Semi-solid-state lithium battery and terminal comprising same

Abstract

A semi-solid-state lithium battery, comprising an electrolyte, a separator provided in the electrolyte and a positive electrode plate and a negative electrode plate respectively provided on two sides of the separator; the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on the positive electrode current collector; the positive electrode active layer is doped with 0.1-5 wt% of an oxide electrolyte, and the oxide electrolyte has a D50 of 0.05-1.2 μm; and the negative electrode plate comprises a negative electrode current collector and a negative electrode active layer provided on the negative electrode current collector. The doping of an oxide electrolyte in the positive electrode active layer can reduce the lowest liquid retention coefficient and the expansion rate of 1000 cls of high-temperature cycling of a battery, and improves the performances such as the capacity retention rate of 1000 cls of high-temperature cycling, the capacity retention rate at -20ºC, the number of cycles at -20ºC, the 2C / 0.2 C rate discharge capacity and the hot box temperature of the battery.

Description

Semi-solid lithium battery and terminal containing the same

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 27, 2023, with application number 202311262558.2 and invention name “Semi-solid lithium battery and terminal containing the same”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a semi-solid lithium battery and a terminal containing the same. Background Art

[0003] The impedance of lithium-ion batteries is composed of ohmic internal resistance, SEI film interface impedance, charge transfer impedance, ion diffusion internal resistance, etc. As the battery energy density increases, the battery's interface impedance gradually increases, and the battery's low-temperature performance and high-temperature performance decrease accordingly, resulting in a shorter battery life of mobile electronic devices.

[0004] Summary of the Invention

[0005] The present application provides a semi-solid lithium battery and a terminal containing the same. The semi-solid lithium battery provided in the present application has good high-temperature performance, low-temperature performance and high-rate discharge capacity, and can extend the battery life of terminals such as mobile electronic devices at high or low temperatures.

[0006] The present application provides a semi-solid lithium battery, comprising:

[0007] electrolyte;

[0008] a diaphragm disposed in the electrolyte;

[0009] A positive electrode sheet and a negative electrode sheet are respectively arranged on both sides of the diaphragm;

[0010] The positive electrode plate includes a positive electrode current collector and a positive electrode active layer disposed on the positive electrode current collector; the positive electrode active layer is doped with 0.1 wt% to 5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1.2 μm;

[0011] The negative electrode plate includes a negative electrode current collector and a negative electrode active layer disposed on the negative electrode current collector.

[0012] This application adds an oxide electrolyte with a D50 of 0.05μm to 1.2μm at a doping level of 0.1wt% to 5wt% to the positive electrode material to form a positive electrode active layer. This can reduce the battery's minimum liquid retention coefficient from 1.55g / Ah to below 1.41g / Ah; reduce the expansion rate after 1000cls of high-temperature cycling from 15% to below 13.1%; improve the battery's capacity retention after 1000cls of high-temperature cycling from 58% to over 70%; improve the capacity retention at -20°C from approximately 50% to over 55%; significantly increase the number of -20°C loading cycles from 20 to over 50; improve the 2C / 0.2C rate discharge capacity, but the improvement is not significant; and increase the hot box temperature from 126°C to over 130°C. Experimental results show that either too small or too large an oxide electrolyte particle size has no significant effect on the aforementioned properties and may even deteriorate the aforementioned properties, especially the number of low-temperature loading cycles.

[0013] Furthermore, the present application adds an oxide electrolyte with a D50 of 0.05μm to 1.2μm at a doping amount of 0.1wt% to 5wt% to the negative electrode material to form a negative electrode active layer, that is, both the positive electrode active layer and the negative electrode active layer are doped with the oxide electrolyte, which can further reduce the minimum liquid retention coefficient of the battery to below 1.35g / Ah; reduce the expansion rate of the high-temperature cycle of 1000cls to below 12.2%; increase the capacity retention rate of the battery after 1000cls of high-temperature cycle to above 70%; increase the capacity retention rate at -20℃ to above 60%; increase the number of -20℃ loading cycles to above 60 times; increase the 2C / 0.2C rate discharge capacity to above 94%; and increase the hot box temperature to above 132℃. However, if the oxide electrolyte particle size is too small or too large, it will have no significant effect on further improving the above-mentioned performance, but will instead affect the performance improvement brought about by doping the oxide electrolyte in the positive electrode active layer.

