An oxide solid electrolyte material, a method for preparing the same, and an application thereof

Abstract

The application provides an oxide solid electrolyte material and a preparation method and application thereof, relates to the technical field of electrolyte material preparation, and the preparation method comprises the following steps: 1) preparing pure-phase lithium borate according to a certain proportion of BLiO2 and Li2O and B4Li2O7 under certain conditions; 2) mixing, ball-milling or wet ball-milling / drying the lithium borate with a zirconium source, a lithium source and a dopant according to a certain proportion; 3) then tabletting, performing one-time high-temperature solid-phase sintering, crushing and the like; 4) finally mixing and ball-milling the LZBO after doping modification and a coating agent, tabletting, and performing two-time high-temperature solid-phase sintering, crushing and the like to obtain the LZBO material. The application reduces the reaction temperature, improves the product purity and production efficiency, and realizes energy saving and emission reduction by means of innovative raw material combination and process steps in view of the defects of the traditional high-temperature solid-phase synthesis method. The application improves the ionic conductivity, the compaction density, the battery rate, the cycle performance and the like, and widens the application range.

Description

Technical Field

[0001] This invention relates to the field of electrolyte material preparation technology, and in particular to an oxide solid electrolyte material, its preparation method, and its application. Background Technology

[0002] With the rapid development of new energy vehicles, the demand for power batteries continues to increase. However, the core factors affecting or restricting the development of power batteries are resources such as nickel, cobalt, and lithium. Among them, lithium resources have a crucial impact on the cost of batteries and vehicles.

[0003] With the rapid development of new energy technologies, various battery technologies, including lightweight, long-range, and high-energy-density batteries, are gradually improving. However, liquid lithium-ion batteries still have certain disadvantages in terms of safety and energy density compared to solid-state or semi-solid-state batteries. The core technology for semi-solid-state and solid-state batteries lies in the research and application of solid-state electrolytes. Currently, solid-state electrolytes include polymer solid-state electrolytes, oxide solid-state electrolytes, sulfide solid-state electrolytes, halide solid-state electrolytes, and nitride solid-state electrolytes, each with its own advantages and disadvantages.

[0004] Oxide electrolytes are compounds containing lithium, oxygen, and other components (phosphorus, titanium, aluminum, lanthanum, germanium, zinc, zirconium, etc.). They are mainly classified into crystalline and amorphous states. In research, the amorphous state is mainly LiPON type, while the crystalline state includes garnet type, perovskite type, anti-perovskite type, and fast ion type. Oxide solid electrolytes have advantages such as high safety, high thermal stability, wide electrochemical window, low cost, abundant resources, high mechanical strength, and relatively mature preparation processes. However, traditional preparation techniques, such as high-temperature solid-phase synthesis, have inherent defects such as high energy consumption, poor product purity control, low production efficiency, low ionic conductivity, and low compaction density. Therefore, an innovative preparation method is urgently needed.

[0005] With the continuous advancement of materials science and the synthesis of new materials, different types of oxides are constantly being discovered and applied. Therefore, there is an urgent need to research and develop a new type of oxide solid electrolyte material with high ionic conductivity, high compaction density, high purity, low cost, high efficiency and easy preparation. Summary of the Invention

[0006] One of the objectives of this invention is to provide a method for preparing oxide solid electrolyte materials. This method develops an LBZrO solid electrolyte, which, compared with traditional synthesis methods for similar oxide solid electrolytes, improves ionic conductivity, purity, and compaction density while reducing reaction temperature and increasing production efficiency, thereby achieving energy conservation and emission reduction and promoting green production.

[0007] The second objective of this invention is to provide an oxide solid electrolyte material prepared by the above-mentioned preparation method.

[0008] A third objective of this invention is to provide an application of the above-mentioned oxide solid electrolyte material in battery manufacturing.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] In a first aspect, the present invention provides a method for preparing an oxide solid electrolyte material, comprising the following steps:

[0011] (1) BLiO2, Li2O and B4Li2O7 were mixed and ball-milled to obtain mixed lithium borate, and then pre-sintered to obtain pure phase lithium borate;

[0012] (2) The lithium borate obtained in step (1) is dry-mixed and ball-milled with a zirconium source, a lithium source, and a dopant to obtain a mixture containing lithium zirconium borate; or,

[0013] The lithium borate obtained in step (1) is wet-mixed and ball-milled with a slurry containing zirconium source, lithium source and dopant, and then filtered and dried to obtain a mixture containing zirconium borate and lithium borate.

[0014] The dopants include combinations of TiO2, AlPO4, Al(OH)3 and Al2O3;

[0015] (3) After pressing the mixture containing lithium zirconium borate obtained in step (2) into tablets, it is sintered once under an inert atmosphere, crushed and sieved to obtain doped modified lithium zirconium borate.

[0016] (4) The doped modified lithium zirconium borate obtained in step (3) is mixed with a coating agent and ball-milled. After being pressed into tablets, it is sintered again under an inert atmosphere, crushed, and sieved to obtain an oxide solid electrolyte material.

[0017] The coating agent includes a combination of Ti / P compounds, Al(OH)3, and Li compounds. The Ti / P compounds are TiP2O7 or Ti3(PO4)4, and the Li compounds are C2H3O2Li or LiOH.

