Single-phase lithium ion-electron mixed conductor, single-phase high-entropy lithium ion-electron mixed conductor and application thereof

Abstract

The invention provides a single-phase lithium ion-electron mixed conductor as shown in a formula (LiaLnb AEc) TMO3. The invention also provides a single-phase high-entropy lithium ion-electron mixed conductor as shown in a formula (LiaLn1bLn2c... LnXnAE1n1AE2n2... AEYnm) TMO3, and a preparation method of the single-phase high-entropy lithium ion-electron mixed conductor. The invention also provides an application of the mixed conductor in a solid-state lithium ion battery. The single-phase lithium ion-electron mixed conductor or the single-phase high-entropy lithium ion-electron mixed conductor provided by the invention is used as a positive electrode additive material or a positive electrode framework of the solid-state lithium ion battery, an electron-ion transmission network is constructed, the conductivity of positive electrode charges is improved, the loading capacity of an active material is increased, and the service life of the solid-state lithium ion battery is prolonged. Therefore, the power density and the energy density of the solid-state battery can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state batteries, and particularly to a single-phase lithium-ion-electron mixed conductor, a single-phase high-entropy lithium-ion-electron mixed conductor, and their applications. Background Art

[0002] All-solid-state lithium batteries are considered to be one of the best energy storage devices for solving battery safety and energy density. Due to the advantages of good mechanical properties and wide voltage window of solid electrolytes, they can be adapted to electrode materials with higher theoretical capacities to exhibit higher energy densities. Compared with traditional lithium batteries, all-solid-state batteries use non-flammable solid lithium-ion conductors as electrolytes, effectively avoiding the safety problems caused by thermal runaway of the battery.

[0003] However, the problem of charge transfer at the positive electrode interface is one of the key problems commonly existing in all-solid-state lithium metal batteries. According to the classification of solid electrolytes, all-solid-state lithium metal batteries can be divided into sulfide-based all-solid-state lithium metal batteries, halide-based all-solid-state lithium metal batteries, polymer-based all-solid-state lithium metal batteries, and oxide-based all-solid-state lithium metal batteries.

[0004] In oxide-based all-solid-state batteries, due to the large rigidity of oxide electrolytes, it is difficult to achieve sufficient contact at the interface between the positive electrode and the electrolyte. The thermodynamic instability between the positive electrode material and the electrolyte during high-temperature co-firing and the low intrinsic conductivity of the active material result in a large interfacial impedance at the positive electrode of oxide-based solid-state batteries, seriously affecting the cycle and power density of the battery and limiting its practical application. And during the positive electrode reaction process, the active material needs to be in contact with lithium ions and electrons simultaneously.

[0005] For sulfide-based, halide-based, and polymer-based solid electrolytes, although there is no problem of poor solid-solid interface contact caused by the excessive rigidity of oxide-based solid electrolytes. However, the carrier transport ability of common positive electrode active materials is poor, and a certain amount of conductive additives need to be added to establish an efficient carrier migration path, such as ionic solid electrolytes (20-40 wt%) and electronic carbonaceous materials (1-5 wt%). But in the composite positive electrode, Li + and e - are transported along mutually curved conduction paths, thus increasing the carrier migration barrier. In addition, when e - and Li + meet at the heterojunction of the positive electrode active material, any isolated conductive additive particles, if they cannot transport electrons from the current collector or transport Li + from the electrolyte layer, will significantly reduce the number of positive electrode Li + extraction / insertion sites or weaken the activity of these sites. These two disadvantages further reduce the energy density of all-solid-state batteries.

[0006] Therefore, it is of great significance to provide a suitable cathode additive material to facilitate the improvement of the energy density of all-solid-state batteries. Summary of the Invention

[0007] The technical problem solved by the present invention is to provide a single-phase lithium-ion-electron mixed conductor and a single-phase high-entropy lithium-ion-electron mixed conductor. The mixed conductors provided in this application are applied in all-solid-state lithium-ion batteries, which can improve the energy density and power density of all-solid-state lithium-ion batteries.

