New composition for a novel diffusion-dependent electrode

Abstract

This invention relates to a new composition A composition having a general formula Li[6(1-x)] / xM(1-x) / xTiS(5-3x) / x X(1-x) / x, wherein 0 < x < 1.0, M is one or a combination of elements selected from the group of P, Sb, Sn, As, Nb, and V, and wherein X is an element selected from F, Cl, Br, and I, which can be used as a novel "diffusion-dependent" electrode; to a method for preparing such composition, to the use of this composition for preparing a positive or a negative electrode active material; to a positive electrode active material or to a negative electrode active material for solid state batteries obtained by using the new composition and to a battery comprising the said electrode active material.

Description

[0001] NEW COMPOSITION FOR A NOVEL DIFFUSION-DEPENDENT ELECTRODE

[0002] TECHNICAL FIELD

[0003] This invention relates to a new composition and a new material which can be used as a novel "diffusion-dependent" electrode; to the method for preparing such composition, to the use of this composition for preparing a positive or negative electrode active material; to a positive electrode active material or a negative electrode active material for solid state batteries obtained by using the new composition and to a battery comprising the said electrode active material.

[0004] BACKGROUND

[0005] All-solid-state lithium-ion batteries (ASSB) represent a promising battery technology thanks to the replacement of the volatile and flammable state-of-the-art liquid electrolyte by a solid electrolyte.

[0006] All-solid-state lithium batteries, which are regarded as promising next-generation energy storage devices, have enormous potential to simultaneously enhance both energy density and safety compared to conventional lithium-ion batteries. All-solid-state lithium batteries require a well-designed electrode structure to efficiently charge and discharge active materials. A composite-type electrode, which involves a solid electrolyte in the electrode manufacturing process, has been demonstrated. Accordingly, careful spatial placement of the active material and solid electrolyte particles in the composite electrode is highly important. [Energy Storage Materials 41 (2021 ) 289-296]

[0007] To avoid the complexity of the composite electrode, the diffusion-dependent electrode, which consists almost entirely of active material, has been demonstrated as an alternative all-solid- state electrode structure with higher energy density. As a prerequisite for the fabrication of the diffusion-dependent electrode, mechanically ductile active materials are desirable so that interparticle lithium-ion diffusion between the active material particles occurs over their closecontact interface. Also, the active materials should have high electronic conductivity to deliver sufficient electrons from the current collector to the interface between this electrode and the electrolyte layer for smooth electrochemical reaction. [Energy Storage Materials 41 (2021) 289-296]

[0008] An all-solid-state diffusion-dependent cathode that uses titanium disulfide (TiSz) has been disclosed wherein no solid electrolyte was used. TiS? has been reported to display high electronic conductivity and to stably store lithium-ions through intercalation reaction (theoretical capacity of TiS?: ~ 239 mAh / g). A TiS? cell with a lithium metal anode and a LiePSsCI (LPSCI) solid electrolyte layer was disclosed as an ASSB however, the achieved areal capacity of the pristine TiS? cathode was <0.5 mAh / cm2, which is far lower than its theoretical areal capacity (5.43 mAh / cm2) while that of the ball-milled TiS? was close to the theoretical capacity. A TiS2 / LPSCI composite electrode as a homogeneous mixture with a fixed weight ratio (TiS2 / LPSCI, 7 / 3) has been disclosed. Its overall capacity was the same as the one for a ball-milled TiS2 [Energy Storage Materials 41 (2021) 289-296]

[0009] Sulfur-based materials offer several advantages over conventional oxide-based counterparts in ASSB technology: better compatibility with the solid state electrolyte (SSE), better conductivities, competitive in term of energy density, etc. Despite these significant benefits, S-based cathodes suffer from their relatively low operating voltage. With a voltage of 2V (vs Li+ / Li), S-based materials fall short, especially when compared to oxide-based cathode materials like NMC (LiNixCoyMni-x-yCh with x typically larger than 0.8).

[0010] One potential strategy to overcome this limitation is to achieve high loading levels within the battery system to counterbalance the low voltage output.

[0011] TiS2 as diffusion-dependent cathode needs to reach a targeted volumetric energy density of at least 600 Wh / L. This implies reaching high loading level which is correlated with a thick electrode. As a result, there is a decrease in the diffusion coefficient leading to a drop in cell performance.

