LITHIUM ALUMINUM TITANIUM PHOSPHATE (LATP) CONTAINING POSITIVE ELECTRODE AND BATTERY CONTAINING IT

Abstract

A positive electrode for a lithium-ion cycling battery comprises a physical mixture of electroactive material particles and lithium aluminum titanium phosphate (LATP) particles. The electroactive material particles comprise a manganese-based, lithium-rich oxide. The electroactive material particles have a first mean particle diameter (D1), the LATP particles have a second mean particle diameter (D2), and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 4:1 and less than or equal to 1000:1. The electroactive material particles (38) have a protective interface obtained by calcining the mixture of electroactive material particles (38) and LATP particles (40) prior to forming the positive electrode (24).

Description

INTRODUCTION

[0001] The present disclosure relates to positive electrodes for batteries that cycle lithium ions, and in particular to particulate additives for positive electrodes comprising lithium-rich oxides and manganese-based oxides as electroactive positive electrode materials.

[0002] A lithium battery with a positive electrode is disclosed in US Patent 2023 / 0 216 023 A1.

[0003] Lithium-ion cycling batteries generally comprise a positive electrode, a negative electrode spaced apart from the positive electrode, and an ionically conductive electrolyte that provides a medium for conducting lithium ions between the positive and negative electrodes during battery discharge and charging. The electrodes may be made of composite materials and include a mixture of electrochemically active (electroactive) material particles, a polymer binder, and optionally an electrically conductive material. The batteries may include additives to prevent unwanted chemical reactions between the electroactive material particles in the electrodes and the electrolyte during battery cycling. Such additives may, for example, promote the formation of robust solid electrolyte interlayers on the surfaces of the electroactive material particles in the electrodes.

[0004] One objective of the invention is to prevent undesirable electrolyte reactions in a lithium-ion cycling battery. SUMMARY

[0005] To solve this problem, a positive electrode with the features of claim 1 and a battery with the features of claim 7 are provided. Advantageous embodiments can be found in the dependent claims, the description, and the accompanying drawings.

[0006] A positive electrode according to the present invention comprises a physical mixture of electroactive material particles and lithium aluminum titanium phosphate particles (LATP particles). The electroactive material particles comprise a manganese-based, lithium-rich oxide. The LATP particles are essentially amorphous, separate from the electroactive material particles, and not physically or chemically bound to them. The electroactive material particles have a first mean particle diameter (D1), the LATP particles have a second mean particle diameter (D2), and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 4:1 and less than or equal to 1000:1.The electroactive material particles have a protective interface obtained by calcining the mixture of electroactive material particles and LATP particles before forming the positive electrode.

[0007] The LATP particles can form lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x (PO4)3 include, where 0.1 ≤ x ≤ 0.6.

[0008] The LATP particles can be present in the positive electrode in an amount that, based on the total weight of the electroactive material particles in the positive electrode, is more than or equal to 0.5% and less than or equal to 4%.

[0009] The ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) can be greater than or equal to 18:1 and less than or equal to 200:1.

[0010] The second mean particle diameter of the LATP particles can be greater than or equal to 10 nanometers and less than or equal to 2 micrometers.

[0011] The first mean particle diameter of the electroactive material particles can be greater than or equal to 8 micrometers and less than or equal to 12 micrometers.

[0012] The electroactive material particles can comprise a layered, lithium-rich, manganese-based transition metal oxide, which is represented by the formula Li 1+x Me 1-x O2 is represented where 0 < x ≤ 0.33, Me includes at least one transition metal and Me contains more than 50% manganese (Mn) on an atomic basis.

[0013] The electroactive material particles can make up more than or equal to 90% of the positive electrode by weight.

[0014] The positive electrode may also include a polymer binder and optionally an electrically conductive material.

[0015] The battery according to the invention, which cycles lithium ions, comprises a negative electrode and a positive electrode spaced apart from the negative electrode. The negative electrode comprises an electroactive negative electrode material. The positive electrode comprises a physical mixture of electroactive material particles and lithium aluminum titanium phosphate (LATP) particles. The electroactive material particles comprise a manganese-based, lithium-rich oxide. The electroactive material particles have a first mean particle diameter (D1), the LATP particles have a second mean particle diameter (D2), and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 18:1 and less than or equal to 200:1. The LATP particles comprise lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x(PO4)3, where 0.1 ≤ x ≤ 0.6. The electroactive material particles have a protective interface obtained by calcining the mixture of electroactive material particles and LATP particles before forming the positive electrode.

[0016] The electroactive material particles can make up more than or equal to 90% of the positive electrode by weight.

[0017] The LATP particles can be present in the positive electrode in an amount that, based on the total weight of the electroactive material particles in the positive electrode, is more than or equal to 0.5% and less than or equal to 4%.

[0018] The second mean particle diameter of the LATP particles can be greater than or equal to 50 nanometers and less than or equal to 0.5 micrometers, and the first mean particle diameter of the electroactive material particles can be greater than or equal to 9 micrometers and less than or equal to 10 micrometers.

[0019] The electroactive material particles can comprise a layered, lithium-rich, manganese-based transition metal oxide, which is represented by the formula Li 1+x Me 1-x O2 is represented where 0 < x ≤ 0.33, Me includes at least one transition metal and Me contains more than 50% manganese (Mn) on an atomic basis.

[0020] After initial and / or repeated cycling of the battery, the positive electrode may further comprise lithium phosphate and / or lithium titanium phosphate oxide.

