Polymer coated electrode active material, preparation and use thereof

Abstract

The present invention provides a coated particulate material comprising a plurality of core particles wherein each core particle comprises at least one compound of formula (I), Li1 + w [Ni1-x-y-zCoxMnyMz] 1-wO2, and the surface of the core particles exhibits a coating comprising at least one polycationic organic polymer or at least one polyanionic organic polymer.

Description

[0001] The present invention relates to polymer coated electrode active materials, in particular polymer coated NCM type cathode active materials, for improving the cycle stability of electrode active materials in electronic devices (e.g. batteries). The present invention also relates to the manufacture of polymer coated electrode active materials and their use. The preferred use of polymer coated electrode active materials is their use as electrode active materials in lithium ion batteries (lithium ion electrochemical cells), most preferably in solid state lithium ion batteries (also called solid state lithium ion electrochemical cells).

[0002] describe Technical Background

[0003] Thiophosphate-based solid-state batteries (SSBs), especially solid-state lithium-ion batteries, or solid-state lithium-ion electrochemical cells, with a high-nickel ternary cathode material LiNi 1-x- y Co x Mn y O 2 (NCM), represents a promising next-generation energy storage technology due to its expected high specific discharge capacity and improved safety. However, an important issue that needs to be overcome in the process of achieving large-scale high energy density applications is the rapid capacity decay during battery cycling. Generally, during the cycling of NCM, the formation of interfaces and cracks leads to contact loss and increased lithium diffusion path length. In this paper, a uniform polymer coating on NCM is obtained by a spray drying process. The thickness of this coating may be, for example, 4 nm, which can stabilize the electrode active material (e.g., NCM) and the solid electrolyte (SE) (e.g., Li 6 PS 5 Cl). The exemplary electrochemical evaluations provided herein confirmed that long-term cycling performance and active material utilization were significantly improved compared to uncoated NCM. Therefore, the coating effectively inhibits the degradation of the NCM / SE interface, especially the formation of oxidized species. In addition, the polymer coating (for example, by using poly ((4-vinylbenzyl) trimethylammonium bis (trifluoromethanesulfonyl imide)), PVBTA-TFSI) reduces the extent of particle cracking. Overall, the experimental results provide an example of a scalable process using a novel polycationic coating on NCM for the next generation of SSBs.

[0004] Polymer coatings of electrode materials are known in the prior art. However, known polymer coatings are based on neutral polymers, such as described in US20220069337 A1 and WO 2021 / 254215 A1 (e.g. PVP, polyvinylpyrrolidone). US20220069337 A1 and WO 2021 / 254215 A1 serve as exemplary reference materials according to the prior art and highlight the unexpected and surprising improvement in the cycling stability of the present invention disclosed below (see below). Fig.13 ).

[0005] The coating disclosed in US20220069337 A1 also requires photocuring to form a final coating, while the coating of the present invention disclosed below in this article does not require photocuring, thereby greatly reducing the complexity of coating manufacturing compared to the prior art.

[0006] WO 2021 / 254215 A1 only mentions that ionic compounds are contained in binder polymers, thus indicating that they are only applicable to optimizing binder polymers, which themselves are only supporting compounds (supportive compounds) for optimizing the mechanical properties of the coating disclosed in WO 2021 / 254215 A1. There is no suggestion in WO 2021 / 254215 A1 that binder polymers also exert technical effects in addition to changing mechanical properties, while the polyelectrolyte polymers according to the present invention disclosed herein do have technical effects in optimizing cyclic stability, as shown below. The polyelectrolyte polymers according to the present invention disclosed herein are materials with technical effects, not just types or parts of supporting binder polymers. Therefore, WO 2021 / 254215 A1 does not provide any suggestion of the subject matter of the present invention disclosed below.

[0007] Solid-state lithium batteries (SSBs) use solid electrolytes (SEs) instead of organic liquid electrolytes, which are expected to fundamentally solve battery safety issues and are ideal chemical power sources for electric vehicles and large-scale energy storage. In order to obtain higher energy density, intercalation cathode active materials and thiophosphate-based SEs have attracted widespread attention. High-nickel ternary cathode materials LiNi 1-x-y Co x Mn y O 2 (NCM) is regarded as a promising cathode material for lithium batteries due to its high energy density and low cost. However, severe capacity fade caused by interfacial degradation is observed when NCM and thiophosphate-based SE are used. Generally, interfacial degradation reactions between NCM and SE produce undesirable interfacial layers that interfere with lithium ion and electron transport. Even at zero charge state, chemical reactions occur at the NCM / SE interface, leading to harmful capacity fade.

[0008] During the charge process of the first cycle, the electrochemical degradation of the interface with the solid electrolyte slowed down the lithium transport due to the low electrochemical stability window of the thiophosphate-based SE. However, the discharge process usually reached 2.6 V vs. Li + / Li, which is not enough to trigger the reduction. Therefore, the oxidation of SE is much slower in subsequent cycles. Since the thiophosphate-based SE directly contacts the NCM, the oxygen and lithium atoms in the surface area of ​​the NCM react with the electrolyte, resulting in structural degradation of the passivation layer on the NCM surface and between the NCM and SE. SO can be detected at the NCM / SE interface by time-of-flight secondary ion mass spectrometry (ToF-SIMS). x n- and PO x n- and other oxidizing substances, and SO can be detected by differential electrochemical mass spectrometry during the cycle. 2 Oxygen loss leads to mechanical cracking, which plays an important role in interface degradation. On the other hand, lattice shrinkage and expansion of NCMs lead to capacity decay, while SSBs have an even greater negative impact than lithium-ion batteries (LIBs) due to contact loss between SE and cathode materials. Therefore, research efforts have been devoted to improving the stability of the electrode-electrolyte interface, but have been unsuccessful so far.

[0009] In order to improve the interfacial stability between NCM and thiophosphate-based SE, surface modification by coating on NCM has been extensively studied. Generally, compared with atomic layer deposition, it is difficult to obtain thin and uniform coatings by wet and dry coating processes. Therefore, atomic layer deposition, such as HfO 2 Coated NCMs. Many research efforts have focused on inorganic oxides as coating materials, such as LiNbO 3 , Li 6 ZnB 4 O 14 、LiAlO 2 , Li 2 ZrO 3 , Li 4 Ti 5 O 12 and Li 3 B 11 O 18. Such inorganic coatings are hard and brittle and therefore tend to break when subjected to mechanical stresses, such as during the cyclic charging and discharging process of the battery. Therefore, it is not possible to provide an inorganic coating that reliably and completely covers the surface of the active electrode material that is subjected to mechanical stress. Compared to inorganic coatings, polymer coatings are relatively soft and can be evenly coated on the substrate if there are forces between the functional groups and the NCM; for example, polyvinylpyrrolidone (PVP) can be used as a surfactant to modify the surface of metal oxides. Although poly(3,4-ethylenedioxythiophene) modification of carbon additives in NCMs and SSBs by molecular layer deposition has been studied, polymer-coated NCMs have so far mostly been used only in lithium-ion batteries with liquid electrolytes. It has been previously unknown and unexpected that polymer coatings of NCMs can be combined with solid electrolytes, especially with thiophosphate-based solid electrolytes. A problem that has not been solved so far with polymer coatings of NCMs with polyelectrolyte polymers is that coating NCMs with polyelectrolyte polymers requires solvents that are stable to the NCM, which means that the solvent used to dissolve the polyelectrolyte polymer during the coating process must not be able to remove the Li + -Ions are dissolved (extracted) from the NCM.

[0010] According to the present invention, the polyelectrolyte polymer or polyelectrolyte organic polymer disclosed herein includes polycationic polymers and polyanionic polymers (also synonymously referred to as polycationic organic polymers or polyanionic organic polymers, respectively cationic polymers, cationic organic polymers, anionic polymers, anionic organic polymers). All types of polyelectrolyte polymers include polymers composed of monomers having one or more charged functional groups (plus counterions), which either participate in the polymerization reaction or do not participate in the polymerization reaction, that is, the polymer molecule of the polyelectrolyte polymer obtains its polyelectrolyte structure (polycation or polyanion) by polymerizing monomers in which each monomer part has at least one charged functional group. As known in the prior art, as a polyelectrolyte polymer (polycation or polyanion), it is not required that the monomer already contains more than one charged functional group-the polyelectrolyte structure is achieved by monomer polymerization, regardless of how many charged functional groups the monomer has and what type of charged functional groups.

[0011] Furthermore, it is not necessary that all monomers constituting the polyelectrolyte polymer according to the present invention have at least one charged functional group (plus counterion). The polyelectrolyte polymer according to the present invention is also a copolymer, consisting of one or more monomers having at least one charged functional group and one or more polymers having no charged functional group, the polyelectrolyte polymer being formed by copolymerizing at least one monomer having at least one charged functional group with at least one monomer having no charged functional group.

[0012] According to the usage in the prior art, polyelectrolyte polymers (polycationic polymers, polyanionic polymers) are also referred to herein as cationic organic polymers, anionic organic polymers in short synonymously, because due to polymerization, a polymer cannot have only one charged functional group per polymer molecule, even if a monomer or a class of monomers (in the case of copolymers) has only one charged functional group. Therefore, polycationic polymer / cationic polymer and polyanionic polymer / anionic polymer are well-known synonym pairs.

[0013] Contact with water must be avoided in particular when handling NCM. However, cationic (or polycationic) polymers such as PVBTA-CL and LiTFSI can only be dissolved in water or other polar organic solvents, which are unstable to NCM. On the other hand, after PVBTA-Cl ion exchange to form PVBTA-LiTFSI, surprisingly, PVBTA-TFSI can be dissolved in acetone instead of water. Solutions of PVBTA-TFSI in acetone are stable to NCM and are easy to operate through a spray drying process. Through this novel and hitherto uncommon method, we have successfully coated NCM with a polymer without affecting the stability of the NCM. It is obvious to any ordinary technician in the field that these results obtained by the example of the combination of PVBTA-TFSI and NCM herein can also be applied to other polycationic polymers combined with other cathode active materials (such as NCA) without departing from the scope of the present invention.

