阅读说明：本技术 固体电解质材料和用其制作的固态电池 (Solid electrolyte material and solid-state battery using the same ) 是由 布赖恩·E·弗朗西斯科 希瑟·A·S·普拉特 柯林·R·贝克尔 乔舒亚·伯特纳-加勒特 于 2018-03-27 设计创作，主要内容包括：固体电解质材料包含Li、T、X和A,其中T是P、As、Si、Ge、Al和B中的至少一种；X是一种或多种卤素或是N；A是S和Se中的一种或多种。所述固体电解质材料在用<Image he="68" wi="593" file="DDA0002188295880000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>的X射线衍射测量中在17.8°±0.75°和19.2°±0.75°处具有峰并且可以包括玻璃陶瓷和/或混合晶相。(The solid electrolyte material contains Li, T, X and A, wherein T is at least one of P, As, Si, Ge, Al and B; x is one or more halogens or is N; a is one or more of S and Se. The solid electrolyte material is in use Has peaks at 17.8 ° ± 0.75 ° and 19.2 ° ± 0.75 ° in X-ray diffraction measurements and may include glass-ceramic and/or mixed crystal phases.)

1. A solid electrolyte material comprising:

li, T, X and A, wherein T is at least one element selected from the group consisting of P, As, Si, Ge, Al and B; x is one or more halogens or is N; a is one or more of S and Se; and the solid electrolyte material is in useAt 17.8 ° ± 0.75 ° and 19.2 in X-ray diffraction measurement of (A)Peaks at ± 0.75 °.

2. The solid electrolyte material of claim 1 wherein the composition can be described by the general formula:

Li_1-a-b-c-dP_aT_bA_cX_d

wherein a is more than or equal to 0 and less than or equal to 0.129, b is more than or equal to 0 and less than or equal to 0.096, c is more than or equal to 0.316 and less than or equal to 0.484, and d is more than or equal to 0.012 and less than or equal to 0.125.

3. The solid electrolyte material of claim 2 wherein a-0.111, b-0, c-0.444, d-0.056, a-S and X-Cl.

4. The solid electrolyte material of claim 1 further comprising at least one of a glass-ceramic phase, a crystalline phase, and a mixed phase.

5. The solid electrolyte material of claim 1 wherein a mixed phase is included in useA crystalline phase containing peaks at 20.2 ° ± 0.75 ° and 23.6 ° ± 0.75 °, and/or 21.0 ° ± 0.75 ° and 28.0 ° ± 0.75 °, and/or 17.5 ° ± 0.75 ° and 18.2 ° ± 0.75 ° in the X-ray diffraction measurement of (b).

6. The solid electrolyte material according to claim 5, wherein a ratio of peak intensity of a peak at 19.2 ° ± 0.75 ° to a peak at 17.5 ° ± 0.75 ° is 1 or more.

7. A lithium solid-state battery including a positive electrode active material layer containing a positive electrode active material; a negative electrode active material layer containing a negative electrode active material; and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, wherein at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises the solid electrolyte material of claim 1.

8. A method of producing a sulfide solid electrolyte material comprising a glass-ceramic, the glass-ceramic comprising: li, T, X and A, wherein T is at least one of P, As, Si, Ge, Al and B; x is one or more halogens or N; a is one or more of S and Se; the method comprises mixing and milling a mixture containing an element A or a compound Li₂A. Sulfides of T or T and compounds LiX or Li₃N such that the mixture is amorphous under X-ray diffraction; and heating the sulfide glass at a heat treatment temperature equal to or higher than a crystallization temperature of the sulfide glass to synthesize a glass ceramic, the glass ceramic being usedHas peaks at 17.8 ° ± 0.75 ° and 19.2 ° ± 0.75 ° in the X-ray diffraction measurement of (a).

Technical Field

Various embodiments described herein relate to the following fields: solid-state primary and secondary electrochemical cells, electrodes and electrode materials, electrolytes and electrolyte compositions and corresponding methods of making and using the same.

Summary of The Invention

In an embodiment, the solid electrolyte material comprises Li, T, X, and a, wherein T is at least one of P, As, Si, Ge, Al, and B; x is halogen or N; a is one or more of S and Se. The solid electrolyte material is used inHas peaks at 2 theta of 17.8 deg. + -0.75 deg. and 19.2 deg. + -0.75 deg. and may include glass-ceramic and/or mixed crystal phases.

Drawings

The disclosure may be understood by reference to the following detailed description taken in conjunction with the accompanying drawings, which are briefly described below. It should be noted that for clarity of explanation, certain elements in the drawings may not be drawn to scale.

