Surface modified electrodes, preparation methods, and electrochemical uses

Abstract

The present technology relates to modifying the surface of an electrode film with a series of thin layers, each of which is, for example, 15 microns or less, where a first thin layer comprises an inorganic compound (such as a ceramic) in a solvating polymer, the inorganic compound being present in the first thin layer in a weight ratio of inorganic compound to solvating polymer ranging from about 1:20 to about 20:1 in the first thin layer. Electrochemical cells containing these modified electrodes are also described, as are secondary batteries containing them.

Description

[Technical field]

[0001] Related Applications This application claims priority under applicable law to Canadian Patent Application No. 3,128,220, filed August 13, 2021, the contents of which are incorporated by reference in their entirety and for all purposes.

[0002] Technical Field The present application relates to electrodes comprising an electrode material film having at least one modified surface, processes for their manufacture, and electrochemical cells containing them. [Background technology]

[0003] Technology background The liquid electrolytes used in lithium-ion batteries are flammable and slowly decompose to form a passive layer on the surface of the lithium film or at the interface of the solid electrolyte (SEI, short for "solid electrolyte interface" or "solid electrolyte interphase"), which irreversibly consumes lithium and reduces the battery's coulombic efficiency. Furthermore, the lithium anode undergoes significant morphological changes during battery cycling, leading to the formation of lithium dendrites. These usually migrate through the electrolyte and can eventually cause short circuits. Safety concerns and demands for higher energy density have spurred research into the development of all-solid-state lithium rechargeable batteries with either polymer or ceramic electrolytes, because both are more stable against lithium metal and reduce the growth of lithium dendrites. However, loss of reactivity and poor contact between solid interfaces in these all-solid-state batteries remain problems.

[0004] A simple and more industrially applicable method to protect the lithium surface is to coat the surface with a polymer or a polymer / lithium salt mixture by spraying, dipping, centrifugation or using the so-called doctor blade method (N. Delaporte, et al., Front. Mater., 2019, 6, 267). The polymer chosen must be stable at low temperatures towards lithium and ionic conductors. In a sense, the polymer layer deposited on the lithium surface should be comparable to the solid polymer electrolytes (SPEs) commonly reported in the literature, in order to remain rubbery at room temperature and to maintain a lithium conductivity similar to that of liquid electrolytes, with a low glass transition (T g ) In order to accommodate the deformation of the lithium during cycling, and in particular to avoid the formation of lithium dendrites, the polymer must have good flexibility and be characterized by a high Young's modulus.

[0005] A few examples of polymers used in this type of protective layer are polyacrylic acid (PAA) (N.-W. Li, et al., Angew. Chem. Int. Ed., 2018, 57, 1505-1509), poly(vinylidene carbonate-co-acrylonitrile) (SM Choi et al., J. Power Sources, 2013, 244, 363-368), poly(ethylene glycol) dimethacrylate (YM Lee, et al., J. Power Sources, 2003, 119-121, 964-972), PEDOT-co-PEG copolymers (G. Ma, et al., J. Mater. Chem. A, 2014, 2, 19355-19359 and IS Kang, et al., J. Electrochem. Soc., 2014, 161 (1), A53-A57), polymers obtained from the direct polymerization of acetylene on lithium (DG Belov, et al., Synth. Met., 2006, 156, 745-751), in situ polymerized α-ethyl cyanoacrylate (Z. Hu, et al., Chem. Mater., 2017, 29, 4682-4689), and polymers formed from the copolymer Kynar™ 2801 and the curable monomer 1,6-hexanediol diacrylate (N.-S. Choi, et al., Solid State Ion., 2004, 172, 19-24). The latter group also investigated the incorporation of ionic receptors into the polymer mixtures (N.-S. Choi, et al., Electrochem. Commun., 2004, 6, 1238-1242).

[0006] Some work has been carried out on the incorporation of solid fillers, typically ceramic, into polymers for lithium surface modification. For example, inorganic fillers (e.g., Al2O3, TiO2, BaTiO3) have been mixed with polymers to obtain hybrid organic-inorganic composite electrolytes.

[0007] Freshly synthesized spherical Cu3N particles with a size of less than 100 nm and a mixture of styrene butadiene rubber (SBR) copolymer were deposited on the lithium surface by doctor blade (Y. Liu, et al., Adv. Mater., 2017, 29, 1605531). Upon contact with lithium, Cu3N is transformed into Li3N with high lithium conductivity. Li4Ti5O 12 / Li (LTO / Li) cells were assembled with liquid electrolyte, and better electrochemical performance was obtained using lithium protected by a mixture of Cu3N and SBR.

[0008] A 20 μm protective layer composed of Al2O3 particles (1.7 μm average diameter) and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), deposited on the lithium surface, has been presented to improve the life of lithium-oxygen batteries (DJ Lee, et al., Electrochem. Commun., 2014, 40, 45-48). The Co3O4-SuperP / Li battery has this protective layer and a liquid electrolyte. The effect of similarly modified lithium has also been studied by Gao and his colleagues (HK Jing et al., J. Mater. Chem. A, 2015, 3, 12213-12219), but the focus was on improving lithium-sulfur batteries. In this example, 100 nm Al2O3 spheres were used with PVDF as a binder, and the mixture prepared in DMF solvent was spin-coated on lithium foil. The battery assembly was then carried out with the liquid electrolyte.

[0009] A 25 μm porous layer of polyimide containing Al2O3 (grain size about 10 nm) as a filler has also been presented to limit lithium growth (see Z. Peng et al., J. Mater. Chem. A, 2016, 4, 2427-2432). The method involves the formation of a film called a "skin layer" by contacting lithium with additives present in the liquid electrolyte (such as fluoroethylene carbonate (FEC), vinylene carbonate (VC), or hexamethylene diisocyanate (HDI)). A Cu / LiFePO4 electrochemical cell containing this liquid electrolyte was tested to demonstrate the utility of the polyimide / Al2O3 layer in preventing dendrite formation and electrolyte decomposition. The protective layers described in the three previous paragraphs are suitable for use with a liquid electrolyte that is porous and can permeate therethrough. This type of layer is therefore not suitable for use with a solid electrolyte, since the solid electrolyte must be able to make intimate contact with the surface of the electrode (or its protective layer) and allow the conduction of ions from the electrolyte to the active electrode material. [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] N. Delaporte, et al., Front. Mater., 2019, 6, 267 [Non-Patent Document 2] N.-W. Li, et al., Angew. Chem. Int. Ed., 2018, 57, 1505-1509 [Non-Patent Document 3] SM Choi et al., J. Power Sources, 2013, 244, 363-368 [Non-Patent Document 4] YM Lee, et al., J. Power Sources, 2003, 119-121, 964-972 [Non-Patent Document 5] G. Ma, et al., J. Mater. Chem. A, 2014, 2, 19355-19359 [Non-Patent Document 6] IS Kang, et al., J. Electrochem. Soc., 2014, 161 (1), A53-A57 [Non-Patent Document 7] DG Belov, et al., Synth. Met., 2006, 156, 745-751 [Non-Patent Document 8] Z. Hu, et al., Chem. Mater., 2017, 29, 4682-4689 [Non-Patent Document 9] N.-S. Choi, et al., Solid State Ion., 2004, 172, 19-24 [Non-Patent Document 10] N.-S. Choi, et al., Electrochem. Commun., 2004, 6, 1238-1242 [Non-Patent Document 11] Y. Liu, et al., Adv. Mater., 2017, 29, 1605531 [Non-Patent Document 12] DJ Lee, et al., Electrochem. Commun., 2014, 40, 45-48 [Non-Patent Document 13] HK Jing et al., J. Mater. Chem. A, 2015, 3, 12213-12219 [Non-Patent Document 14] Z. Peng et al., J. Mater. Chem. A, 2016, 4, 2427-2432 Summary of the Invention [Means for solving the problem]

[0011] overview According to a first aspect, the present technology provides an electrode comprising an electrode film modified with a first thin layer and a second thin layer, the electrode film comprising: - the electrode film includes a first and a second surface, the first surface being optionally pretreated; - a first thin layer comprising an inorganic compound in a solvating polymer, and optionally an ionic salt and / or a plasticizer, the first thin layer being disposed on a first surface of the electrode film and having an average thickness of about 15 μm or less, and a weight ratio "inorganic compound:solvating polymer" in the first thin layer ranging from about 1:20 to about 20:1; - a second thin layer comprises a solvating polymer, an ionic salt, and optionally a plasticizer, the second thin layer being disposed on the first thin layer and having an average thickness of about 15 μm or less; The solvating polymer of the first layer is the same as or different from the solvating polymer of the second layer; Concerning electrodes.

[0012] In one embodiment, the solvating polymer of the first lamina is crosslinked and / or the solvating polymer of the second lamina is crosslinked, in another embodiment, the solvating polymer of the first lamina is not crosslinked and / or the solvating polymer of the second lamina is not crosslinked.

[0013] According to one embodiment, the electrode film is a current collector, for example a current collector comprising an electronically conducting solid support such as a metal foil or grid (copper, nickel, etc.), a carbon or carbon-containing film (carbon paper, free-standing graphene, etc.), or other solid support (polymer, glass, etc.) that comprises an electronically conducting layer (such as a current collector print).

[0014] According to another embodiment, the electrode film comprises a metal film, for example comprising lithium (eg, containing less than 1000 ppm (ie, less than 0.1 wt %) of impurities) or an alloy containing lithium. In one embodiment, the metal film comprises an alloy of lithium with an element selected from alkali metals other than lithium (such as Na, K, Rb, and Cs), alkaline earth metals (such as Mg, Ca, Sr, and Ba), rare earth metals (such as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), zirconium, copper, silver, bismuth, cobalt, manganese, zinc, aluminum, silicon, tin, antimony, cadmium, mercury, lead, molybdenum, iron, boron, indium, thallium, nickel, and germanium (e.g., Zr, Cu, Ag, Bi, Co, Zn, Al, Si, Sn, Sb, Cd, Hg, Pb, Mn, B, In, Tl, Ni, or Ge). According to one embodiment, the alloy comprises at least 75% by weight lithium, or between 85% and 99.9% by weight lithium.

[0015] According to a further embodiment, the electrode film further comprises a pretreatment layer on the first surface, which is in contact with the first thin layer. In one embodiment, the pretreatment layer comprises a compound selected from silane, phosphonate, borate, organic salt or compound, carbon (e.g., graphite, graphene, etc.), inorganic salt or compound (e.g., LiF, Li3N, Li3P, LiNO3, Li3PO4, etc.), or a thin layer of an element (such as the elements defined above for alloys) that is different from or forms an alloy with the metal of the electrode film at the surface, said pretreatment layer having an average thickness of less than 5 μm, or less than 3 μm, or less than 1 μm, or less than 500 nm, or less than 200 nm, or less than 100 nm, or less than 50 nm. In one embodiment, the first surface of the electrode film is pretreated by stamping.

[0016] According to one embodiment, the inorganic compound is in particulate form (e.g., spherical, rod-shaped, needle-shaped, etc.). For example, the average particle size can be less than 1 μm, or less than 500 nm, or less than 300 nm, or less than 200 nm, or between 1 nm and 500 nm, or between 10 nm and 500 nm, or between 50 nm and 500 nm, or between 100 nm and 500 nm, or between 1 nm and 300 nm, or between 10 nm and 300 nm, or between 50 nm and 300 nm, or between 100 nm and 300 nm, or between 1 nm and 200 nm, or between 10 nm and 200 nm, or between 50 nm and 200 nm, or between 100 nm and 200 nm, or between 1 nm and 100 nm, or between 10 nm and 100 nm, or between 25 nm and 100 nm, or between 50 nm and 100 nm.

[0017] In another embodiment, the inorganic compound comprises a ceramic. In one embodiment, the inorganic compound is selected from the group consisting of Al2O3, Mg2B2O5, Na2O·2B2O3, xMgO·yB2O3·zH2O, TiO2, ZrO2, ZnO, Ti2O3, SiO2, Cr2O3, CeO2, B2O3, B2O, SrBi4Ti4O 15 , LLTO, LLZO, LAGP, LATP, Fe2O3, BaTiO3, γ-LiAlO2, metal / carbon mixtures (Sn+C, Zn+C, Ni2P+C, etc.), molecular sieves and zeolites (e.g., aluminosilicates, mesoporous silicas), sulfide ceramics (Li7P3S 11 ), glass ceramics (such as LIPON), and other ceramics, and combinations thereof.

[0018] According to additional embodiments, the particles of inorganic compound further comprise organic groups covalently grafted to their surface, for example said groups being selected from crosslinkable groups (e.g. organic groups containing acrylate, methacrylate, vinyl, glycidyl, mercapto functional groups, etc.), aryl groups, alkylene oxide or poly(alkylene oxide) groups, and other organic groups, or combinations thereof, optionally comprising a spacer group between the organic group and the particles of inorganic compound. In one embodiment, the grafted organic group comprises a poly(alkylene oxide) chain bound to the particles of inorganic compound by a spacer group. In another embodiment, the spacer group is selected from silane or halogenated silane, phosphonate, carboxylate, catechol, (meth)acrylate or poly(meth)acrylate, alkylene or polyalkylene group, and combinations thereof.

[0019] According to one embodiment, the inorganic compound particles have a small specific surface area (e.g., less than 80 m 2 / g or less than 40m 2 / g). According to another embodiment, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer ranges from about 2:5 to about 4:1, or from about 2:5 to about 2:1, or from about 1:2 to about 2:1, or from about 4:5 to about 2:1, or from about 1:1 to about 2:1, or from about 4:5 to about 3:2. In yet another embodiment, the inorganic compound particles have a high specific surface area (e.g., less than 80 m 2 / g or greater, or 120m 2 / g or greater). In yet another embodiment, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer ranges from about 1:20 to about 2:1, or from about 2:5 to about 2:1, or from about 2:5 to about 6:5, or from about 1:20 to about 6:5, or from about 2:5 to about 1:1, or from about 1:20 to about 1:1, or from about 2:5 to about 4:5, or from about 1:20 to about 4:5.