[0014] Furthermore, the present application provides a coating including an oxide electrolyte on at least one side of the diaphragm, preferably on both sides, which can further reduce the minimum liquid retention coefficient of the battery to below 1.30g / Ah; reduce the expansion rate of the high-temperature cycle of 1000cls to below 11.5%; increase the capacity retention rate of the battery after 1000cls of high-temperature cycle to more than 77%; increase the capacity retention rate at -20°C to more than 65%; increase the number of loading times at -20°C to more than 90 times; increase the 2C / 0.2C rate discharge capacity to more than 95%; and increase the hot box temperature to above 134°C.

[0015] Furthermore, the present application provides a coating including an oxide electrolyte between the positive electrode current collector and the positive electrode active layer and / or between the negative electrode current collector and the negative electrode active layer to further improve the safety performance of the battery, especially the needle puncture safety and extrusion safety.

[0016] This application introduces an oxidizing electrolyte with a D50 of 0.05μm to 1.2μm into the positive active layer and the negative active layer, and further forms a coating containing the oxidizing electrolyte on the separator and the current collector, thereby reducing the ion transfer impedance at the electrode / electrolyte interface, making the positive and negative electrodes have an interface with faster ion transfer, while improving the stability of the electrode / electrolyte interface, thereby significantly improving the low-temperature performance, rate discharge performance, high-temperature performance and safety of the battery. The lithium-ion battery provided by this application can be used in consumer products, such as terminals, including mobile phones, watches, tablets and other devices; it can also be used in power products, such as automobiles, etc., which can significantly improve the performance of the product at low and high temperatures and extend its endurance.

[0017] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution or beneficial effect is included in at least one embodiment. Therefore, the description of a technical feature, technical solution or beneficial effect in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in the present embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that the embodiment can be implemented without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in specific embodiments that do not embody all embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical methods of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments.

[0019] FIG1 is a schematic structural diagram of a semi-solid lithium battery provided in a first embodiment of the present application;

[0020] FIG2 is a schematic structural diagram of a semi-solid lithium battery provided in a second embodiment of the present application;

[0021] FIG3 is a schematic structural diagram of a semi-solid lithium battery provided in a third embodiment of the present application;

[0022] FIG4 shows the -20°C capacity retention rate of the batteries provided in Comparative Example 1 and Example 5;

[0023] FIG5 is the SOC-RSS curves of the batteries provided in Comparative Example 1 and Example 5. DETAILED DESCRIPTION

[0024] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0025] Unless otherwise defined, the technical or scientific terms used in this application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The words "first", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0026] This application discloses a semi-solid lithium battery, comprising:

[0027] electrolyte;

[0028] a diaphragm disposed in the electrolyte;

[0029] A positive electrode sheet and a negative electrode sheet are respectively arranged on both sides of the diaphragm;

[0030] The positive electrode plate includes a positive electrode current collector and a positive electrode active layer disposed on the positive electrode current collector; the positive electrode active layer is doped with 0.1 wt% to 5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1.2 μm;

[0031] The negative electrode plate includes a negative electrode current collector and a negative electrode active layer disposed on the negative electrode current collector.

[0032] Refer to Figure 1, which is a schematic structural diagram of a semi-solid lithium battery provided in the first embodiment of the present application, wherein 11 is an electrolyte, 12 is a separator, 13 is a positive electrode current collector, 14 is a positive electrode active layer, 15 is a negative electrode current collector, and 16 is a negative electrode active layer.