[0014] Furthermore (as will be apparent to one of ordinary skill in the art), the present invention is applicable not only to solid electrolytes, but also to liquid electrolytes and polymer electrolytes. In all cases, mechanical degradation of the NCM leads to particle fracture during cycling, and our coating helps mitigate this degradation mechanism. Thus, without departing from the scope of the present invention, our invention can be advantageously applied to all batteries using any type of electrolyte. Summary of the invention

[0015] An object of the present invention is to provide polymer-coated electrode active materials which are simple and inexpensive to prepare and which exhibit very high cycle stability in electronic devices such as batteries.

[0016] High cycle stability - for example - preferably by reducing phosphate (PO x ˉ) and / or sulfate / sulfite (SO xThe high cycling stability is also demonstrated by the finding that pristine NCM cells exhibit more fragmentation / cracking within and between the (sintered) particles than cells prepared using coated NCM particles.

[0017] As understood herein, the electrode active material includes a cathode active material and an anode active material. The cathode active material is a preferred electrode active material. Among the cathode active materials, the high nickel ternary cathode material LiNi 1-x-y Co x Mn y O 2 (NCM) is the most preferred electrode active material.

[0018] The thiophosphate-based solid electrolyte according to the present invention is an argyrodite-type thiophosphate, such as Li 6 PS 5 Cl(LPSCI) and Li 7+o-p M IV o M V 1-o Ch 6-p X p Type of thiophosphate, in which M IV =Si, Ge, Sn; M V =P, Sb; Ch = O, S, Se; X = Cl, Br, I, BH 4 and 0≤o≤1; 0≤p≤2. In addition to thiophosphate-based solid electrolytes, other solid electrolytes may be used without departing from the scope of the present invention, such as NASICON-type solid electrolytes, such as Li 1+ x Al x Ti 2-x (PO 4 ) 3 (LATP), those of the garnet type, such as Li 7 La 3 Zr 2 O 12 (LLZO), perovskite-type solid electrolytes, such as Li 3x La 2 / 3-x TiO 3 (LLTO), LGPS type solid electrolytes, such as Li 10 G 2 S 12 .

[0019] Surprisingly, we have found that the polymer coating of the active electrode material according to the present invention effectively reduces oxygen-containing species (e.g. SO x n- and PO x n- ) in (for example) thiophosphate-based solid electrolytes, or (for example) on the surface of NCMs, and by doing so effectively enhances the cycling stability of the active electrode materials to a large extent.

[0020] Therefore, in order to achieve the above-mentioned objectives, the present invention provides a polymer coating for an active electrode material and an active electrode material with the polymer coating, as well as their use in electronic devices (such as batteries, especially solid-state lithium-ion batteries, or solid-state lithium-ion electrochemical cells).

[0021] The polymer coating according to the invention comprises a thermoplastic polymer or a non-thermoplastic polymer or a combination of both types of polymers.

[0022] In addition to using polycationic organic polymers to coat NCM, the scope of the present invention also includes the use of polyanionic organic polymers, such as poly(acrylic acid), graphene oxide, polysaccharide gums (e.g., xanthan gum), poly(vinyl alcohol), polydopamine, chitosan, sulfonated polymers (e.g., sulfonated tetrafluoroethylene based fluoropolymer copolymers), poly(styrene sulfonate), poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate, sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfone copolymers (e.g., copolymers with sulfonated polyphenylene sulfone).

[0043] The polyanionic organic polymers listed herein are not intended to limit the scope of the invention. Suitable counterions for polyanionic organic polymers include, but are not limited to, aluminum (III), barium (II), beryllium (II), calcium (II), chromium (III), copper (I), copper (II), gold (I), gold (III), hydrogen (I), iron (II), iron (III), lead (II), lead (IV), lithium (I), magnesium (II), manganese (II), manganese (III), manganese (IV), mercury (II), potassium (I), silver (I), sodium (I), strontium (II), tin (II), tin (IV), zinc (II), polyatomic cations such as ammonium, hydronium, mercury (I), Li (II), and ions such as iodine. + Na + K + Ca 2+ Mg 2+ Al 3+ Polyatomic cations, NH 4 + , ammonium derivatives, NR 3 H + NR 2 H 2 + 、NRH 3 + R is independently selected from the list comprising alkyl, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, which list should not be construed as limiting the scope of the present invention.

[0023] By combining each type of polyelectrolyte polymer with one or more neutral polymers, forming a diluted polyelectrolyte polymer (i.e., polyelectrolyte polymer combined with neutral polymer), similar positive effects on the long-term stability of NCM have also been found. Combining each type of polyelectrolyte polymer with at least one neutral polymer herein means that different polymers are mechanically mixed, such as by compounding, co-solutions, etc., or chemically combine them together, such as by copolymerization. Therefore, the copolymer composed of polycationic organic polymer and neutral organic polymer or polyanionic organic polymer and neutral organic polymer is also a polycationic organic polymer or polyanionic organic polymer of the present invention. Suitable neutral polymer is a neutral polymer that each molecular part of neutral polymer comprises at least one amide group, and the at least one amide group is located in the main chain of polymer chain or in the side chain of the polymer chain of neutral polymer. The example of suitable neutral polymer is polyvinyl pyrrolidone, poly-(N-vinyl formamide), polyamide. The list of these examples should not be construed as limiting the scope of the present invention.

[0024] The polymer coatings disclosed herein are particularly suitable for coating NCMs that are to be used in solid-state lithium-ion batteries / solid-state lithium-ion electrochemical cells together with thiophosphate-based solid electrolytes. In other embodiments, the polymer coatings disclosed herein can also be used to coat, for example, NCMs that are to be used in lithium-ion batteries together with liquid electrolytes or polymer electrolytes. When combined with liquid electrolytes, unlike inorganic coatings, polymer coatings can swell with the liquid electrolyte, thereby reducing the resistance of the battery and increasing the storage capacity. Some polymers with specific functional groups, such as poly(ethylene carbonate), can even increase the lithium transport number. Similarly, polymer electrolytes are more compatible with polymer coatings than inorganic coatings.

[0025] The polyelectrolyte polymers according to the invention can also be prepared by oxidation, reduction, protonation and / or ion exchange of uncharged matrix polymers, by which reactions polycationic or polyanionic polymers are formed.

[0026] In order to have a uniform coating, the invention disclosed herein teaches the use of spray-dried polyelectrolyte solutions to coat active electrode materials, especially NCM materials. Spray drying can be classified as an industrially applied wet coating method. In addition, since polyelectrolytes are easily absorbed on metal oxides due to electrostatic effects, the present invention uses poly((4-vinylbenzyl)trimethylammonium bis(trifluoromethanesulfonimide)) (PVBTA-TFSI) as an example of a coating material for NCM according to the present invention, but this example should not be construed as limiting the scope of the present invention. PVBTA-TFSI is uniformly coated on the surface of NCM, and the cycle performance of PVBTA-TFSI-coated NCM batteries is significantly improved compared to the original NCM batteries. Without being bound by a certain theory, this article also describes in detail key physical phenomena, such as contact loss, electrochemically inactive interface layers, and lithium diffusion paths, by discussing exemplary applied cathode composite materials and electrochemical performance results.

[0027] Overall, comparison of oxidative decomposition products by ToF-SIMS confirmed that polymer coatings, such as the use of PVBTA-TFSI, significantly improved interfacial stability at the CAM / SSE interface, which is in good agreement with the electrochemical data shown herein. PVBTA-TFSI has been synthesized by free radical polymerization as an exemplary polymer according to the present invention and used for NCM coating by spray drying, which is a scalable and controllable process. TEM and Tof-SIMS showed that 1wt% polymer had a uniform coating with a thickness of about 4nm. In terms of electrochemical analysis, the exemplary PVBTA-TFSI coating on the NCM surface improved the cyclic stability of thiophosphate-based SSBs. Correspondingly, EIS and active mass calculations showed that the polymer coating reduced interfacial degradation. In addition, Tof-SIMS confirmed the electrochemical data by showing that less oxidized species were formed at the interface of the polymer-coated NCM. On the other hand, FIB-SEM confirmed the GITT and lithium diffusion length calculations, i.e., particle rupture in the NCM was alleviated by the polymer coating. Overall, polymer coatings, e.g., PVBTA-TFSI, improve cycling stability by reducing mechanical degradation, thus acting as a protective layer to reduce interfacial degradation.

[0028] Li-based anionic polyelectrolyte-coated NCMs are also a key solution to address the capacity loss at the NCM / SE interface, thereby improving the overall performance of NCMs in SSBs. Polyvinylpyrrolidone (PVP) can form a strong interfacial bond with cathode materials and lithium-based anionic polyelectrolytes via electrostatic forces. Therefore, in this study, we combined the above ideas to introduce the first polymer composite-coated NCM for SSBs. We utilized a mixture of PVP and lithiated polyphenylene sulfone sulfonate (LiPPSS) as the LiNi 0.9 Mn 0.05 Co 0.05 O 2 The coating material of (NCM90) is denoted as LiPPSS / PVP-NCM90. By utilizing the electrostatic interaction between LiPPSS, PVP and NCM90, spray drying is used to form a uniform and thin polymer coating on NCM90. The use of this thin LiPPSS / PVP polyelectrolyte complex or diluted polyelectrolyte polymer coating on NCM90 can not only minimize contact losses but also optimize cycling performance. In addition, we deeply studied the degradation at the interface and the length of the lithium diffusion path within the cathode composite, providing further evidence for the enhanced electrochemical performance.

[0029] Characterization of anionic polymer coated NCM90:

[0030] Regarding the studies on the use of polyanionic polymers, we adopted a similar approach to that applied to the experiments conducted on polycationic polymers, namely, applying the anionic polymer coating to NCM90 using a spray coating method. Our previous studies determined that 1wt% polymer (relative to the weight of NCM90) provided the optimal coating thickness, resulting in excellent electrochemical performance and the most uniform coating. Therefore, we used 1wt% polymer (relative to the weight of NCM90) as a comparison standard using the spray coating method described below. However, it was observed that the water and alcohol solvents in the coating process resulted in Li + Therefore, these solvents need to be avoided because they are leached from NCM. To solve this problem, NCM90 was first coated with lithium polyphenylene sulfone sulfonate (LiPPSS) because it is easily soluble in dimethylformamide (DMF). In addition, sulfonated poly(phenylene sulfone) with highly electron-deficient aromatic rings exhibits excellent thermal and thermo-oxidative stability compared to other sulfonated poly(arylene). However, as Fig.19As shown, an energy selective backscattering (ESB) detector combined with a scanning electron microscope (SEM) revealed that the coating was not uniform, characterized by the detachment of some polymer particles from the NCM90 surface. This result indicates that the electrostatic forces between LiPPSS and NCM90 were not sufficient to obtain a uniform coating.