[0020] According to additional embodiments, the average thickness of the first thin layer is between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm. According to another embodiment, the average thickness of the second thin layer is between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between about 2 μm and about 5 μm, or between about 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm. In yet another embodiment, the total average thickness of the first and second thin layers is in the range of about 1 μm to about 30 μm, or about 1 μm to about 25 μm, or about 5 μm to about 25 μm, or about 1 μm to about 20 μm, or about 1 μm to about 16 μm, or about 2 μm to about 12 μm, or about 3 μm to about 15 μm, or about 3 μm to about 12 μm, or about 4 μm to about 15 μm, or about 4 μm to about 12 μm.

[0021] According to another embodiment, the solvating polymer is independently selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, polyvinyl alcohol, polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, and optionally includes crosslinking units derived from crosslinkable functional groups (e.g., acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, and the like).

[0022] According to a preferred embodiment, at least one of the first and second thin layers further comprises a plasticizer, for example the first thin layer and the second thin layer further comprise a plasticizer. In one embodiment, the plasticizer is selected from the following types of liquids: glycol diethers (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonates (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate), lactones (such as gamma-butyrolactone), adiponitrile, and ionic liquids.

[0023] According to a further embodiment, at least one of the first and second thin layers further comprises a lithium salt. In one embodiment, the first and second thin layers further comprise a lithium salt. In another embodiment, the lithium salt is lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyano-imidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3). , lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(CO)2] (LBBB), and combinations thereof.

[0024] According to another embodiment of the first aspect, the electrode further comprises a current collector in contact with the second surface of the electrode film.

[0025] According to a second aspect, the present technology relates to an electrochemical cell comprising an anode and a cathode, at least one of which is as defined above. In one embodiment, the anode is as defined above and the cathode comprises a film of a cathode material, including a cathode electrochemically active material, optionally a binder, and optionally a conductive material.

[0026] According to one embodiment, the positive electrode electrochemically active material is selected from metal phosphates, lithiated metal phosphates, metal oxides, and lithiated metal oxides. In another embodiment, the positive electrode electrochemically active material is LiM'PO4 (wherein M' is Fe, Ni, Mn, Co, or a combination thereof), LiV3O8, VO5F, LiV2O5, LiMn2O4, LiM"O2 (wherein M" is Mn, Co, Ni, or a combination thereof (NMC, LiMn x Co y Ni z Li(NiM''')O2 (wherein x+y+z=1), Li(NiM''')O2 (wherein M''' is Mn, Co, Al, Fe, Cr, Ti, Zr, or a combination thereof), elemental sulfur, elemental selenium, elemental iodine, iron(III) fluoride, copper(II) fluoride, lithium iodide, carbon-based active materials, organic cathode active materials (e.g., polyimides, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi4), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), π-conjugated dicarboxylates, and anthraquinones), or combinations of two or more of these materials, if compatible with each other.

[0027] In another embodiment, the positive electrode electrochemically active material is in the form of particles that are optionally coated (eg, with a polymer, ceramic, carbon, or a combination of two or more thereof).

[0028] In further embodiments, the film of positive electrode material comprises a first and second surface, the first surface facing the negative electrode and carrying a thin third layer comprising a solvating polymer and an ionic salt, the thin third layer having an average thickness of about 50 μm or less, about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm. In one embodiment, the solvating polymer is as defined above. In another embodiment, the salt is a lithium salt, for example as defined above. According to another embodiment, the third thin layer further comprises a plasticizer, for example as defined above.

[0029] According to one embodiment of the second aspect, the electrochemical cell excludes the presence of a solid polymer electrolyte layer.

[0030] According to an alternative embodiment of the second aspect, the electrochemical cell further comprises a solid electrolyte layer comprising a polymer and a lithium salt. In one embodiment, the electrolyte polymer is selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers, optionally including crosslinkable units), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, poly(vinyl alcohol), polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, wherein the solvating polymer is optionally crosslinked.

[0031] In another embodiment, the lithium salt of the solid electrolyte layer is lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyano-imidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiN Lithium fluoride (LiF), lithium perchlorate (LiClO3), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(CO2)2] (LBBB), and combinations thereof.

[0032] According to another embodiment, the solid electrolyte further comprises a ceramic.

[0033] According to a third aspect, the present technology provides an electrochemical cell comprising a negative electrode and a positive electrode: (a) a negative electrode comprising a negative electrode film having a first and a second surface, the first surface being optionally pretreated, said negative electrode comprising a first lamina comprising an inorganic compound in a solvating polymer, and optionally an ionic salt and / or a plasticizer, the first lamina disposed on the first surface of the negative electrode film and having an average thickness of about 15 μm or less, the weight ratio of "inorganic compound:solvating polymer" in the first lamina being in the range of about 1:20 to about 20:1; (b) the negative electrode comprises a second thin layer comprising a solvating polymer, an ionic salt, and optionally a plasticizer, the second thin layer disposed on the first thin layer and having an average thickness of about 15 μm or less, the solvating polymer of the first layer being the same as or different from the solvating polymer of the second layer; and / or a positive electrode comprising a positive electrode material film comprising a positive electrode electrochemically active material, optionally a binder, and optionally a conductive material, the positive electrode material film comprising first and second surfaces, the first surface facing the negative electrode and carrying a solvating polymer, a third thin layer comprising an ionic salt, the third thin layer having an average thickness of about 50 μm or less; The electrochemical cell excludes the presence of an additional solid polymer electrolyte layer. Concerning electrochemical cells.

[0034] According to one embodiment, the electrochemical cell includes a second thin layer, the solvating polymer of the second thin layer being crosslinked or not crosslinked. According to another embodiment, the electrochemical cell includes a third thin layer, the solvating polymer of the third thin layer being crosslinked or not crosslinked. According to one example, the electrochemical cell includes a second thin layer and a third thin layer.

[0035] In one embodiment, the solvating polymer of the first lamina is crosslinked. In an alternative embodiment, the solvating polymer of the first lamina is not crosslinked.

[0036] According to one embodiment, the negative electrode film is a current collector, for example a current collector comprising an electronically conducting solid support such as a metal foil or grid (copper, nickel, etc.), a carbon or carbon-containing film (carbon paper, free-standing graphene, etc.), or other solid support (polymer, glass, etc.) that comprises an electronically conducting layer (such as a current collector print).

[0037] According to another embodiment, the negative electrode film comprises a metal film, for example comprising lithium or an alloy containing lithium. According to one embodiment, the metal film comprises lithium with impurities of less than 1000 ppm (i.e., less than 0.1 wt.%). According to another embodiment, the metal film comprises lithium and other metals, such as alkali metals (such as Na, K, Rb, and Cs), alkaline earth metals (such as Mg, Ca, Sr, and Ba), rare earth metals (such as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), zirconium, copper, silver, bismuth, cobalt, manganese, zinc, aluminum, silicon, tin, antimony, etc. and an element selected from the group consisting of arsenic, cadmium, mercury, lead, molybdenum, iron, boron, indium, thallium, nickel, and germanium (e.g., Zr, Cu, Ag, Bi, Co, Zn, Al, Si, Sn, Sb, Cd, Hg, Pb, Mn, B, In, Tl, Ni, or Ge), for example the alloy may contain at least 75% lithium by weight, or between 85% and 99.9% lithium by weight.

[0038] In one embodiment, the negative electrode film further comprises a pretreatment layer on the first surface in contact with the first thin layer. According to one embodiment, the pretreatment layer comprises a compound selected from silanes, phosphonates, borates, organic salts or compounds, carbon (e.g., graphite, graphene, etc.), inorganic salts or compounds (e.g., LiF, Li3N, Li3P, LiNO3, Li3PO4, etc.), or a thin layer of an element (such as those defined above) that is different from or forms an alloy with the metal of the metal film at the surface, said pretreatment layer having an average thickness of less than 5 μm, or less than 3 μm, or less than 1 μm, or less than 500 nm, or less than 200 nm, or less than 100 nm, or less than 50 nm. In another embodiment, the first surface of the negative electrode film is pretreated by stamping.

[0039] In another embodiment, the inorganic compound is in particulate form (e.g., spherical, rod-shaped, needle-shaped, etc.), e.g., having an average size of less than 1 μm, less than 500 nm, or less than 300 nm, or less than 200 nm, or between 1 nm and 500 nm, or between 10 nm and 500 nm, or between 50 nm and 500 nm, or between 100 nm and 500 nm, or between 1 nm and 300 nm, or between 10 nm and 300 nm, or between 50 nm and 300 nm, or between 100 nm and 300 nm, or between 1 nm and 200 nm, or between 10 nm and 200 nm, or between 50 nm and 200 nm, or between 100 nm and 200 nm, or between 1 nm and 100 nm, or between 10 nm and 100 nm, or between 25 nm and 100 nm, or between 50 nm and 100 nm.

[0040] According to one embodiment, the inorganic compound comprises a ceramic. According to another embodiment, the inorganic compound is Al2O3, Mg2B2O5, Na2O·2B2O3, xMgO·yB2O3·zH2O, TiO2, ZrO2, ZnO, Ti2O3, SiO2, Cr2O3, CeO2, B2O3, B2O, SrBi4Ti4O 15 , LLTO, LLZO, LAGP, LATP, Fe2O3, BaTiO3, γ-LiAlO2, metal / carbon mixtures (e.g., Sn+C, Zn+C, Ni2P+C), molecular sieves and zeolites (e.g., aluminosilicates, mesoporous silica), sulfide ceramics (Li7P3S 11 ), glass-ceramics (such as LIPON), and other ceramics, and combinations thereof.

[0041] In another embodiment, the inorganic particle further comprises an organic group covalently grafted onto its surface, for example said group is selected from a crosslinkable group (e.g. an organic group containing an acrylate functional group, a methacrylate functional group, a vinyl functional group, a glycidyl functional group, a mercapto functional group, etc.), an aryl group, an alkylene oxide or poly(alkylene oxide) group, and other organic groups, or a combination thereof, optionally comprising a spacer group between the organic group and the inorganic particle. In one embodiment, the grafted organic group comprises a poly(alkylene oxide) chain bound to the inorganic particle by a spacer group. For example, the spacer group may be selected from a silane or halogenated silane, a phosphonate, a carboxylate, a catechol, a (meth)acrylate or poly(meth)acrylate, an alkylene or polyalkylene group, and a combination thereof.

[0042] According to one embodiment, the inorganic compound particles have a small specific surface area (e.g., less than 80 m 2 / g or less than 40m 2 / g). According to another embodiment, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer ranges from about 2:5 to about 4:1, or from about 2:5 to about 2:1, or from about 1:2 to about 2:1, or from about 4:5 to about 2:1, or from about 1:1 to about 2:1, or from about 4:5 to about 3:2. In another embodiment, the inorganic compound particles have a high specific surface area (e.g., less than 80 m 2 / g and greater, or 120m 2 / g and greater). In yet another embodiment, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer ranges from about 1:20 to about 2:1, or from about 2:5 to about 2:1, or from about 2:5 to about 6:5, or from about 1:20 to about 6:5, or from about 2:5 to about 1:1, or from about 1:20 to about 1:1, or from about 2:5 to about 4:5, or from about 1:20 to about 4:5.

[0043] According to one embodiment, the average thickness of the first thin layer is between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm.

[0044] According to another embodiment, the average thickness of the second thin layer is between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, or between 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm.

[0045] According to yet another embodiment, a second lamina is present and the total average thickness of the first and second lamina is in the range of about 1 μm to about 30 μm, or about 1 μm to about 25 μm, or about 5 μm to about 25 μm, or about 1 μm to about 20 μm, or about 1 μm to about 16 μm, or about 2 μm to about 12 μm, or about 3 μm to about 15 μm, or about 3 μm to about 12 μm, or about 4 μm to about 15 μm, or about 4 μm to about 12 μm.

[0046] In one embodiment, the average thickness of the third thin layer is about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm.

[0047] In yet another embodiment, a second lamina and a third lamina are present, and the total average thickness of the first, second, and third lamina is in the range of about 3 μm to about 60 μm, or about 10 μm to about 50 μm, or about 15 μm to about 30 μm, or about 3 μm to about 30 μm, or about 3 μm to about 25 μm, or about 5 μm to about 25 μm, or about 5 μm to about 20 μm, or about 8 μm to about 15 μm, or about 8 μm to about 12 μm, or about 5 μm to about 15 μm, or about 5 μm to about 12 μm, or about 5 μm to about 15 μm, or about 9 μm to about 15 μm.

[0048] According to one embodiment, the solvating polymer is independently selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, poly(vinyl alcohol), polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, and optionally includes crosslinking units derived from crosslinkable functional groups (e.g., acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, and the like).

[0049] According to another embodiment, at least one of the first and second thin layers further comprises a plasticizer, or the first and second thin layers further comprise a plasticizer, and / or the third thin layer further comprises a plasticizer. In one embodiment, the plasticizer is selected from the following types of liquids: glycol diethers (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonates (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate), lactones (such as γ-butyrolactone), adiponitrile, and ionic liquids.

[0050] According to a further embodiment, at least one of the first, second and third thin layers further comprises a lithium salt, or the first, second and third thin layers further comprise a lithium salt. In one embodiment, the lithium salt is selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyano-imidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), The lithium fluoride is selected from lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(CO)2] (LBBB), and combinations thereof.

[0051] According to yet another embodiment, the negative electrode further comprises a current collector in contact with the second surface of the negative electrode film. In one embodiment, the positive electrode further comprises a current collector in contact with the second surface of the positive electrode material film.