[0012] It is an object of the present invention to provide a new composition and a new material which can be used as a novel "diffusion-dependent" electrode designed to address the challenge of low operating voltage in S-based materials.

[0013] It is a further object of the present invention to provide a method for preparing said new composition.

[0014] It is a further object of the present invention to provide a battery comprising said material.

[0015] SUMMARY

[0016] In a first aspect, the object of the present invention is achieved by providing a novel composition having a general formula (I)

[0017] Li[6(i-x)] / x M(i-X) / xTiS(5-3x) / x X(i-x) / x (LiMTiSX), wherein 0 < x < 1, in particular wherein 0 < x < 1.0, M is one or a combination of elements selected from the group of P, Sb, Sn, As, Nb, and V, but this list is not exclusive, and X is an element selected from F, Cl, Br, and I, specifically designed to address the challenge of low operating voltage in S-based materials.

[0018] With LiMTiSX, inventors aim to achieve high loading levels compared to pure TiS2, thereby enhancing the overall performance and efficiency of ASSB systems. Inventors studied the addition of LiePSsCI (LPSCI) followed by milling to improve the overall performance in term of capacity of the new material. LPSCI is used as a precursor for the synthesis of a new material. Inventors achieved homogeneous distribution of all the elements (for example Ti, S, Cl, P), the formation of a homogenous new material with change of the voltage profile, increase of the voltage, pre- lithiation of the cathode, increase of the capacity vs Ball-milled (BM) TiS?.

[0019] The new composition shows a significant increase of the capacity, in particular compared to TiS? after more than one cycle.

[0020] In a second aspect, the object of the present invention is achieved by the use of the composition for preparing a positive or negative electrode active material.

[0021] In a third aspect, present invention relates to a positive electrode active material or to a negative electrode active material for solid state batteries obtained by using the new composition.

[0022] In a fourth aspect, present invention relates to a method for preparing the composition, wherein said composition is prepared by a solid-state mechanochemical reaction.

[0023] In a further aspect present invention relates to a battery comprising the electrode active material and the use of the battery.

[0024] BRIEF DESCRIPTION OF THE FIGURES

[0025] Figure 1: XRD patterns of Pristine TiS? and ball-milled TiS?.

[0026] Figure 2: XRD patterns of the ball milled TiS? (BM-TiS? ) and the new LPTiSCI materials according to embodiments of the present invention.

[0027] Figure 3: SEM images of BM-TiS? and the LiPTiSCI materials according to embodiments of the present invention.

[0028] Figure 4: EDX images of the LiPTiSCI materials according to embodiments of the present invention.

[0029] DETAILED DESCRIPTION

[0030] In the following detailed description, preferred embodiments are described in detail to enable practice of the invention. Although the invention is described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. To the contrary, the invention includes numerous alternatives, modifications and equivalents as will become apparent from consideration of the following detailed description and accompanying drawings.

[0031] The term "comprising", as used herein and in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to compositions consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the composition are A and B. Accordingly, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of".

[0032] The term "positive electrode active material" (also known as a cathode active material) as used herein and in the claims is defined as a material which is electrochemically active in a positive electrode or cathode. By active material, it must be understood to be a material capable to capture and release Li ions when subjected to a voltage change over a predetermined period of time. The term "negative electrode active material" (also known as an anode active material) as used herein and in the claims is defined as a material which is electrochemically active in a negative electrode or anode.

[0033] As used herein, the term "amorphous," refers to a material that is not crystalline or that does not contain a majority crystalline phase. Amorphous refers to a material that does not evidence a crystalline property, for example, well-defined X-ray diffraction peaks as measured by X-ray diffraction. An amorphous material is at least primarily amorphous and characterized as having more amorphous components than crystalline components. Substantially amorphous refers to a material that does not include well defined X-ray diffraction peaks or that is characterized by an X-ray diffraction pattern that includes broad reflections that are recognized by a person having ordinary skill in the art as having the majority constituent component phase as an amorphous phase. A material that is substantially amorphous may have nano-sized domains of crystallinity, but which are still characterized by an X-ray diffraction pattern to be primarily in an amorphous phase. In a substantially amorphous material, transmission electron microscopy (TEM) selected area diffraction pattern (SADP) may evidence regions of crystallinity, but would also evidence a majority of the volume of the material as amorphous.