[0008] In view of this, this application provides a single-phase lithium-ion-electron mixed conductor as shown in formula (Ⅰ),

[0009] (Li a Ln b AE c )TMO3 (Ⅰ);

[0010] Wherein, a + b + c ≤ 1, Ln is selected from one or more of the lanthanide elements, AE is selected from one or more of the alkaline earth metal elements, and TM is selected from one or more of Mn, Fe, Co, Cr, and Ni.

[0011] In some specific embodiments, the crystal structure of the single-phase lithium-ion-electron mixed conductor is a perovskite structure.

[0012] In some specific embodiments, the single-phase lithium-ion-electron mixed conductor is selected from Li x (La 0.5-x Sr 0.5 )CoO3, wherein, 0 < x < 0.5.

[0013] In some specific embodiments, the single-phase lithium-ion-electron mixed conductor is selected from Li x (Nd 0.5-x Sr 0.5 )CoO3, wherein, 0 < x < 0.5.

[0014] In some specific embodiments, the single-phase lithium-ion-electron mixed conductor is selected from Li x (Pr 0.5-x Sr 0.5 )CoO3, wherein, 0 < x < 0.5.

[0015] This application also provides a single-phase high-entropy lithium-ion-electron mixed conductor as shown in formula (Ⅱ),

[0016] (Li a Ln1 b Ln2 c …LnX n AE1 n1 AE2n2 …AEY nm )TMO3 (II);

[0017] Among them, Ln1 to LnX are selected from one or more of the lanthanide elements, AE1 to AEY are selected from one or more of the alkaline earth metal elements, TM is selected from one or more of Mn, Fe, Co, Cr, and Ni, and a + b + c + ··· + n1 + n2 + ······ + nm ≤ 1.

[0018] In some specific embodiments, the crystal structure of the single-phase high-entropy lithium ion-electron mixed conductor is a perovskite structure.

[0019] In some specific embodiments, the lanthanide elements are selected from one or more of La, Pr, and Nd.

[0020] In some specific embodiments, the single-phase high-entropy lithium ion-electron mixed conductor is selected from (LiLaPrNdSrBa) 1 / 6 CoO3.

[0021] This application also provides a solid-state lithium ion battery, including a positive electrode and a solid electrolyte, characterized in that the material of the positive electrode includes a mixed conductor, and the mixed conductor is the single-phase lithium ion-electron mixed conductor described in the above solution and / or the single-phase high-entropy lithium ion-electron mixed conductor described in the above solution.

[0022] This application provides a single-phase lithium ion-electron mixed conductor as shown in the formula (Li a Ln b AE c )TMO3, and this application also provides a single-phase high-entropy lithium ion-electron mixed conductor as shown in the formula (Li a Ln1 b Ln2 c …LnX n AE1 n1 AE2 n2 …AEY nm )TMO3; The single-phase lithium ion-electron mixed conductor or single-phase high-entropy lithium ion-electron mixed conductor provided by this application can form an effective electron-ion transport network, can expand the positive electrode active sites to the entire surface of the positive electrode active material, reduce the total impedance of the solid-state lithium ion battery, thereby improving the power density of the solid-state lithium ion battery. At the same time, the above mixed conductor as a positive electrode additive material can load a higher proportion of the positive electrode active material, thereby improving the energy density of the solid-state lithium ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 XRD pattern of the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0024] Figure 2 TEM surface morphology photograph of the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0025] Figure 3 EDS spectrum of the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0026] Figure 4 Curvature graph of the lithium ion conductivity test result of the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0027] Figure 5 Curvature graph of the electron conductivity test result of the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0028] Figure 6 XRD spectrum of the single-phase lithium ion-electron mixed conductor prepared in Example 3 of the present invention;