[0031] like Fig. 20 Further exploration using infrared spectroscopy showed that PVP exhibited a strong electrostatic attraction to LiPPSS, with the C=O stretching blue-shifted from 1669 to 1656 cm -1 was confirmed. Unlike polyanions such as polyacrylic acid (PAA), which tend to precipitate immediately when mixed with PVP, when PVP and LiPPSS were dissolved, the two polymers formed a stable, transparent solution without separation of complex polymer particles. This property is advantageous for the spray drying process. Subsequently, we determined a weight ratio of PVP to LiPPSS of 1:1 for coating on NCM90, henceforth named LiPPSS / PVP-NCM90. ESB and SEM demonstrated that the surface polymer particles of LiPPSS / PVP-NCM90 were significantly reduced, such as Fig.19 This observation indicates that a uniform and homogeneous coating was formed on NCM90 using the LiPPSS / PVP composite.

[0032] Rate performance evaluation

[0033] like Fig.21 As shown, the rate capability of coated NCM90 (including NCM90 coated with 1wt% polyvinylpyrrolidone (PVP-NCM90), LiPPSS / PVP-NCM90, NCM90 coated with 1wt% poly((4-vinylbenzyl)trimethylammonium bis(trifluoromethanesulfonimide)) (PVBTATFSI-NCM90) and NCM90 coated with 1wt% polymethyl methacrylate (PMMA-NCM90)) was compared with the performance of pristine NCM90 (pNCM90) under different conditions of rate of 0.1C, 0.25C, 0.5C, 1C. This evaluation utilized particle-type SSB, NCM / Li 6 PS 5 Cl / VGCF||Li 6 PS 5 Cl||In-Li.

[0034] exist Fig.21In the present study, PVP-NCM90 SSB has only a discharge capacity of 138 mAh / g and a Coulombic efficiency of 70% in the first 0.1C cycle, which is much lower than pNCM90 SSB (183 mAh / g and 77% Coulombic efficiency), PVBTATFSI-NCM90 SSB (170 mAh / g and 79% Coulombic efficiency) and LiPPSS / PVP-NCM90 SSB (188 mAh / g and 80% Coulombic efficiency). In addition, PVP-NCM90 SSB exhibits lower rate performance than LiPPSS / PVP-NCM90 and pNCM90 SSB at all C rates. Without being bound by a certain theory, this may be attributed to the uncharged and ionically conductive PVP coating, which may hinder Li ion transport. However, the relatively low capacity of PVP-NCM90 SSB means that not all NCM90 surfaces are completely blocked. This difference may originate from the battery preparation process, including cathode composite mixing and battery pressing, which may cause the PVP coating to fall off or be damaged, exposing the NCM90 surface. A similar effect was also observed in PMMA-NCM90, whose capacity in the first cycle (156 mAh / g and 74% Coulombic efficiency) was much lower than that of pNCM90, PVBTATFSI-NCM90, and LiPPSS / PVP-NCM90.

[0035] exist Fig.21 In the first cycle shown, LiPPSS / PVP-NCM90SSB exhibits a lower charge capacity (234 mAh / g) at 0.1C rate compared to pNCM90 SSB (237 mAh / g). However, during the first cycle discharge, its discharge capacity (188 mAh / g) and coulombic efficiency (80% coulombic efficiency) at 0.1C rate exceeded those of pNCM90SSB (183 mAh / g and 77% coulombic efficiency). The improvement in discharge capacity and coulombic efficiency of LiPPSS / PVP-NCM90 SSB may be due to the reduction of side reactions, which is promoted by the LiPPSS / PVP composite coating.

[0036] Fig. 22 It is shown that the LiPPSS / PVP composite coating reduces the Li 6 PS 5 In addition, in the first cycle charging step, the dQ / dE diagrams of LiPPSS / PVP-NCM90 SSB and pNCM90SSB showed a decrease of 3.48 V (vs. Li + / Li-In) or above or 4.1V (vs.Li + / Li) is comparable to the area around, indicating that the coating does not hinder the H2+H3 phase transition process. In addition, when LiPPSS / PVP-NCM90SSB was evaluated at different discharge rates, especially 0.25C, 0.5C and 1C, its rate performance showed significant improvement compared with pNCM90 and other coated NCM90 SSB. This enhancement can be attributed to the fact that the composite coating of LiPPSS / PVP is more obvious and effective at higher C rates. In addition, in the 25th cycle, LiPPSS / PVP-NCM90 SSB showed better reversibility than pNCM90SSB, as shown in Fig.23 In summary, LiPPSS / PVP-NCM90 SSBs consistently outperform pNCM90 and other coated NCM90 SSBs at all C rates. The superior performance of LiPPSS / PVP-NCM90 SSBs is mainly attributed to the reduction of side reactions by implementing LiPPSS / PVP composite coatings without sacrificing the H2+H3 phase transition process.

[0037] Cycling performance and active mass calculation

[0038] To further investigate the 0.1C cycling performance, we assembled LiPPSS / PVP-NCM90 and NCM / Li 6 PS 5 Cl / VGCF||Li 6 PS 5 pNCM90 SSB with Cl||In-Li composition for direct comparison.

[0039] Fig.24 The 0.1C cycling performance between LiPPSS / PVP-NCM90 and pNCM90 cells was compared. Initially, the discharge capacity of LiPPSS / PVP-NCM90 was 190mAh / g, while the capacity of pNCM90 was lower at 180mAh / g. After 100 0.1C cycles, LiPPSS / PVP-NCM90 had the highest capacity retention of 78.3%, while the capacity retention of pNCM90 was around 69%. After 152 cycles, the capacity retention of LiPPSS / PVP-NCM90 was 71.6%, while the capacity retention of pNCM90 was around 59.6%. The higher capacity retention of LiPPSS / PVP-NCM90 indicates that the 1wt% LiPPSS / PVP composite coating enhances the long-term cycling stability of NCM in SSBs.

[0040] Fig.25 Based on the reference (such as Fig.26 A comprehensive comparison of the effective mass calculation results (shown in Figure 2). In this study, active mass refers to the amount of active material that participates in the reaction.

[0041] After the 152nd cycle, LiPPSS / PVP-NCM90 showed an active mass retention of 83.7%, while pNCM had a lower retention of 78.8%. The degradation of active mass is mainly attributed to contact loss, which has a major impact. This means that the LiPPSS / PVP composite coating on NCM in SSBs can significantly improve the overall performance by mitigating the detrimental contact loss. The term “contact loss” is used to cover two basic surface degradation mechanisms that affect battery performance: the formation of an electrochemically inactive interface layer due to undesirable side reactions (including chemical, electrochemical, and chemomechanical degradation), and the contact loss between NCM and Li. 6 PS 5 These mechanisms reduce the physical separation between NCM and Li during cycling. 6 PS 5 The effective contact area between Cl leads to active mass loss and increased interfacial resistance. Although the two contact loss mechanisms are different, their effects on battery performance are similar, making it difficult to distinguish them experimentally.

[0042] Conversely, factors such as passivation layers that hinder lithium and electron transport and particle cracking within NCMs can prolong lithium diffusion pathways and interfere with effective Li+ / -conversion during battery cycling. + transport. This increased lithium diffusion path length leads to the difference between cycling performance and active mass retention values. A properly optimized coating can effectively counteract interface degradation and particle fracture. This results in a stable interface and ensures a shorter, more unobstructed lithium ion diffusion path. Through examples of detailed embodiments of the present invention, we describe how LiPPSS / PVP composite coatings promote stable interfaces and support shorter, more unobstructed lithium ion diffusion paths, thereby improving battery performance.

[0043] PEDOT and Li 6 PS 5 The stability window between Cl

[0044] In order to evaluate the interaction of poly(3,4-ethylenedioxythiophene) (PEDOT) and polyethylene glycol (PEO) with Li 6 PS 5 To investigate the electrochemical compatibility of Cl, VGCFs were coated onto PEDOT or PEO using the spray drying technique described above. These coated VGCFs were then used as working electrodes to identify potential side reactions. The electrochemical stability was examined by cyclic voltammetry ranging from 0 V to 4 V (vs. Li + / Li-In), using VGCF / Li 6 PS 5Cl was used as the working electrode, and Li-In alloy was used as the reference electrode and counter electrode. Comparing the current density and onset potential between uncoated, PEDOT-coated, or PEO-coated VGCF, it was detected that both PEDOT and PEO were at 3.7 V (vs. Li + / Li-In) and an obvious peak current appears around 1000 Hz. This indicates that PEDOT and PEO are 6 PS 5 Cl are not electrochemically stable, making them unsuitable for coating applications (see Fig. 27 ).

[0045] Specific embodiments of the invention

[0046] It is well known to those skilled in the art that whenever a range of values ​​is given (e.g., time, temperature, particle size, concentration, BET specific surface area, etc.), not only the explicitly named range is referred to, but all other sub-ranges within the explicitly named range are also considered and implicitly disclosed in the present disclosure.

[0047] Exemplary Reagents and Materials Used

[0048] (Vinylbenzyl)trimethylammonium chloride (VBTA-Cl) monomer, reagent grade sodium persulfate (Na 2 S 2 O 8 ) initiator, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and vapor-grown carbon fiber (VGCF) were purchased from Sigma-Aldrich. Single crystal high nickel NCM83 (LiNi 0.83 Mn 0.06 Co 0.11 O 2 ) was purchased from MSE Supplies (particle size about 3-5 μm, BET specific surface area about 0.5-0.9 m 2 / g). 6 PS 5 Cl (LPSCl) was purchased from NEI. Indium foil was purchased from chemPUR GmbH, with a thickness of 100 μm, and punched into a circular electrode with a diameter of 9 mm. Lithium foil was purchased from Albemarle Rockwood Lithium GmbH, with a thickness of 125 μm, and punched into a circular electrode with a diameter of 6 mm.