[0021] In a method for producing a positive electrode for a lithium-ion cycling battery, according to one or more embodiments of the present disclosure, a solid mixture is produced comprising electroactive material particles and lithium aluminum titanium phosphate (LATP) particles. The electroactive material particles comprise a manganese-based, lithium-rich oxide. In the solid mixture, the electroactive material particles have a first mean particle diameter (D1), the LATP particles have a second mean particle diameter (D2) that is smaller than the first mean particle diameter, and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 4:1 and less than or equal to 1000:1.The solid mixture is heated to an elevated temperature to form a calcined mixture comprising the electroactive material particles and the LATP particles. An electrode precursor mixture is prepared, comprising the calcined mixture, a polymer binder, and a solvent. The electrode precursor mixture is applied to a substrate to form an electrode precursor layer. The solvent is then removed from the electrode precursor layer to form the positive electrode.

[0022] The solid mixture can be heated to an elevated temperature of more than or equal to 450 degrees Celsius and less than or equal to 650 degrees Celsius to form the calcined mixture.

[0023] Further applications of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples serve only for illustration and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure will be better understood from the detailed description and the accompanying drawings, whereby: Fig. 1 is a schematic perspective view of a motor vehicle powered by a battery pack with multiple battery modules. Fig. 2 A schematic cross-sectional view of a section of one of the battery modules of Fig. 1 is, where the battery module comprises multiple electrochemical cells or batteries that cycle lithium ions. Fig.Figure 3 is a schematic cross-sectional view of a battery that cycles lithium ions, wherein the battery comprises a positive electrode, a negative electrode, a porous separator and an electrolyte that penetrates the positive and negative electrodes and the porous separator.

[0025] Reference symbols may be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0026] The positive electrodes disclosed herein comprise a physical mixture of electroactive material particles of the positive electrode and lithium aluminum titanium phosphate (LATP) particles and can be used in batteries that cycle lithium ions to improve their cycling stability.

[0027] Fig.Figure 1 represents a motor vehicle 2 powered by an electric motor 4, which draws power from a battery pack 6 with one or more battery modules 8. The battery modules 8 can be connected electrically in series and / or parallel to meet the required capacity and power requirements of the electric motor 4. The vehicle 2 can be a purely electric vehicle powered exclusively by the electric motor 4, or the vehicle 2 can be a hybrid electric vehicle powered by the electric motor 4 and an internal combustion engine (not shown).

[0028] As in Fig.As shown in Figure 2, each battery module 8 comprises one or more electrochemical cells or batteries 10 that cycle lithium ions. In practice, the batteries 10 in the battery module 8 are often assembled as a stack of layers, including negative electrode layers 12, negative electrode current collectors 13, positive electrode layers 14, positive electrode current collectors 15, and separator layers 16. Each battery 10 is defined as a negative electrode layer 12 and a positive electrode layer 14, separated from each other by a separator layer 16. In practice, the separator layer 16 may be infiltrated with an electrolyte that provides a medium for conducting lithium ions between the negative electrode layer 12 and the positive electrode layer 14, or the separator layer 16 itself may act as the electrolyte.The layers 12 of the negative electrode are arranged on the current collectors 13 of the negative electrode and are electrically connected to them, and the layers 14 of the positive electrode are arranged on the current collectors 15 of the positive electrode and are electrically connected to them. As in . Fig. As shown in Figure 2, for efficiency reasons the layers can be stacked such that some of the current collectors 13 of the negative electrode and some of the current collectors 15 of the positive electrode are double-sided, each comprising layers 12 of the negative electrode or layers 14 of the positive electrode on both sides. In this arrangement, adjacent layers 12 of the negative electrode and layers 14 of the positive electrode each share a single current collector 13 of the negative electrode or a single current collector 15 of the positive electrode.

[0029] Fig.Figure 3 represents an electrochemical cell or battery 20 that cycles lithium ions. The battery 20 can generate an electric current when discharged, which can be used to supply a load device (e.g., the electric motor 4), and can be recharged by connecting it to a power source. As shown in Fig. 1 and Fig.In addition to the batteries 10 shown, battery 20 can be used in some aspects to supply energy to an electric motor 4 of a motor vehicle 2. Additionally or alternatively, battery 20 can also be used in other transportation applications (e.g., motorcycles, boats, tractors, buses, motorhomes, caravans, tanks, and aircraft) and to supply power to stationary and / or portable electronic devices, components, and equipment used in a variety of other industries and applications, such as industrial, residential, and commercial buildings, consumer goods, industrial plants and machinery, agricultural equipment, and heavy machinery, to name just a few.

[0030] The battery 20 comprises a negative electrode 22, a positive electrode 24, a separator 26, and an electrolyte 28, which provides a medium for conducting lithium ions between the negative electrode 22 and the positive electrode 24. The negative electrode 22 is located on a main surface of a current collector 30 of the negative electrode, and the positive electrode 24 is located on a main surface of a current collector 32 of the positive electrode. In practice, the current collector 30 of the negative electrode and the current collector 32 of the positive electrode are electrically connected to a power source or load 34 (e.g., the electric motor 4) via an external circuit 36. The negative electrode 22 and the positive electrode 24 are configured such that an electrochemical potential difference arises between the negative electrode 22 and the positive electrode 24 when the battery 20 is at least partially charged.During the discharge of battery 20, the electrochemical potential between the negative electrode 22 and the positive electrode 24 leads to spontaneous reduction and oxidation reactions (redox) within the battery 20 and to the release of lithium ions and electrons from the negative electrode 22. The released lithium ions migrate from the negative electrode 22 through the separator 26 and the electrolyte 28 to the positive electrode 24, while the electrons migrate from the negative electrode 22 to the positive electrode 24 via the external circuit 36, which generates an electric current.After the negative electrode 22 has been partially or completely discharged of lithium, the battery 20 can be recharged by connecting the negative electrode 22 and the positive electrode 24 to the power source 34. This causes non-spontaneous redox reactions within the battery 20 and results in the release of lithium ions and electrons from the positive electrode 24. The repeated discharging and charging of the battery 20 can be referred to as "cycling," with one complete charge followed by one complete discharge constituting a full cycle.

