lithium salt.

The invention relates to an electrochemical element comprising: -a negative electrode comprising an active material; -a 2024/022807 positive electrode comprising an active material comprising a lithium manganese iron phosphate; -a gel electrolyte comprising a matrix which is a polymer obtained by crosslinking a monomer comprising at least two acrylate groups, whereby a liquid mixture comprising at least one solvent, at least one lithium salt and a free-radical polymerisation thermal initiator is incorporated therein.

An electrolyte composition comprising: a) a solvent comprising: a mixture of at least two saturated cyclic carbonates, at least one of these saturated cyclic carbonates being fluorinated, at least one ether, said at least one saturated cyclic carbonate representing at most 1.5% by weight of the solvent, said at least one ether representing at least 40% by weight of the solvent; b) at least one lithium salt other than lithium difluorophosphate; c) lithium difluorophosphate in an amount representing from 0.1 to 1% by weight relative to the sum of weight of the solvent and weight of said at least one lithium salt. The use of this composition in an electrochemical cell comprising a lithium anode allows increased performance of the cell when it is discharged under a strong current at low temperature, and limited self-discharging when in operation at ambient temperature.

Disclosed is an electrolyte composition comprising: a) a solvent comprising: i) either a mixture of 1,1,1,3,3,3-hexaflu-oro-2-methoxypropane (HFMP) or of 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (HFMFP), of monofluoroethylene carbonate (F1EC) and of 2,2,2-trifluoroethyl methyl carbonate (F3EMC), ii) or a mixture of 1,1,1,3,3,3-hexafluoro-2-methoxypropane (HFMP) or of 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (HFMFP), of monofluoroethylene carbonate (F1EC) and of 2,2,2-trifluoroethyl acetate (F3EA), b) at least one lithium salt, the cation of which is the cation of an alkali metal.

An electrochemical cell of the lithium/sulfur type comprising: a) a cathode comprising: i) microporous carbon in the form of particles, the particle size distribution being characterized by a median volume diameter Dv 50 of the particles which is greater than or equal to 1 μm and less than or equal to 5 μm; ii) sulfur having an oxidation degree in the range of 0 to −2 in the pores of the microporous carbon; b) an electrolyte comprising a solvent, said solvent comprising at least one fluorinated carbonate; c) an anode composed of lithium metal or of a lithium metal alloy. The electrochemical cell exhibits an improved specific gravimetry and an improved life cycle.

An electrolyte composition for a lithium-ion electrochemical element, comprising: at least one lithium tetrafluoride or hexafluoride salt, the salts of lithium bis(fluorosulfonyl)imide LiFSI, vinylene carbonate, ethylene sulfate, at least one organic solvent chosen from the group consisting of cyclic or linear carbonates, cyclic or linear esters, cyclic or linear ethers and a mixture thereof. The use of this composition in a lithium-ion electrochemical element increases the service life of the element, in particular under low and high temperature cycling conditions.

A lithium/sulfur electrochemical element ( 1 ) comprising: a cathode ( 2 ) comprising: i) carbon having a porous structure ( 5 ) comprising pores with a mean diameter less than or equal to 6 nm; ii) sulfur having a degree of oxidation between 0 and −2 in the pores of the carbon; b) an electrolyte comprising: i) at least one organic solvent which is a carbonate; ii) one or more salts, at least one salt being lithium bis(fluorosulfonyl)imide; c) an anode ( 4 ) comprising lithium metal or a metallic alloy of lithium. Such an element provides increased safety of use because it limits the quantity of hydrogen sulfide that can be emitted in the event of an electrolyte leak or in the event of exposure of an electrode of the element to water.

The present invention relates to sulfide solid electrolytes having improved conductivity, a process for the preparation thereof, and electrochemical elements and batteries containing same.

An electrochemical cell including a container including an electrochemical spiral bundle including: a positive electrode including an active material selected from among SOCl 2 , SO 2 , SO 2 Cl; CF x where x≤1.5; MnO 2 , FeS 2 , V 2 O 5 , I 2 , Bi 2 O 3 , Bi 2 Pb 2 O 5 , CuCl 2 , CuF 2 , CuO, Cu 4 O(PO 4 ) 2 , CuS, FeS, MoO 3 , Ni 3 S 2 , AgCl, Ag 2 CrO 4 , SVO, MO 6 S 8 , and a mixture of a plurality thereof; a separator; and a negative electrode including an active material made of lithium metal or of a lithium-based alloy. The outer face of the spiral, facing the container, is formed by the positive electrode, and a strip of lithium or of a lithium-based alloy at least partially covers the inner face of the container. The strip pressed against the inner face of the container makes it possible to make use of an outer face of the positive electrode which forms the last turn of the spirally-wound electrode plate group.

The present application relates to fluoropolymer-based, solvent-free electrode formulations obtained by extrusion and/or comprising one or more co-binders including TPU, to electrodes containing the same and to corresponding electrochemical elements and storage cells.