[0049] Exemplary Synthesis of PVBTA-TFSI

[0050] pass Figure 1The route shown is to synthesize poly((4-vinylbenzyl)trimethylammonium bis(trifluoromethanesulfonimide)) (PVBTA-TFSI). First, 5 g of vinylbenzyltrimethylammonium chloride (VBTA-Cl) and 0.3 ml of saturated Na 2 S 2 O 8 The solution was mixed in 20 ml of deionized water for free radical polymerization and then heated and heated at 75 °C with N 2 Flow purge for 48 hours (VBTA-Cl:Na 2 S 2 O 8 = 1:0.3). After polymerization, PVBTA-Cl was purified by dialysis with a large amount of deionized water and further concentrated by a rotary evaporator. The concentrated polymer solution was then added dropwise to a LiTFSI solution (7.5 g LiTFSI dissolved in 20 g deionized water) and stirred overnight for ion exchange. Once PVBTA-Cl was dropped into the LiTFSI solution, PVBTA-TFSI precipitated immediately. After the ion exchange reaction, PVBTA-TFSI was washed three times by centrifugation with deionized water to remove the residual LiTFSI and separate the PVBTA-TFSI solid. Afterwards, PVBTA-TFSI was placed in a vacuum drying oven and dried at 80°C for 72 hours, and then stored in a glove box. 1 H NMR (400 MHz, deuterated acetone): δ1.36-1.99 (H1, H2), δ2.05 (acetone-d6), δ3.14 (H6), δ4.4-4.9 (H5), δ6.5-7.4 (H3, H4). FT-IR of PVBTA-TFSI (cm -1 ):973(CN telescopic),1346,1326,1176,1132,1050(TFSI - ), 1612, 1480, 1422 (aromatic C=C stretching), 3043, 2922, 2852 (alkyl CH stretching), 3400 (H2O). FT-IR of PVBTA-Cl (cm -1 ):973 (CN stretching), 1612, 1480, 1422 (aromatic C=C stretching), 3015, 2922, 2852 (alkyl CH stretching), 3400 (H2O). FT-IR of LiTFSI (cm -1 ):1327(SO 2 Asymmetric telescopic), 1245 (CF 3 Symmetrical telescopic), 1204(CF 3 Symmetrical expansion), 1147 (SO 2 Symmetrical telescopic), 1065 (asymmetric S 2 N expansion).

[0051] Exemplary preparation of PVBTA-TFSI coated NCMs

[0052] like Figure 1 As shown, a small spray dryer B-290 from BUCHI was used to coat PVBTA-TFSI on NCM. 0.1 g (5 wt% compared to NCM) or 0.02 g (1 wt% compared to NCM) of polymer was mixed with 2 g of NCM and 30 g of acetone as precursor. The mixing step was carried out with vigorous stirring and took about 1 hour to ensure that the particle agglomerates were broken into smaller sizes. The inlet temperature was 150 ° C and the volume flow rate (i.e., the suction volume of the vacuum pump) was 37 m 3 / hour, the feed rate of polymer solution was 8 mL / min, N 2 The flow rate was 40 L / min. The spray drying conditions have been optimized to obtain the highest yield of about 50 to 70 wt%. In addition, 5 wt% polymer-coated NCM and 1 wt% polymer-coated NCM were denoted as 5P-NCM and 1P-NCM, respectively. In addition, 5 wt% PVP-coated NCM followed the same steps as above, but ethanol was used as the solvent.

[0053] X-ray diffraction (XRD)

[0054] XRD was used to characterize PVBTA-TFSI, and the chemical stability between PVBTA-TFSI and LiTFSI and LPSCl was examined using Panalytical Empyrean XRD with Cu Kα radiation. The diffraction pattern was collected from 10° to 85°, with a step size of 0.026°, a Soller slit of 0.04 rad., and an anti-scattering slit of 1 / 2°. In order to examine the chemical stability between PVBTA-TFSI or LiTFSI and LPSCl, PVBTA-TFSI or LiTFSI was mixed with LPSCl in a weight ratio of 1:1 (about 500 mg in total), ground in an agate mortar, and then pressed into pellets (8 mm in diameter). Afterwards, the pellets were heated and kept at 80°C for 24 hours, and then ground in an agate mortar to turn the pellets into powder. Finally, the heated powder was characterized by XRD.

[0055] Thermogravimetric analysis (TGA)

[0056] Using STA 409PC (Netzsch- TGA measurements were performed on approximately 20 mg of sample at a temperature range of 25°C to 1000°C in air / O 2 at a heating rate of 10°C / sec.

[0057] 1H Nuclear Magnetic Resonance (1H NMR)

[0058] The 1H NMR spectra of PVBTA-TFSI were recorded on a Bruker Avance II at 400 MHz in deuterated acetone.

[0059] Fourier Transform Infrared Spectroscopy (FT-IR)

[0060] FT-IR spectra of PVBTA-TFSI, PVBTA-Cl and LiTFSI were obtained on an ATR-FTIR Thermo FischerScientific ID5 ATR spectrometer (550 to 4000 cm -1 ) were recorded on a total of 96 scans. To examine the chemical stability between PVBTA-TFSI or LiTFSI and LPSCl, PVBTA-TFSI or LiTFSI was mixed with LPSCl in an agate mortar and then pressed into pellets. Subsequently, the pellets were heated and kept at 80 °C for 24 h. FT-IR spectra were measured in pellet form before and after the heating process.

[0061] Brunauer-Emmett-Teller Analysis (BET)

[0062] The specific surface area calculations of polymer-coated NCMs and pristine NCMs were measured by the BET method. Before the measurements, the samples were evacuated in a standard glass tube at 120 °C for 12 h. The BET measurements were then performed in an automatic gas adsorption station (Autosorb-1-MP, Quantachrome Instruments) maintained at 77 K by liquid nitrogen in a standard cryostat.

[0063] Scanning Electron Microscopy (SEM)

[0064] The morphology of NCM was characterized by SEM (Merlin, Zeiss) at an accelerating voltage of 3 kV and an accelerating current of 200 pA. Backscattered electron images and secondary electron SEM images were taken by SEM. For sample preparation, polymer coatings and pristine NCM were measured in powder form, tightly adhered to a conductive carbon tape.

[0065] Focused ion beam scanning electron microscopy (FIB-SEM)

[0066] The cross sections of coated and pristine NCM powders and cathode composite pellets were analyzed using a XEIA Xe plasma FIB (TESCAN). For sample preparation, FIB pits were milled at low angles using a 1 nA Xe ion beam at -135 °C maintained in liquid nitrogen without any polishing steps. Afterwards, backscattered electron images and secondary electron SEM images were taken at an accelerating voltage of 3 kV and an accelerating current of 200 pA.

[0067] Energy Dispersive X-ray Spectroscopy (EDS)

[0068] Energy dispersive X-ray spectroscopy (X-Max-Extreme detector, Oxford Instruments) was used to characterize the coatings on NCM after SEM or FIB-SEM measurements. However, in order to obtain more precise signals from EDS, the accelerating voltage and current were increased to 5 kV and 2 nA, respectively. In addition, the working distance was controlled at 5.5-5.6 mm. The elements analyzed were carbon and sulfur.

[0069] Transmission electron microscopy (TEM)

[0070] The TEM images are bright field images in order to provide maximum contrast between the inorganic core and the organic coating of the electrode active material. Methods for making such images are well known in the art and therefore need not be described here. The TEM equipment used was a TVIPS TEMCam XF416FS camera mounted on a JEOL JEM-3010 microscope, operating at 300 kV accelerating voltage.

[0071] Time-of-flight secondary ion mass spectrometry (ToF-SIMS)

[0072] The ToF-SIMS technique is well known in the prior art and therefore does not need to be described here. The equipment used is an M6 Hybrid SIMS (IONTOF GmbH), combined with a 30 kV double cluster primary ion gun for analysis, and a 5 kV Ar gas cluster source (GCIB) for depth profiling (sputtering). The sample was prepared in a glove box and transferred to the measurement chamber using a LEICA EM VCT500 shuttle (Leica Microsystems). The evaluation tool for ToF-SIMS data is the software package SurfaceLab 7.2 (IONTOF GmbH).

[0073] Electrode composites and battery components

[0074] All battery tests were performed using pellet-type battery housings. First, 60 mg of LPSCl was pressed into pellets in a peek cylinder insulator. Next, 70 wt% of the original or coated NCM, 30 wt% of LPSCl, and an additional 1 wt% of VGCF were mixed in an agate mortar for about 20 minutes to prepare the cathode composite. Then 12 mg of the cathode composite was pressed on one side of the electrolyte. Finally, indium (thickness 100 μm, diameter 9 mm) and lithium foil (thickness 125 μm, diameter 6 mm) were pressed on the other side as the anode. After assembly, the entire battery stack was pressed at 30 kN for 3 minutes to obtain a solid electrolyte of about 400 μm and a cathode composite of about 30 μm. The entire battery was analyzed under an external aluminum frame (~50 MPa) before electrochemical analysis.

[0075] Further exemplary details:

[0076] To perform cyclic voltammetry, an asymmetric cell with the following setup was prepared: InLi|Li 6 PS 5 Cl|Li 6 PS 5 To prepare 100 mg of cathode composite material, 9.09 mg of VGCF (9.1 = wt%) was added to 90.90 mg of Li 6 PS 5 Cl and mortared for 15 min. To prepare the cell for analysis, 80 mg of Li 6 PS 5 Cl was pressed into pellets and used as separators in PEEK cylindrical insulators. 30 mg of Li 6 PS 5 The Cl-carbon fiber composite was pressed on one side of the electrolyte. Finally, indium (thickness 100 μm, diameter 9 mm) and lithium foil (thickness 125 μm, diameter 6 mm) were pressed on the other side as anode. After the cell was assembled, the entire cell stack was pressed at 30 kN for 3 minutes. The entire cell was analyzed under an external aluminum frame (~50 MPa) before electrochemical analysis.