[0029] Figure 7 Curvature graph of the lithium ion conductivity test result of the single-phase lithium ion-electron mixed conductor prepared in Example 3 of the present invention;

[0030] Figure 8 Curvature graph of the electrochemical performance of the solid-state lithium ion battery based on the high-entropy lithium ion-electron mixed conductor prepared in Example 1 of the present invention;

[0031] Figure 9 Curvature graph of the electrochemical performance of the solid-state lithium ion battery based on the single-phase lithium ion-electron mixed conductor prepared in Example 3 of the present invention. Detailed implementation manners

[0032] For further understanding of the present invention, the preferred implementation manners of the present invention will be described below in conjunction with embodiments. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0033] In view of the performance requirements of the energy density and power density of all-solid-state batteries in the prior art, the present application provides a single-phase lithium ion-electron mixed conductor and a single-phase high-entropy lithium ion-electron mixed conductor. By introducing the above two mixed conductors into a solid-state lithium ion battery respectively as a positive electrode additive material or a positive electrode framework, an electron-ion transmission network can be constructed, the charge conduction ability of the positive electrode can be improved, and it is beneficial to increase the loading amount of the active material, which helps to improve the power density and energy density of the solid-state battery. Specifically, the present application first provides a single-phase lithium ion-electron mixed conductor as shown in formula (Ⅰ),

[0034] (Li a Ln b AE c)TMO3(I);

[0035] wherein, a + b + c ≤ 1, Ln is selected from one or more of lanthanide elements, AE is selected from one or more of alkaline earth metal elements, and TM is selected from one or more of Mn, Fe, Co, Cr, and Ni.

[0036] In the above-mentioned single-phase lithium-ion and electron mixed conductor, the (Li a Ln b AE c )TMO3 is a kind of ceramic material with high electronic conductivity, and its crystal structure belongs to the perovskite structure. Among them, TM includes Mn, Fe, Co, Cr, Ni and other elements or their combinations, Ln is one or more of lanthanide elements. For example, Ln includes one or more of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). In a specific embodiment, Ln is selected from one or two of La and Pr. AE is an alkaline earth group element or its combination. For example, the alkaline earth group elements include one or more of Be, Mg, Ca, Sr, Ba, and Ra. In a specific embodiment, the AE is selected from Sr or Ba. TM is selected from one of Mn, Fe, Cr, Co, and Ni. In a specific embodiment, TM is selected from Co. In the present application, Li can lattice-substitute part of Ln or part of AE.

[0037] Specifically, Co occupies the B position of the perovskite, and Li occupies the La lattice of (La 0.5 Sr 0.5 )CoO3, forming a ratio of Li x (La 0.5-x Sr 0.5 )CoO3 (0 < x < 0.5). Further, the single-phase lithium-ion and electron mixed conductor described in the present application is selected from Li x (Nd 0.5-x Sr 0.5 )CoO3, where 0 < x < 0.5; or, the single-phase lithium-ion and electron mixed conductor is selected from Li x (Pr 0.5- x Sr 0.5 )CoO3, where 0 < x < 0.5.

[0038] The crystal structure of the single-phase lithium-ion and electron mixed conductor described in the present application is the perovskite structure.

[0039] In the present application, the preparation method of the single-phase lithium ion-electron mixed conductor is not particularly limited; for example, ingredients are proportioned according to the elemental ratio of the single-phase lithium ion-electron mixed conductor, and the obtained mixture is ball-milled to obtain a single-phase lithium ion-electron mixed conductor precursor, and then the precursor is sintered to carry out a solid-phase reaction; the ball milling can be carried out by a planetary ball mill or a high-energy ball mill, and the present application has no particular limitation in this regard; the sintering can be carried out in a muffle furnace; the above-mentioned solid-phase method is used to prepare a single-phase lithium ion-electron mixed conductor, and a sol-gel method or a combustion method can also be used. Further, in order to obtain a dense single-phase lithium ion-electron mixed conductor, the powder after the above-mentioned solid-phase reaction can be cold isostatically pressed and then sintered, and the sintering method can be furnace sintering, flash sintering, or Joule heat ultra-fast high-temperature sintering and other methods.