[0018] The following is a detailed explanation:

[0019] Step (1):

[0020] In some embodiments, the purity of BLiO2, Li2O, and B4Li2O7 in step (1) is ≥99.9%, and their D50 particle size is 1.0μm to 15.0μm, preferably 2.0μm to 12.0μm, and more preferably 2.0μm to 8.0μm;

[0021] In some embodiments, the mass ratio of BLiO2, Li2O and B4Li2O7 in step (1) is 0.6-1:0.6-1:0.5-1, preferably 0.8-1:0.8-1:0.6-1, and more preferably 1:1:1;

[0022] The mixed ball milling equipment includes high-energy ball mills, ball mills, jar mills, etc.; the mixed ball milling media are one of zirconia balls, agate balls, stainless steel grinding balls, and cemented carbide grinding balls, with zirconia balls or agate balls being preferred.

[0023] In some embodiments, the rotation speed of the ball mill in step (1) is 100-1500 rpm, preferably 200-1400 rpm, more preferably 300-1280 rpm; the ball milling time is 0.5-8.0 h, preferably 1-6.0 h, more preferably 2.0-5.0 h; and the ball-to-material ratio of the ball mill is 2-20:1, preferably 3-18:1, more preferably 3-12:1.

[0024] In some embodiments, the initial lithium borate particle size after ball milling in step (1) is 0.8-1.2 μm;

[0025] The pre-sintering equipment is one of the following: microwave synthesizer, microwave reactor, microwave catalytic synthesizer, vacuum box furnace, vacuum tube furnace, or rotary furnace; microwave catalytic synthesizer or vacuum box furnace is preferred.

[0026] In some embodiments, the pre-sintering temperature in step (1) is 100-800°C, preferably 200-740°C, more preferably 300-680°C; the pre-sintering isothermal time is 1-6.0h, preferably 1.5-5.0h, more preferably 2.0-4.0h;

[0027] In some embodiments, the pre-sintering atmosphere in step (1) is either argon or nitrogen;

[0028] Step (2):

[0029] In some embodiments, the zirconium source in step (2) is selected from Zr(CO3)2, Zr(OH)4, ZrO2, Zr 0.92 O2Y 0.08 Zr 0.97 O2Y 0.03 One or more of the following zirconium sources: Zr(CH3COO)4, ZrB2, ZrF4, ZrSiO4, Li2ZrO3, Zr(HPO4)2, ZrCl4, Zr(CH3COO)4·4H2O, Zr(C6H5O7)2, Zr(NO3)4, and ZrS2; preferably, the zirconium source is Zr(CO3)2, Zr(OH)4, ZrO2, or ZrS2. 0.92 O2Y0.08 Zr 0.97 O2Y 0.03 One or more of them;

[0030] In some embodiments, the lithium source in step (2) is one or more selected from LiOH, LiOH·H2O, Li2CO3, LiNO3, Li3BO3, LiBO2, Li2O, LiI, LiCl or C2H3O2Li; preferably, the lithium source is one or more selected from Li2O, Li2CO3, LiOH·H2O.

[0031] In some embodiments, the mass of the dopant in step (2) accounts for 0.01% to 6% of the total mass of the lithium source, lithium borate and zirconium source, preferably 0.04% to 4%, more preferably 0.06% to 3%, wherein the mass ratio of lithium source, lithium borate, zirconium source and dopant is 1 to 10: 1 to 3: 1 to 3, preferably 2 to 8: 1 to 2: 1 to 2, more preferably 2 to 6: 1: 1;

[0032] The mass ratio here refers to the mass ratio of dry powder; if a wet process is used, it refers to the mass of the corresponding dry powder in the slurry. The total solid content of lithium source, zirconium source, and dopant in the wet slurry is 20-50%, preferably 25-40%, more preferably 28-35%, and the slurry solvent is pure water.

[0033] Preferably, the zirconium source is ZrO2 or Zr 0.92 O2Y 0.08 or Zr 0.97 O2Y 0.03 The purity is ≥99.9%, and its D50 particle size is 0.02μm~2.0μm, preferably 0.02μm~1.5μm, and more preferably 0.04μm~1.0μm;

[0034] Preferably, the zirconium source Zr(CO3)2 or Zr(OH)4 has a purity ≥99.5% and a D50 particle size of 0.04μm to 3.0μm, more preferably 0.04μm to 2.0μm, and even more preferably 0.4μm to 1.5μm;

[0035] Preferably, the lithium source Li2O has a purity of ≥99.9% and a D50 particle size of 1.0μm~10.0μm, more preferably 2.0μm~8.0μm, and even more preferably 2.0μm~5.0μm;

[0036] Preferably, the lithium source Li2CO3 has a purity of ≥99.5% and a D50 particle size of 1.0μm~10.0μm, more preferably 2.0μm~8.0μm, and even more preferably 2.0μm~5.0μm;

[0037] Preferably, the lithium source LiOH·H2O has a purity of ≥99.0% and a D50 particle size of 1.0μm~10.0μm, more preferably 2.0μm~8.0μm, and even more preferably 2.0μm~5.0μm;

[0038] In some embodiments, the mass ratio of the total mass of lithium source, lithium borate and zirconium source to TiO2 in step (2) is 1.0:0.0001 to 0.02, preferably 1:0.0004 to 0.015, and more preferably 1:0.0006 to 0.01;

[0039] The total mass ratio of lithium source, lithium borate and zirconium source to AlPO4 is 1.0:0.0001 to 0.02, preferably 1:0.0004 to 0.015, and more preferably 1:0.0006 to 0.01;

[0040] The total mass ratio of lithium source, lithium borate and zirconium source to Al(OH)3 is 1.0:0.0001 to 0.020, preferably 1:0.0004 to 0.020, and more preferably 1:0.0006 to 0.018;

[0041] The mass ratio of the total mass of lithium source, lithium borate and zirconium source to Al2O3 is 1.0:0.0001 to 0.06, preferably 1:0.0004 to 0.04, and more preferably 1:0.0006 to 0.03.