[0077] Electrochemical analysis

[0078] At 25°C, at 2.0 and 3.7V (vs.Li + The battery was charged and discharged within the voltage window between Li-I / Li-In for cycling stability, chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analysis. Cycling stability was performed on a MACCOR electrochemical workstation. In addition, EIS and CA were performed by a VMP-300 (BioLogic) electrochemical workstation. Figure 2The whole process is also predicted. The cycling tests were performed at two different currents, 0.1C and 0.25C; however, the EIS measurements were performed at 0.1C. Initially, the battery was charged to 3.15V (vs. Li + / Li-In), then CA is maintained at 3.15V (vs.Li + / Li-In) until the current drops below 1%. Afterwards, the EIS (vs. Li + / Li-In) with a frequency range of 1 MHz to 100 Hz. The sinusoidal amplitude applied for EIS was 10 mV (for 1 MHz to 10 mHz); 5 mV (for 10 mHz to 1 mHz); and 3 mV (for 1 mHz to 100 Hz). The 0.25C cycling stability was run for 200 cycles, and the impedance of the 1st, 2nd, 53rd, 104th, 155th, and 206th cycles was measured at 3.15 V at 0.1C, as shown in Figure 2. Figure 3 As shown in the example. Figure 4 As shown in (a), the 0.1C cycle stability was run for 100 cycles, and the impedance of the 1st to 5th, 10th, 30th, 50th and 100th cycles were measured at 3.15V and 0.1C. The process of how to perform impedance fitting is well known to those of ordinary skill in the art. The low-frequency part is caused by the limited space Warburg behavior (Z fs ) fitting, whose function is described below. The galvanostatic intermittent titration technique (GITT) combined with EIS was measured on a VMP-300 (BioLogic) electrochemical workstation to determine the diffusion coefficient after 100 cycles at 0.1C. The coated NCM battery and the original NCM battery were charged or discharged once every 20 minutes, and then relaxed (relaxation) for 2 hours after each charge or discharge pulse to record the open circuit voltage (VOC). EIS was applied after each relaxation, with a frequency range of 1MHz to 1mHz and a sinusoidal amplitude of 10mV.

[0079] Further exemplary details:

[0080] At 25°C, at 2.0V and 3.7V (vs.Li + The battery was charged and discharged within a voltage window between 100V and 100V for 0.1C cycling performance. The battery was kept at open circuit voltage for 3 hours before measurement. Cyclic voltammetry measurements were made using a two-electrode configuration with a Li-In alloy anode as the reference electrode. First, the battery was charged and discharged at 1 mV s -1The scan rate was scanned from OCV to 4 V (relative to the reference electrode) for oxidation scan, then reverse scan was performed to 0 V and then returned to the starting potential.

[0081] Characterization of PVBTA-TFSI coated NCMs

[0082] Polyelectrolytes, such as PVBTA-TFSI, have an affinity for inorganic surfaces and produce electrostatic effects on metal oxide surfaces, which means that polyelectrolytes have the potential to be promising coating materials for inorganic substrates. Therefore, PVBTA-TFSI is used as an exemplary coating material within the subject matter of the present invention because it has a surprising chemical stability and is therefore compatible with thiophosphate-based solid electrolytes (such as LPSCLs). However, since conventional wet coating methods usually produce uneven coatings on the particle surface, a spray coating method is introduced herein because it may obtain a uniform coating on the NCM. Figure 1 The schematic diagram of the polymer synthesis and spraying process using NCM / PVBTA-TFSI / acetone as precursor is shown exemplarily. The precursor is heated to a temperature (e.g., 150°C) far above the boiling point of the solvent (e.g., acetone) and is ejected from the nozzle. The coating process is then carried out during the drying process in the drying chamber. Finally, the dried powder is collected in the collection chamber by a vacuum pump. The spray drying method can generally obtain two different types of coating products, depending on the particle size. First, if the particle is smaller than the ejected droplet, the particle can be wrapped in the droplet to form a uniform coating. Secondly, if the particle is larger than the droplet, there will be many exposed parts on the particle surface after drying. By using the Mini Spray Dryer B-290 from BUCHI, a drop of solution is about 25 μm, which is much larger than NCM particles (about 3 μm to 5 μm). Therefore, according to the present invention, a uniform coating is achieved, and a uniform coating is most preferably achieved. However, non-uniform coatings are also included within the scope of the present invention, which produce local deviations from the average value of the thickness.

[0083] The structure of PVBTA-TFSI was confirmed by 1H NMR spectrum, which was consistent with the 1H NMR spectrum of the literature, such as Figure 5 After the polymerization and ion exchange process, the chemical shift of the double bond in the PVBTA-TFSI spectrum ( 1 H NMR: 1In the HNMR spectrum, δ = 6.71ppm, 5.82ppm and 5.26ppm) completely disappeared; instead, a new proton absorption peak appeared at δ = 1.5ppm, indicating that the polymerization has been completed. In addition, the protons of aromatic protons (H3, 4), benzyl protons (H5) and trimethylammonium cations (H6) still exist in the PVBTA-TFSI spectrum, indicating that the main chain structure of the polymer is stable after anion exchange. Figure 6 The IR spectra of PVBTA-Cl and PVBTA-TFSI after anion exchange are shown. Compared with PVBTA-Cl, PVBTA-TFSI has a -1 、1176cm -1 、1132cm -1 and 1050cm -1 New characteristic bands are shown at 2 Telescopic, CF3 asymmetric telescopic, symmetric SO 2 These new peaks in the PVBTA-TFSI spectrum are attributed to the TFSI anion groups, indicating that the anion exchange was successful. Figure 7 As shown, XRD was utilized to measure whether there was any crystalline phase from LiTFSI. It can be seen that PVBTA-TFSI only showed a broad amorphous peak at about 20°, indicating that PVBTA-TFSI was an amorphous polymer without any LiTFSI precipitation. The chemical stability between NCM and LPSC1 was investigated by heating LPSC1 and PVBTATFSI at 80 °C for 24 h, and then the samples were examined by XRD and FT-IR measurements before and after heating, as shown in Figure 2. Fig. 8A (FTIR) and Figure 8B (XRD) results show that PVBTA-TFSI is chemically stable to LPSC1. In addition, the thermal stability of PVBTA-TFSI was measured by TGA, as shown in Fig. 9 The decomposition temperature of PVBTA-TFSI is about 365°C, and most of the decomposition occurs at about 400°C to 600°C, which is much higher than the temperature used for coating (150°C).

[0084] The Brunauer-Emmett-Teller (BET) model was used to evaluate the specific surface areas of the coated NCM and the original NCM. For example, the surface areas of the original NCM, 5P-NCM, and 1P-NCM were 0.593 m 2 / g, 0.291m 2 / g and 0.412m 2 / g. Although SEM can hardly distinguish the difference in particle aggregation between the original NCM and the polymer-coated NCM, BET measurements show that the surface area decreases as the coating weight percentage becomes higher. This may be because the polymer makes the agglomeration more severe. TEM was recorded in the form of bright field TEM images to enhance the contrast between the coating and the NCM particles. Fig.10 ), confirming that all observed particles were uniformly coated with only small deviations in thickness, e.g. Fig.10 As shown in ((a) - pristine NCM, (b) - 1P-NCM, (c) - 5P-NCM). 1P-NCM has a uniform coating of about 4 nm, while 5P-NCM has a thicker coating of about 10 nm.

[0085] To characterize the coating composition and distribution more precisely, ToF-SIMS was used as a surface-sensitive technique with its high lateral resolution (less than 50 nm). To chemically identify the coating on the NCM particle structure, pressed PVBTA-TFSI powder was measured as a reference material. Due to the collision cascade initiated by the high-energy analysis, CH 2 OFˉ, SNOˉ and CF 3 These fragments were also formed on the coated samples, confirming the presence of the PVBTA-TFSI coating on the NCM particles.

[0086] In general, combining the results of SEM, TEM and ToF-SIMS, the PVBTA-TFSI coating microstructure can be defined as follows: the coating is uniformly distributed and completely covers the NCM particles. Although the 1wt% coating thickness is about 4nm, the 5wt% coating is thicker (about 10nm). In some embodiments, the coating has local polymer aggregates on the surface with a thickness of, for example, 40 to 100nm (observed in the example of a 5wt% coating with a thickness of 10nm; any ordinary technician in the field knows that the local polymer aggregation will vary with the value of the average thickness and have corresponding sizes). Based on these analysis results, both 1wt% and 5wt% coatings effectively prevent direct physical contact between CAM and SSE and thus stabilize the interface.

[0087] Electrochemical characterization

[0088] Rate performance test

[0089] The performance of the coated cathodes was defined and evaluated by rate capability and cycling stability compared with pristine NCM. Fig.11As shown in (a), different C-rate performances were studied to elucidate the rate performance. Initially, the performance of PVBTA-TFSI coated NCM was not better than that of pristine NCM. However, at 0.5C and 1C rates, the 1wt% coated NCM showed better performance, and the 5wt% coated NCM cell had the same capacity as the pristine NCM cell. Without being bound by a certain theory, the better rate performance of the 1wt% coated NCM at 0.5C and 1C rates may be due to the protection of the polymer coating after several cycles. In addition, at the 25th cycle, as shown in Fig.12 As shown in (b), the coated NCM shows better reversibility during the discharge process. Fig.11 (b) Differentially amplified the voltage from 2V to 3V (vs. Li + The constant current charge and discharge curves of the electrode ( / Li-In) were plotted. The current decreases with increasing polymer content. This suggests that the polymer protects the electrode from electrochemical degradation due to the unstable interface between the electrode and the electrolyte, an effect that occurs mainly in the first cycle. However, as Fig.12 As shown in (a), the protective layer enables the coated cell to have a larger overpotential of about 3 V (vs. Li) compared to the pristine cell in the first cycle. + / Li-In).

[0090] In order to observe the effect of PVBTA-TFSI coating on battery performance, Figure 4 (a)) and 0.25C( Figure 4 (d)) 5P-NCM, 1P-NCM and pristine NCM batteries were cycled at constant current. During the cycling process, EIS test was performed at 3.15V (vs. Li) at a current of 0.1C in a specific cycle. + / Li-In). Select 3.15V (vs.Li + / Li-In) potential to ensure sufficiently high lithium diffusion coefficient and minimum charge transfer resistance (R ct ) while avoiding significant degradation during the measurement. In addition, the impedance of the layered oxide cathode material depends on the charge state of the electrode, so it is necessary to measure the impedance at a fixed potential. To ensure that the impedance can be measured in a sufficiently stable state, CA is used before the EIS measurement. The cell voltage is stabilized at 3.15 V (vs. Li + / Li-In) until the current drops below 1%. This allows the Li + Diffusion into the CAM particles to balance the lithium concentration within the NCM particles. In addition, after each charge and discharge process, the VOC was recorded with a 2-hour relaxation time to calculate the active mass.