[0040] The present invention also provides a single-phase high-entropy lithium ion-electron mixed conductor as shown in formula (Ⅱ),

[0041] (Li a Ln1 b Ln2 c …LnX n AE1 n1 AE2 n2 …AEY nm )TMO3(Ⅱ);

[0042] Wherein, Ln1 to LnX are selected from one or more of the lanthanide elements, AE1 to AE Y are selected from one or more of the alkaline earth metal elements, TM is selected from one or more of Mn, Fe, Co, Cr and Ni, and a + b + c + ··· + n1 + n2 + ······ + nm ≤ 1.

[0043] In the above single-phase high-entropy lithium ion-electron mixed conductor, (Li a Ln1 b Ln2 c …Ln2 n AE1 n1 AE1 n2 …AE1 nm)TMO3 is a type of ceramic material with high electronic conductivity. Its crystal structure belongs to the perovskite structure, where TM includes one or more of Mn, Fe, Cr, Co, Ni, and other elements, Ln is various lanthanide elements, including one or more of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). In a specific embodiment, Ln is selected from La, Pr, and Nd; AE is an alkaline earth element or a combination thereof. For example, alkaline earth elements include one or more of Be, Mg, Ca, Sr, Ba, and Ra. In a specific embodiment, AE is selected from Sr and Ba. a + b + c + …… + n1 + n2 + …… nm = 1. Preferably, (Li a Ln1 b Ln2 c …Ln2 n AE1 n1 AE1 n2 …AE1 nm )TMO3 is (LiLn1Ln2Ln3AE1AE2) 1 / 6 TMO3; preferably, TM is Co, occupying the B position of the perovskite; more preferably, Ln1 = La, Ln2 = Pr, Ln3 = Nd, AE1 = Sr, AE2 = Ba; Li occupies the A-site lattice of the perovskite, forming a ratio of (LiLaPrNdSrBa) 1 / 6 CoO3.

[0044] In this application, there is no particular limitation on the preparation method of the single-phase high-entropy lithium ion-electron mixed conductor; for example, ingredients are proportioned according to the element ratio of the single-phase high-entropy lithium ion-electron mixed conductor, and the obtained mixture is ball-milled to obtain a precursor of the single-phase high-entropy lithium ion-electron mixed conductor, and then the precursor is sintered for solid-phase reaction; the above solid-phase method is used to prepare the single-phase high-entropy lithium ion-electron mixed conductor, and the sol-gel method or combustion method can also be used; the ball-milling can be carried out by a planetary ball mill or a high-energy ball mill, and there is no particular limitation in this application; the sintering can be carried out in a muffle furnace. Further, in order to obtain a dense single-phase high-entropy lithium ion-electron mixed conductor, the powder after the above solid-phase reaction can be cold isostatically pressed and then sintered, and the sintering method can be furnace sintering, flash sintering, or Joule heat ultra-fast high-temperature sintering, etc.

[0045] Furthermore, this application also provides a solid-state lithium ion battery, including a positive electrode and a solid electrolyte. The material of the positive electrode includes a mixed conductor, and the mixed conductor is the above-mentioned single-phase lithium ion-electron mixed conductor and / or the above-mentioned single-phase high-entropy lithium ion-electron mixed conductor.