Fig. 1 is a schematic cross-sectional view of an exemplary configuration of a lithium solid-state electrochemical cell including a solid electrode composition, according to an embodiment.

Fig. 2 is a flow diagram of a process of producing a solid electrolyte composition according to an embodiment.

Fig. 3 is an X-ray diffraction measurement diagram of a solid electrolyte composition produced by the method shown in fig. 2 according to an embodiment.

Fig. 4 is a graph showing improvement in capacity retention rate of a solid-state electrochemical cell using the solid electrolyte composition of the present invention as compared to a prior art solid electrolyte composition according to an embodiment.

Detailed description of the embodiments

In the following description, specific details are provided to provide a thorough understanding of various embodiments of the invention. However, once the specification, its claims, and the drawings have been read and understood, those skilled in the art will understand that some embodiments of the present invention may be practiced without strictly following some of the specific details set forth herein. Additionally, some well-known methods, procedures, apparatus, and systems that may be used in various embodiments described herein have not been disclosed in detail in order to avoid obscuring the present invention.

The increasing number and variety of mobile devices, the development of hybrid/electric vehicles, and the development of internet of things devices are driving a greater demand for battery technology with improved reliability, capacity (Ah), thermal characteristics, life, and recharging performance. Currently, while lithium solid state battery technology provides potential increases in safety, packaging efficiency, and enables new high energy chemicals, improvements are still needed.

Fig. 1 is a schematic cross-sectional view of an exemplary construction of a lithium solid-state electrochemical cell comprising an electrode composition of the present invention. The lithium solid-state battery 100 includes a positive electrode (current collector) 110, a positive electrode active material layer (cathode) 120, a solid electrolyte layer 130, a negative electrode active material layer (anode) 140, and a negative electrode (current collector) 150. The solid electrolyte layer 130 may be formed between the positive electrode active material layer 120 and the negative electrode active material layer 140. The positive electrode 110 electrically contacts the positive electrode active material layer 120, and the negative electrode 150 electrically contacts the negative electrode active material layer 140. The solid electrolyte compositions described herein may form part of the positive electrode active material layer 120, the negative electrode active material layer 140, and the solid electrolyte layer 130.

The positive electrode 110 may be formed of a material including, but not limited to, aluminum, nickel, titanium, stainless steel, or carbon. Similarly, the negative electrode 150 may be formed of copper, nickel, stainless steel, or carbon. The anode 150 may be omitted entirely if the anode active material 140 possesses sufficient electronic conductivity and mechanical strength. The positive electrode active material layer 120 may include at least a positive electrode active material including, but not limited to, a metal oxide, a metal phosphate, a metal sulfide, sulfur, lithium sulfide, oxygen, or air, and may further include a solid electrolyte material (such as the solid electrolyte compositions described herein), a conductive material, and/or a binder. Examples of conductive materials include, but are not limited to, carbon (carbon black, graphite, carbon nanotubes, carbon fibers, graphene), metal particles, filaments, or other structures. Examples of binders include, but are not limited to, polyvinyl chloride (PVC), polyaniline, poly (methyl methacrylate) ("PMMA"), nitrile butadiene rubber ("NBR"), styrene-butadiene rubber (SBR), PVD, or polystyrene. The positive electrode active material layer 120 may include a solid electrolyte composition as described herein at, for example, 5 vol% to 80 vol%. The thickness of the positive electrode active material layer 120 may be, for example, 1 μm to 1000 μm.

The anode active material layer 140 may include at least an anode active material including, but not limited to, lithium metal, lithium alloy, Si, Sn, graphitic carbon, hard carbon, and may further include a solid electrolyte material (such as the solid electrolyte compositions described herein), a conductive material, and/or a binder. Examples of the conductive material may include those used in the positive electrode material layer. Examples of the binder may include those used in the positive electrode material layer. The negative electrode active material layer 140 may include a solid electrolyte composition as described herein at, for example, 5 vol% to 80 vol%. The thickness of the anode active material layer 140 may be, for example, 1 μm to 1000 μm.

The solid electrolyte material contained within the solid electrolyte layer 130 is preferably a solid electrolyte composition as described herein. The solid electrolyte layer 130 may comprise, for example, 10% to 100% by volume of the solid electrolyte composition as described herein. In addition, the solid electrolyte layer 130 may contain binders or other modifiers. Examples of binders may include those used in the positive electrode material layer as well as additional self-healing polymers and polyethylene oxide (PEO). The thickness of the solid electrolyte layer 130 is preferably 1 μm to 1000 μm.