[0091] For 0.1C cycle performance ( Figure 4(a)), the results show that 1P-NCM has the highest capacity retention of about 86%, while 5P-NCM has a capacity retention of about 75.3%. However, the capacity retention of the original NCM is only about 70.4%. These results are consistent with the 0.25C cycling performance ( Figure 4 (d)) matches, and it is confirmed that 1P-NCM significantly improves the long-term cycle stability of NCM in SSB. However, not all polymers can be used as a protective layer while maintaining a high capacity of about 180mAh / g. Without being bound by a certain theory, it is possible that the intermolecular interactions and the interactions with the cathode material need to be very strong. In addition, the counter ion TFS1- of the polycation may help the lithium ions to be conducted through the thin coating, which itself does not contain lithium, but a small amount of lithium ions can be obtained from the electrolyte or cathode material for lithium ion conduction. Therefore, the scope of the present invention includes: the polyelectrolyte polymer is a polycationic polymer, a polyanionic polymer, a zwitterionic polymer, a polymer complexed with a polycation and a polyanion, or a mixture of two or more of the above polyelectrolyte polymers. The range of lithium ion conductivity that can be used in the polymer coating according to the present invention is very wide, because the thickness of the polymer coating is very small, preferably less than 100nm, so even low ionic conductivity will not be a disadvantage.

[0092] Without being bound by a particular theory, the improvement in the cycling performance of SSBs caused by the present invention may be due to a variety of reasons. First, reducing the contact loss and electrochemically inactive interface layer between the active material and the electrolyte can better utilize the active mass of the cathode material (the actual amount of active material that has been utilized). Interfacial decomposition between the active material and the electrolyte includes chemical, electrochemical, and chemo-mechanical degradation. Interfacial decomposition can form an electrochemically inactive surface or a high resistance layer. In addition, the electrochemically inactive surface layer and chemo-mechanical shrinkage may cause a loss of contact between the NCM and the solid electrolyte, resulting in R ct Another reason for the improvement achieved by the present invention may be that the increase in lithium diffusion path length is mitigated. The lithium diffusion path length may increase due to particle fracture caused by volume changes, contact loss and interface decomposition listed above.

[0093] Contact loss and electrochemically inactive interface layers

[0094] To quantify and analyze the contact loss and electrochemically inactive cathode / electrolyte interface layer, the active mass in the running cell was measured using methods well known to those skilled in the art. Figure 4 (b) and Fig.15 As shown, Figure 4 (b) depicts exemplary measurement results at 0.1C, Fig.15Exemplary measurement results at 0.25C are described. In short: A cell consisting of a NCM cathode and an In / InLi anode with a fixed potential has an equilibrium open circuit potential (VOC). VOC follows a well-defined function with the state of charge representing the lithium content (Li_X) of the NCM. Using reference data ( Fig.14 ), the actual specific capacity (Q) can be determined by the difference in the state of charge after the charge and discharge process. act ). Then the discharge capacity (Q meas ) and Q act , calculate the active mass (m) according to the following formula [1] act ).

[0095] Q meas

[0096] m act =──────[1]

[0097] Q act

[0098] exist Figure 4 (b) Comparison of the m of polymer-coated NCM cells and pristine NCM cells in 0.1C cycling test. act Initially, the m of 1P-NCM, 5P-NCM and original NCM batteries act The active materials for the polymer coating are slightly less than the original material because some parts of the polymer coating on the NCM are too thick, making the NCM insulating. However, after 100 cycles at 0.1C rate, the m of the original, 1P-NCM and 5P-NCM batteries is act The retention rates of the polymer-coated NCM batteries were about 81.1%, 92%, and 85.5%, respectively. Without being bound by a particular theory, the polymer-coated NCM batteries had better m act retention rate, which can be interpreted as the relief of the electrochemically inactive interfacial layer. Nevertheless, 1P-NCM showed better m act Retention rate, because the polymer coating of 5P-NCM hinders ion transport or charge transport to some extent due to its large thickness. The data provided by way of example show that the best results so far are obtained when the thickness is 4nm to 5nm, but these results should not be interpreted as limiting the thickness range. Depending on the ionic conductivity of the polyelectrolyte (e.g., polycationic polymer), the coating thickness can vary between 0.1nm and 1000nm. Similar results can also be observed in the 0.25C cycle test ( Fig.15 ).

[0099] During cycling, EIS measurements were performed at 0.1C, e.g. Figure 4 (c) shows an exemplary result. Fig.16 The interface between the cathode and the solid electrolyte is the one that affects R ct The thicker polymer coating yields a higher R in the first cycle at 3.15 V (vs. Li+ / Li-In). ct (original NCM: 19.24Ω, 1P-NCM: 21.9Ω, 5P-NCM: 28.5Ω), compared with the first cycle act Nevertheless, after 100 cycles, the R ct Compared with the R of 1P-NCM and 5P-NCM batteries (original NCM: 173Ω, 1P-NCM: 115.1Ω, 5P-NCM: 106.9Ω) ct The increase is more obvious. The R ct The significant increase in (without being bound by a particular theory) can be caused by severe contact loss and interface degradation. EIS measurements show that the polymer coating acts as a protective layer at the NCM / LPSC1 interface and is act The results of the calculation and dQ / dV discussion match well. In addition, the 1P-NCM and 5P-NCM cells have similar R after 100 cycles. ct , indicating that 1 wt% polymer coating is sufficient to serve as a protective layer for NCM. EIS measurements of 0.25C cycled cells (see Figure 3 ) also showed the same conclusion as the 0.1C result.

[0100] Lithium diffusion pathways within cathode composites

[0101] Due to contact loss, interface degradation and NCM particle breakage, the lithium diffusion path length within the cathode composite is expected to increase during cycling. As known to those of ordinary skill in the art, the Warburg behavior in EIS is fitted by a particle size distribution (EIS-PSD) model to determine the length of the lithium diffusion path within the cathode composite. Typically, the ideal confined space Warburg behavior describes the diffusion throughout the sample volume, including at the ion blocking boundary at the current collector and the innermost center of the NCM. If the frequency is low enough to reach the blocking boundary, the impedance will have a capacitive-like behavior, with a continuous transition from 45° to 90° in the Nyquist plot. Therefore, in order to obtain confined space Warburg behavior in EIS, a lower cutoff frequency is applied to 100Hz. Confined space Warburg impedance element for cylindrical particles Used to describe Li in NCM + The complex geometry of the diffusion and the thickness of the cylindrical particles (L diff ) can be regarded as the lithium diffusion path length. Therefore, if the lithium diffusion path length increases, the confined space Warburg behavior will manifest itself for larger particles. is the characteristic time constant τ of lithium diffusion i (Eq.[3]) and the volume fraction ΔQ contributed by the particles i The function of (Eq.4).

[0102] and

[0103] Eq. 4 is used to fit the limited-space diffusion tail of the EIS coupled with the transition line model (TLM), which is well known in the art. diff is the total differential capacity of the entire electrode Assuming 340mAh V -1 g -1 (3.15V(vs.Li + / Li-In), and x=0.6), and according to the reference data ( Fig.14 ) is calculated. Assuming 10 at 25°C -11 cm 2 S -1 , cited from well-known literature in the field, is obtained by fitting the semi-finite part of the diffusion tail in EIS. Fitting the impedance gives L diff The value and volume fraction (expressed in culmination form) of Fig.17(a) As shown in Figure 2, the L of the original NCM is significantly higher than that of the 1 wt% coated NCM battery (about 1.0 μm to 2.2 μm) and the 5 wt% coated NCM battery (about 1.0 μm to 2.7 μm). diff The CA results are similar to the EIS-PSD results above. The voltage was maintained at 3.15 V (vs. Li + / Li-In) until the current drops to 1%, allowing the lithium ion concentration in the NCM particles to reach equilibrium. The time taken is positively correlated with the length of the lithium diffusion path, that is, the longer the time, the longer the lithium diffusion path. Fig.17 (b) shows that in the 100th cycle of 0.1C cycling, the original NCM battery takes 599.8 minutes to reach equilibrium. However, the 5wt% coated and 1wt% coated NCM batteries require 459.8 and 347.1 minutes, respectively. CA and EIS-PSD calculation results show that after cycling, the lithium diffusion path length of the original NCM battery is much longer than that of the coated NCM battery. The lithium diffusion path length of the original NCM battery increases significantly, which provides evidence of interface degradation and particle rupture within the particles. In addition, the CA results of the 0.25C cycle are the same as those of the 0.1C cycle.

[0104] In order to compare the lithium transport in the NCM particles after cycling tests, GITT combined with EIS was used to determine the diffusion coefficient after 100 cycles of 0.1C testing. Assume that in the polarization step c 0 The occurrence of can be ignored. In the case of semi-infinite diffusion, the open circuit potential V OC Follow the following formula [5].

[0105]

[0106] V 0 is the open circuit potential V of the previous cycle OC . C 0 is the equilibrium concentration, i.e. the lithium concentration before the polarization step. w After each relaxation process, the EIS is used to calculate the Z Re The Warburg coefficient determined from the ω data. W is the enhancement factor, which is It means that if only one ion and electron species is considered, the activity gradient is related to the concentration gradient. In addition, n, F, and A are the number of transferred electrons, the Faraday constant, and the electrochemically active electrode surface, respectively. Since NCM may lose contact with the electrolyte during the cycle, the electrochemically active surface A after the cycle is estimated: A = (BET area of ​​NCM) × (active mass after cycle) / (active mass before cycle). W can be supported by GITT experiments according to formula [5]. Therefore, ( Fig.18 (b)) can be obtained by formula [6] and from EIS ( Fig.18 (a)) The obtained Z w In addition, since the surface area of ​​the active material may change due to grinding and mixing during the preparation of the cathode composite, the apparent diffusion coefficient is used in this paper

[0107] from Fig.18 (b) It can be clearly seen that after 100 cycles, the original NCM battery is much lower than that of the coated NCM battery. However, the Highest, 1P-NCM battery Slightly lower than 5P-NCM battery. The original NCM battery The reason for the lowest value may be (without being bound by theory) that the cracking inside the original NCM particles is more serious than that of the coated NCM. However, increasing the polymer content used for coating can hinder the cracking, resulting in a lower value for the 5 wt% coated NCM cell. Highest.

