Solid-state battery, battery pack, and electric device

Abstract

This application provides a solid-state battery, a battery pack, and an electrical device, relating to the field of solid-state batteries. The solid-state battery includes a positive electrode, an electrolyte layer, and an ion-conducting layer disposed between the positive electrode and the electrolyte layer. The positive electrode comprises a halide electrolyte, and the electrolyte layer comprises a sulfide electrolyte. The ion-conducting layer has good ion-conducting ability and good chemical and electrochemical stability, which can prevent direct contact between the sulfide and halide electrolytes and suppress side reactions at their interface, giving the battery good cycle performance.

Description

Technical Field

[0001] This application belongs to the field of solid-state battery technology, specifically relating to a solid-state battery, a battery pack, and an electrical device. Background Technology

[0002] Compared to traditional lithium-ion batteries based on liquid electrolytes, solid-state batteries based on solid electrolytes exhibit higher energy density and better safety, thus being considered the most promising next-generation battery system. The core of solid-state batteries is the solid electrolyte, which is mainly divided into three categories: sulfide, halide, and oxide. Among them, halide electrolytes have higher ionic conductivity (>1 mS / cm) and a higher oxidation window (>4V vs Li). + Due to its advantages such as Li, it is often used in composite cathodes. However, when it comes into direct contact with Li or Li-In alloy anodes, it generates byproducts that are ion-electron mixed conductors, which limits the application of halide electrolytes.

[0003] Related technologies indicate that metal ions in halide electrolytes readily react with sulfur ions in sulfides to form metal sulfide byproducts, leading to increased impedance and consequently poor cycling performance. Summary of the Invention

[0004] In view of this, this application provides a solid-state battery, a battery pack, and an electrical device. The solid-state battery introduces an ion-conducting layer between the positive electrode and the electrolyte layer. This ion-conducting layer has excellent ion-conducting ability and good chemical and electrochemical stability. It can prevent direct contact between sulfide and halide electrolytes and suppress side reactions at the interface between the two, thus giving the battery good cycle performance.

[0005] The first aspect of this application provides a solid-state battery, the solid-state battery including a positive electrode, an electrolyte layer and an ion-conducting layer disposed between the positive electrode and the electrolyte layer, the positive electrode including a halide electrolyte and the electrolyte layer including a sulfide electrolyte.

[0006] In this application, the ion-conducting layer provides a highly efficient lithium-ion migration channel. It has high chemical stability and can act as a barrier to isolate sulfide and halide electrolytes, suppress interfacial side reactions and impedance growth. It also has good compatibility with electrode materials, maintains structural stability over a wide voltage range and under different environments, and exhibits good cycling performance during long cycles.

[0007] The second aspect of this application provides a solid-state battery pack with solid-state batteries as described in the first aspect of this application, comprising at least two solid-state batteries as described in the first aspect of this application. The solid-state battery pack provided by this application has good cycle performance and excellent electrochemical performance, which is beneficial for its use.

[0008] The third aspect of this application provides an electrical device with a solid-state battery as described in the first aspect of this application or a solid-state battery pack as described in the second aspect of this application. The electrical device provided by this application has excellent performance and strong product competitiveness. Attached Figure Description

[0009] Figure 1 This is a partial structural diagram of a solid-state battery provided in Embodiment 1 of this application.

[0010] Figure reference numerals: 101-positive electrode; 102-ion-conducting layer; 103-electrolyte layer. Detailed Implementation

[0011] To enable those skilled in the art to better understand the solutions of this application, a further detailed description of this application is provided below. The specific embodiments listed below are merely descriptions of the principles and features of this application; the examples are only for explaining this application and are not intended to limit its scope. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0012] Against the backdrop of ever-increasing energy demand, solid-state batteries, as a highly promising new type of energy storage device, have attracted much attention. Traditional lithium-ion batteries use liquid electrolytes, which pose safety hazards such as leakage, flammability, and poor thermal stability, making it difficult to meet the stringent requirements of electric vehicles and large-scale energy storage for high-safety, high-energy-density batteries. Solid-state batteries, with their use of solid electrolytes, are expected to overcome the performance bottlenecks of traditional batteries, achieving a dual improvement in energy density and safety, and becoming a key development direction for next-generation battery technology.