[0046] The single-phase lithium ion-electron mixed conductor and the single-phase high-entropy lithium ion-electron mixed conductor provided by this application represent the highest level of electronic conductivity in similar systems reported in the literature. They also have good ionic conductivity and a large regulation space. Moreover, the high mixed conductivity can reduce the electrochemical impedance of the positive electrode while increasing the loading of the positive electrode active material. The single-phase mixed conducting framework forms an effective electron-ion transport network, which can extend the positive electrode active sites to the entire surface of the active material, reducing the total impedance of the battery and thus increasing the power density and energy density of the solid-state lithium-ion battery. At the same time, the mixed conductor has a redox range similar to that of the high-voltage lithium-ion positive electrode material, which can meet the mixed conductivity during the charge and discharge process of the battery. The above-mentioned mixed conductor of the present invention has a perovskite crystal structure consistent with the cathode of a solid oxide fuel cell. In addition, the mixed conductor provided by this application can be synthesized only through simple solid-phase or solution methods.

[0047] To further understand the present invention, the following examples are used to elaborate in detail on the mixed conductor provided by the present invention and its applications. The protection scope of the present invention is not limited by the following examples.

[0048] Example 1 (LiLaPrNdSrBa) 1 / 6 Preparation of CoO3 single-phase high-entropy lithium ion-electron mixed conductor

[0049] Single-phase high-entropy lithium ion-electron mixed conductor precursor: Using Li2CO3, LiOH, LiNO3, lithium citrate, La2O3, Pr6O 11 , Nd2O3, Co2O3, BaCO3, SrCO3 as raw materials, proportioned according to the stoichiometric ratio of each element, adding ethanol and putting it into a ball milling tank, using a QM-3SP2 planetary ball mill to ball mill all the precursors at 30 Hz for 48 h. After ball milling is completed, the precursor is obtained, and then dried in an oven at 100 °C for 12 h to obtain the lithium ion-electron mixed conductor precursor;

[0050] Phase formation of lithium ion-electron mixed conductor: Placing the high-entropy lithium ion-electron mixed conductor precursor in a muffle furnace at 1000 °C for 6 h of solid-phase reaction to obtain the high-entropy lithium ion-electron mixed conductor phase-formed powder.

[0051] Preparation of lithium ion-electron mixed conductor dense sheet: Isostatically cold pressing the above-obtained high-entropy lithium ion-electron mixed conductor phase-formed powder at 120 MPa (or pressing it into a block with a uniaxial press, and sintering the obtained block in a muffle furnace at 1200 °C for 6 h to obtain a dense high-entropy lithium ion-electron mixed conductor dense sheet.

[0052] Example 2

[0053] 1) XRD characterization of materials

[0054] Put the single-phase high-entropy lithium-ion and electron mixed conductor forming powder prepared in Example 1 into the sample cell, and perform phase analysis by an X-ray diffractometer. As Figure 1 shown, Figure 1 This is the XRD pattern of the high-entropy lithium-ion and electron mixed conductor of the present invention. It can be seen that under different component doping, the mixed conductor system exhibits a single-phase perovskite structure.

[0055] 2) TEM characterization of the material surface

[0056] Disperse the high-entropy lithium-ion and electron mixed conductor forming powder (LiLaPrNdSrBa) 1 / 6 CoO3 prepared in Example 1 in a solvent, and use TEM lattice fringe testing. Figure 2 This is the surface TEM morphology of the high-entropy lithium-ion and electron mixed conductor prepared in Example 1 of the present invention. From Figure 2 it can be seen that the lattice constant of this material is (110) plane spacing is 0.277 nm, (100) plane spacing is 0.396 nm, (1-11) plane spacing is 0.23 nm, verifying that this material has a perovskite structure.

[0057] 3) EDS characterization of the material surface

[0058] Disperse the high-entropy lithium-ion and electron mixed conductor forming powder (LiLaPrNdSrBa) 1 / 6 CoO3 prepared in Example 1 in a solvent, and perform EDS characterization using TEM; Figure 3 This is the EDS spectrum of the high-entropy lithium-ion and electron mixed conductor prepared in Example 1 of the present invention. From Figure 3 it can be seen that each element is evenly distributed throughout the grains, and the absence of segregation indicates that no impurities are generated in the material.