[0108] Morphology and interface stability after cycling

[0109] Small-angle FIB-SEM was used to observe the morphological changes of the cathode composites after cycling. The original NCM battery showed more fragmentation inside the particles than the coated NCM battery, and the 5P-NCM battery showed the least rupture. Without being bound by a particular theory, one reason for the reduced rupture may be that less lithium is extracted from the NCM, especially during the H2+H3 phase transition during the charging step, where the volume change is most dramatic. However, the polymer-coated NCM battery and the original NCM battery showed no significant difference at 4.1 V (vs. Li + / Li) and the area under the dQ / dV curve are similar, indicating that all NCM batteries have similar H2+H3 phase transition processes, such as Fig.12(a) is shown. Therefore, the reduction of cracks in the coated NCM is because the polymer reduces the volume expansion and contraction of the NCM positive electrode material during the cycle. In order to optimize this effect, the thickness of the coating is increased. Since the conductivity decreases with the increase of the coating thickness, there is an optimal thickness of the coating, ranging from 0.1nm to 1000nm, and so far, the optimal thickness range of the coating for exemplary testing is about 4nm to about 5nm.

[0110] The comparative ToF-SIMS experiments of the original NCM and the coated NCM disclosed herein provide evidence for the reduction of electrolyte decomposition products, and thus the present invention exerts a positive influence on the electrochemical cycling stability of the electrode active material, especially the cathode active material and the electrolyte combination. Those skilled in the art are familiar with how to perform such comparative ToF-SIMS measurements, for example, how to set the following experimental parameters:

[0111] - the number of cycles (e.g. up to several hundred cycles) that the electrochemical cell is to be run before disassembly and investigation;

[0112] - selection of the decomposition processes to be considered (e.g. processes between current collector and solid electrolyte and / or between carbon additive and solid electrolyte and / or between CAM (i.e. the coating according to the invention) and solid electrolyte;

[0113] -Choose an indicator molecule that indicates oxidative decomposition, such as phosphate (PO x ˉ);

[0114] - Choose appropriate parameters to provide sufficient statistical reliability of the experimental results (e.g., measuring up to 10 or even more spectra per sample).

[0115] The experimental results are as follows:

[0116] - For the coated samples, the amount of POx (especially POˉ, PO 2 ˉ and PO 3 ˉ) was significantly reduced, demonstrating that the 1wt% and 5wt% PVBTA-TFSI coatings tested in the exemplary embodiment effectively reduced the formation of phosphate. Therefore, the PVBTA-TFSI coating tested in the exemplary embodiment inhibited the decomposition of the thiophosphate-based solid electrolyte. The detectable PO in the 1wt% coating 2 ˉ and PO 3 ˉThe fragments are more than those in the 5wt% coating, proving that thicker coatings can more effectively inhibit the decomposition of solid electrolytes than thinner coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0117] Figure 1 : Schematic illustration of the process of PVBTA-TFSI synthesis and spraying of NCM particles with PVBTA-TFSI.

[0118] Figure 2 : Schematic diagram of electrochemical analysis. The charging process is represented by solid arrows, and the discharging process is represented by dashed arrows. ASSB is charged to 3.15V (vs. Li + / Li-In), and then keep the potential at 3.15V (vs.Li + / Li-In) until the current drops below 1%. Afterwards, the EIS is measured from 1 MHz to 100 Hz. Subsequently, the ASSB is charged to 3.7 V (vs. Li + / Li-In), followed by a 2-hour relaxation process. Finally, the ASSB was discharged to 3.7 V (vs. Li + / Li-In), and then the same relaxation process for 2 hours. For the sake of clarity, it should be pointed out that Figure 2 The inset graphic of the first (main) part is copied and enlarged again, with Figure 2 The correlation between the inserted graph and the enlarged copy of the inserted graph can be easily recognized by the depicted values ​​and the progression of the curves.

[0119] Figure 3 : Exemplary depiction of the EIS of 1P-NCM, 5P-NCM and pristine NCM cells, each measured at 0.25C after chronoamperometry.

[0120] Figure 4 : Exemplary description: (a) long-term cycling performance at 0.1C, (b) corresponding active mass evolution at 0.1C, (c) Nyquist curves of the first and 100th cycles (measured at 0.1C), (d) long-term cycling performance at 0.25C.

[0121] Figure 5 : PVBTATFSI (400 MHz, deuterated acetone) is described exemplarily. 1 H NMR spectrum: δ1.36-1.99 (H1, H2), δ2.05 (acetone-d6), δ3.14 (H6), δ4.4-4.9 (H5), δ6.5-7.4 (H3, H4).

[0122] Figure 6 : Exemplary description of the FT-IR spectra of PVBTA-TFSI, PBVTA-Cl and LiTFSI. FT-IR (cm -1 ): 973 (CN stretch), 1346, 1326, 1176, 1132, 1050 (TFSI -)、1612、1480、1422(aromatic C=C stretching)、3043、2922、2852(alkyl CH stretching)、3400(H2O). FT-IR of PVBTA-Cl (cm -1 ): 973 (CN stretching), 1612, 1480, 1422 (aromatic C=C stretching), 3015, 2922, 2852 (alkyl CH stretching), 3400 (H2O). FT-IR of LiTFSI (cm -1 ):1327(SO 2 Asymmetric telescopic), 1245 (CF 3 Symmetrical telescopic), 1204 (CF 3 Asymmetric telescopic), 1147 (SO 2 Symmetrical telescopic), 1065 (asymmetric S 2 N expansion).

[0123] Figure 7 : Exemplary description of XRD measurements. The XRD of LiTFSI and LiTFSI demonstrates that PVBTA-TFSI is an amorphous polymer.

[0124] Fig. 8A : Exemplary description of infrared spectra. There is no difference in the FT-IR of PVBTATFSI mixed with LPSCL before and after heating.

[0125] Figure 8B : The peaks of the XRD pattern of PVBTATFSI after mixing with LPSCL and heating completely match those of the XRD pattern of PVBTATFSI before heating.

[0126] Fig. 9 : TGA analysis of PVBTA-TFSI, showing an example of the upper temperature limit of spray drying. (Air / O 2 , heating rate is 10°C / sec).

[0127] Fig.10 : Exemplary TEM images of (a) pristine NCM, (b) 1P-NCM and (c) 5P-NCM. TEM (and ToF-SIMS evaluation, data not shown) confirmed the complete and uniform coverage of the PVBTA-TFSI coating on the NCM CAM (ie, NCM particles, exemplary coating).

[0128] Fig.11 :(a) Rate performance test, (b) Differential capacitance of the first cycle at 0..1C (from 2 to 3V (vs.Li +Figure 2 shows an exemplary comparison of the coated and pristine NCM cells at different C rates for the 25th cycle at 0.1C. The inset in part (b) is additionally enlarged outside part (b) for easier reading.

[0129] Fig.12 : Exemplary comparison of differential capacitance plots of polymer-coated NCM cells and pristine NCM cells at (a) the first cycle at 0.1C and (b) the 25th cycle at 0.1C.

[0130] Fig.13 : Exemplary comparison of 0.1C cycle stability of original NCM, 5P-NCM and 5wt% PVP coated NCM (the first one, original NCM and the latter one, PVP coated NCM, are comparative examples according to the prior art). 5P-NCM and 5wt% PVP coated NCM have similar capacity retention rates, but different initial capacities. As is well known in the prior art, the capacity retention rate is extremely dependent on the initial capacity. As the initial capacity increases, the capacity retention rate decreases rapidly. Therefore, although the initial retention rates of 5P-NCM (according to the present invention) and 5wt% PVP coated NCM (prior art) are different, the capacity retention rate values ​​are similar, which is an unexpected and special effect of the improvement in capacity retention rate.

[0131] Fig.14 :Li x Ni 0.83 Mn 0.06 Co 0.11 O 2 x and V in OC The exemplary relationship between V and C is obtained by constant current charging and discharging of a liquid lithium-ion battery at 0.02C. After each 20-minute charge and discharge, the battery is allowed to rest for 2 hours, and V is obtained. OC In addition, Li x Ni 0.83 Mn 0.06 Co 0.11 O 2 The x in can be calculated from the current and time.

[0132] Fig.15 : Exemplary comparison of the corresponding active mass evolution under 0.25C cycling test.

[0133] Fig.16 : Example data of EIS measurement

[0134] Fig.17 : Lithium diffusion path length L measured by (a) EIS-PSD model and (b) CA diff An exemplary evolution of .

[0135] Fig.18 :(a) Warburg coefficient (Zw) determined by EIS, and (b) diffusion coefficient Exemplary description of measurements by the GITT method.

[0136] Fig.19 : ESB and SEM images, exemplarily demonstrating the significant reduction of surface polymer particles in the LiPPSS / PVP-NCM90 coating.

[0137] Fig. 20 : IR spectroscopy exemplarily shows that PVP exhibits a strong electrostatic attraction to LiPPSS.

[0138] Fig.21 : Exemplary comparison of the rate performance of differently coated NCMs.

[0139] Fig. 22 : Exemplary data show that LiPPSS / PVP composite coating or LiPPSS / PVP diluted coating reduces Li 6 PS 5 The electrochemical side reactions of C.

[0140] Fig.23 : Exemplary selected data show that the reversibility of LiPPSS / PVP-NCM90 SSB is better than that of pNCM90 SSB.

[0141] Fig.24 : Exemplary comparison of 0.1C cycling performance between LiPPSS / PVP-NCM90 and pNCM90 cells.

[0142] Fig.25 : An exemplary comprehensive comparison of activity mass calculation results.

[0143] Fig.26 :Li x Ni 0.9 Mn 0.05 Co 0.05 O 2 Example reference data of the VOC function related to the exponent x in .