[0013] In the research and development of solid-state batteries, the selection and optimization of electrolyte materials are crucial. Sulfide electrolytes, due to their high room-temperature ionic conductivity, provide efficient ion transport channels for batteries, exhibiting significant advantages in improving battery power density and becoming one of the research hotspots in the field of solid-state electrolytes. However, sulfide electrolytes have shortcomings in electrochemical stability and interfacial compatibility, especially when in contact with halide electrolytes, where interfacial side reactions are highly likely to occur. These side reactions not only lead to a sharp increase in the internal impedance of the battery, hindering smooth ion transport, but also cause electrolyte decomposition and performance degradation, severely affecting the battery's cycle life and overall performance.

[0014] On the other hand, while halide electrolytes possess unique properties in some aspects, their interfacial compatibility with other electrolytes is equally problematic. During battery charging and discharging, halide electrolytes readily react with sulfide electrolytes, forming an unstable interfacial layer. This further increases the battery's interfacial resistance and reduces its energy conversion efficiency and cycle stability.

[0015] Therefore, embodiments of this application provide a solid-state battery. The solid-state battery includes a positive electrode, an electrolyte layer, and an ion-conducting layer disposed between the positive electrode and the electrolyte layer. The positive electrode includes a halide electrolyte, and the electrolyte layer includes a sulfide electrolyte.

[0016] In this application, the ion-conducting layer can provide a highly efficient lithium-ion migration channel; it has high chemical stability and can act as a barrier to isolate sulfide and halide electrolytes, suppress interfacial side reactions and impedance growth, and has good compatibility with electrode materials. It is structurally stable over a wide voltage range and under different environments, and has good cycling performance during long cycles.

[0017] Understandably, during the battery manufacturing process, the ion-conducting layer can be placed on the surface of the positive electrode and then combined with the electrolyte layer, or it can be placed on the surface of the electrolyte layer and then combined with the positive electrode.

[0018] In one embodiment of this application, the ion-conducting layer includes a fast ion conductor, the fast ion conductor having a room temperature ionic conductivity of 10. -7 S / cm~10 -8 S / cm. In this application, room temperature ionic conductivity refers to ionic conductivity at 25°C. Fast ion conductors within this conductivity range can provide efficient channels for lithium-ion migration, ensuring smooth transfer of lithium ions between the positive electrode (containing halide electrolyte) and the electrolyte layer (containing sulfide electrolyte), reducing ion transport resistance, improving the ion conduction efficiency of the battery, and thus optimizing the charge and discharge rate and cycle performance of the battery.

[0019] In one embodiment of this application, the fast ion conductor includes a compound with the structural formula LiMPO4, where M is at least one of Mg, Ca, and Zn. LiMPO4 exhibits high ionic conductivity and low reactivity with electrode materials, effectively suppressing the growth of interfacial impedance and maintaining a low internal resistance throughout long-term cycling. This ensures smooth ion transport, improves the cycle stability of solid-state batteries, and provides excellent chemical stability. It can form a barrier between the halide-containing cathode and the sulfide-containing electrolyte layer, reducing the occurrence of side reactions. For example, the room-temperature ionic conductivity of LiMgPO4 is typically 7 × 10⁻⁶. -7 S / cm~9×10 -7 The room-temperature ionic conductivity of LiCaPO4 is typically 4 × 10⁻⁶ S / cm. -7 S / cm~6×10 -7 The room-temperature ionic conductivity of LiZnPO4 is typically 2 × 10⁻⁶ S / cm. -7 S / cm~3×10 -7 S / cm.

[0020] In one embodiment of this application, the sulfide electrolyte includes a product with the structural formula Li. 6-aPS 5-a X 1+a In compounds where X is a halogen atom and a = 0–1, Li 6-a PS 5-a X 1+a The structure achieves lattice expansion and vacancy control through halogen substitution, combining high ionic conductivity and low interfacial impedance, which can further improve the performance of solid-state batteries.

[0021] In one embodiment of this application, the sulfide electrolyte can be prepared by the following method:

[0022] (1) According to the stoichiometric ratio, grind the corresponding masses of Li2S, P2S5 and LiX in a mortar for 10-30 min;

[0023] (2) Pour the mixture from step 1 into a ball mill jar, add zirconium oxide or alumina balls, with a ball-to-material ratio of 30:1-15:1, and mix and ball mill at 400-550 rpm for 3-5 hours.