[0059] 4) Conductivity characterization

[0060] Use methods such as AC impedance to characterize the electronic conductivity and ionic conductivity of the high-entropy lithium-ion and electron mixed conductor prepared in Example 1. As Figure 4 and Figure 5 shown, Figure 4 This is the test result of the lithium-ion conductivity of the high-entropy lithium-ion and electron mixed conductor. Figure 5 This is the test result of the electronic conductivity of the high-entropy lithium-ion and electron mixed conductor. From Figure 4 and Figure 5 it can be seen that the high-entropy mixed conductor (LiLaPrNdSrBa) 1 / 6 CoO3 has excellent ionic conductivity (σ i > 2.3*10 -4S / cm), while having good electronic conductivity (σ e > 1100 S / cm).

[0061] Example 3 Li 0.125 (La 0.375 Sr 0.5 ) Preparation of CoO3 single-phase lithium ion-electron mixed conductor

[0062] Single-phase lithium ion-electron hybrid precursor: Using Li2CO3, LiOH, LiNO3, lithium citrate, La2O3, and SrCO3 as raw materials, proportioned according to the stoichiometric ratio of each element, adding ethanol into a ball milling tank, and ball milling all precursors for 3 h at 20 Hz with a high-energy ball mill. After ball milling, the precursor is obtained, and then dried in an oven at 80 °C for 10 h to obtain the lithium ion-electron mixed conductor precursor;

[0063] Lithium ion-electron mixed conductor phase formation: The lithium ion-electron mixed conductor precursor is placed in a muffle furnace at 1000 °C for 6 h of solid-phase reaction to obtain the single-phase lithium ion-electron mixed conductor phase-formed powder.

[0064] Li 0.125 (Pr 0.375 Sr 0.5 )CoO3 and Li 0.125 (Nd 0.375 Sr 0.5 )CoO3 are prepared in the same way as the above method, with the difference that: the selection of raw materials is adjusted, which are: Pr6O 11 and SrCO3, Nd2O3 and SrCO3.

[0065] The single-phase lithium ion-electron mixed conductor phase-formed powder prepared above is respectively placed in a sample cell, and phase analysis is carried out by an X-ray diffractometer, as Figure 6 shown; Figure 6 This is the XRD pattern of the single-phase lithium ion-electron mixed conductor prepared in this example. It can be seen that under different component doping, the single-phase lithium ion-electron mixed conductor system exhibits a perovskite single-phase structure.

[0066] The lithium ion conductivity of the lithium ion-electron mixed conductor prepared above is characterized by methods such as alternating current impedance, as Figure 7 shown, Figure 7 is the lithium ion conductivity test result of the lithium ion-electron mixed conductor Li 0.125 (La 0.375 Sr 0.5 )CoO3. It can be seen from Figure 7 that the mixed conductor Li 0.125 (La 0.375 Sr0.5 ) CoO3 has excellent lithium ion conductivity.

[0067] Example 4 Application of a single-phase lithium ion-electron mixed conductor based on the cathode of a solid oxide fuel cell in a solid-state lithium ion battery

[0068] 1) Preparation of composite cathode: Weigh 0.15 g, 0.20 g, and 0.65 g of Li2CO3-Li3BO3, mixed conductor, and LiCoO2 respectively, add an appropriate amount of N-methyl-2-pyrrolidone (NMP), put them into a ball milling jar, and use a QM-3SP2 planetary ball mill (or high-energy ball mill) to ball mill all the precursors at 20 Hz for 1 h (0.5 h for high-energy ball milling). After ball milling, obtain the NMP suspension of the composite cathode; the above mixed conductors are the single-phase high-entropy lithium ion-electron mixed conductor prepared in Example 1 and the single-phase lithium ion-electron mixed conductor Li 0.125 (La 0.375 Sr 0.5 )CoO3;

[0069] 2) Preparation of the bilayer structure of solid electrolyte and composite cathode: Uniformly coat the suspension obtained in step 1) on the dense electrolyte sheet lithium lanthanum zirconium oxide, then put it into an 80 °C oven for drying treatment. After drying, perform rapid heat treatment for 10 s by the ultra-fast high-temperature sintering (UHS) method to obtain a dense electrolyte-composite cathode bilayer structure;

[0070] 3) Preparation of all-solid-state battery: Coat molten lithium on the electrolyte-composite cathode bilayer ceramic structure obtained in step 2) in an argon atmosphere to obtain a complete oxide-based all-solid-state battery.