[0052] According to one embodiment, the positive electrode electrochemically active material is selected from metal phosphates, lithiated metal phosphates, metal oxides, and lithiated metal oxides. In another embodiment, the positive electrode electrochemically active material is LiM'PO4 (wherein M' is Fe, Ni, Mn, Co, or a combination thereof), LiV3O8, VO5F, LiV2O5, LiMn2O4, LiM"O2 (wherein M" is Mn, Co, Ni, or a combination thereof (NMC, LiMnx Co y Ni z and the like), Li(NiM''')O2 (where M''' is Mn, Co, Al, Fe, Cr, Ti, Zr, or a combination thereof, elemental sulfur, elemental selenium, elemental iodine, iron(III) fluoride, copper(II) fluoride, lithium iodide, carbon-based active materials, organic cathode active materials (e.g., polyimides, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi4), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), π-conjugated dicarboxylates, and anthraquinones), or combinations of two or more of these materials, if compatible with each other. In another embodiment, the positive electrode electrochemically active material is in the form of particles that are optionally coated (eg, with a polymer, ceramic, carbon, or a combination of two or more thereof).

[0053] According to a fourth aspect, the present technology relates to an electrochemical accumulator comprising at least one electrochemical cell as defined above. According to one embodiment, the electrochemical accumulator is a lithium battery or a lithium-ion battery.

[0054] According to a fifth aspect, the present technology relates to the use of an electrochemical accumulator as defined above in a mobile device, an electric or hybrid vehicle or in the storage of renewable energy. According to one embodiment, the mobile device is selected from a mobile phone, a camera, a tablet and a laptop. [Brief description of the drawings]

[0055] [Figure 1] FIG. 1 shows (a) an R-ray diffraction diagram and (b) a scanning electron microscope image of the Ni2P powder (Ni12P5 phase) obtained according to Example 1(a).

[0056] [Diagram 2] FIG. 2 shows (a) thermogravimetric curves for Al2O3 (solid line) and Al2O3-polymer (dashed line) and (b) a photograph of a lithium strip with a 1 μm thin layer of polymer 1+Al2O3 ceramic-polymer according to Example 1(b).

[0057] [Diagram 3] FIG. 3 shows the conductivity measurements on stainless steel of polymer films A1 to A5 described in Example 2(a) between 20° C. and 80° C.

[0058] [Figure 4] FIG. 4 shows schematics of various cell configurations including polymer+inorganic layer on anode and (a) polymer electrolyte; (b) polymer layer and polymer electrolyte on cathode; (c) inorganic-free second layer on polymer+inorganic layer and polymer electrolyte; (d) inorganic-free second layer on polymer+inorganic layer (no polymer electrolyte); (e) polymer layer on cathode (no polymer electrolyte); and (f) inorganic-free second layer on polymer+inorganic layer, polymer layer on cathode (no polymer electrolyte).

[0059] [Diagram 5] FIG. 5 shows (a) the results of galvanostatic cycling obtained at 50° C. and C / 6 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with lithium having layers B1(i) to B3(i) according to Example 3(a) (every 20 cycles at C / 6 and 2 cycles at C / 12); and (b) an indication of the capacity drop during cycling for the same batteries.

[0060] [Figure 6]FIG. 6 shows (a) the results of galvanostatic cycling obtained at 50° C. and C / 6 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with lithium having layers B1 to B3 according to Example 3(b) (every 20 cycles at C / 6 and 2 cycles at C / 12); and (b) the indication of capacity drop during cycling for the same batteries.

[0061] [Figure 7] FIG. 7 shows (a) the galvanostatic cycling results obtained at 50° C. and C / 6 (2 cycles at C / 12 after every 20 cycles at C / 6) for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with lithium with layers B1 to B3 according to Example 3(c) (solid percentages of 17, 21, and 24%); and (b) the display of capacity drop during cycling for the same batteries.

[0062] [Figure 8] 8 shows data on (a) galvanostatic cycling and (b) coulombic efficiency obtained at 50° C. and C / 3 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with a 4 μm layer of polymer 1 with 130% Al2O3-polymer (C1 cell according to Example 3(d)). The scheme shows the assembly of the C1 battery.

[0063] [Figure 9] Figure 9 shows data on (a) galvanostatic cycling and (b) coulombic efficiency obtained at 50 °C and C / 3 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with a 4 μm layer of polymer 1 with 130% Al2O3-polymer, and with LFP cathodes with 2 or 4 μm layers of polymer (C2-a and C2-b cells according to Example 3(d)). The scheme shows the assembly of C2-a and C2-b cells.

[0064] [Figure 10] 10 shows data on (a) galvanostatic cycling and (b) coulombic efficiency obtained at 50° C. and C / 3 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with a 4 μm layer of polymer 1 with 130% Al2O3-polymer and a second 4 μm layer of polymer 1 (C3 cell according to Example 3(d)). The scheme shows the assembly of the C3 battery.

[0065] [Figure 11] 11 shows data on (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50° C. and C / 3 for LFP / polymer electrolyte / Li batteries assembled without polymer electrolyte, with unmodified lithium (reference) and with a 4 μm layer of polymer 1 with 130% Al2O3-polymer and with a second 9 or 12 μm layer of polymer 1 (C4-a and C4-b batteries according to Example 3(d)). The scheme shows the assembly of C4-a and C4-b cells.

[0066] [Figure 12] Figure 12 shows data on (a) galvanostatic cycling and (b) coulombic efficiency obtained at 50 °C and C / 3 for LFP / polymer electrolyte / Li batteries assembled without polymer electrolyte (C5-a, C5-b, and C-5-c cells according to Example 3(d)) with unmodified lithium (reference) and with lithium with a 4 μm layer of polymer 1 containing 130% Al2O3-polymer and LFP cathodes with 5, 8 or 11 μm polymer layers. The scheme shows the assembly of C5-a, C5-b, and C-5-c cells.

[0067] [Figure 13]13 shows data on (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50° C. and C / 3 for unmodified lithium (reference) and lithium with a 4 μm layer of polymer 1 with 130% Al2O3-polymer and a second 3 or 4 μm layer of polymer 1, and LFP cathode with a 4 μm polymer layer (C6-a and C6-b cells according to Example 3(d)). The scheme shows the assembly of C6-a and C6-b cells.

[0068] [Figure 14] FIG. 14 shows the galvanostatic cycling behavior obtained at 50° C. and C / 3 for an LFP / polymer electrolyte / Li battery assembled with unmodified lithium (reference) and then with lithium with a 5 μm layer of polymer 1 containing 30% Ni2P and 17% carbon according to Example 3(e).

[0069] [Figure 15-1] FIG. 15 shows data on (a) cycling stability (discharge capacity), (b) average voltage, and (c) coulombic efficiency obtained during galvanostatic cycling at 50° C. and C / 3 for two LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and two C7 batteries described in Example 4. [Figure 15-2] Same as above.

[0070] [Figure 16] FIG. 16 shows data on (a) cycling stability (discharge capacity) and (b) coulombic efficiency obtained during galvanostatic cycling at 50° C. and C / 3 for two LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and three C8 batteries described in Example 4.

[0071] [Figure 17]FIG. 17 shows data on (a) discharge capacity and (b) coulombic efficiency obtained during cycling at rates ranging from C / 6 to 1C at 50° C. for an LFP / polymer electrolyte / Li battery assembled with unmodified lithium (reference) and two C9 cells described in Example 4.

[0072] [Figure 18] FIG. 18 shows the galvanostatic cycling behavior obtained at C / 3 (a) and C / 6 (b) at 50° C. for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and lithium modified with (a) inorganic molecules (PCl3) and (b) a thin metal layer (Zn) according to Example 5.

[0073] [Figure 19] FIG. 19 shows photographs of lithium strips processed through (a) PCl3 treatment and (b) PCl3 treatment and subsequent Polymer1+Al2O3-polymer deposition according to Example 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0074] Detailed Description All technical and scientific terms and expressions used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nevertheless, definitions of some of the terms and expressions used are provided below.

[0075] The term "about" as used herein means approximately, within a range, and around. When the term "about" is used in relation to a numerical value, it can modify the numerical value, for example, to have a 10% variation above and below its nominal value. This term can also take into account, for example, experimental error characteristic of a measuring device, or rounding of values.

[0076] When a range of values ​​is referred to in this application, the lower and upper limits of the range are always included in the definition unless otherwise specified. For example, "between x and y" or "from x to y" means a range that includes the limits x and y, unless otherwise indicated. For example, a range "between 1 and 50" i.e. includes the values ​​1 and 50.

[0077] The chemical structures described herein are drawn according to conventions in the art, and when an atom, such as a drawn carbon atom, appears to contain incomplete valences, it is assumed that the valences are satisfied by one or more hydrogen atoms, even if not explicitly drawn.

[0078] The term "alkyl" as used herein refers to a saturated hydrocarbon group having from 1 to 20 carbon atoms, including straight-chain or branched alkyl groups. Non-limiting examples of alkyls may include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, tert-butyl, sec-butyl, isobutyl, and similar groups. Similarly, an "alkylene" group refers to an alkyl group positioned between two other groups. Examples of alkylene groups include methylene, ethylene, propylene, and the like. "C1-C n Alkyl" and "C1-C n The term "alkylene" refers to an alkyl or alkylene group having from 1 to "n" carbon atoms.

[0079] Thus, this document describes a surface modification of an electrode film and an electrode comprising the modified electrode film. More specifically, the surface of the electrode film is modified by a stack of at least two thin layers, each of which is about 15 μm or less thick.

[0080] According to one example, the electrode film can be a metal film, such as one comprising an alkali metal (such as lithium) or an alloy containing primarily an alkali metal (such as lithium).

[0081] According to another embodiment, the electrode film is a current collector, which comprises an electronically conducting solid support, such as a metal foil or grid (e.g., copper, nickel, etc.), a carbon or carbon-containing film (e.g., carbon paper, free-standing graphene, etc.), or other solid support (polymer, glass, etc.) that comprises an electronically conducting layer (current collector print, etc.), which can be lithiated, for example, during a first charge-discharge cycle. This lithiation process then generally occurs at the surface of the electronically conducting solid support, or for a grid, inside the mesh or inside the pretreatment layer, in either case the lithiation occurs at the surface of the electronically conducting solid support that is in contact with the first thin layer.

[0082] In this case, surface modification means the deposition of a series of two ion-conducting thin films that act as a barrier to dendrite formation but do not react substantially with the surface of the electrode film, the thin film elements being mainly unreacted.

[0083] The surface of the electrode film is modified by depositing on one of its surfaces a first thin layer comprising an inorganic compound in a solvating polymer, and optionally an ionic salt and / or a plasticizer. The first thin layer has an average thickness of about 15 μm or less. The inorganic compound is present in the first thin layer in a weight ratio of "inorganic compound:solvating polymer" in the first thin layer ranging from about 1:20 to about 20:1. The solvating polymer in the first layer may be crosslinked or uncrosslinked. The second thin layer comprises a solvating polymer, an ionic salt, and optionally a plasticizer, the second thin layer being disposed on the first thin layer and having an average thickness of about 15 μm or less. The solvating polymer of the first layer is the same or different from the solvating polymer of the second layer.

[0084] The inorganic compound is preferably in particulate form (e.g., spherical, rod-shaped, needle-shaped, etc.). The average particle size is preferably on the nanometer scale, for example less than 1 μm, less than 500 nm, or less than 300 nm, or less than 200 nm, or between 1 nm and 500 nm, or between 10 nm and 500 nm, or between 50 nm and 500 nm, or between 100 nm and 500 nm, or between 1 nm and 300 nm, or between 10 nm and 300 nm, or between 50 nm and 300 nm, or between 100 nm and 300 nm, or between 1 nm and 200 nm, or between 10 nm and 200 nm, or between 50 nm and 200 nm, or between 100 nm and 200 nm, or between 1 nm and 100 nm, or between 10 nm and 100 nm, or between 25 nm and 100 nm, or between 50 nm and 100 nm.

[0085] Non-limiting examples of inorganic compounds include the compounds Al2O3, Mg2B2O5, Na2O·2B2O3, xMgO·yB2O3·zH2O, TiO2, ZrO2, ZnO, Ti2O3, SiO2, Cr2O3, CeO2, B2O3, B2O, SrBi4Ti4O 15 , LLTO, LLZO, LAGP, LATP, Fe2O3, BaTiO3, γ-LiAlO2, metal / carbon mixtures (Sn+C, Zn+C, Ni2P+C, etc.), molecular sieves or zeolites (e.g., aluminosilicates, mesoporous silicas), sulfide ceramics (Li7P3S 11 ), glass ceramics (such as LIPON), and other ceramics, and combinations thereof.

[0086] The surface of the inorganic particle can also be modified by an organic group covalently grafted to the surface. For example, the group can be selected from one of crosslinkable groups (e.g., organic groups containing acrylate, methacrylate, vinyl, glycidyl, mercapto functional groups, etc.), aryl, alkylene oxide or poly(alkylene oxide) groups, and other organic groups, or combinations thereof, and can optionally include a spacer group between the organic group and the inorganic particle.

[0087] According to other embodiments, the crosslinkable groups may include silane or halogenated silane, phosphonate, carboxylate, catechol, (meth)acrylate or poly(meth)acrylate, alkylene or polyalkylene functional groups, and combinations thereof. Scheme 1 shows an example of a grafting method for a silane containing a propyl methacrylate group. Scheme 1 [ka]

[0088] In this example, the methacrylate group present on the propylsilane functionality can then react with a compatible group to form a polymer chain, such as a polyether, etc. An example of this type of reaction is shown below in Scheme 3.

[0089] In some cases, inorganic particles have a small specific surface area (e.g., 80 m 2 / g or less than 40m 2 / g or less). In this case, the concentration of the inorganic compound in the first thin layer may be relatively high. For example, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer may be in the range of about 2:5 to about 4:1, or about 2:5 to about 2:1, or about 1:2 to about 2:1, or about 4:5 to about 2:1, or about 1:1 to about 2:1, or about 4:5 to about 3:2.