[0034] The term "median particle size D50" (also known as median particle size by volume Dv50), as defined herein, can be interchangeably used with the terms "D50" or "d50" or "median particle size" or "a median particle size (d50 or D50)". D50 is defined herein as the particle size at 50% of the cumulative volume% distributions. D50 is typically determined by laser diffraction particle size analysis. DIO and D90 (or DvlO and Dv90) are defined as particle sizes at 10% and 90% of cumulative volume% distribution when measured by laser scattering method as described in this specification, respectively.

[0035] The term "span", as used in the text, is defined as (D90 - DIO) divided by D50; i.e. (D90- D10) / D50. The term "narrow span" stands for a span of 1.0 or less than 1.0.

[0036] An "all-solid-state secondary battery" can mean a secondary battery in which a cathode, an anode, and an electrolyte are formed together. Depending on the electrolyte they can be divided into an organic (polymer)-based all-solid-state secondary battery based on a polymer (e.g., polyethylene oxide, etc.), and an inorganic all-solid-state secondary battery based on Li-P-S, etc.

[0037] New composition

[0038] In a first aspect, the object of the present invention is achieved by providing a novel composition having a general formula (I) Li[6(i-x)] / x M(i-x) / x TiS(5-3x) / x X(i-x) / x (LiMTiSX) (I), wherein 0 < x < 1.0, M is one or a combination of elements selected from the group of P, Sb, Sn, As, Nb, and V, and X is an element selected from F, Cl, Br, and I, specifically designed to address the challenge of low operating voltage in S-based materials.

[0039] In an embodiment, the composition of the present invention is amorphous and / or comprises nanocrystalline domains.

[0040] In an embodiment, the composition of the present invention has no diffraction peak having a full width at half maximum of less than 1° in the 20 range in X-ray diffraction using CuKo radiation.

[0041] In an embodiment, the composition of the present invention 0.50<x<1.0. Further, x may be 0.55<x, 0.60<x, 0.65<x, or 0.70<x and / or x < 0.95.

[0042] With LiMTiSX, inventors aim to achieve high loading levels compared to pure TiS?, thereby enhancing the overall performance and efficiency of ASSB systems. Inventors studied the addition of a Lithium Metal Sulfur Halogen such as LPSCI to promote Li diffusion and ionic conductivity of the new material.

[0043] LPSCI may in particular be used as a precursor for the synthesis of a new material. Inventors achieved homogeneous distribution of all the element (for example Ti, S, Cl, P), the formation of a homogenous new material with change of the voltage profile, increase of the voltage, pre-lithiation of the cathode, increase of the capacity vs Ball-milled TiS?. A new material is obtained with different properties than ball-milled TiS?.

[0044] The new composition shows a significant increase of the capacity. In one embodiment the composition of the present invention X is Cl and M is P.

[0045] In one embodiment the composition of the present invention, the composition is Li0.32P0.05TiS2.27CI0.05, Li0.66P0.11TiS2.56CI0.11, Li1.06P0.i8TiS2.88CI0.i8 or Li2.57P0.43TiS4.14d0.43.

[0046] In another embodiment of the composition of the present invention, X is Br and M is Sb. In another embodiment the invention relates to Li2.50Sb0.42TiS4.09Br0.42.

[0047] In another embodiment of the composition of the present invention, X is Br and M is P.

[0048] In an embodiment of the composition of the present invention, the particle size distribution value D50 is in the range of 5 to 50 pm, in particular 6 to 48pm.

[0049] The composition of the present invention may be a composition for a negative electrode active material or for a positive electrode active material.

[0050] In a second aspect, the present invention concerns the use of claimed composition for preparing a positive or negative electrode active material.

[0051] Positive or negative electrode active material

[0052] In a third aspect, present invention relates to a positive electrode active material or to a negative electrode active material for solid state batteries comprising a composition according to the first aspect of the present invention in any of its embodiments or combination of embodiments.