[0042] Preferably, the TiO2 purity is ≥99.9%, and its D50 particle size is 0.04μm~5.0μm, more preferably 0.1μm~4.0μm, and even more preferably 0.4μm~3.0μm;

[0043] Preferably, the AlPO4 purity is ≥99.9%, and its D50 particle size is 0.05μm~4.0μm, more preferably 0.1μm~3.0μm, and even more preferably 0.3μm~3.0μm;

[0044] Preferably, the purity of Al(OH)3 is ≥99.9%, and its D50 particle size is 0.04μm~6.0μm, more preferably 0.1μm~5.0μm, and even more preferably 0.4μm~3.0μm.

[0045] Preferably, the Al2O3 has a purity of ≥99.9% and a D50 particle size of 0.04μm to 6.0μm, more preferably 0.1μm to 5.0μm, and even more preferably 0.4μm to 3.0μm.

[0046] In some embodiments, the rotation speed of the dry and wet ball milling in step (2) is 200 to 2500 rpm, preferably 300 to 2200 rpm, and more preferably 1000 to 2200 rpm;

[0047] The time for ball milling the dry and wet methods is 1.0 to 10.0 h, preferably 2.0 to 8.0 h, and more preferably 3.0 to 6.0 h;

[0048] The ball-to-material ratio of dry and wet ball milling is 3 to 20:1, preferably 4 to 18:1, and more preferably 5 to 12:1;

[0049] In some embodiments, the particle size of the mixture containing lithium zirconium borate after ball milling in step (2) is 0.7 to 1.0 μm.

[0050] Step (3):

[0051] The mixture containing lithium zirconium borate is loaded into a corundum sagger and pressed into sheets, then transferred to a sintering equipment. It is subjected to high-temperature primary sintering under a slightly positive or slightly negative inert atmosphere (argon or nitrogen). After airflow crushing, sieving, and demagnetization, the doped and modified lithium zirconium borate product is obtained.

[0052] In some embodiments, the tableting pressure in step (3) is 18-36 MPa, preferably 20-34 MPa, more preferably 24-32 MPa; the tableting time is 1-20 s, preferably 2-15 s, more preferably 3-10 s;

[0053] The sintering equipment includes a vacuum box-type atmosphere furnace, a vacuum tube furnace, and an atmosphere roller kiln, with a vacuum box-type atmosphere furnace and an atmosphere roller kiln being preferred.

[0054] In some embodiments, the sintering temperature in step (3) is 200-2400°C, preferably 400-1800°C, more preferably 600-1500°C; and the sintering time is 2-32h, preferably 3-24h, more preferably 3-18h.

[0055] In some embodiments, the pressure of the first sintering in step (3) is a slightly positive pressure or a slightly negative pressure. The slightly positive pressure is 10 to 200 Pa, preferably 15 to 120 Pa, more preferably 20 to 100 Pa, and the slightly negative pressure is -15 to -180 Pa, preferably -18 to -120 Pa, more preferably -25 to -100 Pa.

[0056] In some embodiments, the particle size of the doped modified lithium zirconate obtained in step (3) is 300 nm to 1.0 μm.

[0057] Step (4):

[0058] Doped and modified lithium zirconium borate is dry-mixed with a coating agent and ball-milled. The mixture is then loaded into a corundum sagger, pressed into sheets, and transferred to a sintering device. It undergoes high-temperature secondary sintering under a slightly positive or slightly negative inert atmosphere (argon or nitrogen). After crushing, sieving, and demagnetizing, the coated and modified lithium zirconium borate product is obtained.

[0059] In some embodiments, the mass ratio of doped modified lithium zirconium borate to the total amount of coating agent in step (4) is 1:0.0001 to 0.040, preferably 1:0.0004 to 0.036, and more preferably 1:0.0006 to 0.032;

[0060] Preferably, the mass ratio of doped modified lithium zirconium borate to C2H3O2Li is 1:0.0001 to 0.020, more preferably 1:0.0002 to 0.018, and even more preferably 1:0.0003 to 0.016;

[0061] The mass ratio of doped modified lithium zirconium borate to LiOH is 1:0.0001 to 0.020, preferably 1:0.0002 to 0.018, and more preferably 1:0.0003 to 0.016;

[0062] The mass ratio of doped modified lithium zirconium borate to TiP2O7 is 1:0.0001 to 0.020, preferably 1:0.0002 to 0.018, and more preferably 1:0.0003 to 0.016;

[0063] The mass ratio of doped modified lithium zirconium borate to Ti3(PO4)4 is 1:0.0001 to 0.010, preferably 1:0.0002 to 0.009, and more preferably 1:0.0003 to 0.008;

[0064] The mass ratio of doped modified lithium zirconium borate to Al(OH)3 is 1:0.0001 to 0.010, preferably 1:0.0002 to 0.009, and more preferably 1:0.0003 to 0.008;

[0065] Preferably, the anhydrous C2H3O2Li has a purity ≥99.0%, and its D 50 Particle size ranges from 20nm to 100nm;

[0066] Preferably, the anhydrous LiOH has a purity of ≥99.5% and a D50 particle size of 20nm-100nm;

[0067] Preferably, the purity of TiP2O7 is ≥99.0%, and its D50 particle size is 200nm-500nm;

[0068] Preferably, the purity of Ti3(PO4)4 is ≥99.0%, and its D50 particle size is 200nm-500nm;

[0069] Preferably, the purity of Al(OH)3 is ≥99.5%, and its D50 particle size is 200nm-500nm.