[0033] The semi-solid lithium battery provided in the present application includes an electrolyte 11, which is a non-aqueous solvent electrolyte, including a non-aqueous solvent, a lithium salt and optional additives. The non-aqueous solvent includes a cyclic carbonate and a chain carbonate. In some specific implementations, the cyclic carbonate includes but is not limited to one or more of ethylene carbonate (EC) or propylene carbonate (PC), and the chain carbonate includes but is not limited to one or more of dimethyl carbonate (DMC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC). In some possible implementations, the non-aqueous solvent includes ethylene carbonate, propylene carbonate and diethyl carbonate, and the mass ratio of ethylene carbonate, propylene carbonate and diethyl carbonate is preferably 1 to 5:1 to 5:1 to 5, more preferably 3:3:4. The lithium salt is an electrolyte, including but not limited to one or more of lithium hexafluorophosphate, lithium difluorooxalatoborate, lithium difluorophosphate (LiPO2F2) and lithium difluorosulfonyl imide (LiFSI), preferably lithium hexafluorophosphate. The concentration of the lithium salt in the electrolyte is preferably 10 wt% to 20 wt%, more preferably 12.5 wt% to 16 wt%. The present application has no particular restrictions on the type and amount of the additive, which can be selected according to the battery function, and this application will not elaborate on this.

[0034] The semi-solid lithium battery provided herein includes a separator 12 disposed in an electrolyte 11. The separator 12 is used to separate the positive electrode from the negative electrode. The material and thickness of the separator are not particularly limited in this application; any separator commonly used in the art can be used, such as a 9μm thick PE separator.

[0035] In the semi-solid-state battery provided herein, the positive electrode sheet is disposed on one side of the separator 12, and the negative electrode sheet is disposed on the other side of the separator 12. The positive electrode sheet includes a positive electrode current collector 13 and a positive electrode active layer 14 disposed on the positive electrode current collector. The present application does not particularly limit the positive electrode current collector 13; any positive electrode current collector well known to those skilled in the art may be used, such as an 8 μm thick aluminum foil.

[0036] The present application dopes 0.1wt% to 5wt% of an oxide electrolyte with a D50 of 0.05μm to 1.2μm into the positive electrode active layer, which can reduce the minimum liquid retention coefficient of the battery, reduce the expansion rate of 1000cls of high-temperature cycles, improve the capacity retention rate of the battery after 1000cls of high-temperature cycles, improve the capacity retention rate at -20℃, increase the number of loading times at -20℃, increase the 2C / 0.2C rate discharge capacity, and increase the hot box temperature. Experimental results show that when the oxide electrolyte particle size is too small, for example, less than 10nm, or too large, for example, greater than 1.5μm, there is no significant improvement on the above-mentioned performance, and it may even deteriorate the above-mentioned performance, especially the number of low-temperature loading times. In some specific implementations, the positive electrode active layer includes a positive electrode active material, a conductive agent, a binder, and an oxide electrolyte, wherein the positive electrode active material includes but is not limited to one or more of a ternary positive electrode material, lithium cobalt oxide, manganese-rich lithium, nickel manganese spinel, lithium iron phosphate, lithium iron manganese phosphate, and lithium manganese oxide; wherein the chemical formula of the ternary positive electrode material can be LiNi x Co y Mn 1-x-y O2, 0.7<x<1, 0<y<0.3. The conductive agent includes but is not limited to one or more of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotubes, metal powder, and carbon fiber; the binder includes but is not limited to one or more of styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), and polyethylene oxide (PEO). In some specific implementations, the mass ratio of the positive electrode active material, the conductive agent, and the binder is 70-99:0.5-15:0.5-15, preferably 75-99:1-10:1-10, and more preferably 80-99:1-5:1-5.