[0090] In other cases, inorganic particles have a high specific surface area (e.g., 80 m2 / g or greater, or 120m 2 / g or more). In this case, the greater the porosity of the inorganic compound, the greater the amount of polymer that may be required, and the concentration of the inorganic compound in the first thin layer will be lower. Then, for example, the weight ratio of "inorganic compound:solvating polymer" in the first thin layer may range from about 1:20 to about 2:1, or from about 2:5 to about 2:1, from about 2:5 to about 6:5, or from about 1:20 to about 6:5, or from about 2:5 to about 1:1, or from about 1:20 to about 1:1, or from about 2:5 to about 4:5, or from about 1:20 to about 4:5.

[0091] As mentioned above, the average thickness of the first and second thin layers is such that the latter is considered a modification of the electrode surface rather than an electrolyte layer. As mentioned above, the average thickness of the first and second thin layers is less than 15 μm, respectively.

[0092] For example, in the first thin layer, the average thickness can be between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm.

[0093] With respect to the second thin layer, its average thickness can be between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, or between about 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm.

[0094] For example, the total average thickness of the first and second thin layers may be in the range of about 1 μm to about 30 μm, or about 1 μm to about 25 μm, or about 5 μm to about 25 μm, or about 1 μm to about 20 μm, or about 1 μm to about 16 μm, or about 2 μm to about 12 μm, or about 3 μm to about 15 μm, or about 3 μm to about 12 μm, or about 4 μm to about 15 μm, or about 4 μm to about 12 μm.

[0095] The polymers present in the first and / or second layers are independently selected from polymers containing ionic solvation units, particularly lithium ions. Examples of solvation polymers include linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, polyvinyl alcohol, polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, optionally containing crosslinking units derived from crosslinkable functional groups (e.g., acrylate, methacrylate, vinyl, glycidyl, mercapto, etc.).

[0096] According to some embodiments, at least one of the first and second thin layers further comprises a plasticizer. The first and second thin layers may each comprise a plasticizer. In some alternatives, only the first thin layer further comprises a plasticizer. The plasticizers used are generally known to be compatible with electrochemical cells and cycle operating conditions. They generally comprise organic liquids with relatively high boiling points. Non-limiting examples of plasticizers include glycol diethers (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonates (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate), lactones (such as gamma-butyrolactone), adiponitrile, ionic liquids, and similar types of liquids.

[0097] According to a preferred embodiment, at least one of the first and second thin layers further comprises a lithium salt, for example both layers may comprise a lithium salt. Non-limiting examples of lithium salts include lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyano-imidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride. (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkylphosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(CO)2] (LBBB), or a combination of two or more thereof.

[0098] As mentioned above, the electrode film may include a metal film, preferably a metal film of lithium or an alloy containing lithium, optionally on a current collector. When the metal film is a lithium film, it is composed of lithium containing less than 1000 ppm (i.e., less than 0.1 wt%) of impurities. Alternatively, the lithium alloy may include at least 75 wt% lithium, or between 85% and 99.9 wt% lithium. The alloy may further comprise an element selected from alkali metals other than lithium (such as Na, K, Rb, and Cs), alkaline earth metals (such as Mg, Ca, Sr, and Ba), rare earth metals (such as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), zirconium, copper, silver, bismuth, cobalt, manganese, zinc, aluminum, silicon, tin, antimony, cadmium, mercury, lead, molybdenum, iron, boron, indium, thallium, nickel, and germanium (e.g., Zr, Cu, Ag, Bi, Co, Zn, Al, Si, Sn, Sb, Cd, Hg, Pb, Mn, B, In, Tl, Ni, or Ge).

[0099] The electrode film may further comprise a pretreatment layer on the first surface in contact with the first thin layer. For example, the pretreatment layer comprises a thin layer of a compound selected from silanes, phosphonates, borates, organic salts or compounds, carbon (e.g., graphite, graphene, etc.), inorganic salts or compounds (e.g., LiF, Li3N, Li3P, LiNO3, Li3PO4, etc.), or an element that is different from the metal of the electrode film or forms an alloy with it at the surface (e.g., an element defined above with reference to alloys), said pretreatment layer having an average thickness of less than 1 μm, or less than 500 nm, or less than 200 nm, or less than 100 nm, or less than 50 nm. The pretreatment layer is generally produced by contacting the first surface of the electrode film with an organic or inorganic compound using known processes. For example, contacting a lithium film with PCl3 generally produces Li3P and / or Li3PO4. Similarly, deposition of a powder or a very thin film of a metal element different from the metal of the electrode film, for example selected from the elements defined above, can produce a thin alloy layer.

[0100] For example, a pretreatment layer is formed on the electrode film before the first thin layer is applied. The surface of the electrode film can also be treated, for example by stamping, before the first thin layer is applied.

[0101] In another embodiment, the electrode includes a current collector in contact with the second surface of the electrode film.

[0102] Electrochemical cells comprising the surface modified electrodes of the present invention are also contemplated. For example, such electrochemical cells comprise a negative electrode and a positive electrode, at least one of which is as defined herein and can be illustrated, for example, in Figures 4(c), (d), and (f). According to a preferred embodiment, the negative electrode is as defined herein and comprises an electrode film as defined above; the positive electrode comprises a film of a positive electrode material, including a positive electrochemically active material, optionally a binder, and optionally a conductive material.

[0103] For example, the positive electrode electrochemically active material may be selected from metal phosphates, lithiated metal phosphates, metal oxides, and lithiated metal oxides, as well as other materials such as elemental sulfur, selenium or iodine, iron (III) fluoride, copper (II) fluoride, lithium iodide, carbon-based active materials, etc. Examples of positive electrode electrochemically active materials include LiM'PO4 (where M' is Fe, Ni, Mn, Co, or a combination thereof), LiV3O8, VO5F, LiV2O5, LiMn2O4, LiM"O2 (where M" is Mn, Co, Ni, or a combination thereof) (NMC, LiMn x Co y Ni z Li(NiM''')O2 (wherein x+y+z=1), Li(NiM''')O2 (wherein M''' is Mn, Co, Al, Fe, Cr, Ti, Zr, or a combination thereof), elemental sulfur, elemental selenium, elemental iodine, iron(III) fluoride, copper(II) fluoride, lithium iodide, carbon-based active materials, organic cathode active materials such as polyimide, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), tetramethylphenyl methacrylate ... Examples of suitable materials include tra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi4), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), π-conjugated dicarboxylates, and anthraquinones, or combinations of two or more of these materials, if compatible with each other and with the negative electrode, e.g., with the lithium electrode. The positive electrode electrochemically active material is preferably in the form of particles, which may be optionally coated, e.g., with a polymer, ceramic, carbon, or combinations of two or more of these.

[0104] Examples of conductive materials that can be included in the electrode material include carbon black (e.g., Ketjen™, Denka™, Shawinigan, acetylene black, etc.), graphite, graphene, carbon nanotubes, carbon fibers (including carbon nanofibers, vapor grown carbon fibers (VGCF), etc.), non-powdered carbon obtained by carbonization of organic precursors (e.g., as a coating on a particle), or a combination of at least two of these.

[0105] Non-limiting examples of electrode material binders include the polymeric binders described above in connection with the thin layer or below for the electrolyte, as well as rubber-type binders such as SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), and ACM (acrylate rubber), or fluorinated polymer-type binders such as PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), and combinations thereof. Some binders, such as rubber-type binders, may contain additives such as CMC (carboxymethylcellulose).

[0106] Other additives may be present in the electrode material, such as lithium salts, or inorganic particles such as ceramics or glasses, or other compatible active materials (eg, sulfur).

[0107] According to one example, a film of a cathode material includes a first and a second surface, the first surface facing the anode and carrying a thin third layer comprising a solvating polymer (e.g., as defined above), an ionic salt (e.g., as defined above), the thin third layer having an average thickness of about 50 μm or less, about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or about 10 μm or less. or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm. The third thin layer may, for example, comprise a plasticizer as defined above.

[0108] The positive electrode material can be deposited on a current collector (e.g., aluminum, copper). According to one example, the current collector is carbon coated aluminum.

[0109] According to one example, the electrochemical cell excludes the presence of a solid polymer electrolyte layer, e.g., excludes electrolyte layers having a thickness greater than 15 μm, or 20 μm or greater, and it is understood that the cell also does not include any other type of electrolyte, e.g., a liquid or gel impregnating the separator.

[0110] Alternatively, the electrochemical cell further comprises a solid electrolyte layer comprising a polymer and a lithium salt. For example, the polymer from the electrolyte may be selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers, and optionally containing crosslinkable units), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, poly(vinyl alcohol), polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, the solvating polymer being optionally crosslinked. The lithium salt may be as defined above in connection with the thin layer. The solid electrolyte may further comprise a ceramic.

[0111] According to an alternative embodiment, the present document also relates to an electrochemical cell comprising a negative electrode and a positive electrode, the negative electrode comprising a negative electrode film and the positive electrode comprising a positive electrode material film comprising a positive electrode electrochemically active material, optionally a binder, and optionally a conductive material:

[0112] (a) a negative electrode film comprising a first and a second surface, the first surface being optionally pretreated, said negative electrode comprising a first lamina comprising an inorganic compound in a solvating polymer, and optionally an ionic salt and / or a plasticizer, the first lamina disposed on the first surface of the negative electrode film and having an average thickness of about 15 μm or less, the weight ratio of "inorganic compound:solvating polymer" in the first lamina being in the range of about 1:20 to about 20:1; (b) the negative electrode comprises a second thin layer comprising a solvating polymer, an ionic salt, and optionally a plasticizer, the second thin layer disposed on the first thin layer and having an average thickness of about 15 μm or less, the solvating polymer of the first layer being the same as or different from the solvating polymer of the second layer; and / or the positive electrode material film includes a first and a second surface, the first surface facing the negative electrode and carrying a thin third layer comprising a solvated polymer and an ionic salt, the thin third layer having an average thickness of about 50 μm or less, or about 15 μm or less; The electrochemical cell excludes the presence of an additional solid polymer electrolyte layer. The electrochemical cell also excludes any other type of additional electrolyte, thereby precluding the use of, for example, a liquid or gel-type electrolyte impregnated into the separator. Examples of such cells are shown in Figures 4(d), (e), and (f).

[0113] According to one embodiment, the electrochemical cell includes a second thin layer. In another embodiment, the electrochemical cell includes a third thin layer. In yet another embodiment, the electrochemical cell includes a second and a third thin layer.

[0114] The solvating polymer of each of the lamina is independently as defined herein and may be independently crosslinked or non-crosslinked. According to one example, the solvating polymer of at least one of the first, second and third layers is not crosslinked. According to one example, the solvating polymer of the first layer is not crosslinked. According to another example, the solvating polymer of the second layer is not crosslinked. The solvating polymer in each of the first, second and third layers may be not crosslinked. Or the polymer in the third layer is crosslinked and the first and second layers are not crosslinked. Alternatively, the solvating polymer in each of the first, second and third layers may be crosslinked.

[0115] As with the electrode films described above, the negative electrode film of the electrochemical cell of the invention is a current collector, which may be, for example, a current collector comprising an electronically conductive solid support, such as a metal foil or grid (e.g., copper, nickel, etc.), a carbon or carbon-containing film (e.g., carbon paper, free-standing graphene, etc.), or other solid support (polymer, glass, etc.) that comprises an electronically conductive layer (such as a current collector print). Alternatively, the negative electrode film may comprise a metal film, such as, for example, lithium or an alloy containing lithium, which may also be a film of lithium and its alloys as defined above. The negative electrode film of the invention may also comprise a pretreatment layer as described above.

[0116] The inorganic material of the first thin layer is as defined above and can be included in the same weight ratios as discussed above.

[0117] The average thickness of the first thin layer can be between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm.

[0118] The average thickness of the second thin layer can be between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between about 2 μm and about 5 μm, or between about 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm.

[0119] In fact, when a second lamina is present, the total average thickness of the first and second lamina is preferably in the range of from about 1 μm to about 30 μm, or from about 1 μm to about 25 μm, or from about 5 μm to about 25 μm, or from about 1 μm to about 20 μm, or from about 1 μm to about 16 μm, or from about 2 μm to about 12 μm, or from about 3 μm to about 15 μm, or from about 3 μm to about 12 μm, or from about 4 μm to about 15 μm, or from about 4 μm to about 12 μm.

[0120] The average thickness of the third thin layer is about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm.

[0121] It may be noted that when only one of the second and third lamina is present, the layer present may have a slightly larger thickness. When both the second and third lamina are present, they will be thinner, and the total average thickness of the first, second and third lamina may be in the range of about 3 μm to about 60 μm, or about 10 μm to about 50 μm, or about 15 μm to about 30 μm, or about 3 μm to about 30 μm, or about 3 μm to about 25 μm, or about 5 μm to about 25 μm, or about 5 μm to about 20 μm, or about 8 μm to about 15 μm, or about 8 μm to about 12 μm, or about 5 μm to about 15 μm, or about 5 μm to about 12 μm, or about 5 μm to about 15 μm, or about 9 μm to about 15 μm.

[0122] According to some embodiments, at least one of the first and second thin layers further comprises a plasticizer, preferably the first and second thin layers further comprise a plasticizer. The third thin layer may also further comprise a plasticizer. The plasticizer is also as defined above. Similarly, at least one of the first, second and third thin layers may further comprise a lithium salt, preferably each of the three layers. The lithium salt is also as defined above.

[0123] The negative electrode may further include a current collector in contact with the second surface of the negative electrode film. Similarly, the positive electrode may further include a current collector in contact with the second surface of the positive electrode material film. The positive electrode material is also as defined with reference to the preceding electrochemical cell.

[0124] This document relates to an electrochemical accumulator comprising at least one electrochemical cell as defined herein, for example the electrochemical accumulator being a lithium battery or a lithium ion battery.

[0125] According to another aspect, the electrochemical accumulator of the present application is intended for use in mobile devices, such as mobile phones, cameras, tablets or laptops, in electric or hybrid vehicles, or in renewable energy storage.