Although shown as a layered structure in fig. 1, it is well known that other shapes and configurations of solid-state electrochemical cells are possible. Most commonly, a lithium solid-state battery may be produced by sequentially laminating and press-fitting a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer between electrodes, and provided with a case.

Fig. 2 is a flow diagram of a process for producing a solid electrolyte composition that can be used in the construction of a secondary electrochemical cell. Process 200 begins with a preparation step 210 in which any preparation actions such as precursor synthesis, purification, and equipment preparation may occur. After any initial preparation, the process 200 proceeds to step 220, where the sulfur, lithium, and other compounds (e.g., as described herein) may be combined with suitable solvents and/or other liquids. Exemplary sulfur compounds can include, for example, elemental sulfur, phosphorus pentasulfide (P), typically in powder form₂S₅) And lithium sulfide (Li)₂S). Exemplary lithium compounds can include, for example, lithium metal (Li), lithium sulfide (Li), which is typically in powder form₂S), lithium chloride (LiCl) and lithium nitride (Li)₃N). Exemplary solvents may include, for example, but are not limited to, aprotic chain hydrocarbons such as heptane, aromatic hydrocarbons such as xylene, and other solvents that have a low tendency to generate hydrogen sulfide gas when contacted with the precursor or final electrolyte composition. The solvent is not particularly limited as long as it partially or completely remains in a liquid state at the desired milling temperature during the milling process and does not participate in detrimental reactions with the solid electrolyte precursor or the final solid electrolyte composition. The proportions and amounts of the various compounds are not particularly limitedProvided that the combination allows synthesis of the desired compositions and phases as indicated by the presence of specific X-ray diffraction characteristics. The proportions and amounts may vary depending on the particular synthesis conditions. For example, as the solid electrolyte composition is adjusted, the ratio of solvent volume to precursor mass may need to be adjusted to ensure that the precursor is completely milled to produce the desired solid electrolyte phase discussed herein.

The amount of the solvent added to the combination is not limited as long as the amount supports synthesis of the desired composition of the solid electrolyte material. A variety of solvents may be mixed together with the compound. Additional materials, such as co-solvents or polymers, may also be added during this step. Alternatively, the synthesis may be carried out in the absence of a solvent.

Next, in step 230, the composition may be mixed and/or milled for a predetermined period of time and temperature to produce a solid electrolyte as described above. The mixing time is not particularly limited as long as it allows for appropriate homogenization and reaction of the precursors to produce a solid electrolyte. The mixing temperature is not particularly limited as long as it allows proper mixing and is not so high that the precursor enters a gaseous state. For example, suitable mixing may be achieved over a period of 10 minutes to 60 hours and at a temperature of 20 to 120 degrees celsius. Mixing can be achieved using, for example, a planetary ball mill or an attritor mill.

Next, in step 240, the composition may be dried in an inert atmosphere such as argon or nitrogen or under vacuum for a predetermined period of time and temperature. After drying, a heat treatment may be performed during step 250 to crystallize the dried material. The temperature of the heat treatment is not particularly limited as long as the temperature is equal to or higher than the crystallization temperature required to produce the crystal phase of the present invention. The material resulting from the heat treatment step 250 may be a single phase or may contain other crystalline phases and a small amount of precursor phase.

In general, the heat treatment time is not limited as long as the heat treatment time allows for the production of the desired composition and phase. This time may preferably be, for example, one minute to 24 hours. In addition, the heat treatment is preferably performed in an inert gas atmosphere (e.g., argon) or under vacuum.

In a final step 260, the completed composition may be used to construct an electrochemical cell, such as the cell of fig. 1.

Other synthetic routes may also be used. For example, a method comprising mixing suitable precursors providing the components Li, T, X and a in a solvent capable of causing a reaction between the precursors, removing the solvent, and heat treating at a temperature equal to or higher than the crystallization temperature of the material may be used to synthesize the solid electrolyte material discussed herein.

Example 1

Will contain 15.5g Li₂S (Lorad Chemicals Co.), 25.0g P₂S₅(Sigma-Aldrich Co.) and 9.5g LiCl (Sigma-Aldrich Co.) were added to a 500ml zirconia milling jar with zirconia milling media and a compatible solvent (e.g., xylene or heptane). The mixture was milled in a Retsch PM 100 planetary ball mill at 400RPM for 18 hours. The material was collected and dried at 70 ℃ and then heated to 200 ℃ in an inert (argon or nitrogen) environment. The resulting powder may then be used in the positive electrode active material layer, the solid electrolyte layer, and/or the negative electrode active material layer.