[0031] The positive electrode 24 is designed to store and release lithium ions during the charging and discharging of the battery 20. The positive electrode 24 has the form of a continuous porous layer and can be arranged on the main surface of the current collector 32 of the positive electrode. As shown in Fig.As shown in Figure 3, the positive electrode 24 comprises electroactive material particles 38, lithium aluminum titanium phosphate (LATP) particles 40, a polymeric binder 42, and optionally an electrically conductive material (not shown). The electroactive material particles 38, the LATP particles 40, the polymeric binder 42, and the optional electrically conductive material can be substantially homogeneously distributed over the positive electrode 24. In some aspects, the positive electrode 24 can have a porosity of more than or equal to 10%, or optionally more than or equal to 20% and less than or equal to 40%, or optionally less than or equal to 30%.

[0032] The electroactive material particles 38 can constitute, based on weight, more than or equal to 50%, optionally more than or equal to 60%, optionally more than or equal to 70%, optionally more than or equal to 90%, or optionally more than or equal to 95% and less than or equal to 98% of the positive electrode 24. The electroactive material particles 38 can have a mean particle diameter of more than or equal to 8 micrometers (µm), or optionally more than or equal to 9 micrometers and less than or equal to 12 micrometers, or optionally less than or equal to 10 micrometers. In some aspects, the electroactive material particles 38 can have a substantially equiaxial structure and an aspect ratio of greater than or equal to 1 and less than or equal to 2, optionally less than or equal to 1.5, or optionally less than or equal to 1.2.

[0033] The electroactive material particles 38 of the positive electrode 24 comprise an electroactive material (an electroactive material of the positive electrode) formulated to store and release lithium ions by undergoing a reversible redox reaction with lithium at a higher electrochemical potential than the electroactive material of the negative electrode 22, such that an electrochemical potential difference exists between the negative electrode 22 and the positive electrode 24. The electroactive material particles 38 may comprise a material capable of storing and releasing lithium or a material capable of undergoing a conversion reaction with lithium. In aspects where the electroactive material particles 38 comprise an intercalation host material that enables the reversible storage or intercalation of lithium ions, the electroactive material particles 38 may comprise a lithium transition metal oxide.The electroactive material particles 38 can, for example, be a layered lithium transition metal oxide of the formula LiMeO2 and / or Li2MeO3, a layered lithium-rich transition metal oxide of the formula Li. 1+x Me 1-x O2 (with 0 < x ≤ 0.33), an olivine-type lithium transition metal oxide represented by the formula LiMePO4, a monoclinic-type lithium transition metal oxide represented by the formula Li3Me2(PO4)3, a spinel-type lithium transition metal oxide represented by the formula LiMe2O4, a tavorite represented by one or both of the following formulas LiMeSO4F or LiMePO4F, or a combination thereof, where Me is a transition metal (e.g., Co, Ni, Mn, Fe, Al, V, or a combination thereof).

[0034] In embodiments, the electroactive material particles 38 can comprise an electroactive “high-voltage” material and have an upper limit potential of more than or equal to 4.3 V, optionally more than or equal to 4.4 V, optionally more than or equal to 4.6 V, or optionally more than or equal to 4.8 V and less than or equal to 5 V relative to Li + / exhibit Li. In some aspects, the electroactive material particles 38 can comprise a layered, lithium-rich, manganese-based transition metal oxide, which is given by the formula Li 1+x Me 1-xO2 is represented, where 0 < x ≤ 0.33 and Me comprises, on an atomic basis, more than or equal to approximately 50% manganese (Mn), or optionally more than or equal to 60% Mn and less than or equal to 100% Mn, or optionally less than or equal to 70% Mn. In some embodiments, Me may comprise Mn, Ni, and Co. In other embodiments, Me may comprise Mn and Ni. Such layered, lithium-rich, manganese-based transition metal oxides can have an upper limit potential of at least 4.6 V relative to Li. + / Li exhibit.

[0035] The LATP particles 40 are designed to form a protective interface between the electroactive material particles 38 and the electrolyte 28, which infiltrates the positive electrode 24 and helps to prevent and / or inhibit unwanted chemical reactions between the electroactive material particles 38 and the electrolyte 28 during the cycling of the battery 20, without hindering the transfer of lithium ions between the electroactive material particles 38 and the electrolyte 28.

[0036] The LATP particles 40 are formulated to be electrochemically inactive, electrically insulating, ionically conductive, and chemically compatible with the other components of the positive electrode 24. The LATP particles 40 can form lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x(PO4)3, where x is greater than or equal to 0.1, optionally greater than or equal to 0.2, or optionally greater than or equal to 0.3 and less than or equal to 0.6, or optionally less than or equal to 0.5. In some aspects, the LATP particles can be lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x (PO4)3, where x is approximately 0.4. In some aspects, the LATP particles 40 can decompose during the initial and / or repeated cycling of the battery 20 and form electrically insulating and ionically conductive Li-, Ti-, P- and / or O-containing compounds, such as lithium phosphate (Li3PO4) and / or lithium titanium phosphate oxide (e.g., LiTiPO5), which can contribute to the formation of a protective interface between the electroactive material particles 38 and the electrolyte 28.