[0024] (3) Place the mixture from step 2 into an Al2O3 magnetic boat and place it in a tube furnace. Heat it at 350-450℃ for 3-5 hours under vacuum, with a heating rate of 3-5℃ / min.

[0025] In one embodiment of this application, the halide electrolyte includes a structure with the formula Li a M b Cl c Compounds in which M is at least one of In, Zr, and Sc, 6 ≥ a > 0, 1 ≥ b > 0, and 6 ≥ c > 0. Li a M b Cl c It can be used as a cathode additive in solid-state batteries to reduce interfacial impedance, stabilize electrode structure, and has good compatibility, thereby improving the electrochemical performance of solid-state batteries.

[0026] In one embodiment of this application, the halide electrolyte can be prepared by the following method:

[0027] (1) Based on the designed stoichiometric ratio, add the corresponding masses of LiCl and MCl. b (M is In, Zr or Sc metal ions) Grind in a mortar for 10-30 minutes;

[0028] (2) Pour the mixture from step 1 into a ball mill jar, add zirconium oxide or alumina balls, with a ball-to-material ratio of 30:1-15:1, and mix and ball mill at 400-600 rpm for 3-8 hours.

[0029] (3) After step 2 is completed, the mixture from step 2 is placed in an Al2O3 magnetic boat and placed in a tube furnace. It is heated at 200-300℃ for 2-5 hours under vacuum, with a heating rate of 3-5℃ / min.

[0030] In one embodiment of this application, the thickness of the ion-conducting layer is 1-5 nm. When the ion-conducting layer thickness is 1-5 nm, it can isolate the halide and sulfide electrolytes, suppress side reactions, reduce the consumption of electrolyte by byproducts, and minimize abnormal growth in interfacial impedance. Simultaneously, this thickness of ion-conducting layer can alleviate the stress caused by electrode volume changes during charging and discharging, reduce the risk of interfacial stripping, and maintain a stable ion transport path during long-term cycling, thereby improving cycle performance. For example, the thickness of the ion-conducting layer can be one of 1 nm, 2 nm, 3 nm, 4 nm, or 5 nm.

[0031] In one embodiment of this application, the positive electrode includes a positive electrode active material, and the mass ratio of the positive electrode active material to the halide electrolyte is (2.4-9):1. When the mass ratio of the positive electrode active material to the halide electrolyte in the positive electrode is within the range of (2.4-9):1, synergistic optimization of the two can be achieved: the halide electrolyte can fully fill the gaps between the positive electrode active materials and construct a continuous ion conduction path, effectively reducing interface impedance to ensure rapid lithium ion migration; at the same time, it can avoid the battery capacity being affected by insufficient relative content of positive electrode active material due to excessive halide electrolyte content; simultaneously, at this ratio, the halide can form a stable protective interface layer on the surface of the positive electrode active material, inhibiting the structural degradation of the active material and the dissolution of transition metals, thereby improving the battery rate performance and cycle stability while taking into account high capacity output, and achieving optimization of the overall performance of the solid-state battery. For example, the mass ratio of the positive electrode active material to the halide electrolyte can be at least one of 3:1, 4:1, 5:1, 6:1, 7:1, and 8:1.

[0032] In one embodiment of this application, the positive electrode active material can be of various types, commonly including ternary lithium-ion materials (such as LiNi). x Co y Mn 1-x-y O2, where x and y can form NCM523, NCM622, NCM811, etc., depending on the composition ratio, lithium iron phosphate (LiFePO4, LFP), lithium cobalt oxide (LiCoO2, LCO), lithium manganese oxide (LiMn2O4, LMO), and lithium-rich manganese-based materials (xLi2MnO3·(1-x)LiMO2, where M is a transition metal such as Ni or Co).