[0070] In some embodiments, the tableting pressure in step (4) is 10-20 MPa, preferably 12-18 MPa, more preferably 14-16 MPa; the tableting time is 1-10 s, preferably 2-8 s, more preferably 3-6 s;

[0071] The sintering equipment includes a vacuum box-type atmosphere furnace, a vacuum tube furnace, and an atmosphere roller kiln, with a vacuum box-type atmosphere furnace and an atmosphere roller kiln being preferred.

[0072] In some embodiments, the secondary sintering temperature in step (4) is 100-1100℃, preferably 150-1000℃, more preferably 200-980℃; the secondary sintering time is 1-10h, preferably 1.5-8h, more preferably 2-6h;

[0073] In some embodiments, the pressure of secondary sintering in step (4) is a slightly positive pressure or a slightly negative pressure. The slightly positive pressure is 10 to 150 Pa, preferably 15 to 100 Pa, more preferably 20 to 80 Pa, and the slightly negative pressure is -15 to -150 Pa, preferably -18 to -100 Pa, more preferably -25 to -80 Pa.

[0074] In some embodiments, the particle size of the oxide solid electrolyte material obtained in step (4) is 50 nm to 900 nm.

[0075] Secondly, the present invention provides an oxide solid electrolyte material prepared by the above preparation method.

[0076] The prepared oxide solid-state electrolytic lithium zirconium borate (LZBO) has the following general chemical formula: Li a Zr x B y M b O3, where 1.0≤a≤10.0, 1.0≤x≤3.0, 1.0≤y≤3.0, 0<b≤0.13, and M is the total molar amount of Ti, Al, P doping and surface doping coating.

[0077] The lithium zirconium borate (LZBO) solid electrolyte prepared by the method described above is an inorganic material with multiple functional properties. It has the characteristics of electronic-grade functional material with high ionic conductivity, high compaction density, high purity, and easy processing. It has significant application value in the fields of positive and negative electrode material modification, slurry and electrode modification, separator coating, ceramics, glass, and catalysts related to new energy lithium batteries.

[0078] Thirdly, the present invention provides an application of oxide solid electrolyte material in the preparation of secondary batteries.

[0079] Applications in the fields of all-solid-state batteries and semi-solid-state batteries; preferably, the secondary battery is a lithium-ion battery.

[0080] Technical effects:

[0081] The method described in this invention improves the ionic conductivity and compaction density of lithium zirconium borate (LZBO) through innovative raw material combinations, reduces residual alkali content, and effectively lowers the reaction temperature, thereby reducing energy consumption.

[0082] The method described in this invention significantly improves the purity of the product by introducing specific additives to improve the solid-phase reaction;

[0083] The method described in this invention further improves the performance of lithium zirconium borate (LZBO) through secondary high-temperature modification.

[0084] The method described in this invention is simple to operate, and the resulting product has high purity and low impurity content, possessing the performance characteristics and application advantages of solid electrolytes in the new energy field.

[0085] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Attached Figure Description

[0086] Figure 1 This is a process flow diagram of the preparation method of the oxide solid electrolyte material of the present invention;

[0087] Figure 2 SEM images of the solid electrolyte materials prepared in Examples 1-3 of this invention; Detailed Implementation

[0088] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0089] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0090] In the following embodiments of the present invention, the lithium metaborate, lithium oxide, lithium boride, zirconium source, lithium source, dopant, and coating agent selected can be commercially available raw materials of the same required specifications, or they can be prepared according to traditional synthesis methods.

[0091] Example 1

[0092] A method for preparing an oxide solid electrolyte material, such as Figure 1 As shown, it includes the following steps:

[0093] (1) First, weigh 50g each of BLiO2, Li2O, and B4Li2O7 powder (D50: 2.5μm), put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0094] (2) Weigh out Li2O (D50: 2.5μm) and Zr 0.97 O2Y 0.03 The following powders obtained in step (1) were added to a high-energy mixing ball mill at a ball-to-particle ratio of 100g, 50g, 50g, 1.28g, 0.40g, 0.44g, and 0.36g respectively: lithium borate (D50: 2.0μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm). The powders were ball-to-particle ratio of 10:1 and ball-to-particle ratio of 2000rpm for 5.0h. After ball milling, the D50 particle size range was 0.7-1.0μm.

[0095] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0096] (4) Weigh 120g, 0.264g, 0.432g, and 0.216g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3), TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, the coated and modified lithium zirconium borate (LZBO) product is obtained. SEM image as follows Figure 2 As shown.

[0097] Example 2

[0098] A method for preparing an oxide solid electrolyte material includes the following steps:

[0099] (1) First, weigh 50g each of BLiO2, Li2O, and B4Li2O7 powder (D50: 2.5μm), put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0100] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 The following powders obtained in step (1) were 100g, 50g, 50g, 0.96g, 0.36g, 0.36g, and 0.24g respectively: lithium borate (D50: 2.0μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm). They were added to a high-energy mixing ball mill jar at a ball-to-particle ratio of 10:1 and ball-milled at 2000rpm for 5.0h. The D50 particle size range after ball milling was 0.7-1.0μm.

[0101] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0102] (4) Weigh 120g, 0.312g, 0.456g, and 0.216g of the lithium zirconium borate matrix obtained by doping modification in step (3), TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Add them to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them to a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, the coated modified lithium zirconium borate (LZBO) product is obtained. SEM image as follows. Figure 2 As shown.