[0037] In some specific implementations, the positive electrode active layer is doped with 0.1wt% to 5wt% of an oxide electrolyte, that is, the oxide electrolyte accounts for 0.1wt% to 5wt% of the total amount of the positive electrode active material, the conductive agent and the binder, preferably 0.2wt% to 4wt%, and more preferably 0.5wt% to 3wt%. The D50 of the oxide electrolyte is 0.05μm to 1.2μm, preferably 0.08μm to 1μm, and more preferably 0.1μm to 1μm. The oxide electrolyte can be selected from one or more of NASICON structure materials, perovskite structure materials, antiperovskite structure materials, LISICON structure and garnet structure materials, including but not limited to Li 1.4 Al 0.4 Ti 1.6 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 (PO4)3、Li7La3Zr2O 12 、Li 6.4 La3Zr2Ta 0.6 O 12 and La 0.56 Li 0.33 TiO3, etc., preferably Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0038] In some specific implementations, the negative electrode plate includes a negative electrode current collector 15 and a negative electrode active layer 16 disposed on the negative electrode current collector 15. The present application has no particular limitation on the negative electrode current collector 15, and any negative electrode current collector well known to those skilled in the art can be used, such as a copper foil with a thickness of 8 μm.

[0039] In some specific implementations, the negative electrode active layer includes a negative electrode active material, a conductive agent and a binder, wherein the negative electrode active material includes but is not limited to one or more of carbon materials, silicon-based materials, metallic lithium or lithium alloys, preferably one or both of graphite or silicon-based materials; the conductive agent includes but is not limited to one or more of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotubes, metal powder, and carbon fiber; the binder includes but is not limited to one or more of styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), and polyethylene oxide (PEO). In some specific implementations, the mass ratio of the negative electrode active material, the conductive agent, and the binder is 70-99:0.5-15:0.5-15, preferably 75-99:1-10:1-10, and more preferably 80-99:1-5:1-5.

[0040] In some specific implementations, the present application dopes the negative electrode active layer with an oxide electrolyte containing 0.1wt% to 5wt% and a D50 of 0.05μm to 1.2μm, further reducing the battery's minimum fluid retention coefficient, lowering the expansion rate after 1000 cls of high-temperature cycling, improving the battery's capacity retention after 1000 cls of high-temperature cycling, improving the capacity retention at -20°C, increasing the number of -20°C discharge cycles, increasing the 2C / 0.2C rate discharge capacity, and increasing the hot box temperature. Experimental results show that oxide electrolyte particle sizes that are too small, for example, less than 10nm, or too large, for example, greater than 1.5μm, have no significant effect on the aforementioned properties and may even deteriorate these properties, especially the number of low-temperature discharge cycles.

[0041] In some specific implementations, the negative electrode active layer is doped with 0.1wt% to 5wt% of an oxide electrolyte, that is, the oxide electrolyte accounts for 0.1wt% to 5wt% of the total amount of the negative electrode active material, the conductive agent and the binder, preferably 0.2wt% to 4wt%, and more preferably 0.5wt% to 3wt%. The D50 of the oxide electrolyte is 0.05μm to 1.2μm, preferably 0.08μm to 1μm, and more preferably 0.1μm to 1μm. The oxide electrolyte can be selected from one or more of NASICON structure materials, perovskite structure materials, antiperovskite structure materials, LISICON structure and garnet structure materials, including but not limited to Li 1.4 Al 0.4 Ti 1.6 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 (PO4)3、Li7La3Zr2O 12 、Li 6.4 La3Zr2Ta 0.6 O 12 and La 0.56 Li 0.33 TiO3, etc., preferably Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0042] In some specific implementations, at least one side of the diaphragm is provided with a coating including an oxide electrolyte. See Figure 2, which is a structural schematic diagram of a semi-solid lithium battery provided in the second embodiment of the present application, wherein 21 is an electrolyte, 22 is a diaphragm, 23 is a positive electrode current collector, 24 is a positive electrode active layer, 25 is a negative electrode current collector, 26 is a negative electrode active layer, 221 is a first coating, and 222 is a second coating.