[0037] The mean particle diameter of the LATP particles 40 and the amount of LATP particles 40 contained in the positive electrode 24 can be selected based on the mean particle diameter and the amount of electroactive material particles 38 contained in the positive electrode 24. For example, the electroactive material particles 38 can have a first mean particle diameter (D1), and the LATP particles 40 can have a second mean particle diameter (D2) that is smaller than the first mean particle diameter (D1) of the electroactive material particles 38. In certain aspects, the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) can be greater than or equal to 4:1, or optionally greater than or equal to 18:1 and less than or equal to 1000:1, or optionally less than or equal to 200:1.In some aspects, the LATP particles 40 can have a mean particle diameter of more than or equal to 10 nanometers (nm), or optionally more than or equal to 50 nanometers and less than or equal to 2 micrometers, or optionally less than or equal to 0.5 micrometers. In some aspects, the LATP particles 40 in the positive electrode 24 can be contained in an amount that, relative to the total weight of the electroactive material particles 38 in the positive electrode 24, is more than or equal to 0.5%, optionally more than or equal to 1%, or optionally more than or equal to 1.5% and less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2.5%, or optionally less than or equal to 2%.In some aspects, this can mean that the LATP particles 40 constitute, by weight, more than or equal to 0.55%, optionally more than or equal to 1%, or optionally more than or equal to 1.5% and less than or equal to 3.8%, optionally less than or equal to 3%, optionally less than or equal to 2.5%, or optionally less than or equal to 2% of the positive electrode 24.

[0038] The LATP particles 40 can have an essentially equiaxial structure and an aspect ratio greater than or equal to 1 and less than or equal to 2, optionally less than or equal to 1.5, or optionally less than or equal to 1.2. The LATP particles 40 are essentially amorphous (non-crystalline), meaning that the LATP particles 40 can be less than or equal to 1% crystalline, optionally less than or equal to 0.1% crystalline, or optionally 0% crystalline.

[0039] The electroactive material particles 38 and the LATP particles 40 are present in the positive electrode 24 as a physical mixture of discrete particles, meaning that the LATP particles 40 are not physically or chemically bonded to the electroactive material particles 38 in the positive electrode 24. Furthermore, the LATP particles 40 are not present as a uniform and / or continuous coating on the surfaces of the electroactive material particles 38 in the positive electrode 24. Without being bound to the theory, it is assumed that the composition of the LATP particles 40 and their relatively small average particle diameter compared to that of the electroactive material particles 38 allow the LATP particles 40 to form a robust but discontinuous network around the electroactive material particles 38.Furthermore, it is assumed that the composition of the LATP particles 40 and the relatively small mean particle diameter of the LATP particles 40 compared to that of the electroactive material particles 38, enable the LATP particles 40 to form an interface between the electroactive material particles 38 and the electrolyte 28, which effectively prevents the occurrence of undesired chemical reactions between the electroactive material particles 38 and the electrolyte 28 during the cycling of the battery 20, without inhibiting the transfer of lithium ions between the electroactive material particles 38 and the electrolyte 28 and without inhibiting the movement of lithium ions through the positive electrode 24.

[0040] The polymeric binder 42 is electrochemically inactive and can be incorporated into the positive electrode 24 to provide structural integrity to the positive electrode 24 and / or to help the positive electrode 24 adhere to the main surface of the positive electrode current collector 32. Examples of polymeric binders include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber, styrene-butadiene rubber (SBR), carboxymethylcellulose (CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), styrene-ethylene-butylene-styrene copolymer (SEBS), polyacrylates, alginates, polyacrylic acid, and combinations thereof. The polymeric binder 42 can constitute more than or equal to 1% or optionally more than or equal to 2% and less than or equal to 10% or optionally less than or equal to 5% of the positive electrode 24 by weight.

[0041] The optional electrically conductive material is electrochemically inactive and can be included in the positive electrode 24 to provide sufficient electrical conductivity to support electron percolation through it. Examples of electrically conductive materials include carbon-based materials, metals (e.g., nickel), and / or electrically conductive polymers. Examples of electrically conductive carbon-based materials include carbon black (CB) (e.g., acetylene black), graphite, graphene (e.g., graphene nanoplatelets, GNP), graphene oxide, carbon nanotubes (CNTs), and / or carbon fibers (e.g., carbon nanofibers). Examples of electrically conductive polymers include polyaniline, polythiophene, polyacetylene, and / or polypyrrole.When included in the positive electrode 24, the optional electrically conductive material can constitute more than 0%, optionally more than or equal to 1% and less than or equal to 10%, or optionally less than or equal to 5% of the positive electrode 24.

[0042] The negative electrode 22 is designed to store and release lithium ions to facilitate the charging and discharging of the battery 20, respectively. The negative electrode 22 can take the form of a continuous layer of material arranged on a major surface of the current collector 30 of the negative electrode. The negative electrode 22 comprises an electroactive material (negative electrode electroactive material) that can store and release lithium ions by undergoing a reversible redox reaction with lithium during the charging and discharging of the battery 20. Examples of negative electrode electroactive materials include lithium, lithium-based materials (e.g., lithium-silicon alloys, aluminum, indium, and / or tin), carbon-based materials (e.g., graphite, activated carbon, carbon black, hard carbon, soft carbon, and / or graphene), silicon, silicon-based materials (e.g.,Alloys of silicon and lithium, tin, iron, aluminum and / or cobalt), silicon oxide, silicon oxide-based materials (e.g., lithium silicon oxide), tin oxide, aluminum, indium, zinc, germanium, titanium oxide, lithium titanate and combinations thereof. The electroactive material of the negative electrode 22 can constitute, by weight, more than or equal to approximately 50%, optionally more than or equal to approximately 60%, or optionally more than or equal to approximately 70% and less than or equal to approximately 97%, optionally less than or equal to approximately 90%, or optionally less than or equal to approximately 80% of the negative electrode 22.