[0103] Example 3

[0104] A method for preparing an oxide solid electrolyte material includes the following steps:

[0105] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0106] (2) Weigh out LiOH·H2O (D50: 2.5μm) and Zr 0.97 O2Y 0.03 The following powders obtained in step (1) were added in 150g, 50g, 50g, 1.95g, 0.55g, 0.60g, and 0.70g respectively: lithium borate (D50: 2.0μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm). They were then added to a high-energy mixing ball mill jar at a ball-to-particle ratio of 10:1 and ball-milled at 2000rpm for 5.0h. The D50 particle size range after ball milling was 0.7-1.0μm.

[0107] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0108] (4) Weigh 120g, 0.264g, 0.432g, and 0.216g of the doped and modified lithium zirconium borate (LZBO) matrix obtained in step (3) and TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm), respectively. Add them to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, place them in a corundum crucible and press them into sheets at 15MPa for 5s. Then, transfer them to a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, obtain the coated and modified lithium zirconium borate (LZBO) product. SEM image as follows. Figure 2 As shown.

[0109] Example 4

[0110] A method for preparing an oxide solid electrolyte material includes the following steps:

[0111] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0112] (2) Weigh 100g, 50g, 50g, 1.92g, 0.40g, 0.56g, and 0.84g of the following powders obtained in step (1): Li2CO3 (D50: 2.5μm), Zr(CO3)2 (D50: 2.0μm), lithium borate (D50: 1.1μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm), respectively. Add them to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 2000rpm for 5.0h. After ball milling, the D50 particle size range is 0.7-1.0μm.

[0113] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 300 nm-1.0 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0114] (4) Weigh 120g, 0.288g, 0.576g, and 0.264g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3) and TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, the coated and modified lithium zirconium borate (LZBO) product is obtained.

[0115] Example 5

[0116] A method for preparing an oxide solid electrolyte material includes the following steps:

[0117] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 8:1, and then ball mill at 1200rpm for 4.0h. Take a sample and test the particle size with laser to find that D50 = 1.1μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0118] (2) Weigh 100g, 50g, 50g, 1.92g, 0.40g, 0.56g, and 0.84g of the following powders obtained in step (1): Li2CO3 (D50: 2.5μm), Zr(OH)4 (D50: 2.0μm), lithium borate (D50: 1.1μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm), respectively. Add them to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 2000rpm for 5.0h. After ball milling, the D50 particle size range is 0.7-1.0μm.

[0119] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0120] (4) Weigh 120g, 0.288g, 0.576g, and 0.264g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3) and TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, obtain the coated modified lithium zirconium borate (LZBO) product.

[0121] Example 6

[0122] A method for preparing an oxide solid electrolyte material includes the following steps:

[0123] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0124] (2) Weigh 100g, 50g, 50g, 1.92g, 0.40g, 0.56g, and 0.84g of the following powders obtained in step (1): Li2CO3 (D50: 2.5μm), ZrO2 (D50: 2.0μm), lithium borate (D50: 1.1μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm), respectively. Add them to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 2000rpm for 5.0h. After ball milling, the D50 particle size range is 0.7-1.0μm.

[0125] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0126] (4) Weigh 120g, 0.288g, 0.576g, and 0.264g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3) and TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, obtain the coated modified lithium zirconium borate (LZBO) product.

[0127] Example 7

[0128] A method for preparing an oxide solid electrolyte material includes the following steps:

[0129] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0130] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08The following powders obtained in step (1) were added to a high-energy mixing ball mill at a ball-to-particle ratio of 100g, 50g, 50g, 0.96g, 0.36g, 0.40g, and 0.32g respectively: lithium borate (D50: 2.0μm), TiO2 (D50: 1.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm). The powders were ball-to-particle ratio of 10:1 and ball-to-particle ratio of 10.1g. The mixture was ball-milled at 2000rpm for 5.0h. The D50 particle size range after ball milling was 0.7-1.0μm.

[0131] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0132] (4) Weigh 120g, 0.216g, 0.432g, and 0.216g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3) and Ti3(PO4)4 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, obtain the coated modified lithium zirconium borate (LZBO) product.

[0133] Example 8

[0134] A method for preparing an oxide solid electrolyte material includes the following steps:

[0135] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0136] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 The following powders obtained in step (1) were added to a high-energy mixing ball mill jar at a ball-to-particle ratio of 10:1:1:1:1:1:1:2:2:2:2:2:3:2:3:2:3:3:2:3:3:2:3:3:3:3:4:3:2:3:3:3:3:4:3:3:4:3:3:4:5 ...5:3:4:5:3:4:5:3:5:5:3:4:5:3:5:5:3:4:5:3:5:5:3:4:5:3:5:5:3:4:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:4:5:5:3:5:5:3:5:5:3:4:5:5:3

[0137] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0138] (4) Weigh 120g, 0.240g, 0.492g, and 0.252g of the lithium zirconium borate (LZBO) matrix obtained by doping and modification in step (3) and Ti3(PO4)4 (D50: 300nm), Al(OH)3 (D50: 300nm), and LiOH (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, obtain the coated modified lithium zirconium borate (LZBO) product.

[0139] Example 9

[0140] A method for preparing an oxide solid electrolyte material includes the following steps:

[0141] (1) First, weigh 50g each of BLiO2, Li2O and B4Li2O7 (D50: 2.5μm) powder, put them into a high-energy mixing ball mill jar at a ball-to-powder ratio of 8:1, and then ball mill at 1200rpm for 4.0h. After ball milling, the particle size in the D50 range is 0.8-1.2μm. Then transfer it to a microwave catalytic synthesizer, introduce argon gas, and heat it to 600℃ at 5℃ / min for 2.0h.