[0126] This document also relates to a process for preparing the surface modified electrodes described herein, comprising: (i) mixing an inorganic compound and a solvated polymer in a solvent, optionally including a salt and / or a plasticizer; (ii) spreading the mixture obtained in (i) on the electrode surface; (iii) removing the solvent to obtain a first thin layer; (iv) mixing a solvated polymer and a salt in a solvent, optionally including a plasticizer; (v) spreading the mixture obtained in (iv) on the first thin layer obtained in (iii); and (vi) removing the solvent.

[0127] When steps (i) and / or (iv) further comprise a cross-linking agent, the process may further comprise a polymer cross-linking step (e.g. ionically, thermally or by irradiation) before, after or between steps (iii) and / or (vi), respectively.

[0128] When the electrode is a metal film, such as lithium, steps (ii), (iii), (v), and / or (vi) are preferably carried out under vacuum or in an anhydrous chamber which may be filled with an inert gas, such as argon.

[0129] Alternatively, when the polymer is crosslinkable and sufficiently liquid prior to crosslinking, the process can exclude the presence of a solvent and avoid steps (iii) and / or (vi).

[0130] The mixing step can be carried out by various methods used in the field of the present technology, for example such methods may include planetary mixers, ball mixers, disk mixers, ultrasonic mixers (e.g. sonotrode mixers), homogenizers (such as rotor-stator homogenizers), etc.

[0131] Spreading can be accomplished by conventional methods using, for example, rollers such as rolling mill rollers coated with the mixture (including continuous roll-to-roll processing methods), doctor blades, spray coating, centrifugation, printing, and the like.

[0132] The organic solvent used can be any solvent that does not react with the electrode film, e.g., does not react with lithium when the electrode film contains lithium metal. Examples include tetrahydrofuran (THF), dimethylsulfoxide (DMSO), heptane, toluene, or combinations thereof. EXAMPLES

[0133] The following non-limiting examples are illustrative embodiments and should not be construed to further limit the scope of the invention. These examples will be better understood with reference to the accompanying figures.

[0134] Unless otherwise specified, numerical values ​​expressing the amount, preparation conditions, concentrations, properties, etc. of ingredients used herein shall be understood in each case to be modified by the term "about". At the very least, each numerical parameter should be interpreted in light of the reported significant digits and by applying ordinary rounding techniques. Thus, unless otherwise indicated, the numerical parameters set forth herein are approximations that may vary depending on the properties sought. Nevertheless, while the parameters defining the broadest realizations are approximations, the numerical values ​​presented in the following examples are reported as precisely as possible. However, any numerical value inherently contains certain error ranges obtained from variations in experiments, measurements, statistical analyses, and the like. Example 1 Ceramic synthesis and characterization (a) Synthesis and characterization of Ni2P

[0135] Ni2P nanoparticles are synthesized by the liquid route using a vacuum lamp ("Schlenk line"), but can also be synthesized by other known means, for example under pressurized solvothermal conditions using an autoclave.

[0136] 0.9962 g of Ni(acac)2 and 20 mL of 1-octadecene are added to a 250 mL three-neck flask containing a magnetic stir bar. The mixture is gently stirred (500 RPM) and the temperature of the mixture is allowed to increase to 120° C. The reaction mixture is then stirred at this temperature under vacuum for 30 minutes to remove volatile impurities and traces of water. The system is then purged with argon, which is bubbled through the liquid for at least 5 minutes. 8 mL of tri-n-octylphosphine is then introduced through the septum using a syringe. The mixture is then heated to 320° C. and allowed to react for 20 hours.

[0137] The mixture is then slowly cooled to room temperature and centrifuged in a small 25 mL centrifuge tube at 10,000 RPM for 30 minutes. The powder is easier to recover due to the absence of surfactant. The light brown supernatant is removed, the powder is redispersed in ethanol, and the resulting black liquid is centrifuged again. This step is repeated three more times. A black powder is obtained in approximately 90% yield.

[0138] Figure 1(a) shows the X-ray diffraction pattern of the powder of the obtained material. The peaks obtained are relatively broad and not very intense, confirming the nanometer size of the Ni2P particles. Only one phase is obtained, which is in fact Ni 12 P5 phase. Figure 1(b) shows the Ni 12 1 shows a scanning microscope image of P5 powder, where a single phase is clearly visible and consists of small spherical particles with a diameter of about 20 nm. (b) Synthesis and characterization of modified Al2O3 (Al2O3-polymer)

[0139] The bonding of the polymer to the ceramic surface is carried out in two steps. For demonstration purposes, Al2O3 powder (needle-like, ca. 164 μm) was used. 2 / g) was used. First, a silanization reaction is carried out on the surface of the Al2O3 particles to attach crosslinkable groups. Scheme 2 shows this first surface modification step. Scheme 2 [ka]

[0140] Approximately 10 g of Al2O3 powder is dispersed in 100 mL of toluene using an ultrasonic rod. The mixture is poured into a 250 mL glass round-bottom flask equipped with an air condenser. The mixture is kept under stirring and the system is purged with nitrogen for 10 minutes. Approximately 1 g of 3-(trimethoxysilyl)propyl methacrylate is then added and the liquid is kept at 90°C for 17 hours. Once the liquid has returned to room temperature, it is centrifuged (5000 RPM, 20 minutes) using a 250 mL centrifuge tube. The resulting powder is cleaned with acetone three times by centrifugation and then dried under vacuum at 140°C for at least 24 hours.

[0141] The second step consists in the polymerization of the polyethylene glycol units on the surface of the Al2O3 particles. Scheme 3 shows the reaction protocol. Scheme 3 [ka]

[0142] The modified powder prepared above is dispersed again in toluene using the same dispersion method. Nitrogen is bubbled into the liquid to remove traces of oxygen. Polyethylene glycol methacrylate (Mn=500g / mol) is added in a ratio of 15% by weight relative to the alumina, followed by 0.5% by weight of azobisisobutyronitrile (AIBN).

[0143] The assembly is equipped with an air condenser and a flow of nitrogen is maintained throughout the reaction. The temperature is set at 80°C for 17 hours. When the liquid returns to room temperature, it is centrifuged (5000 RPM, 20 minutes) using a 250 mL centrifuge tube. The resulting powder is cleaned with acetone by centrifugation three times, then dried at 120°C under vacuum for at least 24 hours. This powder is called Al2O3-polymer.

[0144] Figure 2(a) shows the thermogravimetric curves for Al2O3 (solid line) and Al2O3-polymer (dashed line) powders. The continuous mass loss between 200 and 600 °C for the modified powders means that about 10% of the polymer is in the final composite. Figure 2(b) shows an example of a coating (1 μm thin layer) made on a lithium strip with an ink composed of Polymer 1 + Al2O3-polymer. Polymer 1 refers to the polymer detailed in US Pat. No. 6,903,174, which contains crosslinkable groups. Example 2 Ink formulation for electrode surface modification (a) Polymer ink (no inorganic compounds) i. Polymer inks A1-A5 (without inorganic compounds) and conductivity test

[0145] A plasticizer, tetraethylene glycol dimethyl ether (TEGDME), is used to increase the ionic conductivity of the lithium deposit. Inks were prepared according to the proportions shown in Table 1 by mixing polymer 1 with lithium salt (LiTFSI) in a molar ratio of O:Li=20:1 and with various amounts of TEGDME (ranging from 8 to 40% by weight of polymer 1). A crosslinker, Irgacure-651™, was also added at 0.5% by weight relative to the weight of polymer 1.

[0146] The deposition was carried out by doctor blade on a 50 μm thick stainless steel strip on a coating table. The strip was left to rest for 5 minutes in a fume hood and then inserted in a box equipped with an ultraviolet (UV) lamp under a nitrogen flow. After 5 minutes of nitrogen purging, the film was crosslinked under UV light for 2 minutes.

[0147] These films are then assembled into button cells and conductivity measurements are taken at various temperatures between 20 and 80° C. FIG. 3 shows the conductivity measurements recorded at various temperatures for the various films A1 to A5 deposited on stainless steel. Compared to film A1 with polymer 1 and without TEGDME, almost an order of magnitude higher conductivity is obtained after adding only 8% TEGDME. At 50° C., a very good conductivity of 1.02×10 -3 S / cm are obtained for film A5 containing 40% TEGDME. The mechanical strength of the film is also very good, despite the presence of 40% liquid (TEGDME). ii. Polymer ink A6 (for cathode coating)

[0148] In a plastic container compatible with a Thinky type planetary mixer, an appropriate amount of polymer 1 is introduced along with an amount of LiTFSI salt adjusted to obtain a 20:1 O:Li molar ratio. Tetrahydrofuran (THF), an anhydrous solvent, is added in an amount sufficient to obtain an 18.5% solids solution (polymer + salt) after mixing. The solution is mixed in the planetary mixer at 2000 RPM for 3 minutes. This mixing step is repeated 7 times. iii. Polymer Ink A7 (for cathode coating)

[0149] In a plastic container compatible with a Thinky type planetary mixer, an appropriate amount of polymer 1 is introduced with an amount of LiTFSI salt adjusted to obtain a 25:1 O:Li molar ratio. An amount of plasticizer (TEGDME) equal to 40% of the polymer weight is added. A second anhydrous solvent, tetrahydrofuran (THF), is added in an amount sufficient to obtain a 21% solids (polymer + salt + TEGDME) solution after mixing. In this calculation, TEGDME is included in the solids content. Finally, 0.5% by weight of Irgacure™ relative to the polymer is added as a crosslinking agent. The solution is mixed in a planetary mixer at 2000 RPM for 10 minutes, three times. iv. Polymer Ink A8 with Plasticizer (for second layer coating)

[0150] For coating on lithium, a slightly higher concentration of 44% TEGDME was chosen for the polymer-inorganic and polymer films to promote intermixing of the ceramic particles, adhesion and good conductivity of the deposited layers.

[0151] For the second lithium coating, which does not contain ceramic, the polymer solution is prepared as follows: In a plastic container compatible with a Thinky type planetary mixer, an appropriate amount of polymer 1 is introduced together with an amount of LiTFSI salt to obtain a 20:1 O:Li molar ratio. Then 44% by weight of TEGDME relative to the polymer is added, and all is mixed in a planetary mixer at 2000 RPM for 3 minutes. THF is added in an amount sufficient to give a solution containing 18.1% solids (polymer + salt) after mixing. The solution is mixed in a planetary mixer at 2000 RPM for 3 minutes. This mixing step is repeated 6 times. v. Polymer Ink A9 (for spray application of the second layer)

[0152] A precise amount of polymer 2 is added to a glass bottle. Polymer 2 refers to the polymer detailed in U.S. Pat. No. 6,903,174, except that it does not contain crosslinkable groups. An amount of LiTFSI salt is added to give a 20:1 O:Li molar ratio. THF solvent is added to obtain a very dilute solution of the polymer with salt. Typically, a solution containing 4% solids is obtained (salt + polymer). The solution is quickly homogenized by simple hand mixing. [Table 1] a.Percentages are by weight relative to the weight of Polymer 1. (b) Polymer-inorganic inks B1 to B5 (for anode coating) i. Step 1 (B1 to B3 including Al2O3-polymer ceramic)

[0153] In a plastic container compatible with a Thinky type planetary mixer, a suitable amount of polymer 1 is introduced together with an amount of LiTFSI salt adjusted to obtain a molar ratio of O:Li of 20:1. Then, 44% by weight of TEGDME relative to the polymer is added and everything is mixed in a planetary mixer at 2000 RPM for 3 minutes. After standing for 2 minutes, an amount of Al2O3-polymer ceramic corresponding to a ratio of 56% to 130% of the polymer weight is added and everything is mixed again at 2000 RPM for 3 minutes. This mixing step is repeated four times. The resulting homogeneous and agglomerate-free ink is diluted with anhydrous THF to obtain a solution containing 17% solids (polymer + salt + ceramic). The solution is mixed twice at 2000 RPM for 3 minutes.

[0154] The compositions of inks B1 to B3 (excluding solvent) are listed in Table 2. In some experiments, Irgacure™ (0.5% by weight relative to the polymer) was also added as a crosslinker. These compositions can then be designated B1(i) to B3(i), where (i) indicates the additional presence of Irgacure™. ii. Step 2 (B4 with metal / carbon mixture)

[0155] Further tests were carried out with nanometer-scale Sn or Zn metal particles, as well as with the metal phosphide Ni2P. 2 Carbon black with spherical particles of 0.1 g / g was used. In a plastic container, a suitable amount of polymer 1 is introduced with a sufficient amount of LiTFSI salt to obtain a molar O:Li ratio of 20:1. Then, 44% by weight of TEGDME relative to the polymer is added and everything is mixed with a disk mixer (Ultra-Turrax® type) at 1000 RPM for 2 minutes until a homogeneous liquid is obtained. Then, an amount of Sn, Zn, or Ni2P (Ni2P prepared according to Example 1(a)) between 30 and 90% by weight relative to the polymer is added. 12P5 phase) is introduced into a plastic container. Then 10% to 20% by weight of carbon is added. The total content is mixed in a disc mixer at 2500 RPM for 8 minutes. A sufficient amount of THF is added to obtain a solution containing 17% solids (polymer + salt + carbon + metals) after mixing. Finally, after the THF is introduced, the solution is mixed one last time in a disc mixer at 2500 RPM for 2 minutes.