[0043] The present application provides a coating containing a solid oxide on at least one side of the diaphragm, which can further reduce the minimum liquid retention coefficient of the battery to below 1.30g / Ah; reduce the expansion rate of the high-temperature cycle of 1000cls to below 11.5%; increase the capacity retention rate of the battery after 1000cls of high-temperature cycle to more than 77%; increase the capacity retention rate at -20°C to more than 65%; increase the number of loading times at -20°C to more than 90 times; increase the 2C / 0.2C rate discharge capacity to more than 95%; and increase the hot box temperature to above 134°C.

[0044] In the semi-solid lithium battery provided in the second embodiment, the electrolyte 21, the separator 22, the positive electrode current collector 23, the positive electrode active layer 24, the negative electrode current collector 25 and the negative electrode active layer 26 are as described above, and will not be repeated herein.

[0045] In some specific implementations, the first coating 221 includes an oxide electrolyte and a binder, and the mass ratio of the solid oxide electrolyte to the binder is preferably 0.05-0.5:5-15, more preferably 0.1-0.2:8-12. The thickness of the first coating 221 is preferably 0.5μm-5μm, more preferably 1μm-2μm. The oxide electrolyte and binder are as described above, and this application will not repeat them here. Similarly, the second coating 222 is similar to the first coating 221, and they can be the same or different, and this application will not repeat them here.

[0046] Furthermore, the present application provides a coating comprising an oxide electrolyte between the positive electrode current collector and the positive electrode active layer and / or between the negative electrode current collector and the negative electrode active layer to further improve the safety performance of the battery, especially the safety against needle puncture and extrusion. Referring to FIG3 , FIG3 is a schematic structural diagram of a semi-solid lithium battery provided in the third embodiment of the present application, wherein 31 is an electrolyte, 32 is a separator, 33 is a positive electrode current collector, 34 is a positive electrode active layer, 35 is a negative electrode current collector, 36 is a negative electrode active layer, 321 is a first coating, 322 is a second coating, 331 is a third coating, and 351 is a fourth coating.

[0047] In the semi-solid lithium battery provided in the third embodiment, the electrolyte 31, the separator 32, the positive electrode current collector 33, the positive electrode active layer 34, the negative electrode current collector 35, the negative electrode active layer 36, the first coating 321, and the second coating 322 are as described above, and will not be repeated here in this application.

[0048] In some specific implementations, the third coating 331 includes an oxide electrolyte and a binder, and the mass ratio of the solid oxide electrolyte to the binder is preferably 0.05-0.5:5-15, more preferably 0.1-0.2:8-12. The thickness of the third coating 331 is preferably 0.5μm-5μm, more preferably 1μm-2μm. The oxide electrolyte and binder are as described above, and this application will not repeat them here. Similarly, the fourth coating 351 is similar to the third coating 331, and they can be the same or different, and this application will not repeat them here.

[0049] In some specific implementations, the present invention provides a fifth coating layer comprising an oxide electrolyte on the side of the positive electrode current collector distal from the positive electrode active layer, and / or provides a sixth coating layer comprising an oxide electrolyte on the side of the negative electrode current collector distal from the negative electrode active layer. The fifth and sixth coating layers are similar to the first coating layer and are not further described herein.

[0050] In some specific implementations, the positive electrode active layer is doped with 0.15 wt% to 3.5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1 μm; the oxide electrolyte is selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0051] In some specific implementations, the negative electrode active layer is doped with 0.15 wt% to 3.5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1 μm; the oxide electrolyte is selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3.

[0052] In some specific implementations, in the first coating and the second coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0053] In some specific implementations, in the third coating and the fourth coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0054] In some specific implementations, in the fifth coating and the sixth coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

[0055] In some specific implementations, the semi-solid lithium battery provided in the present application has the following performance parameters: a minimum liquid retention coefficient of 1.25 to 1.45 g / Ah; a capacity retention rate of more than 65% after 1000 cls of high-temperature cycling; an expansion rate of less than 14% after 1000 cls of high-temperature cycling; a capacity retention rate of more than 55% at -20°C; a number of loading times at -20°C of more than 45 times; a 2C / 0.2C rate discharge capacity of more than 92%; and a hot box temperature of more than 130°C.