[0142] (2) Weigh out Li2CO3 (D50: 2.5μm), lithium borate powder (D50: 1.1μm) obtained in step (1), and Zr with a solid content of 30%. 0.92 O2Y 0.08 Slurries of TiO2 (D50: 2.0μm), AlPO4 (D50: 1.0μm), Al2O3 (D50: 1.0μm), and Al(OH)3 (D50: 1.0μm) in quantities of 100g, 50g, 166.67g, 3.2g, 1.2g, 1.2g, and 0.80g respectively, along with 350g of pure water, were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1. The mixture was wet-milled at 1800rpm for 4.0h, resulting in a D50 particle size range of 0.7-1.0μm. The resulting slurry was then spray-dried to a moisture content below 1.5%.

[0143] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.0 μm. Finally, it is sieved to remove magnetism to obtain the doped and modified lithium zirconium borate (LZBO) matrix.

[0144] (4) Weigh 120g, 0.312g, 0.456g, and 0.216g of the lithium zirconium borate matrix obtained by doping and modification in step (3), TiP2O7 (D50: 300nm), Al(OH)3 (D50: 300nm), and C2H3O2Li (D50: 80nm) respectively. Put them into a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball mill at 1800rpm for 4.0h. Then, put them into a corundum sagger and press them into tablets at 15MPa for 5s. Then, transfer them into a vacuum box-type atmosphere furnace and heat them to 460℃ at 5℃ / min under dry air for 1.0h. Then, heat them to 800℃ at 5℃ / min for 3.0h. After cooling, put them into an air jet mill to crush them to 50nm-900nm. Finally, after sieving and removing the magnetism, the coated and modified lithium zirconium borate (LZBO) product is obtained.

[0145] Comparative Example 1

[0146] The difference from Example 2 is that only one high-temperature synthesis was used, and no doping or coating was performed, including the following steps:

[0147] (1) Same as Example 2;

[0148] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 100g, 50g, and 50g of lithium borate powder (D50: 2.0μm) obtained in step (1) were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball-milled at 2000rpm for 5.0h. A sample was taken and tested with a laser particle size analyzer and the D50 was found to be 1.2μm.

[0149] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 seconds. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 1000℃ at 5℃ / min for 6.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 50 nm-900 nm. Finally, it is sieved to remove magnetism to obtain lithium zirconium borate (LZBO).

[0150] Comparative Example 2

[0151] The difference from Example 2 is that no elemental doping modification was performed, and the following steps were included:

[0152] (1) Same as Example 2;

[0153] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 100g, 50g, and 50g of lithium borate powder (D50: 2.0μm) obtained in step (1) were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball-milled at 2000rpm for 5.0h. A sample was taken and tested with a laser particle size analyzer and the D50 was found to be 1.2μm.

[0154] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 1000℃ at 5℃ / min for 6.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is sieved to remove magnetism to obtain lithium zirconium borate (LZBO) matrix.

[0155] (4) Same as Example 2.

[0156] Comparative Example 3

[0157] The difference from Example 2 is that no coating or secondary sintering was performed, and the following steps were included:

[0158] (1) and (2) are the same as in Example 2;

[0159] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 1000℃ at 5℃ / min for 6.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is demagnetized by sieving to obtain lithium zirconium borate (LZBO).

[0160] Comparative Example 4

[0161] The difference from Example 2 is that lithium zirconium borate (LZBO) is synthesized in a one-step process without doping or coating, including the following steps:

[0162] Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 120g, 60g, 20g, 20g, and 20g of BLiO2 (D50: 2.0μm), Li2O (D50: 2.5μm), and B4Li2O7 (D50: 2.5μm) were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball-milled at 2000rpm for 12.0h. The resulting material was then loaded into a corundum crucible and pressed into tablets at 28MPa for 8s. The tablets were then transferred to a vacuum chamber furnace and heated to 1400℃ at 5℃ / min under dry air for 1.0h. The temperature was then lowered to 1100℃ at 5℃ / min and held for 12.0h. Finally, the temperature was lowered to 280℃ at 5℃ / min and held for 1.0h. After cooling, the tablets were ground to 50nm-900nm using an air jet mill. Finally, the tablets were sieved to remove magnetic material, yielding lithium zirconium borate (LZBO).

[0163] Comparative Example 5

[0164] The difference from Example 2 is that only one high-temperature synthesis was used, the sintering conditions remained the same, and no doping or coating was performed, including the following steps:

[0165] (1) Same as Example 2;

[0166] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08100g, 50g, and 50g of lithium borate powder (D50: 2.0μm) obtained in step (1) were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball-milled at 2000rpm for 5.0h. A sample was taken and tested with a laser particle size analyzer and the D50 was found to be 1.2μm.

[0167] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 seconds. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 50 nm-900 nm. Finally, it is demagnetized by sieving to obtain lithium zirconium borate (LZBO).

[0168] Comparative Example 6

[0169] The difference from Example 2 is that the sintering conditions remain the same and no elemental doping modification is performed, including the following steps:

[0170] (1) Same as Example 2;

[0171] (2) Weigh out Li2CO3 (D50: 2.5μm) and Zr 0.92 O2Y 0.08 100g, 50g, and 50g of lithium borate powder (D50: 2.0μm) obtained in step (1) were added to a high-energy mixing ball mill jar at a ball-to-material ratio of 10:1 and ball-milled at 2000rpm for 5.0h. A sample was taken and tested with a laser particle size analyzer and the D50 was found to be 1.2μm.