[0053] Negative or positive electrode active materials according to present invention are suitable for use as cathode, as anode and as electrolyte material in solid state batteries. Though the discussion below may address specific examples (e.g. examples for a cathode only), it will be understood that such examples are non-limiting and that invention is equally applicable to other uses (e.g. an anode, an electrolyte, etc.).

[0054] Method

[0055] In a fourth aspect, present invention relates to a method for preparing a composition according to the first aspect of the present invention in any of its embodiments or combination of embodiments, wherein said composition is prepared by a solid-state mechanochemical reaction.

[0056] The present invention provides a method for preparing a novel material through a milling of a transition metal-bearing material (for example TiS2) with Lithium Metal Sulfur Halogen (for example LiePSsCI (LPSCI), LiePSsI, or LiePSsBr. This method results in the formation of a new material, not merely a simple mixture, that demonstrates improved electrochemical performance as a cathode active material in comparison of pristine TiS?.

[0057] In one preferred embodiment of this method the milling is performed by a dry milling process such as dry bead (ball). As alternative milling technique the method can use a wet milling process.

[0058] The process parameters, such as milling duration, speed, and atmosphere, are optimized to ensure the formation of a homogeneous material. Ratios from x>0 to x<l are evaluated.

[0059] The milling duration may range from Ih to 20h and the milling speed may rangefrom 100 to 600 rpm;The milling process atmosphere is preferably performed under argon.

[0060] Preparation of LiPTiSCI material

[0061] In one embodiment of the method the new material is obtained by weighing TiS? and LPSCI at different ratio x = 0.95, 0.9, 0.85, or 0.7 [xTiS? + (l-x)LPSCI] and corresponding respectively to the formulas Li0.32P0.05TiS2.27CI0.05, Lio.66Po.11TiS2.56do.11, Li1.06P0.i8TiS2.88d0. is, and Li2.57P0.43TiS4.14CI0.43. These mixtures are then placed in a zirconia jar (ZrC>2 250 ml) filled with zirconia balls (460 g, 3 mm in diameter) and mechanically milled at 550 rpm for 20 h using a planetary ball mill (5 min run I 5 min pause).

[0062] Battery

[0063] Specifically, an all-solid-state battery according to the present invention includes a positive electrode, a negative electrode, and a solid electrolyte , preferably a sulfide based solid electrolyte, interposed between the positive electrode and the negative electrode.

[0064] In a further aspect, the present invention provides a battery comprising the positive or negative electrode active material as described above according to the third aspect of the invention.

[0065] In a preferred embodiment the battery is a lithium-ion battery, preferably a lithium-ion rechargeable battery. Preferably the battery comprises a positive electrode comprising the active material according to the present invention, a negative electrode, an electrode, and a separator.

[0066] In a another embodiment the battery may comprise a liquid electrolyte, such as a lithium salt in an organic solvent. Preferably, the battery further a positive electrode comprising the active material according to the present invention, an anode comprising a anode active material. Suitable electrochemically active anode materials are those known in the art. For example, the anode may comprise graphitic carbon, or a metal alloy comprising lithium. Use

[0067] In additional aspect the present invention concerns a use of a battery according to the the present invention, in any of its embodiments or combination of embodiments, in either one of a portable computer, a tablet, a mobile phone, an energy storage system (ESS), an electric vehicle (EV) or in a hybrid electric vehicle (HEV), preferably in an electric vehicle or in a hybrid electric vehicle.

[0068] EXAMPLES and EXPERIMENTAL TESTS

[0069] The invention is described below in greater details with reference to examples, but the invention is not limited in any way by these examples, as long as it does not exceed the scope and spirit of the present invention.

[0070] Experimental tests used in the examples

[0071] The following analysis methods are used in the Examples:

[0072] Powder X-ray Diffraction (XRD):

[0073] XRD patterns are recorded on a Bruker D8 Advance X-ray diffractometer in the 10-80 2-theta range in a 0.015 degree scan step. Scan speed is set to 3.0 degree per minute. The copper target X-ray tube is operated at 40KV and 40mA. The LynxEye XE-T detector is used to capture the diffracted X-rays at 3.3 degree opening. The collected XRD patterns comprise KAIpha Cu radiations with typical wavelengths KAIphal =1.5418 A. The incident beam optic setup comprises a 1-degree divergence slit (DS) and 2.5 degree vertical Soller slit. The diffracted beam optic setup includes an automatic anti-scatter slit (SS), and 2.5 degree vertical Soller slit. To prevent fluctuations the temperature is kept near room temperature at all the time.