[0043] In embodiments, the electroactive material of the negative electrode 22 can be a silicon oxide-based material (e.g., Si, SiO₂). x and / or Li y SiO x) and a carbon-based material (e.g., graphite). In this case, the silicon oxide-based material can constitute more than or equal to 10% and less than or equal to 70%, or optionally less than or equal to 30%, of the electroactive material of the negative electrode 22 by weight, and the carbon-based material (e.g., graphite) can constitute more than or equal to 30%, or optionally more than or equal to 70% and less than or equal to 90%, of the electroactive material of the negative electrode 22 by weight.

[0044] In embodiments, the negative electrode 22 can be porous, and the electroactive material of the negative electrode 22 can be a particulate material. In embodiments where the electroactive material of the negative electrode 22 is a particulate material, the particles of the electroactive material of the negative electrode 22 can be mixed with a polymeric binder and optionally an electrically conductive material. The same polymeric binders and / or electrically conductive materials disclosed above with respect to the positive electrode 24 can be used in the negative electrode 22 in substantially the same amounts. In other embodiments, the electroactive material of the negative electrode 22 can be formed from lithium, and the negative electrode 22 can be in the form of a non-porous metal film or foil, such as a lithium metal film or foil.In this case, the negative electrode 22 can comprise more than 97 wt.% lithium or optionally more than 99 wt.% lithium. In embodiments in which the electroactive material of the negative electrode 22 is formed from lithium, the negative electrode 22 can be substantially free of elements or compounds that undergo a reversible redox reaction with lithium during operation of the battery 20. Furthermore, in embodiments in which the electroactive material of the negative electrode 22 is formed from lithium, the negative electrode 22 can be substantially free of a polymeric binder.

[0045] The separator 26 physically separates the negative electrode 22 and the positive electrode 24 from each other and electrically isolates them while allowing the passage of lithium ions. The separator 26 has an open microporous structure and can comprise an organic and / or inorganic material. For example, the separator 26 can comprise a polymer. Examples of polymers for the separator 26 include polyolefins (e.g., polyethylene, PE, and / or polypropylene, PP), polyamide (PA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), and combinations thereof. In one form, the separator 26 can comprise a polymer laminate, e.g., a laminate of PE and PP. In some aspects, the separator 26 can have a ceramic coating (not shown) on one or both sides. In this case, the ceramic coating can include particles of aluminum oxide (Al2O3) and / or silicon dioxide (SiO2).The separator 26 can have a thickness of more than or equal to approximately 5 micrometers (µm), optionally more than or equal to approximately 10 µm or optionally more than or equal to approximately 20 µm and less than or equal to approximately 500 µm, optionally less than or equal to approximately 200 µm or optionally less than or equal to approximately 50 µm.

[0046] The electrolyte 28 is ionically conductive and provides a medium for conducting lithium ions between the negative electrode 22 and the positive electrode 24. The electrolyte 28 comprises an organic solvent and a lithium salt in the organic solvent.

[0047] The organic solvent may include a non-aqueous aprotic organic solvent. Non-restrictive examples of non-aqueous aprotic organic solvents include cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), fluoroethylene carbonate (FEC), and vinylene carbonate (VC)); linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC)); aliphatic carboxylic acid esters (e.g., methyl formate, methyl acetate, methyl propionate); lactones (e.g., γ-butyrolactone, γ-valerolactone, and / or δ-valerolactone); and nitriles (e.g., succinonitrile, glutaronitrile, and / or adiponitrile). sulfones (e.g., tetramethylene sulfone, ethyl methyl sulfone, vinyl sulfone, phenyl sulfone, 4-fluorophenyl sulfone, benzyl sulfone and / or sulfolane); aliphatic ethers (e.g., triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dimethoxypropane, 1,2-dimethoxyethane, 1,2-diethoxyethane and / or ethoxymethoxyethane); cyclic ethers (e.g., 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane); phosphates (e.g., triethyl phosphate and / or trimethyl phosphate); and combinations thereof. In some aspects, the organic solvent may comprise a mixture of a cyclic carbonate and a linear carbonate. The organic solvent may constitute, by weight, more than or equal to 80%, or optionally more than or equal to 85% and less than or equal to 95%, or optionally less than or equal to 90% of electrolyte 28.

[0048] The lithium salt is soluble in the organic solvent and provides a passage for lithium ions through the electrolyte 28. The lithium salt can be an inorganic lithium salt, an organic lithium salt, or a combination thereof. Examples of lithium salts include lithium hexafluorophosphate (LiPF6), lithium difluorophosphate (LiPO2F2), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (Lil), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2) (LiTFSI), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2) (LiFSI), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalato)borate (LiB(C2O4)2) (LiBOB), lithium difluoro(oxalato)borate (LiBF2(C2O4)) (LiDFOB), and combinations thereof. In some aspects, the lithium salt LIPF6 may be included.The lithium salt may be dissolved in the organic solvent at a concentration of more than or equal to 0.5 molar and less than or equal to 1.5 molar. In some aspects, the lithium salt may be dissolved in the organic solvent at a concentration of approximately 1 molar. The lithium salt may constitute, by weight, more than or equal to 5%, optionally more than or equal to 10% and less than or equal to 20%, or optionally less than or equal to 15% of electrolyte 28.