[0156] Ink B4 shown in Table 2 is an example of an ink that contains a mixture of Ni2P and carbon. iii. Procedure 3 (B5-a and B5-b containing Al2O3)

[0157] In a plastic container, a quantity of unmodified alumina (type AKPG15, not sieved) is mixed with THF using a sonotrode (50% power) for 4 minutes (ink B5-a) or an IKA type rotor-stator homogenizer at maximum power for 10 minutes (ink B5-b). Meanwhile, a polymer solution is prepared. It contains an amount of polymer 1 equal in weight to the alumina, to which LiTFSI salt is added to obtain a 20:1 O:Li molar ratio. A mass of plasticizer (TEGDME) equal to 100% of the polymer weight is added, without the addition of a crosslinker. The polymer solution is mixed in a planetary mixer at 2000 RPM for 10 minutes three times. Finally, the solution is poured into a plastic container containing ceramic and THF solvent. The final solution contains about 21% solids (polymer + salt + ceramic + TEGDME). It is stirred one last time in a conical tube before being coated with lithium. [Table 2] a.Percentages are by weight relative to the weight of Polymer 1. b. Variation between B5-a and B5-b due to mixing method (see Example 2(b)(iii)) Example 3 Surface modified electrodes and electrochemical properties

[0158] Examples of cell configurations studied (in accordance with the invention and for comparison) are shown in Figures 4(a) to 4(f). The cells in 4(a) to 4(c) contain a polymer electrolyte, whereas the cells in Figures 4(d) to 4(f) do not. All lithium used contain at least a first thin layer of an inorganic compound in a polymer (denoted Polymer 1 + Al2O3 - Polymer). The cells in Figures 4(c), 4(d), and 4(f) contain a second, ceramic-free layer of Polymer 1 attached to the surface of the first layer. The cells in Figures 4(b), 4(e), and 4(f) contain a layer of Polymer 1 containing a lithium salt on the cathode surface, but do not contain any ceramic or plasticizer. (a) Modified electrode (one cross-linked layer) (Figure 4(a) type cell)

[0159] The coin cells were then filled with LFP cathode (8 mg / cm 2 , composition: carbon-coated LFP:carbon black:polymer 1:LiTFSI in a ratio of about 73:1:19:7), lithium with a layer of polymer 1+Al2O3-polymer, and a free-standing electrolyte based on branched polyethylene oxide with allyl ether type functional groups (hereafter referred to as SPE) film (25 μm thick) were assembled. Polymer 1+Al2O3-polymer inks B1(i), B2(i), and B3(i) were prepared (see Example 2(b) and Table 2). It should be noted that in this example, the film deposited on the lithium was crosslinked (with 0.5 wt. % Irgacure™).

[0160] Coating with these inks was performed on the lithium surface using a doctor blade on a coating table at a speed of 10 mm / s. The lithium was left in a fume hood for 5 minutes and then in an oven at 50° C. for 5 minutes to evaporate the remaining THF. The film was then placed in a box under nitrogen flow equipped with a UV lamp. After 5 minutes of nitrogen purging, the film was crosslinked under UV light for 2 minutes. The thickness of the deposit is about 4 μm after drying and crosslinking.

[0161] A typical assembly is illustrated in FIG. 4(a) (various Al2O3-polymer contents for inks B1(i) to B3(i)). Assemblies are thus made with three lithium coated layers with different polymer modified ceramic contents. FIG. 5(a) shows the galvanostatic cycling performed at 50° C. and C / 6 for the different batteries and for the reference (LFP cathode and lithium anode without modification and free-standing polymer electrolyte). FIG. 5(b) shows the capacity drop during cycling for the same battery. The two batteries are cycled with lithium and the cycling is relatively reproducible. Compared to the cycling for the reference battery, the battery with polymer+ceramic layer gives a higher discharge capacity. As the amount of ceramic increases, the capacity is higher and the cycling is more stable. (b) Modified electrode (one layer without cross-linking) (Figure 4(a) type cell)

[0162] Without the addition of crosslinker (inks B1, B2 and B3), the same deposition was carried out on lithium as the previous one (as in Example 3(a) above), but this time without crosslinking. Concerning the electrochemical performance (see FIG. 6), the conclusions are similar. The more ceramic the polymer layer composition contains, the higher the discharge capacity (FIG. 6(a)) and the more stable the cycling as it proceeds (FIG. 6(b)). Therefore, in the following examples of coating on lithium, the percentage of ceramic was set to 130%. Also, the polymer layer in the following examples is not crosslinked. Above 130%, in this case of ceramic, the layer starts to lose mechanical properties, approaching a layer of the "polymer in ceramic" type. Therefore, coating tests including a double deposition of a polymer layer on lithium were also carried out. (c) Modified electrode (one layer without cross-linking) (Figure 4(a) type cell).

[0163] Further coating tests were carried out keeping the Al2O3-polymer content fixed at 130% (ink B3 according to example 3(b)) and varying the percentage of solids in the ink between 17 and 24% depending on the amount of THF solvent added to the ink. The corresponding galvanostatic cycling obtained at 50°C and C / 6 is shown in Fig. 7(a) and the stability of the cycling is shown in Fig. 7(b). It appears clear that the higher the percentage of solids, the better the discharge capacity. There is only a very slight difference between 21 and 24% solids. The capacity loss (Fig. 7(b)) is very similar in each case of modified lithium and the capacity retention is slightly better with 21% solids in the ink composition. However, it is preferred to use a solids content of about 17% to allow a better dispersion of the ceramic in the ink. Thus in the following examples (first layer on lithium with various fillers such as modified Al2O3, Sn+carbon, Zn+carbon) the solids content with the various ceramics is set to about 17%. (d) Typical cell from Figures 4(a) to 4(f) and comparative cycle behavior (at C / 3).

[0164] Cells corresponding to the representations in FIGS. 4(a) through 4(f) were prepared with the components listed in Table 3. [Table 3] a. "-" indicates the absence of an element, layers A6, A8 and B3 are defined in Example 2. b. Composition of the LFP cathode defined in Example 3(a).

[0165] Figure 8 shows (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50 °C and C / 3 for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with lithium with a 4 μm layer of polymer 1 containing 130% Al2O3-polymer (cell C1). The polymer film is not crosslinked. Compared to the three reference cells, the two C1 cells with modified lithium have better reproducibility and do not show a progressive capacity gain over the first two cycles. The specific discharge capacity is also slightly higher for the cells with modified lithium. Furthermore, better coulombic efficiency (about 99%) is obtained from the second cycle for the cells assembled with lithium containing a ceramic layer, compared to a coulombic efficiency of approximately 91-92% obtained for the reference cells.

[0166] Figure 9 shows (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50 °C and C / 3 for an LFP / polymer electrolyte / Li battery assembled with lithium and unmodified LFP cathodes (reference) and then with lithium and LFP cathodes with 2 or 4 μm polymer layers with a 4 μm layer of polymer 1 with 130% Al2O3-polymer (C2-a and C2-b cells, respectively). The polymer films are not crosslinked. The configuration for the lithium modified cell assembly is shown as an inset in Figure 9(b). Compared to the C1 cell assembly, an LFP cathode with a thin polymer layer was used for the cells of Figure 9 (except for the reference). The overall cell resistance was reduced by the addition of this polymer layer on the LFP cathode, since discharge capacities of about 112 and 115 mAh / g were realized when 4 and 2 μm layers were deposited on the cathode surface, respectively. When this layer was not added to the cathode, the discharge capacity was about 100 mAh / g (see FIG. 8(a)). Again, the reproducibility is very good using polymer layers on both the lithium and cathode, as shown by the two cells cycled with a cathode with a 4 μm polymer layer. The coulombic efficiency is also good for the cells with modified cathodes and anodes. A coulombic efficiency of about 77% is obtained in the first cycle when a cathode modified with a 2 or 4 μm polymer layer is used, compared to only 62 to 66% for the reference cell. This experiment demonstrates that a thin polymer layer on the surface of the electrodes (anode and cathode) allows for better bonding with the free-standing polymer electrolyte, thus reducing the interfacial resistance.

[0167] As mentioned above, the amount of ceramic in the polymer layer deposited on the lithium surface is set to 130%, beyond which the layer loses not only mechanical properties but also adhesive properties. Therefore, a second adhesion layer, containing no ceramic but only polymer, salt, and TEGDME, is deposited on the surface of the first polymer 1+Al2O3-polymer layer to reduce the interfacial resistance between the anode and the polymer electrolyte. The polymer film is not crosslinked. Figure 10 shows (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50 °C and C / 3 for an LFP / polymer electrolyte / Li battery assembled with unmodified lithium (reference), then with a first 4 μm layer of polymer 1 with 130% Al2O3-polymer, and with lithium with a second 4 μm layer of polymer 1 (cell C3). The inset image (Figure 10(b)) provides a better view of the two layers deposited on the lithium surface. The improvement of the interface between the free-standing polymer electrolyte and the anode is clearly visible, since an initial discharge capacity of 121 mAh / g was realized, compared to about 100 mAh / g obtained for the C1 cell when only the Al2O3-polymer layer was deposited on the lithium (see cycling in Figure 8(a)). However, a gradual capacity loss was observed; the layer may not be optimal in this case. The coulombic efficiency reaches 80% at the first cycle for the cycled C3 cell with lithium containing both polymer layers (62 to 66% in the case of the reference cell).

[0168] To ensure the validity of having a second adhesive layer on the lithium surface, certain cell assemblies were used without the addition of free-standing electrolyte. The inset scheme in Figure 11(b) shows the assemblies tested. A second layer of polymer 1 with TEGDME was deposited on the lithium surface with relatively large thicknesses of 9 and 12 μm (C4-a and C4-b cells in Table 3, respectively). Figure 11 shows (a) galvanostatic cycling behavior and (b) coulombic efficiency obtained at 50 °C and C / 3 for LFP / polymer electrolyte / Li batteries assembled with lithium without modification (reference), then C4-a and C4-b batteries. The polymer film is not crosslinked. The difference in capacity is considerable when the free-standing polymer electrolyte is removed, causing many resistance and interface problems in the battery. The first cycle discharge capacity is about 145-149 mAh / g for the battery without polymer electrolyte, compared to 85-90 mAh / g for the reference battery. However, in this case the interface between the cathode with surface defects and the second layer of polymer 1 deposited on the lithium surface is not optimal. In fact, small variations in the discharge capacity (Figure 11(a)) can be observed, but mainly the more important variations are in the coulombic efficiency (Figure 11(b)), typical of interfacial problems. At this stage, the electrochemical results seem more stable with a thicker second polymer layer (12 μm vs. 9 μm), but the determining factor remains the optimization of the interface between the surface of this polymer layer and the cathode surface.

[0169] To confirm that the interface between the polymer layer on the anode and the cathode surface is not optimal and is the cause of the variation in coulombic efficiency, a layer of polymer 1 without TEGDME was deposited on the cathode surface. The inset scheme in Figure 12(b) shows the assemblies tested. Three different polymer layer thicknesses were used, 5, 8 and 11 μm (C5-a, C5-b and C5-c cells in Table 3, respectively). It should be noted that for these cells there is only one layer of polymer 1 + Al2O3-polymer on the lithium surface. The polymer film is not crosslinked. Figure 12 shows (a) galvanostatic cycling and (b) coulombic efficiency obtained at 50 °C and C / 3 for these batteries as well as for a reference for comparison. The electrochemical results are striking: the three cells are reproducible and therefore there is virtually no difference in their cycling (Figure 12(a)). The initial discharge specific capacity is about 145 mAh / g. A gradual drop in capacity is observed, but it seems to stabilize as the cycling proceeds. Coulombic efficiencies approaching 99% are achieved in the first cycle, which is even better than the 62% to 66% for the reference cells. It is important to note that the thickness of the cathode deposit (5, 8 or 11 μm) does not affect the electrochemical cycling behavior under the test conditions.

[0170] Finally, a final series of tests was performed by reducing the thickness of the polymer layer on the cathode, since the thickness of the polymer layer on the cathode appears to have little effect on the cycling stability. Furthermore, to promote adhesion between the cathode and the lithium anode, a second layer of 3 or 4 μm of polymer 1 + TEGDME was deposited on the lithium (cells C6-a and C6-b in Table 3, respectively). The polymer film is not crosslinked. The configuration of these cells is as shown in the inset of Figure 13(b). The galvanostatic cycling and coulombic efficiency obtained at 50 °C and C / 3 for these batteries and for the reference are shown in Figures 13(a) and 13(b). The cycling is very similar to that obtained in Figure 12, fully demonstrating the utility of depositing thin layers directly on the surfaces of the cathode and anode to avoid free-standing polymer electrolytes. Moreover, in this cell configuration, the lithium bears an Al2O3-polymer rich layer that allows the stabilization of the lithium. (e) Modified electrode (one layer without cross-linking) (Figure 4(a) type cell)

[0171] As already mentioned in step 2 of Example 2(b)(iii), an input of inorganic compounds different from Al2O3-polymer was also used. Carbon / metal (M) mixtures were tested with the aim of forming a Li-M alloy during lithium plating from the cathode to the lithium anode. Carbon is also used for electronic conduction in the polymer layer. As an example, two metals were tested (i.e. Sn and Zn), as well as nickel phosphide Ni2P. Only one type of carbon was tested, but others can be used. Figure 14 shows the galvanostatic cycling obtained at 50 °C and C / 3 for an LFP / polymer electrolyte / Li battery assembled with unmodified lithium (reference) and then with lithium with a 5 μm layer of polymer 1 with 30% Ni2P and 17% carbon (layer B4 in Table 2). The polymer film is not crosslinked. This is a first result, but it confirms that the concept works. Compared to the reference battery, an increase in the initial capacity can be seen. However, a gradual drop in capacity can be observed as the cycling proceeds. This type of layer can benefit from cell configurations such as those shown in Figures 4(d) to 4(f), particularly that in Figure 4(f) which corresponds to the C6(a or b) cell shown above, where the Al2O3-polymer can be replaced by the carbon / metal mixture. Example 4 Surface modified electrodes with spray-deposited second layers and electrochemical properties.