[0033] In one embodiment of this application, the ion-conducting layer is prepared by atomic layer deposition. Preparing the ion-conducting layer by atomic layer deposition allows for precise control of the layer thickness (down to the atomic scale), ensuring that the ion-conducting layer uniformly covers the electrolyte layer or the positive electrode surface. This avoids localized obstruction of ion conduction due to uneven thickness and allows for precise control of the interfacial reaction level to reduce side reactions. Simultaneously, this preparation method enhances the adhesion between the ion-conducting layer and the electrolyte layer or positive electrode, suppressing the impedance increase caused by interfacial peeling during charge-discharge cycles, thereby stabilizing the lithium-ion migration path and improving the cycle stability of the solid-state battery.

[0034] In one embodiment of this application, the ion-conducting layer can be prepared by the following method:

[0035] First, 30 mg of Li6PS5X powder was compressed into circular blocks using a powder press at a pressure of 150-300 MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a nanometer-thick LiMPO4 layer. Specifically, lithium tert-butoxide, tert-butanol M metal salt (M being Mg, Ca, or Zn), and trimethyl phosphate were used as the lithium source, metal source, and phosphate source, respectively. An ALD reactor was used as the apparatus for this method, with Ar gas used as both the carrier gas and the purge gas. First, lithium tert-butoxide and tert-butanol M metal salt (M being Mg, Ca, or Zn) in appropriate stoichiometric ratios were introduced into the reaction chamber in a pulsed manner for 3-6 s, followed by purging with Ar gas for 8 s. Finally, trimethyl phosphate in appropriate stoichiometric ratios was introduced into the reaction chamber in a pulsed manner for 1-3 s. During this process, the reactor temperature is controlled at 150-180℃, and the thickness of the LiMPO4 (M is Mg, Ca or Zn) deposition is adjusted by the number of atomic layer deposition cycles.

[0036] This application also provides a battery pack comprising two or more solid-state batteries.

[0037] Typically, a battery pack comprises multiple solid-state batteries as described above, which are connected to form the battery pack. These batteries can be electrically connected using methods conventional in the art, such as series connection, parallel connection, or a hybrid connection including these methods, without particular limitation.

[0038] This application also provides an electrical device, including a solid-state battery or a solid-state battery pack, which serves as the power supply for the electrical device.

[0039] The electrical equipment used in the embodiments of this application can be conventional electrical equipment in the art, such as power equipment (e.g., electric vehicles, electric cars), electronic equipment (e.g., mobile phones, tablets, laptops, digital cameras, etc.), wearable devices (e.g., watches, bracelets, VR glasses, etc.), energy storage power stations, etc., and there are no particular limitations on this.

[0040] The technical solutions of the embodiments of this application will be further described below through multiple examples.

[0041] Example 1

[0042] Preparation of Li3InCl6 halide electrolyte: LiCl and InCl3 were weighed out in a total mass of 15g with a LiCl:InCl3 molar ratio of 3:1. The mixture was then ground in a mortar for 30 min to form mixture A. Mixture A was then poured into a ball mill jar, and zirconia balls were added at a ball-to-material ratio of 30:1. The mixture was ball-milled at 600 rpm for 8 h to obtain mixture B. Finally, mixture B was placed in an Al2O3 magnetic boat and then in a tube furnace. It was heated at 300℃ under vacuum for 5 h at a heating rate of 5℃ / min.

[0043] Preparation of Li6PS5Cl sulfide electrolyte: Li2S, P2S5, and LiCl were weighed out in a total mass of 15g, with a Li2S:P2S5:LiCl molar ratio of 2.5:0.5:1. The mixture was then ground in a mortar for 30 min to form mixture A. Mixture A was then poured into a ball mill jar, and zirconia balls were added at a ball-to-material ratio of 30:1. The mixture was ball-milled at 550 rpm for 5 h to obtain mixture B. Finally, mixture B was placed in an Al2O3 magnetic boat and then placed in a tube furnace. It was heated at 450℃ under vacuum for 5 h at a heating rate of 5℃ / min.

[0044] Preparation of a 1 nm thick LiMgPO4 deposition layer: First, 100 mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300 MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 1 nm thick LiMgPO4 layer. Specifically, lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1 g with a molar ratio of 1:1:1. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and magnesium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6 s, followed by 8 s purging with Ar gas. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3 s. During this process, the reactor temperature was controlled at 180 °C. The thickness of the LiMgPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1 nm. Therefore, it cycles 17 times.