[0049] The current collector 30 of the negative electrode and the current collector 32 of the positive electrode are electrochemically inert and electrically conductive, providing an electrical connection between the external circuit 36 ​​and the negative electrode 22 and the positive electrode 24, respectively. The current collector 30 of the negative electrode and the current collector 32 of the positive electrode can be in the form of non-porous metal foils, perforated metal foils, porous metal grids, or a combination thereof. The current collector 30 of the negative electrode and the current collector 32 of the positive electrode can be made of metal or another suitable electrically conductive material (e.g., carbon).In those aspects where the current collector 30 of the negative electrode and / or the current collector 32 of the positive electrode are made of metal, the metal can be an essentially pure elemental metal or an alloy of an elemental metal and one or more other metallic or non-metallic elements (referred to as "alloying elements"). In some aspects, the current collector 30 of the negative electrode can be made of copper, nickel, or stainless steel, and the current collector 32 of the positive electrode can be made of aluminum. Proceedings

[0050] The positive electrode 24 can be prepared by forming a solid mixture of the electroactive material particles 38 and the LATP particles 40. The solid mixture can optionally be heated to an elevated temperature to form a calcined mixture comprising the electroactive material particles 38 and the LATP particles 40. For example, the solid mixture can be heated to an elevated temperature of more than or equal to 400 degrees Celsius (°C), optionally more than or equal to 450 °C, optionally more than or equal to 500 °C and less than or equal to 700 °C, optionally less than or equal to 650 °C, optionally less than or equal to 600 °C, or optionally less than or equal to 500 °C to form the calcined mixture. An electrode precursor mixture can then be prepared, comprising the calcined mixture, the polymer binder 42, the optional electrically conductive material, and a solvent.The electroactive material particles 38, the LATP particles 40, the polymer binder 42, and the optional electrically conductive material can be present in the electrode precursor mixture in essentially the same proportions as in the positive electrode 24. The electrode precursor mixture can be applied to a substrate to form an electrode precursor layer, and then the solvent can be removed from the electrode precursor layer to form the positive electrode 24.

[0051] Without wishing to be bound by the theory, it is assumed that calcining the solid mixture of the electroactive material particles 38 and the LATP particles 40 before forming the positive electrode 24 can help to create a close connection between the electroactive material particles 38 and the LATP particles 40 without forming a chemical and / or physical bond between the electroactive material particles 38 and the LATP particles 40, and that such an intimate connection can help to form a protective interface around the electroactive material particles 38, which helps to prevent unwanted chemical reactions between the electroactive material particles 38 and the electrolyte 28 during the cycling of the battery 20, without inhibiting the transfer of lithium ions between the electroactive material particles 38 and the electrolyte 28. Experimental

[0052] Complete coin cells with different positive electrode formulations were assembled and evaluated using galvanostatic charge and discharge protocols. All cells included an electrolyte composed of 1.2 molar LiPF6 in a mixture of FEC and DEC (FEC:DEC = 1:4 vol / vol) with 1 wt% LiPO2F2. All cells included a negative electrode made of an electroactive material consisting of a mixture of 5.5 wt% silicon dioxide and graphite, electrically conductive particles, and a polymer binder, with a porosity of 30% and a capacity of 5.5 milliampere-hours per square centimeter (mAh / cm²). 2 ). A positive base electrode was fabricated, comprising: an electroactive material formed from Li2MnO3 (LMR) particles, electrically conductive particles and a polymer binder, with a porosity of 30% and a capacity of 5 mAh / cm². 2, an active mass loading of 23 milligrams per square centimeter (mg / cm²) 2 ) and has a diameter of approximately 12.7 millimeters (mm). The LMR particles have a mean particle diameter in the range of 9 µm to 10 µm and were 100% amorphous.

[0053] LATP-containing positive electrodes according to the embodiments of the present disclosure were produced by adding 2% LATP, based on the total weight of the LMR in the positive base electrode, to the positive base electrode. The LATP-containing positive electrodes were produced by forming physical mixtures of LMR particles and LATP particles (LMR-LATP mixtures) by mixing the LMR particles and the LATP particles for 5 minutes at 500 revolutions per minute (rpm) and subsequently calcining the physical mixtures at either 500 °C or 700 °C. The LMR-LATP mixtures thus produced were 100% amorphous. The LMR-LATP mixtures were then combined with the electrically conductive particles, the polymer binder, and a solvent and mixed for 5 minutes at 500 revolutions per minute to form a slurry.The slurry was applied to a metal substrate in the form of a thin, continuous and essentially uniform layer, and the solvent was subsequently removed from it by evaporation to form the LATP-containing positive electrodes.

[0054] The calcined LMR-LATP mixtures were imaged using a transmission electron microscope (TEM) before the LATP-containing positive electrodes were formed. The TEM images showed that even after calcination of the LMR-LATP mixtures, the LATP particles remained physically separate from the LMR particles, were not physically or chemically bonded to the LMR particles, and did not form a uniform coating on the surfaces of the LMR particles.

[0055] X-ray fluorescence (XRF) images were taken of some of the LATP-containing positive electrodes prior to their assembly into coin cells. The XRF images showed a substantially uniform and homogeneous distribution of titanium (Ti) and phosphorus (P) within the LATP-containing positive electrodes, indicating that the LATP particles are substantially homogeneously distributed within them. Furthermore, the substantially uniform and homogeneous distribution of Ti and P in the LATP-containing positive electrodes suggests that the LATP particles in the manufactured LATP-containing positive electrodes are present as a loose interface rather than as a conformal coating on the LMR particles.