[0172] Other cells according to the invention are configured as shown in Figure 4(f). However, the first thin layer of inorganic compound in the polymer consists of polymer 1 and unmodified alumina (Al2O3). The second thin layer on the lithium is deposited by spraying in a very thin layer and contains polymer 2 rather than polymer 1 and no plasticizer. The cells also contain layers of various thicknesses of polymer 1 on the cathode surface containing lithium salt and plasticizer but no ceramic. Several batteries were prepared for each to be tested in parallel. (a) Preparation of cells C7 to C9 For cell C7, the procedure is as follows:

[0173] Cathode: Ink A7 prepared in Example 2 is applied by doctor blade to the surface of the LFP cathode as described in Example 3(a) to achieve a thickness of 40 μm after crosslinking. Once coated, the cathode is left in a fume hood for 5 minutes, then in an airtight box under nitrogen for 5 minutes, and then crosslinked under UV light for 10 minutes.

[0174] Anode (first layer): Ink B5-a obtained in example 2 is deposited by doctor blade on the surface of the lithium film. The coating is dried for 5 minutes in a fume hood and then in an oven at 50 ° C for 5 minutes before the next step. The thickness of the dried deposit is about 8-9 μm.

[0175] Anode (second layer): The solution obtained for ink A9 prepared in Example 2 is sprayed under a fume hood onto the surface of the first layer on lithium with 60 psi argon pressure, at a distance of about 30 cm, with two passes over the surface of Li. Finally, the modified lithium foil is dried for 5 minutes in a fume hood at 50° C. The layer obtained is very thin (close to 1 μm) but could not be measured precisely.

[0176] The free surface of the polymer on the cathode is then attached to the polymer surface of the second layer on the anode, and the resulting multi-layer material is pressed together to form a pouch-type battery from the material.

[0177] Cell C8 is prepared as for cell C7 by depositing a 30 μm layer instead of 40 μm on the cathode. Ink B5-a is also replaced by ink B5-b resulting in a layer thickness of about 7-8 μm.

[0178] Cell C9 was prepared in the same manner as cell C7, with a 20 μm layer on the cathode instead of 40 μm. [Table 4] The composition of layers A7, A9 and B5 (a and b) is defined in Example 2. b. The composition of the LFP cathode is defined in Example 3(a). c. Ultra-thin layer (thickness not measured) (b) Electrochemical results for cells C7 to C9

[0179] 15 to 17 show the electrochemical results obtained during cycling of cells C7 to C9 in comparison with a LFP / polymer electrolyte / Li cell assembled with unmodified lithium (reference).

[0180] Figure 15(a) shows that cell C7 is more stable during cycling than the reference cell. This aspect is even more evident in Figure 15(c), where a significant drop in coulombic efficiency is observed at about cycle 20 for the reference cell, whereas it remains stable for the C7 cell. Figure 15(b) also shows a higher average voltage for the C7 cell compared to the reference cell.

[0181] 16(a) and 16(b) show the cycling stability and coulombic efficiency results for the C8 cell, which are relatively similar to those obtained for the C7 cell.

[0182] 17 shows the capacity rate results obtained for the C9 cell over five cycles at cycling rates of C / 6, C / 4, C / 3, C / 2, and 1 C, respectively. Greater stability can be observed for the C9 cell compared to the reference cell, especially at increased cycling rates. Example 5 Pretreated electrodes with modified surfaces and electrochemical properties

[0183] An organic, inorganic or metallic pretreatment of the surface of the metal electrode film (in this case lithium) can also be carried out to form a pretreatment layer, which can consist of the formation of a passivation layer, the formation or deposition of a compound, an organic or inorganic salt, or an alloy with a metal different from that of the electrode film.

[0184] Examples of deposition of polymer1+Al2O3-polymer layer (ink B3) were carried out on various lithium films that had undergone pretreatment. Figure 18 shows the galvanostatic cycling behavior obtained at 50 °C, C / 3 (a) and C / 6 (b) for LFP / polymer electrolyte / Li batteries assembled with unmodified lithium (reference) and with lithium pretreated with (a) inorganic molecules (PCl3) and (b) a thin metal layer (Zn). These lithiums showed that they could help stabilize the cycling behavior. The aim is to exert an accumulation effect with the polymer+inorganic compound layer and possibly with a second layer. Therefore, a first pretreatment is recommended to passivate the lithium surface and increase lithium diffusion at its surface, followed by deposition of an anti-dendritic polymer and allowing adhesion with the solid electrolyte (polymer or ceramic type). Figure 19 shows photographs of lithium strips that have undergone (a) treatment with PCl3 and (b) deposition of polymer1+Al2O3-polymer after treatment with PCl3. The first PCl3 deposit is very uniform and gives a light brown color (see FIG. 19(a)). The integrity and quality of this first deposit is not affected by the deposition of the Polymer1+Al2O3-polymer layer, as shown in FIG. 19(b).

[0185] Several modifications can be made to any of the above-described embodiments without departing from the scope of the invention as contemplated. All references, patents, or scientific literature documents mentioned herein are incorporated by reference in their entirety for all purposes.

Claims

1. An electrode comprising an electrode film modified with a first thin layer and a second thin layer, - The electrode film includes first and second surfaces, and the first surface is pretreated as required, - The first thin layer includes an inorganic compound in a solvated polymer that is crosslinked or not crosslinked, and optionally an ionic salt and / or a plasticizer. The first thin layer is disposed on the first surface of the electrode film and has an average thickness of about 15 μm or less. The weight ratio "inorganic compound: solvated polymer" in the first thin layer is in the range of about 1:20 to about 20:1; - The second thin layer includes a solvated polymer that is crosslinked or not crosslinked, an ionic salt, and optionally a plasticizer. The second thin layer is disposed on the first thin layer and has an average thickness of about 15 μm or less, The electrode wherein the solvated polymer of the first layer is the same as or different from the solvated polymer of the second layer.

2. The electrode according to claim 1, wherein the electrode film is a current collector, for example, a metal foil or grid (copper, nickel, etc.), carbon or a carbon-containing film (carbon paper, free-standing graphene, etc.), or another solid support (polymer, glass, etc.) including an electronically conductive solid support such as an electronically conductive layer (current collector print, etc.).

3. The electrode film contains, for example, lithium (preferably the lithium contains impurities of less than 1000 ppm (or less than 0.1% by weight)), or an alloy containing lithium (preferably lithium and an alkali metal other than lithium (such as Na, K, Rb, and Cs), an alkaline earth metal (such as Mg, Ca, Sr, and Ba), a rare earth metal (such as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc.), zirconium, copper, silver, bismuth, cobalt, manganese, zinc, aluminum, silicon, tin, antimony, cadmium, mercury, lead, molybdenum, iron, boron, indium, thallium, nickel, and germanium (for example, an alloy with an element selected from Zr, Cu, Ag, Bi, Co, Zn, Al, Si, Sn, Sb, Cd, Hg, Pb, Mn, B, In, Tl, Ni, or Ge)), and the alloy preferably contains at least 75% by weight of lithium, or lithium between 85% and 99.9% by weight. The electrode according to claim 1.

4. The electrode film further includes a pretreatment layer in contact with the first thin layer on the first surface, and the pretreatment layer preferably includes a compound selected from silane, phosphonate, borate, an organic salt or organic compound, carbon (such as graphite, graphene, etc.), an inorganic salt or inorganic compound (such as LiF, Li3N, Li3P, LiNO3, Li3PO4, etc.), or a thin layer of an element different from the metal of the electrode film or forming an alloy with it on the surface (such as the elements defined in claim 3). The pretreatment layer has an average thickness of less than 5 μm, preferably less than 3 μm, or less than 1 μm, or less than 500 nm, or less than 200 nm, or less than 100 nm, or less than 50 nm, and / or the first surface of the electrode film is pretreated by stamping. The electrode according to any one of claims 1 to 3.

5. The inorganic compound is in particulate form (e.g., spherical, rod-shaped, needle-shaped, etc.), and the average particle size is, for example, less than 1 μm, or less than 500 nm, or less than 300 nm, or less than 200 nm, or between 1 nm and 500 nm, or between 10 nm and 500 nm, or between 50 nm and 500 nm, or between 100 nm and 500 nm, or between 1 nm and 300 nm, or between 10 nm and 300 nm, or between 50 nm and 300 nm, or between 100 nm and 300 nm, or between 1 nm and 200 nm, or between 10 nm and 200 nm, or between 50 nm and 200 nm, or between 100 nm and 200 nm, or between 1 nm and 100 nm, or between 10 nm and 100 nm, or between 25 nm and 100 nm, or between 50 nm and 100 nm. The electrode according to any one of claims 1 to 3.

6. The inorganic compound contains a ceramic, or the inorganic compound is selected from Al₂O₃, Mg₂B₂O₅, Na₂O·2B₂O₃, xMgO·yB₂O₃·zH₂O, TiO₂, ZrO₂, ZnO, Ti₂O₃, SiO₂, Cr₂O₃, CeO₂, B₂O₃, B₂O, SrBi₄Ti₄O₁₅, LLTO, LLZO, LAGP, LATP, Fe₂O₃, BaTiO₃, γ-LiAlO₂, metal / carbon mixtures (such as Sn + C, Zn + C, Ni₂P + C, etc.), molecular sieves and zeolites (e.g., those of aluminosilicate, mesoporous silica), sulfide ceramics (such as Li₇P₃S₁₁), glass ceramics (such as LIPON, etc.), and other ceramics, and combinations thereof. The electrode according to claim 5.

7. The particles of the inorganic compound further include an organic group grafted to its surface by a covalent bond. For example, the group is selected from crosslinkable groups (such as organic groups containing acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, etc.), aryl groups, alkylene oxide or poly(alkylene oxide) groups, and other organic groups, or combinations thereof. Optionally, a spacer group is included between the organic group and the particles of the inorganic compound. Preferably, the grafted organic group includes a poly(alkylene oxide) chain bonded to the inorganic compound particles by a spacer group, and / or the spacer group is preferably selected from silanes or silane halides, phosphonates, carboxylates, catechols, (meth)acrylates or poly(meth)acrylates, alkylene or polyalkylene groups, and combinations thereof. The electrode according to claim 5.

8. The inorganic compound particles have a small specific surface area (e.g., less than 80 m ２ / g, or less than 40 m ２ / g), and / or the weight ratio of the "inorganic compound:solvated polymer" in the first thin layer is in the range of about 2:5 to about 4:1, or about 2:5 to about 2:1, or about 1:2 to about 2:1, or about 4:5 to about 2:1, or about 1:1 to about 2:1, or about 4:5 to about 3:

2. The electrode according to claim 5.

9. The inorganic compound particles have a high specific surface area (e.g., 80 m ２ / g or greater, or 120 m ２ / g or greater), and / or the weight ratio of the "inorganic compound: solvated polymer" in the first thin layer is in the range of from about 1:20 to about 2:1, or from about 2:5 to about 2:1, from about 2:5 to about 6:5, or from about 1:20 to about 6:5, or from about 2:5 to about 1:1, or from about 1:20 to about 1:1, or from about 2:5 to about 4:5, or from about 1:20 to about 4:

5. The electrode according to claim 5.

10. - The average thickness of the first thin layer is between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, and / or - The average thickness of the second thin layer is between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between about 2 μm and about 5 μm, or between about 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm, and / or - The total average thickness of the first and second thin layers is in the range of from about 1 μm to about 30 μm, or from about 1 μm to about 25 μm, or from about 5 μm to about 25 μm, or from about 1 μm to about 20 μm, or from about 1 μm to about 16 μm, or from about 2 μm to about 12 μm, or from about 3 μm to about 15 μm, or from about 3 μm to about 12 μm, or from about 4 μm to about 15 μm, or from about 4 μm to about 12 μm. The electrode according to any one of claims 1 to 3.

11. The electrode according to any one of claims 1 to 3, wherein the solvated polymer is selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, polyvinyl alcohol, polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, and optionally contains crosslinked units derived from crosslinkable functional groups (e.g., acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, etc.).

12. The electrode according to any one of claims 1 to 3, wherein at least one of the first and second thin layers further contains a plasticizer, preferably the first thin layer and the second thin layer further contain a plasticizer, and the plasticizer is preferably selected from liquids such as glycol diether types (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonates (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate, etc.), lactones (such as γ-butyrolactone, etc.), adiponitrile, ionic liquids.

13. At least one of the first and second thin layers further contains a lithium salt, preferably the first thin layer and the second thin layer further contain a lithium salt, and the lithium salt is lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyano-imidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkyl phosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(C6O2)2] (LBBB), and preferably selected from combinations thereof, the electrode according to any one of claims 1 to 3.

14. The electrode according to any one of claims 1 to 3, further comprising a current collector in contact with the second surface of the electrode film.

15. An electrochemical cell comprising a negative electrode and a positive electrode, wherein at least one of the negative electrode and the positive electrode is as defined in any one of claims 1 to 3, preferably the negative electrode is as defined in any one of claims 1 to 3, and the positive electrode comprises a film of a positive electrode material comprising a positive electrode electrochemically active material, a binder if necessary, and a conductive material if necessary. An electrochemical cell.

16. The positive electrode electrochemically active material is selected from metal phosphates, lithiated metal phosphates, metal oxides, and lithiated metal oxides, or the positive electrode electrochemically active material is LiM'PO₄ (where M' is Fe, Ni, Mn, Co, or a combination thereof), LiV₃O₈, V₂O₅F, LiV₂O₅, LiMn₂O₄, LiM"O₂ (where M" is Mn, Co, Ni, or a combination thereof (such as NMC, LiMnₓCoᵧNi zO₂ (where x + y + z = 1), etc.)), Li(NiM''')O₂ (where M''' is Mn, Co, Al, Fe, Cr, Ti, Zr, or a combination thereof), elemental sulfur, elemental selenium, elemental iodine, iron(III) fluoride, copper(II) fluoride, lithium iodide, carbon-based active materials, organic cathode active materials (such as polyimide, poly(2,2,6,6-tetramethylpiperidinyl oxy-4-yl methacrylate) (PTMA), tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi₄), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), π-conjugated dicarboxylates, and anthraquinone, etc.), or, when compatible with each other, a combination of two or more of these materials, and the positive electrode electrochemically active material is preferably in the form of particles optionally coated (e.g., with a polymer, ceramic, carbon, or a combination of two or more of these) according to claim 15 of the electrochemical cell.