[0074] Scanning Electron Microscopy and EDX (SEM-EDX):

[0075] SEM-EDX was used to study the shape, size, and the chemical composition and distribution of different material.

[0076] The morphology of positive electrode active materials is analyzed by a Scanning Electron Microscopy (SEM) technique. The measurement is performed in a dry room with a -40 °C dew points with a ZEISS SIGMA 300 under a high vacuum environment of 8xl0-6Pa at 25 °C. The particles in the image should be well distributed therefore avoiding overlap between particles. This can be achieved by pouring a small amount of powder sample to the adhesive attached on the SEM sample holder and blowing dry air to remove the excess powder. Particle Size Distribution (PSD):

[0077] PSD analysis was used to study the impact of the method of the present invention such ass the milling of TiS2 with LPSCI, on the particle size of the new materials such as LiPTiSCI.

[0078] The dry PSD is measured in a dry room with a -60 °C dew point using a Microtrac MRB Granulometer equipped with a SYNC particles analyzer. To improve the dispersion of the positive electrode active material powder examples, sufficient dispersive pressure is applied. Dio, Dso, and D90 are defined as the particle size at 10%, 50%, and 90% of the cumulative volume% distributions, respectively.

[0079] Chronoamperometry (CA) :

[0080] Chronoamperometry was used to measure the electronic conductivity of BM-TiS? and LiPTiSCI new materials . A BioLogic Potentiostat was used to do all the measurement. The voltage was set at lOmV for 15 min.

[0081] EXAMPLES

[0082] The present invention is further illustrated by the following examples. All the processes below were carried out under argon atmosphere.

[0083] Example 1 to Example 4

[0084] Titanium disulfide (TiSz) and LiePSsCI were respectively bought from LTS Research Laboratories and NEI Corporation.

[0085] Example 1 (EXI), provides a positive electrode active material having an amorphous / nanocrystalline morphology with the formula Li0.32P0.05TiS2.27CI0.05 which was prepared using a solid-state mechanochemical reactions according to the following steps: 14.4 g of titanium disulfide, 1.6 g of LiePSsCI and 456 g of zirconia balls with a diameter of 3 mm were put into a 250 ml ball milling crucible, and a ball milling process was performed. The rotation speed of the ball milling process was 550 rpm. The ball milling process was performed during 20 h with 5 minutes of performance and 5 minutes of rest. In order to minimize the reaction with the atmosphere during the ball milling process, a sealed crucible was used, and sampling was performed in a glove box filled with an inert gas.

[0086] Example 2 (EX2) to Example 4 (EX4) are prepared according to the same method as EXI, except that the mass of titanium disulfide and LiePSsCI is according to Table 1.

[0087] Table 1 : Summary of ratio mixture of the examples

[0088] Comparative Example 1 (CEX1), provides a positive electrode active material having an amorphous / nanocrystalline morphology with the formula BM-TiS? which was prepared using a solid-state mechanochemical reactions according to the following steps:

[0089] 2 g of titanium disulfide and 90 g of zirconia balls with a diameter of 3 mm were put into a 50 ml ball milling crucible, and a ball milling process was performed. The rotation speed of the ball milling process was 550 rpm. The ball milling process was performed during 20 h with 5 minutes of performance and 5 minutes of rest. In order to minimize the reaction with the atmosphere during the ball milling process, a sealed crucible was used, and sampling was performed in a glove box filled with an inert gas.

[0090] SSB preparation and cycling

[0091] 1. SSB Preparation

[0092] Negative electrode preparation

[0093] For the preparation of negative electrode, Li foil (diameter 7 mm, thickness 100 pm) is placed centered on the top of In foil (diameter 9 nm, thickness 100 pm) and pressed to form Li-In alloy negative electrode.

[0094] Separator

[0095] For the preparation of separator which also has a function of the solid electrolyte in a battery, the Li-P-S-CI based solid electrolyte is pelletized with a pressure of 74 MPa in a WC mold with a diameter of 13 mm.