[0045] Example 2

[0046] Preparation of a 2nm thick LiMgPO4 deposition layer: First, 100mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 2nm thick LiMgPO4 layer. Specifically, lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1g, with a molar ratio of 1:1:1 for lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and magnesium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6s, followed by 8s of Ar purging. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3s. During this process, the reactor temperature was controlled at 180℃, and the thickness of the LiMgPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1nm. Therefore, it cycles 34 times.

[0047] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0048] Example 3

[0049] Preparation of a 5nm thick LiMgPO4 deposition layer: First, 100mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 5nm thick LiMgPO4 layer. Specifically, lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1g, with a molar ratio of 1:1:1 for lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and magnesium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6s, followed by purging with Ar gas for 8s. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3s. During this process, the reactor temperature is controlled at 180℃, and the thickness of the LiMgPO4 deposition is adjusted by the number of atomic layer deposition cycles. The thickness of the deposition is 1nm in 17 cycles, so 85 cycles are required.

[0050] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0051] Example 4

[0052] Preparation of a 2nm thick LiCaPO4 deposition layer: First, 100mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 2nm thick LiCaPO4 layer. Specifically, lithium tert-butoxide, calcium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1g, with a molar ratio of 1:1:1 for lithium tert-butoxide, calcium tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and calcium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6s, followed by 8s of Ar purging. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3s. During this process, the reactor temperature was controlled at 180℃, and the thickness of the LiCaPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1nm. Therefore, it cycles 34 times.

[0053] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0054] Example 5

[0055] Preparation of a 2nm thick LiZnPO4 deposition layer: First, 100mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 2nm thick LiZnPO4 layer. Specifically, lithium tert-butoxide, zinc tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1g, with a molar ratio of 1:1:1 for lithium tert-butoxide, zinc tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and zinc tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6s, followed by 8s of Ar purging. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3s. During this process, the reactor temperature was controlled at 180℃, and the thickness of the LiZnPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1nm. Therefore, it cycles 34 times.

[0056] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0057] Example 6

[0058] Preparation of a 7nm thick LiMgPO4 deposition layer: First, 100mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 7nm thick LiMgPO4 layer. Specifically, lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1g, with a molar ratio of 1:1:1 for lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and magnesium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6s, followed by 8s of Ar purging. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3s. During this process, the reactor temperature was controlled at 180℃, and the thickness of the LiMgPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1nm. Therefore, the cycle repeats 119 times.

[0059] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0060] Example 7

[0061] Preparation of a 0.5 nm thick LiMgPO4 deposition layer: First, 100 mg of Li6PS5Cl powder was pressed into a circular block using a powder press at a pressure of 300 MPa. Then, an atomic layer deposition (ALD) method was used to coat one side of the electrolyte block with a 2 nm thick LiMgPO4 layer. Specifically, lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate were weighed in a total volume of 1 g, with a molar ratio of 1:1:1 for lithium tert-butoxide, magnesium tert-butoxide, and trimethyl phosphate. An ALD reactor was used as the apparatus for this method, with Ar gas as both the carrier gas and the purge gas. First, the corresponding masses of lithium tert-butoxide and magnesium tert-butoxide were introduced into the reaction chamber in a pulsed manner for 6 s, followed by 8 s purging with Ar gas. Finally, the corresponding mass of trimethyl phosphate was introduced into the reaction chamber in a pulsed manner for 3 s. During this process, the reactor temperature was controlled at 180 °C. The thickness of the LiMgPO4 deposition was adjusted by the number of ALD cycles, with 17 cycles achieving a thickness of 1 nm. Therefore, the cycle repeats 8 times.

[0062] The preparation of Li3InCl6 halide electrolyte and Li6PS5Cl sulfide electrolyte is the same as in Experiment 1.

[0063] Comparative Example 1

[0064] Preparation of Li3InCl6 halide electrolyte: LiCl and InCl3 were weighed out in a total mass of 15g with a LiCl:InCl3 molar ratio of 3:1. The mixture was then ground in a mortar for 30 min to form mixture A. Mixture A was then poured into a ball mill jar, and zirconia balls were added at a ball-to-material ratio of 30:1. The mixture was ball-milled at 600 rpm for 8 h to obtain mixture B. Finally, mixture B was placed in an Al2O3 magnetic boat and then in a tube furnace. It was heated at 300℃ under vacuum for 5 h at a heating rate of 5℃ / min.