[0144] Fig. 27 :Exemplary display of PEDOT and Li 6 PS 5 Cyclic voltammetry of Cl.

Claims

1. A coated particulate material comprising i) a plurality of core particles, wherein each core particle comprises at least one compound of formula (I), Li 1+w [Ni 1-x-y-z Co x Mr y M z ] 1-w O 2 (I), and / or at least one compound of formula (II), Li 1+w [Ni 1-x-y-z Co x Al y M z ] 1-w O 2 (II), and / or LiNiO 2 , Where 0≤w≤0.3, 0≤x≤1, 0≤y≤1, 0≤z≤0.25, 0≤x+y+z≤1 and M is at least one chemical element independently selected from the list consisting of Be, Mg, Sr, Ba, Al, Ga, In, Tl, transition metals other than Ni, Co and Mn; and ii) the surface of the core particle exhibits a coating comprising at least one polycationic organic polymer or at least one polyanionic organic polymer and at least one type of counter anion, wherein the coating covers at least 50% of the surface of the core particle.

2. The coated particulate material according to claim 1, It is characterized in that The plurality of core particles according to feature i) of claim 1 already comprise a first coating, such that the coating according to feature ii) of claim 1 forms an outer (second) coating of the coated particulate material and the first coating forms an inner coating of the coated particulate material.

3. The coated particulate material according to claim 1 or 2, Features - said at least one polycationic organic polymer is independently selected from the following list of polycationic organic polymers comprising: Poly((4-vinylbenzyl)trimethylammonium), Poly((3-vinylbenzyl)trimethylammonium), Poly((2-vinylbenzyl)trimethylammonium), poly((2-vinylbenzyl)trialkylammonium), Poly((2-vinylbenzyl)triarylammonium), poly((2-vinylbenzyl)alkylarylammonium), Poly((3-vinylbenzyl)trialkylammonium), poly((3-vinylbenzyl)triarylammonium), Poly((3-vinylbenzyl)alkylarylammonium), poly((4-vinylbenzyl)trialkylammonium), Poly((4-vinylbenzyl)triarylammonium), poly((4-vinylbenzyl)alkylarylammonium), Protonated polyaniline, protonated chitosan, protonated polypyrrole, protonated polydiallyldimethylamine, protonated polyethyleneimine, protonated polythiophene, oxidized polyaniline, oxidized chitosan, oxidized polypyrrole, oxidized polydiallyldimethylamine, oxidized polyethyleneimine, oxidized polythiophene, poly(diallyldimethylammonium), poly(allylammonium), poly(1-alkyl-3-vinylimidazole); or - said at least one polyanionic organic polymer is independently selected from the following list of polyanionic organic polymers comprising: Poly(acrylic acid), graphene oxide, Polysaccharide gum (such as xanthan gum), poly (vinyl alcohol), polydopamine, Chitosan, sulfonated polymers (such as poly (styrene sulfonate)), Poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate, sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfone copolymer, Sulfonated poly (2,6-dimethyl-1,4-phenylene oxide), Poly[(4-styrenesulfonyl)(trifluoromethanesulfonyl)imide], poly[(4-styrenesulfonyl)(trifluoromethyl(S-trifluoromethylsulfonylimino)sulfonyl)imide], sulfonated poly(etheretherketone), Poly(3-sulfopropionate of methacrylate), and poly[(4-styrenesulfonyl)(fluorosulfonyl)imide], Phosphonate polymers (eg, poly(vinylphosphonic acid)), polyphosphonates, poly([2-(methacryloyloxy)ethyl]phosphate).

4. A coated particulate material according to any one of the preceding claims 1 to 3, It is characterized in that The at least one polycationic organic polymer or the at least one polyanionic organic polymer is combined with at least one neutral polymer having at least one amide group, and the at least one neutral polymer having at least one amide group is independently selected from the list comprising polyvinylpyrrolidone, poly(N-vinylformamide), polyamide.

5. A coated particulate material according to any one of the preceding claims 1 to 4, It is characterized in that The at least one type of counter anion of the polycationic polymer is independently selected from the list comprising fluoride, chloride, bromide, sulfate, bis(trifluoromethanesulfonyl)imide, tetrafluoroborate, nitrate, hexafluorophosphate, thiocyanate, bis(fluorosulfonyl)imide, azide, borate, BO 3 3- , B 2 O 5 4- , B 4 O 5 (OH) 4 2- , B 4 O 7 2- or The at least one type of counter cation of the polyanionic polymer is independently selected from the list comprising: Aluminum (III), Barium (II), Beryllium (II), Calcium (II), Chromium (III), Copper (I), Copper (II), Gold (I), Gold (III), Hydrogen (I), Iron (II), Iron (III), Lead (II), Lead (IV), Lithium (I), Magnesium (II), Manganese (II), Manganese (III), Manganese (IV), Mercury (II), Potassium (I), Silver (I), Sodium (I), Strontium (II), Tin (II), Tin (IV), Zinc (II), Polyatomic cations, Ammonium, H + , mercury (I), Li + Na + K + Ca 2+ Mg 2+ Al 3+ Polyatomic cations, NH 4 + , ammonium derivatives, NR 3 H + NR 2 H 2 + 、NRH 3 + , wherein R is independently selected from the list comprising alkyl, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl.

6. A coated particulate material according to any one of the preceding claims 1 to 5, It is characterized in that The average value of the thickness of the coating comprising the at least one polycationic organic polymer or the at least one polyanionic organic polymer ranges from 0.1 nm to 100 nm, preferably from 1 nm to 10 nm, most preferably from 2 nm to 5 nm.

7. The coated particulate material according to claim 6, It is characterized in that The thickness of the coating comprising the at least one polycationic organic polymer or the at least one polyanionic organic polymer deviates from the average value of the thickness in at least one area up to plus 1000% of the average value of the thickness and / or up to minus 80% of the average value of the thickness, wherein the at least one area in which the thickness of the coating deviates from the average value of the thickness is defined by at least one measuring point.

8. A method for preparing a coated particulate material according to any one of claims 1 to 7, It is characterized in that The method comprises the following steps a) providing a plurality of core particles according to feature i); b) coating the plurality of core particles provided according to step a) with: at least one polycationic organic polymer, or - at least one polyanionic polymer - A combination of at least one polycationic polymer and at least one neutral polymer or - A combination of at least one polyanionic polymer and at least one neutral polymer.

9. The method according to claim 8, It is characterized in that Step b) comprises: 1) providing or synthesizing the at least one polycationic organic polymer or the at least one polyanionic organic polymer or the combination of the at least one polycationic polymer and at least one neutral polymer or the combination of the at least one polyanionic polymer and at least one neutral polymer; 2) preparing a solution of the at least one polycationic organic polymer or the at least one polyanionic organic polymer or the combination of the at least one polycationic polymer and at least one neutral polymer or the combination of the at least one polyanionic polymer and at least one neutral polymer provided or synthesized according to step 1) in a solvent suitable for spray drying, wherein the solvent suitable for spray drying is a polar aprotic solvent having a boiling point below 200° C.; 3) coating the plurality of core particles provided in step a) with a solution of the at least one polycationic organic polymer, the at least one polyanionic organic polymer, the combination of the at least one polycationic polymer and at least one neutral polymer, or the combination of the at least one polyanionic polymer and at least one neutral polymer prepared in step 2) by spray drying.

10. An electrode for a lithium ion battery, include: - at least one coated particulate material according to any one of claims 1 to 7; - at least one lithium ion conducting solid electrolyte and / or at least one lithium ion conducting liquid electrolyte and / or at least one lithium ion conducting polymer electrolyte; - at least one electrically conductive component independently selected from the list comprising carbon, graphite, graphene, carbon fullerenes, carbon nanotubes.

11. The electrode according to claim 10, It is characterized in that It contains one or more binders.

12. A lithium ion battery, include: - A coated particulate material according to any one of claims 1 to 7 and / or an electrode according to claim 10 or 11; - at least one solid electrolyte, wherein the at least one solid electrolyte is independently selected from the group consisting of solid electrolytes Li 6 PS 5 Cl, Li 7+o-p M IV o M V 1-o Ch 6-p X p , Li 1+m Al m Ti 2-m (PO 4 ) 3 , Li 7 La 3 Zr 2 O 12 , Li 3n La 2 / 3-n TiO 3 , Li 10 G 2 S 12 A list of M IV independently selected from the list comprising Si, Ge, Sn; M V are independently selected from the list comprising P, Sb; Ch is independently selected from the list consisting of O, S, Se; X is independently selected from Cl, Br, I, BH 4 List of; 0 <m≤1、0<n≤0.3、0≤o≤1、0≤p≤2。 13. A lithium ion battery, include: - A coated particulate material according to any one of claims 1 to 7 and / or an electrode according to claim 10 or 11; - at least one liquid electrolyte, wherein the at least one liquid electrolyte comprises at least one lithium salt dissolved in an aprotic solvent or a mixture of at least two aprotic solvents, the at least one aprotic solvent being independently selected from the list of aprotic solvents comprising ethylene carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, fluoroethylene carbonate, dioxolane, dimethylformamide.

14. A lithium ion battery, include: - A coated particulate material according to any one of claims 1 to 7 and / or an electrode according to claim 10 or 11; - at least one polymer electrolyte, wherein the at least one polymer electrolyte - containing at least one polymer independently selected from the group consisting of polyethylene glycol, acrylate polymer, polymethyl methacrylate, polyvinyl pyrrolidone, polyacrylonitrile, wherein - the at least one polymer is cross-linked or non-cross-linked; and / or - The at least one polymer is a homopolymer or a copolymer.

15. A lithium ion battery, include: - A coated particulate material according to any one of claims 1 to 7 and / or an electrode according to claim 10 or 11; - a polymer electrolyte comprising polyethylene oxide comprising at least one lithium salt or at least one single-ion conductor.

16. The lithium ion battery according to claim 13 or 14, It is characterized in that The at least one polymer electrolyte comprises at least one plasticizer and / or at least one ionic liquid and / or at least one liquid electrolyte.

17. Use of a coated particulate material according to any one of claims 1 to 7, - preparing an electrode according to claim 10 or 11; or - Preparation of a lithium ion battery according to any one of claims 12 to 16.

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