[0071] Detect the electrochemical performance of the oxide-based all-solid-state batteries prepared from the above two mixed conductors. The results are as Figure 8 and Figure 9 shown. It can be seen from Figure 8 that the high-entropy electron mixed conductor forms a good electron-ion transport network in the all-solid-state battery, enabling the all-solid-state battery to operate stably at room temperature and having good electrochemical compatibility with the cathode material. It can be seen from Figure 9 that the electron mixed conductor Li 0.125 (La 0.375 Sr 0.5 )CoO3 also plays an effective role in the operation of the all-solid-state battery.

[0072] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0073] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-phase lithium-ion - electron mixed conductor represented by formula (Ⅰ), (Li a Ln b AE c )TMO3(Ⅰ); Among them, a + b + c ≤ 1, Ln is selected from one or more of the lanthanide elements, AE is selected from one or more of the alkaline earth metal elements, and TM is selected from one or more of Mn, Fe, Co, Cr, and Ni.

2. The single-phase lithium ion-electron mixed conductor according to claim 1, wherein The crystal structure of the single-phase lithium-ion - electron mixed conductor is a perovskite structure.

3. The single-phase lithium ion-electron mixed conductor according to claim 1, characterized in that, The single-phase lithium ion-electron mixed conductor is selected from Li x (La 0.5-x Sr 0.5 )CoO3, where 0 < x < 0.

5.

4. The single-phase lithium ion-electron mixed conductor according to claim 1, wherein, The single-phase lithium ion-electron mixed conductor is selected from Li x (Nd 0.5-x Sr 0.5 )CoO3, where 0 < x < 0.

5.

5. The single-phase lithium ion-electron mixed conductor according to claim 1, characterized in that, The single-phase lithium ion-electron mixed conductor is selected from Li x (Pr 0.5-x Sr 0.5 )CoO3, where 0 < x < 0.

5.

6. A single-phase high-entropy lithium-ion - electron mixed conductor represented by formula (Ⅱ), (Li a Ln1 b Ln2 c …LnX n AE1 n1 AE2 n2 …AEY nm )TMO3(Ⅱ); Among them, Ln1 to LnX are selected from one or more of the lanthanide elements, AE1 to AEY are selected from one or more of the alkaline earth metal elements, TM is selected from one or more of Mn, Fe, Co, Cr, and Ni, and a + b + c + ··· + n1 + n2 + ······ + nm ≤ 1.

7. The single-phase high-entropy lithium ion-electron mixed conductor according to claim 6, characterized in that, The crystal structure of the single-phase high-entropy lithium-ion - electron mixed conductor is a perovskite structure.

8. The single-phase high-entropy lithium ion-electron mixed conductor according to claim 6, wherein The lanthanide element is selected from one or more of La, Pr, and Nd.

9. The single-phase high-entropy lithium ion-electron mixed conductor according to claim 6, wherein, The single-phase high-entropy lithium-ion and electron mixed conductor is selected from (LiLaPrNdSrBa) 1 / 6 CoO3.

10. A solid-state lithium-ion battery, comprising a positive electrode and a solid electrolyte, characterized in that, The material of the positive electrode includes a mixed conductor, and the mixed conductor is the single-phase lithium-ion - electron mixed conductor according to any one of claims 1 to 5 and / or the single-phase high-entropy lithium-ion - electron mixed conductor according to any one of claims 6 to 9.

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