[0065] Preparation of Li6PS5Cl sulfide electrolyte: Li2S, P2S5, and LiCl were weighed out in a total mass of 15g, with a Li2S:P2S5:LiCl molar ratio of 2.5:0.5:1. The mixture was then ground in a mortar for 30 min to form mixture A. Mixture A was then poured into a ball mill jar, and zirconia balls were added at a ball-to-material ratio of 30:1. The mixture was ball-milled at 550 rpm for 5 h to obtain mixture B. Finally, mixture B was placed in an Al2O3 magnetic boat and then placed in a tube furnace. It was heated at 450℃ under vacuum for 5 h at a heating rate of 5℃ / min.

[0066] Cyclic performance test:

[0067] LiNi, a positive electrode active material, is a lithium nickel cobalt manganese oxide (LiNi). 0.8 Co 0.1 Mn 0.1 O2, Li3InCl6 electrolyte powder, and vapor-grown carbon fiber (VGCF) are mixed and ground evenly at a ratio of 70:30:1 and set aside for later use.

[0068] In the 1 cm diameter mold battery, for the example, Li6PS5Cl bulk materials of varying thicknesses of LiMPO4 were deposited as the electrolyte layer. For the control group, 0.1 g of Li6PS5Cl powder was poured into the mold battery and cold-pressed at 300 MPa to form the electrolyte layer. The prepared composite cathode powder was then uniformly spread on one side of the solid electrolyte layer and pressed at 500 MPa. Next, a lithium indium anode was placed on the other side of the solid electrolyte layer and pressed at 200 MPa. The prepared mold battery was then tested at 200 MPa. All battery fabrication processes were carried out in an inert atmosphere glove box with a water content <10 ppm and an oxygen content <10 ppm.

[0069] The battery cycle test was conducted using a battery tester with 0.2C charging (1C = 210mAh g-1) and 0.2C discharging, with a voltage range of 2.5-4.3V and 500 cycles. The test results are shown in Table 1.

[0070] Table 1

[0071]

[0072] As shown in Table 1, compared with the capacity retention rate of Comparative Example 1, the Example has a higher capacity retention rate, indicating that the LiMPO4 ionic conductor is beneficial for improving cycling performance.

[0073] The above description represents the preferred embodiments of this application, but should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A solid-state battery, characterized in that, The solid-state battery includes a positive electrode, an electrolyte layer, and an ion-conducting layer disposed between the positive electrode and the electrolyte layer. The positive electrode includes a halide electrolyte, and the electrolyte layer includes a sulfide electrolyte.

2. The solid-state battery according to claim 1, characterized in that, The ion-conducting layer comprises a fast-ion conductor having a room-temperature ionic conductivity of 10 -7 S / cm to 10 -8 S / cm.

3. The solid-state battery according to claim 2, characterized in that, The fast ion conductor includes a compound with the structural formula LiMPO4, where M is at least one of Mg, Ca, and Zn.

4. The solid-state battery according to any one of claims 1-3, characterized in that, The sulfide electrolyte includes a compound of the structural formula Li 6-a PS 5-a X 1+a a compound of the structural formula Li3PS4, X is a halogen atom, and a = 0-1.

5. The solid-state battery according to any one of claims 1-4, characterized in that, The halide electrolyte includes the structure Li a M b Cl c The compound, M is at least one of In, Zr and Sc, 6≥a>0, 1≥b>0, 6≥c>0.

6. The solid-state battery according to any one of claims 1-5, characterized in that, The thickness of the ion-conducting layer is 1-5 nm.

7. The solid-state battery according to any one of claims 1-6, characterized in that, The positive electrode includes a positive electrode active material, and the mass ratio of the positive electrode active material to the halide electrolyte is (2.4-9):

1.

8. The solid-state battery according to any one of claims 1-7, characterized in that, The ion-conducting layer is prepared by atomic layer deposition.

9. A battery pack, characterized in that, It includes at least two solid-state batteries as described in any one of claims 1-8.

10. An electrical appliance, characterized in that, Includes the solid-state battery as described in any one of claims 1-8 or the battery pack as described in claim 9.

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