[0172] (3) The material obtained from the ball milling in step (2) is loaded into a corundum sagger and pressed into tablets at 28 MPa for 8 s. It is then transferred to a vacuum box-type atmosphere furnace and heated to 1200℃ at 5℃ / min under dry air for 1.0 h. Then it is cooled to 850℃ at 5℃ / min for 4.0 h, and then cooled to 280℃ at 5℃ / min for 1.0 h. After cooling, it is fed into an air jet mill to be crushed to 500 nm-1.2 μm. Finally, it is demagnetized by sieving to obtain lithium zirconium borate (LZBO) matrix.

[0173] (4) Same as Example 2.

[0174] Experimental Example

[0175] 1. Physicochemical property testing

[0176] The oxide solid electrolytes prepared in the above examples and comparative examples were tested for physicochemical properties such as particle size, tap density, purity, moisture content, residual alkali, and ionic conductivity. The results are shown in Table 1.

[0177] Table 1. Test results of physicochemical properties of each embodiment and comparative example.

[0178] Particle size D50 (nm) <![CDATA[Tap density g / cm 3 > purity% Moisture ppm residual alkali ppm Ionic conductivity S / cm Exterior color Particle morphology Example 1 394 1.62 99.81 232 6652 <![CDATA[5.62×10 -4 ]]> White Single-particle spherical and near-spherical Example 2 376 1.65 99.84 214 6430 <![CDATA[7.78×10 -4 ]]> White Single-particle spherical and near-spherical Example 3 382 1.63 99.83 186 6346 <![CDATA[6.64×10 -4 ]]> White Single-particle spherical and near-spherical Example 4 458 1.64 99.82 202 6620 <![CDATA[4.41×10 -4 ]]> White Single-particle spherical and near-spherical Example 5 412 1.62 99.83 241 6458 <![CDATA[4.58×10 -4 ]]> White Single-particle spherical and near-spherical Example 6 426 1.67 99.85 180 6786 <![CDATA[5.14×10 -4 ]]> White Single-particle spherical and near-spherical Example 7 404 1.64 99.83 196 6543 <![CDATA[7.46×10 -4 ]]> White Single-particle spherical and near-spherical Example 8 431 1.63 99.82 218 6428 <![CDATA[7.35×10 -4 ]]> White Single-particle spherical and near-spherical Example 9 360 1.64 99.83 238 5160 <![CDATA[7.62×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 1 398 1.34 99.63 316 8184 <![CDATA[2.38×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 2 402 1.38 99.68 283 8041 <![CDATA[2.46×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 3 395 1.42 99.65 294 8235 <![CDATA[2.31×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 4 386 1.25 99.52 335 9246 <![CDATA[1.26×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 5 382 1.22 99.51 402 9682 <![CDATA[1.28×10 -4 ]]> White Single-particle spherical and near-spherical Comparative Example 6 391 1.21 99.48 365 9431 <![CDATA[1.48×10 -4 ]]> White Single-particle spherical and near-spherical

[0179] As can be seen from the test data in Table 1, the ionic conductivity of LZBO oxide solid electrolyte powder after surface doping modification with a certain amount of Ti / Al / P doping and Ti / Al / P / Li synergistic coating is significantly improved. The amount of different modifying elements added, as well as different raw materials, holding temperature, and cooling rate, all play a role in improving the ionic conductivity, and these effects vary to some extent.

[0180] 2. Ratio Performance Test

[0181] The oxide solid electrolytes prepared in the above examples and comparative examples were evaluated for rate performance using the following methods.

[0182] A solid-state battery was fabricated using Ni650728 lithium nickel cobalt manganese oxide as the positive electrode and lithium metal as the negative electrode. The rate performance and cycle performance of the oxide solid-state electrolyte were evaluated. The specific operation method is as follows:

[0183] 1) Mix Ni650728 lithium nickel cobalt manganese oxide, binder PVDF (polyvinylidene fluoride), CNT, conductive agent Super P, and solid electrolyte (LZBO) in a mass ratio of 96.5:1.2:0.6:0.7:1.0, add an appropriate amount of solvent NMP (N-methylpyrrolidone), stir, and prepare a positive electrode slurry (solid content 73%). Coat it on aluminum foil, dry it at 105℃, and then cut it into round pieces with a diameter of 10mm as positive electrode sheets.

[0184] 2) Solid electrolytes LZBO (75%) and PEO (25%) were mixed and ground for 3 hours, then subjected to 95℃.

[0185] A solid electrolyte membrane with a thickness of approximately 85 μm was obtained by hot pressing at 6.8 MPa.

[0186] 3) Assemble CR2032 coin cells in the order of positive electrode sheet - solid electrolyte membrane - lithium foil and perform battery rate and cycle tests.

[0187] The operating voltage range of the above-mentioned lithium secondary battery was set to 3.0V~4.40V. It was charged to 4.40V at a constant current of 0.1C, and then constant voltage was applied to cutoff at 0.01C. Then, it was discharged to 3.0V at currents of 0.1C, 0.2C, 0.5C, 1.0C, and 2.0C, respectively. The specific capacity of the material at discharge rates of 0.1C, 0.2C, 0.5C, 1.0C, and 2.0C was obtained, and then divided by 1C. The test results are shown in Table 2.

[0188] Table 2. Magnification test results for each embodiment and comparative example.

[0189]

[0190] As can be seen from the test data in Table 2, the LZBO oxide solid electrolyte powder modified by a certain amount of Ti / Al / P doping and Ti / Al / P / Li synergistic coating significantly improves the rate capability and cycle performance of the LZBO oxide solid electrolyte compared with the control group. Moreover, the process parameters all play a role in improving the ionic conductivity and there are certain differences.

[0191] It is evident that lithium zirconium borate (LZBO) prepared based on the preparation method and process system of this oxide solid electrolyte material can meet the relevant performance indicators of similar oxide solid electrolytes.