[0056] The present invention also provides a method for preparing the above-mentioned semi-solid lithium battery, comprising the following steps:

[0057] A positive electrode slurry comprising a positive electrode active material, a conductive agent, a binder and an oxide electrolyte is applied on a positive electrode current collector to form a positive electrode active layer to obtain a positive electrode sheet; a negative electrode slurry comprising a negative electrode active material, a conductive agent and a binder is applied on a negative electrode current collector to form a negative electrode active layer to obtain a negative electrode sheet;

[0058] Assemble a semi-solid lithium battery by combining a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte.

[0059] In some specific implementations, the positive electrode slurry can be prepared according to the following method:

[0060] The positive electrode active material, the conductive agent, the binder, the oxide electrolyte and the solvent are mixed to obtain the positive electrode slurry.

[0061] In some specific implementations, the positive electrode slurry can be prepared according to the following method:

[0062] pre-sintering the oxide electrolyte and the positive electrode active material to obtain an oxide electrolyte / positive electrode active material composite;

[0063] The composite, a binder, a conductive agent and a solvent are mixed to obtain a positive electrode slurry.

[0064] In some specific implementations, the pre-sintering temperature is no greater than 400° C., preferably 200-400° C. Pre-sintering the oxide electrolyte and the cathode active material first can make the oxide electrolyte and the cathode active material more uniformly mixed, thereby further improving battery performance.

[0065] After the positive electrode slurry is obtained, the positive electrode slurry is coated on the positive electrode current collector, and the positive electrode sheet is obtained after drying, cold pressing, cutting, slitting and drying.

[0066] In some specific implementations, the negative electrode slurry further includes an oxide electrolyte. The preparation method of the negative electrode plate is similar to the preparation method of the positive electrode plate, and will not be described in detail in this application.

[0067] In some specific implementations, a coating containing an oxide electrolyte is formed on at least one side, preferably on both sides, of the separator, and the preparation method is as follows:

[0068] A slurry containing an oxide electrolyte and a binder is applied to the surface of the diaphragm, and then dried and cold-pressed to form a coating.

[0069] The present application has no particular limitation on the coating method, and coating can be performed by spraying, gravure printing, or the like.

[0070] In some specific implementations, before forming the positive electrode active layer or the negative electrode active layer, a step of forming a coating comprising an oxide electrolyte on the positive electrode current collector or the negative electrode current collector is further included. The coating may be formed on the side of the positive electrode current collector facing the positive electrode active layer or on the side of the negative electrode current collector facing the negative electrode active layer, or may be formed on both sides of the positive electrode current collector or the negative electrode current collector. The method for forming the coating is as described above and will not be further described herein.

[0071] The semi-solid-state lithium-ion battery provided in this application can be used in consumer products, such as terminals, including mobile phones, watches, tablets and other devices; it can also be used in power products, such as automobiles, etc., to improve the product's performance and battery life at low or high temperatures.

[0072] Based on this, the present application also provides a terminal, including the semi-solid lithium battery described in the above technical solution. It will be understood by those skilled in the art that the terminal mentioned in this application can be any device with communication and storage functions, such as a smart phone, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a tablet computer, a personal digital assistant (PAD), a laptop computer, a digital camera, an e-book reader, a portable multimedia player, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a 5G terminal device, etc., and the embodiments of the present application are not limited to this.

[0073] The lithium-ion battery and its preparation method provided by the present application are described in detail below with reference to the embodiments.

[0074] Examples 1 to 8 and Comparative Examples 1 to 4

[0075] (1) Preparation of electrolyte

[0076] In an argon atmosphere glove box with a water content of <10ppm, ethylene carbonate (EC), propylene carbonate (PC) and diethyl carbonate (DEC) were mixed in a mass ratio of 3:3:4 to obtain a non-aqueous solvent, and then fully dried lithium salt LiPF6 was dissolved in the above non-aqueous solvent to make the mass percentage of LiPF6 in the electrolyte reach 12.5%. The mixture was mixed evenly to obtain an electrolyte.