The sulfide solid electrolyte material obtained as described in example 1 contained Li, T, X and a, and was used for identifying a new crystal phaseHas peaks at 17.8 ° ± 0.75 ° and 19.2 ° ± 0.75 ° in the X-ray diffraction measurement of (a). T is at least one of P, As, Si, Ge, Al and B, A is at least one of S and Se, and X is one or more halogens or is N. The chemical composition of the general formula can be represented by Li_1-a-b-c-dP_aT_bA_cX_d(ii) a Wherein a, b, c and d can have values of 0. ltoreq. a.ltoreq.0.129, 0. ltoreq. b.ltoreq.0.096, 0.316. ltoreq. c.ltoreq.0.484, 0.012. ltoreq. d.ltoreq.0.125, or preferably 0.043. ltoreq. a.ltoreq.0.119, 0. ltoreq. b.ltoreq.0.053, 0.343. ltoreq. c.ltoreq.0.475, 0.025. ltoreq. d.ltoreq.0.125, or more preferably 0.083. ltoreq. a.ltoreq.0.112, 0. ltoreq. b.ltoreq.0.011, 0.368. ltoreq. c.0.449. The composition may be a mixed phase material having other crystalline phases consisting of 2 θXRD peaks at 20.2 ° and 23.6 ° and/or peaks at 21.0 ° and 28.0 ° and/or peaks at 17.5 ° and 18.2 ° were identified. The composition may contain a crystalline phase associated with one or more lithium halides.

An exemplary subset of compositions may be defined as Li_4+3x+u*y-zP_1+x-yT_yA_4+4x-zM_1+zWherein u is an integer representing a preferred valence difference between elements in the P and T classes (e.g., P⁵⁺-Al³⁺2) and T and a represent an element as described herein, and M is halogen. The composition can be 0. ltoreq. x.ltoreq.4, 0. ltoreq. y.ltoreq.4, 0. ltoreq. z.ltoreq.7 or preferably 0. ltoreq. x.ltoreq.3, 0. ltoreq. y.ltoreq.1, 0. ltoreq. z.ltoreq.2 or more preferably 1. ltoreq. x.ltoreq.3, 0. ltoreq. y.ltoreq.0.5, 0. ltoreq. z.ltoreq.

Exemplary composition is composed of Li_4+3x+u*y-zP_1+x-yT_yA_4+4x-zM_1+zWherein x ═ 1, y ═ z ═ u ═ 0, a ═ S, and M ═ Cl; after heat treatment, this composition produces the crystalline phase of the present invention. The structure of this crystalline phase facilitates high ionic conductivity, and the presence of the halogen may help to form a stable, low resistance interface to lithium metal and high voltage cathode active materials.

Fig. 3 is an X-ray diffraction measurement chart of the solid electrolyte composition produced by the process shown in fig. 2 according to example 1. For X-ray diffraction (XRD) measurement and display Major new peaks at 17.8 ° ± 0.75 ° and 19.2 ° ± 0.75 ° indicating a previously unknown crystalline phase. Other compositions may be mixed phase materials having other crystalline phases identified by XRD peaks at 20.2 ° and 23.6 ° and/or peaks at 21.0 ° and 28.0 ° and/or peaks at 17.5 ° and 18.2 ° and/or peaks associated with one of the plurality of lithium halides.

Fig. 4 is a graph showing the improvement in capacity retention rate during cycling of a solid-state electrochemical cell using the solid electrolyte composition of the present invention compared to a prior art solid electrolyte composition. Further studies of the compositions described herein show that compositions comprising the new phase exhibit improved resistance and capacity stability at elevated temperatures and charge cut-off voltages. The electrolyte compositions may also have mechanical properties that help to improve the physical contact and coverage of the cathode active material, as evidenced by the near 100% utilization of cathode capacity during cycling. Measured examples of the compositions provide conductivities of about 0.6 to 2mS/cm at room temperature for both pure and mixed phase electrolyte materials in pellets pressed at room temperature. Higher conductivities may be possible by varying the stoichiometry and/or by pressing or other processing methods and conditions at elevated temperatures.

The features described above and those claimed below may be combined in various ways without departing from the scope of the present disclosure. It is therefore to be noted that what is contained in the above description or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. The above-described embodiments should be regarded as examples of the present invention, rather than as limiting the scope of the invention. In addition to the foregoing embodiments of the invention, review of the detailed description and accompanying drawings will show that there are other embodiments of this invention. Accordingly, many combinations, permutations, variations and modifications of the foregoing embodiments of the invention not set forth explicitly herein will fall within the scope of such invention. The following claims are intended to cover the generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.