[0192] The technical solutions of the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solutions of the present invention.

[0193] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A method for preparing an oxide solid electrolyte material, characterized in that, Includes the following steps: (1) BLiO2, Li2O and B4Li2O7 were mixed and ball-milled to obtain mixed lithium borate, and then pre-sintered to obtain pure phase lithium borate; (2) The lithium borate obtained in step (1) is dry-mixed and ball-milled with a zirconium source, a lithium source, and a dopant to obtain a mixture containing lithium zirconium borate; or, The lithium borate obtained in step (1) is wet-mixed and ball-milled with a slurry containing zirconium source, lithium source and dopant, and then filtered and dried to obtain a mixture containing zirconium borate. The dopants include combinations of TiO2, AlPO4, Al(OH)3 and Al2O3; (3) After pressing the mixture containing lithium zirconium borate obtained in step (2) into tablets, it is sintered once under an inert atmosphere, crushed and sieved to obtain doped modified lithium zirconium borate. (4) The doped modified lithium zirconium borate obtained in step (3) is mixed with a coating agent and ball-milled. After pressing into tablets, it is sintered again under an inert atmosphere, crushed, and sieved to obtain an oxide solid electrolyte material. The coating agent includes a combination of Ti / P compounds, Al(OH)3, and Li compounds. The Ti / P compounds are TiP2O7 or Ti3(PO4)4, and the Li compounds are C2H3O2Li or LiOH.

2. The method according to claim 1, characterized in that, In step (1), the mass ratio of BLiO2, Li2O and B4Li2O7 is 0.6~1:0.6~1:0.5~1.

3. The method according to claim 1, characterized in that, In step (1), the rotation speed of the ball mill is 100~1500 rpm; the ball milling time is 0.5~8.0 h; and the ball-to-material ratio is 2~20:

1.

4. The method according to claim 1, characterized in that, In step (1), the pre-sintering temperature is 100~800℃; the pre-sintering constant temperature time is 1~6.0h; and the pre-sintering atmosphere is either argon or nitrogen.

5. The method according to claim 1, characterized in that, In step (2), the zirconium source is selected from Zr(CO3)2, Zr(OH)4, ZrO2, Zr 0.92 O2Y 0.08 Zr 0.97 O2Y 0.03 One or more of the following: Zr(CH3COO)4, ZrB2, ZrF4, ZrSiO4, Li2ZrO3, Zr(HPO4)2, ZrCl4, Zr(CH3COO)4·4H2O, Zr(C6H5O7)2, Zr(NO3)4, and ZrS2: The lithium source is selected from one or more of LiOH, LiOH·H2O, Li2CO3, LiNO3, Li3BO3, LiBO2, Li2O, LiI, LiCl or C2H3O2Li.

6. The method according to claim 1, characterized in that, In step (2), the mass of the dopant accounts for 0.01% to 6% of the total mass of the lithium source, lithium borate and zirconium source, and the mass ratio of lithium source, lithium borate and zirconium source is 1 to 10: 1 to 3: 1 to 3; In step (2), the total mass ratio of lithium source, lithium borate and zirconium source to TiO2 is 1.0:0.0001~0.02; The total mass ratio of lithium source, lithium borate and zirconium source to AlPO4 is 1.0:0.0001~0.02; The total mass ratio of lithium source, lithium borate and zirconium source to Al(OH)3 is 1.0:0.0001~0.02; The total mass ratio of lithium source, lithium borate and zirconium source to Al2O3 is 1.0:0.0001~0.

06.

7. The method according to claim 1, characterized in that, In step (2), the rotation speed of the dry and wet ball mill is 200~2500 rpm; the time of the dry and wet ball mill is 1.0~10.0 h; and the ball-to-material ratio of the dry and wet ball mill is 3~20:

1.

8. The method according to claim 1, characterized in that, In step (3), the tableting pressure is 18~36MPa; the tableting time is 1~20s.

9. The method according to claim 1, characterized in that, In step (3), the sintering temperature is 200-2400℃; the sintering time is 2-32h; the sintering pressure is slightly positive or slightly negative, with the slightly positive pressure being 10-200Pa and the slightly negative pressure being -15--180Pa.

10. The method according to claim 1, characterized in that, In step (4), the mass ratio of doped modified lithium zirconium borate to the total amount of coating agent is 1:0.0001~0.

040.

11. The method according to claim 10, characterized in that, The mass ratio of doped modified lithium zirconium borate to C2H3O2Li is 1:0.0001~0.020; The mass ratio of doped modified lithium zirconium borate to LiOH is 1:0.0001~0.020; The mass ratio of doped modified lithium zirconium borate to TiP2O7 is 1:0.0001~0.020; The mass ratio of doped modified lithium zirconium borate to Ti3(PO4)4 is 1:0.0001~0.010; The mass ratio of doped modified lithium zirconium borate to Al(OH)3 is 1:0.0001~0.

010.

12. The method according to claim 1, characterized in that, In step (4), the tableting pressure is 10~20MPa; the tableting time is 1~10s.

13. The method according to claim 1, characterized in that, In step (4), the secondary sintering temperature is 100-1100℃; the secondary sintering time is 1-10h; and the secondary sintering pressure is slightly positive or slightly negative. The slightly positive pressure is 10-150Pa, and the slightly negative pressure is -15--150Pa.

14. An oxide solid electrolyte material, characterized in that, It is prepared by the preparation method according to any one of claims 1-13.

15. The application of the oxide solid electrolyte material of claim 14 in the preparation of secondary batteries.

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