[0096] Cell assembly

[0097] A sulfide solid-state rechargeable battery is assembled in an argon-filled glovebox. The positive electrode active material was spread on one side of separator and pressed under 370 MPa and the negative electrode was attached to the other side of the separator under 74 MPa. The cell was then put into a pouch cell and a constant pressure of MPa was applied using JIG system.

[0098] 2. SSB Testing

[0099] Each cell is cycled a potentiostat from BioLogic. The initial discharge capacity (DQ1) are measured in constant current mode (CC) at C rate of 20 C in voltage range 2.1 V to 0.4 V (InLi / Li+). DQ2 and DQ3 is the discharge capacity at the 2ndand 3rdcycle, respectively.

[0100] XRD Analysis

[0101] Following ball-milling, the XRD spectrum exhibits pronounced peak broadening alongside a notable reduction in peak intensity (Figure 1). This suggests potential amorphization or the formation of nanocrystalline domains, indicative of structural changes induced by the milling process. Due to this amorphization or formation of nanocrystalline domains With the peak broadening, the X-ray diffraction spectra of the examples, using CuKo radiation, present no diffraction peaks having a full width at half maximum (FWHM) of less than 1° in the 20 range from 10 to 80°.

[0102] This shows that the ball-milling process is different from a simple mixing of the source materials. A simple mixture of crystalline source materials pristine TiS2 and LPSCI, that is without formation of a new single material, would show a composite pattern of diffraction peaks, each corresponding to the individual crystal structures present in the mixture.

[0103] LiPTiSCI materials - Influence of x - XRD Analysis

[0104] For the li6(i- )P(i- )Ti materia Is, from 0.85 < x < 1 no significant change is observed compared to the ball-milled TiS?, suggesting the potential for amorphous, nanocrystalline, or a combination of both structures within the formation of the new material. A subtle leftward shift in some peaks is visible, indicating lithiation of the materials, which confirms the formation of a new material, not merely a physical mixture. However, at x < 0.7 (Li2.57P0.43TiS4.14d0.43 ), in addition to the amorphization and / or formation of nanocrystalline domains, the emergence of an unidentified phase becomes apparent, indicating a transition in the crystalline structure with increasing LPSCI content (Figure 2). The XRD spectra of EXI to EX4 show no diffraction peak having a full width at half maximum of less than 1° in the 29 range of 10-80°.

[0105] Composition according to any one preceding claim wherein 0.50<x<1.0

[0106] SEM Analysis and PSD analysis

[0107] In terms of morphology, the new materials, for x > 0.85 (Li1.06P0.i8TiS2.88 ), exhibit a spherical type morphology akin to Ball-milled-TiS2. However, beyond this concentration, a transition occurs, with dense and larger particles observed, accompanied by the presence of unidentified white spots on the particles. Further analysis through PSD corroborates these observations, showing similar distributions for x > 0.85, but a notable fourfold increase for x < 0.7 (Li2.57P0.43TiS4.14d0.43). Additionally, EDX images show a homogeneous distribution of all elements (Ti, S, P and Cl). The lack of distinction between the precursors' individual elemental distributions further supports the formation of a new, uniform material. In a mere mixture, one would expect to see heterogeneity and distinct regions corresponding to each precursor. The observed uniformity confirms that a chemical reaction has occurred, leading to the creation of a new composite material.

[0108] Table 2: Percentile values of the LiPTiSCI materials

[0109] Electrochemical characterization

[0110] Electronic conductivity

[0111] Table 3: Electronic conductivities of the LiPTiSCI materials

[0112] Cycling performance

[0113] Electrochemical studies have been carried out on BM-TiS? and the four different LiPTiSCI materials using In-Li as the counter electrode. The current were calculated based on pure TiS2. ence of x le 4 is presenting the different theorical capacities and current used during the cycling.

[0114] Table 4: Cycling parameters and discharge capacities ofBM-TiSz and the new LiPTiSCI material at 60°C

[0115] All materials underwent cycling at identical currents and temperature. The evolution of the capacity and voltage profiles clearly demonstrates the benefit of using LiePSsCI as a precursor material to form a new high-performance positive electrode. In fact, all the LiPTiSCI materials exhibit better performance than the ball-milled TiS? material, not only in terms of capacity but also in terms of voltage and capacity retention. Among all the LiPTiSCI materials, Li1.06P0.i8TiS2.88d0. is (x=0.85) and Li2.57P0.43TiS4.14CI0.43 (x=0.7) demonstrate superior cycling performance with a respective areal capacity after the third discharge of 7.71 and 8.87 mAh / cm2.