[0056] Cells with the positive base electrode or a LATP-containing positive electrode were galvanostatically charged and discharged at 25 °C. During formation, the cells were charged and discharged for two cycles using a constant current and constant voltage (CCCV) protocol. First, the cells were charged to 4.6 V at a constant current and a C / 20 rate, then charged at a constant voltage of 4.6 V until the current reached C / 50, followed by a discharge at a constant current and a C / 20 rate to 2.0 V. After formation, the cells were charged and discharged using a CCCV protocol. First, the cells were charged to 4.6 V at a constant current and a C / 3 rate, then charged at a constant voltage of 4.6 V until the current reached C / 20, followed by a discharge at a constant current and a C / 3 rate to 2.0 V.

[0057] After formation, the cells with the positive base electrode and the cells with the LATP-containing positive electrodes were galvanostatically charged and discharged at different C rates; specifically, the cells were cycled at 0.05C for 2 cycles, 0.33C for 3 cycles, 0.5C for 3 cycles, 1C for 3 cycles, 2C for 3 cycles, 4C for 3 cycles, and then 0.33C for 8 cycles. The results showed that the incorporation of the LATP particles into the positive electrodes had no negative impact on the rate performance of the cells, further suggesting that the LATP particles in the LATP-containing positive electrodes thus prepared are not present as a conformal coating on the LMR particles, but instead act as a loose interface that allows easy lithium-ion mobility through the LATP-containing positive electrodes.

[0058] Cells with the positive base electrode exhibited an average specific discharge capacity of approximately 218.5 milliampere-hours per gram (mAh / g) and a discharge capacity retention of approximately 86.96% after 100 cycles.

[0059] Six (6) different LATP-containing positive electrode formulations and their measured specific discharge capacities and retention of discharge capacity after 100 cycles are listed in Table 1 below. Table 1 Example: Positive electrode LATP Mean particle diameter (µm) Calcination temperature (°C) Specific discharge capacity (mAh / g) Maintaining discharge capacity, 100 cycles (%) LMR-LATP-1,22 1,22 no 223,5 90,25 LMR-LATP-2.56 2,56 no 215,8 89,25 LMR-LATP-1,22-500C 1,22 500 205 93,51 LMR-LATP-2,56-500C 2,56 500 223,5 91,32 LMR-LATP-1,22-700C 1,22 700 200,3 88,57 LMR-LATP-2,56-700C 2,56 700 207,9 92,06

[0060] The results of the galvanostatic cycling experiments show that the incorporation of LATP particles into the LATP-containing positive electrodes thus produced increases the retention of discharge capacity, improves cycling stability, and extends the cycle life of cells with LATP-containing positive electrodes compared to cells with the base positive electrode. Without being bound to theory, it is hypothesized that the LATP particles can act as an ionically conductive additive and that the incorporation of LATP particles into the LATP-containing positive electrodes thus produced can help promote the formation of a robust, stable CEI, mitigate the structural degradation of the LMR particles during the cycle, minimize unwanted side reactions between the LMR particles and the electrolyte, and reduce lithium loss.

[0061] Furthermore, the results of the galvanostatic cycling experiments show that calcining the LMR-LATP mixtures before forming the LATP-containing positive electrodes enhances the benefits mediated by the addition of the LATP particles, and that calcining the LMR-LATP mixtures at temperatures of approximately 500 °C leads to better results than calcining the LMR-LATP mixtures at 700 °C.

[0062] Furthermore, the results of the galvanostatic cycling experiments show that the inclusion of LATP particles with a mean particle diameter of either 2.56 µm or 1.22 µm can effectively improve the discharge capacity maintenance of cells with LATP-containing positive electrodes compared to cells with the positive base electrode. When the LATP particles had a relatively small mean particle diameter of 1.22 µm, both the specific discharge capacity and the discharge capacity maintenance of cells containing the LATP-containing positive electrodes were improved compared to cells containing the positive base electrode. This is presumably due to the relatively small LATP particle size, which can allow the formation of a more extensive interface between the LATP particles and the LMR particles within the LATP-containing positive electrodes.When the LATP particles had a larger mean particle diameter of 2.56 µm, the retention of discharge capacity was improved in cells that included the LATP-containing positive electrodes compared to cells that included the positive base electrode, although the initial specific discharge capacity of the cells was lower than that of the cells that included the positive base electrode and the cells that included LATP-containing positive electrodes with LATP particles having a mean particle diameter of 1.22 µm.

[0063] The foregoing description serves only for illustration and is in no way intended to limit the disclosure, its application, or use. It is understood that one or more steps within a process may be carried out in different sequences (or simultaneously). The described embodiments are not mutually exclusive.

[0064] The terminology used herein serves only to describe exemplary embodiments and is not to be understood as restrictive. The singular forms "a," "an," "the," and "the" used herein also include the plural forms unless the context clearly indicates otherwise. The terms "comprise," "comprehensive," "contain," and "exhibit" are inclusive and therefore specify the presence of certain features, elements, compositions, steps, integers, processes, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, processes, elements, components, and / or groups thereof.Although the open terms "comprise," "comprising," "contain," and "have" are to be understood as non-restrictive terms used to describe and claim various embodiments set forth herein, in certain aspects the terms can alternatively be understood as limiting and restrictive terms such as "formed of" or "substantially formed of." Therefore, for each specific embodiment in which compositions, materials, components, elements, constituents, features, integers, processes, and / or process steps are mentioned, the present disclosure expressly includes embodiments formed of or substantially formed of such compositions, materials, components, elements, constituents, features, integers, processes, and / or process steps.In the case of "formed from", the alternative embodiment excludes all additional compositions, materials, components, elements, ingredients, features, integers, operations and / or process steps, whereas in the case of "essentially formed from", all additional compositions, materials, components, elements, ingredients, features, integers, operations and / or process steps that substantially affect the basic and novel features are excluded from such an embodiment, while all compositions, materials, components, elements, ingredients, features, integers, operations and / or process steps that do not substantially affect the basic and novel features may be included in the embodiment.