17. The film of the positive electrode material includes first and second surfaces, the first surface faces the negative electrode, and holds a third thin layer containing a solvated polymer and an ionic salt, the third thin layer having an average thickness of about 50 μm or less, about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, The solvated polymer is preferably selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, polyvinyl alcohol, polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, and optionally includes crosslinked units derived from crosslinkable functional groups (e.g., acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, etc.), The salt is preferably a lithium salt selected from, for example, lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkyl phosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(C6O2)2] (LBBB), and combinations thereof, and / or The electrochemical cell according to claim 16, wherein the third thin layer further contains a plasticizer, which is selected from liquids such as glycol diether type (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonate esters (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate), lactones (such as γ-butyrolactone), adiponitrile, ionic liquids, etc., as needed. Claim 18 The electrochemical cell according to claim 15, wherein the electrochemical cell excludes the presence of a solid polymer electrolyte layer. Claim 19 The electrochemical cell further includes a solid electrolyte layer containing a polymer, a lithium salt, and optionally a ceramic, preferably the electrolyte polymer is a linear or branched polyether polymer (e.g., PEO, PPO, or EO / PO copolymer) containing crosslinkable units as required, poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, poly(vinyl alcohol), polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, the solvated polymer is crosslinked as required, and / or preferably the lithium salt is lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkyl phosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(C6O2)2] (LBBB), and combinations thereof, the electrochemical cell according to claim 15.

20. An electrochemical cell comprising a negative electrode and a positive electrode, (a) The negative electrode includes a negative electrode film including first and second surfaces, the first surface being pretreated as required, the negative electrode including an inorganic compound in a solvated polymer, whether crosslinked or not, and optionally an ionic salt and / or a plasticizer, and a first thin layer, the first thin layer being disposed on the first surface of the negative electrode film and having an average thickness of about 15 μm or less, and the weight ratio of "inorganic compound: solvated polymer" in the first thin layer being in the range of about 1:20 to about 20:

1. (b) The negative electrode includes a second thin layer including a solvated polymer, whether crosslinked or not, an ionic salt, and optionally a plasticizer, the second thin layer being disposed on the first thin layer and having an average thickness of about 15 μm or less, the solvated polymer of the first layer being the same as or different from the solvated polymer of the second layer, and / or (c) The positive electrode includes a positive electrode material film including a positive electrode electrochemically active material, optionally a binder, and optionally a conductive material, the positive electrode material film including first and second surfaces, the first surface facing the negative electrode and holding a third thin layer including a solvated polymer, whether crosslinked or not, and an ionic salt, the third thin layer having an average thickness of about 50 μm or less or about 15 μm or less. (d) The electrochemical cell excludes the presence of an additional solid polymer electrolyte layer and preferably includes the second thin layer. Electrochemical cell. **Claim 21** The electrochemical cell according to claim 20, including the third thin layer. **Claim 22** (e) The negative electrode film is a current collector, for example, a current collector including an electronically conductive solid support such as a metal foil or grid (e.g., copper, nickel, etc.), carbon or a carbon-containing film (e.g., carbon paper, free-standing graphene, etc.), or another solid support (polymer, glass, etc.) including an electronically conductive layer (such as a current collector print). The electrochemical cell according to claim 20. **Claim 23** The negative electrode film contains, for example, lithium (preferably the lithium contains impurities of less than 1000 ppm (i.e., less than 0.1% by weight)) or an alloy containing lithium (preferably lithium and an alkali metal other than lithium (such as Na, K, Rb, and Cs), an alkaline earth metal (such as Mg, Ca, Sr, and Ba), a rare earth metal (such as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc.), zirconium, copper, silver, bismuth, cobalt, manganese, zinc, aluminum, silicon, tin, antimony, cadmium, mercury, lead, molybdenum, iron, boron, indium, thallium, nickel, and germanium (for example, an alloy with an element selected from Zr, Cu, Ag, Bi, Co, Zn, Al, Si, Sn, Sb, Cd, Hg, Pb, Mn, B, In, Tl, Ni, or Ge)), and the alloy preferably contains at least 75% by weight of lithium, or lithium between 85% and 99.9% by weight. The electrochemical cell according to claim 20.

24. The negative electrode film further includes a pretreatment layer contacting the first thin layer on the first surface, and preferably the pretreatment layer is selected from silane, phosphonate, borate, an organic salt or an organic compound, carbon (such as graphite, graphene, etc.), an inorganic salt or an inorganic compound (such as LiF, Li3N, Li3P, LiNO3, Li3PO4, etc.), or a thin layer of an element different from the metal of the negative electrode film or forming an alloy with it on the surface (such as the elements defined in claim 23). The pretreatment layer has an average thickness of less than 5 μm, or less than 3 μm, or less than 1 μm, or less than 500 nm, or less than 200 nm, or less than 100 nm, or less than 50 nm, or the first surface of the negative electrode film is pretreated by stamping. The electrochemical cell according to any one of claims 20 to 23.

25. The inorganic compound is in the form of particles (for example, spherical, rod-shaped, needle-shaped, etc.), and the average size of the particles is preferably less than 1 μm, less than 500 nm, or less than 300 nm, or less than 200 nm, or between 1 nm and 500 nm, or between 10 nm and 500 nm, or between 50 nm and 500 nm, or between 100 nm and 500 nm, or between 1 nm and 300 nm, or between 10 nm and 300 nm, or between 50 nm and 300 nm, or between 100 nm and 300 nm, or between 1 nm and 200 nm, or between 10 nm and 200 nm, or between 50 nm and 200 nm, or between 100 nm and 200 nm, or between 1 nm and 100 nm, or between 10 nm and 100 nm, or between 25 nm and 100 nm, or between 50 nm and 100 nm, the electrochemical cell according to any one of claims 20 to 23.

26. The inorganic compound contains a ceramic, or the inorganic compound is selected from Al₂O₃, Mg₂B₂O₅, Na₂O·2B₂O₃, xMgO·yB₂O₃·zH₂O, TiO₂, ZrO₂, ZnO, Ti₂O₃, SiO₂, Cr₂O₃, CeO₂, B₂O₃, B₂O, SrBi₄Ti₄O₁₅, LLTO, LLZO, LAGP, LATP, Fe₂O₃, BaTiO₃, γ-LiAlO₂, metal / carbon mixtures (such as Sn + C, Zn + C, Ni₂P + C, etc.), molecular sieves and zeolites (for example, those of aluminosilicates, mesoporous silica), sulfide ceramics (such as Li₇P₃S₁₁), glass-ceramics (such as LIPON, etc.), and other ceramics, and combinations thereof, the electrochemical cell according to claim 25.

27. The particles of the inorganic compound further include an organic group grafted to its surface by a covalent bond. For example, the group is selected from a crosslinkable group (such as an organic group containing an acrylate functional group, a methacrylate functional group, a vinyl functional group, a glycidyl functional group, a mercapto functional group, etc.), an aryl group, an alkylene oxide or poly(alkylene oxide) group, and other organic groups, or a combination thereof. Optionally, a spacer group is included between the organic group and the particles of the inorganic compound. Preferably, the grafted organic group includes a poly(alkylene oxide) chain bonded to the inorganic compound particles by a spacer group, and / or preferably the spacer group is selected from a silane or silane halide, a phosphonate, a carboxylate, a catechol, a (meth)acrylate or poly(meth)acrylate, an alkylene or polyalkylene group, and a combination thereof. The electrochemical cell according to claim 25.

28. The inorganic compound particles have a small specific surface area (e.g., less than 80 m ２ / g, or less than 40 m ２ / g), and / or the weight ratio of the "inorganic compound: solvated polymer" in the first thin layer is in the range of about 2:5 to about 4:1, or about 2:5 to about 2:1, or about 1:2 to about 2:1, or about 4:5 to about 2:1, or about 1:1 to about 2:1, or about 4:5 to about 3:

2. The electrochemical cell according to claim 25.

29. The inorganic compound particles have a high specific surface area (e.g., 80 m ２ / g and greater, or 120 m ２ / g and greater), and / or the weight ratio of the "inorganic compound: solvated polymer" in the first thin layer is in the range of about 1:20 to about 2:1, or about 2:5 to about 2:1, about 2:5 to about 6:5, or about 1:20 to about 6:5, or about 2:5 to about 1:1, or about 1:20 to about 1:1, or about 2:5 to about 4:5, or about 1:20 to about 4:

5. The electrochemical cell according to claim 25.

30. - The average thickness of the first thin layer is between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, and / or - The average thickness of the second thin layer is between about 50 nm and about 15 μm, or between about 0.1 μm and about 15 μm, between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, or between 50 nm and about 5 μm, or between about 0.1 μm and about 2 μm, and / or - The second thin layer is present, and the total average thickness of the first and second thin layers is in the range of from about 1 μm to about 30 μm, or from about 1 μm to about 25 μm, or from about 5 μm to about 25 μm, or from about 1 μm to about 20 μm, or from about 1 μm to about 16 μm, or from about 2 μm to about 12 μm, or from about 3 μm to about 15 μm, or from about 3 μm to about 12 μm, or from about 4 μm to about 15 μm, or from about 4 μm to about 12 μm, and / or - The average thickness of the third thin layer is about 40 μm or less, or about 30 μm or less, or about 15 μm or less, or between about 0.5 μm and about 50 μm, or between about 5 μm and about 50 μm, or between about 5 μm and about 40 μm, or between about 0.5 μm and about 15 μm, or between about 1 μm and about 15 μm, or between about 1 μm and about 12 μm, or between about 0.5 μm and about 10 μm, or between about 1 μm and about 10 μm, or between about 2 μm and about 8 μm, or between about 2 μm and about 7 μm, or between 2 μm and about 5 μm, and / or - The second thin layer and the third thin layer are present, and the total average thickness of the first, second, and third thin layers is in the range of from about 3 μm to about 60 μm, or from about 10 μm to about 50 μm, or from about 15 μm to about 30 μm, or from about 3 μm to about 30 μm, or from about 3 μm to about 25 μm, or from about 5 μm to about 25 μm, or from about 5 μm to about 20 μm, or from about 8 μm to about 15 μm, or from about 8 μm to about 12 μm, or from about 5 μm to about 15 μm, or from about 5 μm to about 12 μm, or from about 5 μm to about 15 μm, or from about 9 μm to about 15 μm, The electrochemical cell according to any one of claims 20 to 23.

31. The solvent-solvated polymer is independently selected from linear or branched polyether polymers (e.g., PEO, PPO, or EO / PO copolymers), poly(dimethylsiloxane), poly(alkylene carbonate), poly(alkylene sulfone), poly(alkylene sulfamide), polyurethane, poly(vinyl alcohol), polyacrylonitrile, poly(methyl methacrylate), and copolymers thereof, and optionally contains crosslinking units derived from crosslinkable functional groups (e.g., acrylate functional groups, methacrylate functional groups, vinyl functional groups, glycidyl functional groups, mercapto functional groups, etc.). The electrochemical cell according to any one of claims 20 to 23.

32. At least one of the first and second thin layers further contains a plasticizer, preferably the first thin layer and the second thin layer further contain a plasticizer, and the third thin layer further contains a plasticizer as required. The plasticizer is preferably selected from liquids such as type glycol diethers (such as tetraethylene glycol dimethyl ether (TEGDME)), carbonates (such as propylene carbonate, ethylene carbonate, fluoroethylene carbonate), lactones (such as γ-butyrolactone), adiponitrile, ionic liquids, etc. The electrochemical cell according to any one of claims 20 to 23.

33. At least one of the first, second, and third thin layers further contains a lithium salt, preferably the first, second, and third thin layers further contain a lithium salt, and the lithium salt is lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO3), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiSO3CF3) (LiTf), lithium fluoroalkyl phosphate Li[PF3(CF2CF3)3] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B(OCOCF3)4] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O,O')borate Li[B(C6O2)2] (LBBB), and preferably selected from combinations thereof, an electrochemical cell according to any one of claims 20 to 23.

34. The electrochemical cell according to any one of claims 20 to 23, wherein the negative electrode further comprises a current collector in contact with the second surface of the negative electrode film and / or the positive electrode further comprises a current collector in contact with the second surface of the positive electrode material film.

35. The positive electrode electrochemically active material is selected from metal phosphates, lithiated metal phosphates, metal oxides, and lithiated metal oxides, or the positive electrode electrochemically active material is LiM'PO₄ (where M' is Fe, Ni, Mn, Co, or a combination thereof), LiV₃O₈, V₂O₅F, LiV₂O₅, LiMn₂O₄, LiM''O₂ (where M'' is Mn, Co, Ni, or a combination thereof (such as NMC, LiMnₓCoᵧNi zO₂ where x + y + z = 1)), Li(NiM''')O₂ (where M''' is Mn, Co, Al, Fe, Cr, Ti, Zr, or a combination thereof), elemental sulfur, elemental selenium, elemental iodine, iron(III) fluoride, copper(II) fluoride, lithium iodide, carbon-based active materials, organic cathode active materials (such as polyimide, poly(2,2,6,6-tetramethylpiperidinyl oxy-4-yl methacrylate) (PTMA), tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi₄), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), π-conjugated dicarboxylates, and anthraquinone), or, when compatible with each other, a combination of two or more of these materials, and the positive electrode electrochemically active material is preferably in the form of particles optionally coated (e.g., with a polymer, ceramic, carbon, or a combination of two or more of these) The electrochemical cell according to any one of claims 20 to 23.

36. An electrochemical energy storage battery comprising at least one electrochemical cell as defined in claim 15, wherein the electrochemical energy storage battery is preferably a lithium battery or a lithium-ion battery.

37. An electrochemical energy storage battery comprising at least one electrochemical cell as defined in any one of claims 20 to 23, wherein the electrochemical energy storage battery is a lithium battery or a lithium-ion battery.

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