[0116] The enhanced performance with 0.7 < x < 1 can be attributed to several factors such as:

[0117] The formation of a new phase: The ball-milling process induces chemical interactions and strong physical bonding between TiS2 and LiePSsCI, forming a novel composite phase with optimized properties.

[0118] Improved ionic conductivity: The inclusion of LieMSsX precursor (where M is an element with an oxidation state of +5 , and M could be one or a combination of elements selected from the group of P, Sb, Sn, As, Nb, and V, but this list is not exclusive, X can be Cl, Br, I, or F), a solid electrolyte, enhances the ionic conductivity of the new material, facilitating better lithium-ion transport, on top of the TiS2 input.

[0119] Synergistic Effects: The intimate contact and interaction between TiS2 and LiePSsCI in the new material phase result in synergistic enhancements, where the combined properties exceed those of the individual components.

[0120] Initial Activation : The observation that the second discharge capacity is higher than the first suggests the presence of mobile lithium in the material, confirming that a reaction between TiS2 and LiePSsCI has occurred, resulting in the formation of a new material. This presence of mobile lithium promotes the diffusion of Li through the electrode, contributing to the increase in performance.

[0121] Based on these findings, the Li2.57P0.43TiS4.14d0.43 (x=0.7) material can be selected as the best material for potential application in high-performance batteries. This concentration offers the best balance between improved capacity, operating voltage, electronic conductivity and capacity retention without unnecessary excess of the LiePSsCI. Influence of the loading

[0122] Table 5: Cycling parameters and second discharge capacity of Li2.57P0.43TiS4.14CI0.43 with the increase of the loading

[0123] By increasing the loading up to 52.63 mg / cm2, a very high reversible areal capacity of 10 mAh / cm2was achieved with the Li2.57 P0.43TiS4.14CI0.43 (x=0.7) material.

Claims

CLAIMS1. A composition having a general formula (I)Li[6(l-x)] / xM(l-x) / xTiS(5-3x) / x X(l-x) / x, (I) wherein 0 < x < 1.0, M is one or a combination of elements selected from the group of P, Sb, Sn, As, Nb, and V, and wherein X is an element selected from F, Cl, Br, or I.

2. Composition according to claim 1 wherein the composition is amorphous and / or comprises nanocrystalline domains.

3. Composition according to claim 1 or claim 2 having no diffraction peak having a full width at half maximum of less than 1° in the 20 range of 10° to 80° of a X-ray diffraction spectrum using CuKo radiation.

4. Composition according to any one preceding claim wherein 0.50<x<1.

05. Composition according to any one of claims 1 to 4, wherein X is Cl and M is P.

6. Composition according to any one of claims 1 to 4, wherein X is Br and M is Sb.

7. Composition according to any one preceding claim having a particle size distribution value D50 is in the range of 5 to 50 pm.

8. Use of a composition according to any one preceding claim for preparing a positive or a negative electrode active material.

9. A positive electrode active material for solid state batteries comprising a composition according to any one of claims 1 to 7.

10. A negative electrode active material for solid state batteries comprising a composition according to any one of claims 1 to 7.

11. A method for preparing a composition according to any one of claims 1 to 7, wherein said composition is prepared by a solid-state mechanochemical reaction comprising milling of a transition metal-bearing material with a Lithium Metal Sulfur Halogen.

12. A method according to claim 11 wherein the milling is selected from dry milling and is wet milling.

13. Method according to any one of claims 11 and 12 wherein the transition metal bearing material is TiS?.

14. Method according to any one of claims 11 to 13 wherein the lithium Metal Sulfur halogen is selected from LiePSsCI (LPSCI), LiePSsI, and LiePSsBr.

15. A battery comprising the electrode active material according to claim 9 or 10.

16. Use of a battery according to claim 15 in either one of a portable computer, a tablet, a mobile phone, an energy storage system (ESS), an electric vehicle (EV) or in a hybrid electric vehicle (HEV).

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