[0065] As used herein, the phrase “A, B and / or C” should be interpreted using a non-exclusive logical OR operation as logical (A OR-connected with B OR-connected with C) and not as “at least one of A, at least one of B and at least one of C”.

[0066] As used herein, the terms “composition” and “material” are used interchangeably and, in their broadest sense, refer to a substance comprising at least the preferred chemical constituents, elements, or compounds, but which may also include additional elements, compounds, or substances, including trace impurities, unless otherwise specified. An “X-based” composition or “X-based” material, in its broadest sense, refers to compositions or materials in which “X” is the largest single constituent of the composition or material on a percentage (%) basis. This may include compositions or materials containing more than 50% X as well as those containing less than 50% X, as long as X is the largest single constituent of the composition or material.When a composition or material is described as “essentially free” from a substance, the composition or material may contain less than 5% by weight, optionally less than 3% by weight, optionally less than 1% by weight, or optionally less than 0.1% by weight of the substance.

Claims

[1] Positive electrode (24), comprising: a physical mixture of: electroactive material particles (38) comprising a lithium-rich manganese-based oxide, Lithium aluminum titanium phosphate (LATP) particles (40), wherein the LATP particles (40) are essentially amorphous and separate from the electroactive material particles (38) and are not physically or chemically bound to the electroactive material particles (38), wherein the electroactive material particles (38) have a first mean particle diameter (D1), the LATP particles (40) have a second mean particle diameter (D2), and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 4:1 and less than or equal to 1000:1, and wherein the electroactive material particles (38) have a protective interface obtained by calcining the mixture of electroactive material particles (38) and LATP particles (40) prior to forming the positive electrode (24). [2] Positive electrode (24) according to claim 1, wherein the positive electrode comprises a polymeric binder and / or an electrically conductive material and / or wherein the LATP particles (40) are lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x (PO4)3 include, where 0.1 ≤ x ≤ 0.

6. [3] Positive electrode (24) according to claim 2, wherein the LATP particles (40) are present in the positive electrode (24) in an amount which, based on the total weight of the electroactive material particles (38) in the positive electrode (24), is more than or equal to 0.5 wt.% and less than or equal to 4 wt.%. [4] Positive electrode (24) according to claim 1, wherein the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 18:1 and less than or equal to 200:

1. [5] Positive electrode (24) according to claim 1, wherein the first mean particle diameter (D1) of the electroactive material particles (38) is greater than or equal to 8 micrometers and less than or equal to 12 micrometers and wherein the second mean particle diameter (D2) of the LATP particles (40) is greater than or equal to 10 nanometers and less than or equal to 2 micrometers. [6] Positive electrode (24) according to claim 1, wherein the electroactive material particles (38) comprise a layered lithium-rich manganese-based transition metal oxide, which is described by the formula Li 1+x Me 1-xO2 is represented, where 0 < x ≤ 0.33, where Me comprises at least one transition metal and where Me comprises more than 50% manganese (Mn) on an atomic basis, and where the electroactive material particles (38) constitute more than or equal to 90% of the positive electrode (24) by weight. [7] Battery (20) that cycles lithium ions, comprising: a negative electrode (22) comprising an electroactive negative electrode material; a positive electrode (24) which is spaced apart from the negative electrode (22), wherein the positive electrode (24) comprises a physical mixture of: electroactive material particles (38) comprising a lithium-rich manganese-based oxide, and Lithium aluminum titanium phosphate (LATP) particles (40), the lithium aluminum titanium phosphate with the formula Li 1+x Al x Ti 2-x (PO4)3 include, where 0.1 ≤ x ≤ 0.6, wherein the electroactive material particles (38) have a first mean particle diameter (D1), the LATP particles (40) have a second mean particle diameter (D2), and the ratio of the first mean particle diameter to the second mean particle diameter (D1:D2) is greater than or equal to 18:1 and less than or equal to 200:1, and wherein the electroactive material particles (38) have a protective interface obtained by calcining the mixture of electroactive material particles (38) and LATP particles (40) prior to forming the positive electrode (24). [8] Battery (20) according to claim 7, wherein the electroactive material particles (38) constitute more than or equal to 90% of the positive electrode (24) by weight and wherein the LATP particles (40) are present in the positive electrode (24) in an amount which is more than or equal to 0.5% and less than or equal to 4% by weight of the total weight of the electroactive material particles (38) in the positive electrode (24). [9] Battery (20) according to claim 7, wherein the second mean particle diameter (D2) of the LATP particles (40) is greater than or equal to 50 nanometers and less than or equal to 0.5 micrometers and wherein the first mean particle diameter (D1) of the electroactive material particles (40) is greater than or equal to 9 micrometers and less than or equal to 10 micrometers. [10] Battery (20) according to claim 7, wherein the electroactive material particles (40) comprise a layered lithium-rich manganese-based transition metal oxide, which is described by the formula Li 1+x Me 1-x O2 is represented where 0 < x ≤ 0.33, where Me includes at least one transition metal and where Me contains more than 50% manganese (Mn) on an atomic basis.

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