[0077] (2) Preparation of current collector

[0078] A Cu foil with a thickness of 8 μm was used as the negative electrode current collector, and an Al foil with a thickness of 8 μm was used as the positive electrode current collector.

[0079] (3) Preparation of negative electrode sheet

[0080] The negative electrode active material artificial graphite / Si composite material, the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethyl cellulose (CMC) are mixed in a weight ratio of 97.4:1.2:1.4, and fully stirred and mixed in an appropriate amount of deionized water to form a uniform negative electrode slurry; the slurry is coated on the negative electrode current collector, dried, and cold pressed to obtain a negative electrode sheet.

[0081] (4) Preparation of positive electrode sheet

[0082] Lithium cobalt oxide (LiCoO2), conductive carbon black (Super P), and polyvinylidene fluoride were added to the solid electrolyte in a mass ratio of 97:1.4:1.6 according to the formula shown in Table 1. N-methylpyrrolidone (NMP) was added and stirred evenly using a vacuum mixer to prepare a positive electrode slurry with a solid content of 72wt%. The positive electrode slurry was evenly coated on the positive electrode current collector to form a positive electrode film. The prepared positive electrode film was dried at 85°C, cold pressed, cut into pieces, and slit, and then dried under vacuum conditions at 85°C for 4 hours to obtain a positive electrode sheet.

[0083] Table 1 Lithium-ion battery positive electrode formulas provided by Examples 1 to 8 and Comparative Examples 1 to 4

[0084] (5) Preparation of diaphragm

[0085] Polyethylene (PE) with a thickness of 9 μm was used as the separator;

[0086] (6) Preparation of lithium-ion batteries

[0087] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, with the separator being placed between the positive electrode sheet and the negative electrode sheet to serve as an isolation, and then wound to obtain an electrode assembly; the electrode assembly is placed in an outer packaging aluminum-plastic film, and the electrolyte prepared in step (1) is injected into the dried battery. After vacuum packaging, standing, forming, shaping and other processes, the preparation of the lithium-ion battery is completed.

[0088] The performance of the lithium-ion batteries prepared in the above examples and comparative examples was tested using the following method:

[0089] (1) Lithium-ion battery cycle test method

[0090] Place the battery in a 45°C constant temperature box, charge it to 4.48V at a constant current of 1.5C, charge it to 0.05C at a constant voltage at 4.48V, and then discharge it to 3.0V at a constant current of 1.0C. This is one charge and discharge cycle process. Perform 1000 cycle charge and discharge tests in the above manner to monitor the capacity retention rate and battery cell thickness expansion rate.

[0091] Here, capacity retention rate = remaining discharge capacity / initial discharge capacity × 100%.

[0092] (2) Low-temperature discharge capacity

[0093] Under normal temperature conditions, the battery cell is quickly discharged and left for 5 minutes; then normal charging is performed, and after 5 minutes, the battery cell is discharged at 0.2C to 3.0V. The discharge capacity is recorded as the normal temperature capacity.

[0094] After discharging, let it sit for 5 minutes, then perform normal charging. After standing at -20±2℃ for 2 hours, discharge at 0.2C current to a cutoff voltage of 3.0V. Record the value of discharge capacity / room temperature capacity.

[0095] (3) Rate discharge capacity

[0096] The discharge capacity of the battery cell to be tested is recorded as the room temperature capacity; after standing for 5 minutes, perform normal charging; after standing for 5 minutes, discharge at 2.0C to 3.0V, and record the value of discharge capacity / room temperature capacity.

[0097] (4) Low temperature loading times

[0098] Place the battery in a -20°C thermostat and discharge it at a constant current of 0.2C to 80% SOC. Then, discharge it at a current of 1.5A for 15 seconds and let it rest for 2 seconds. Repeat the discharge-rest cycle until the battery voltage is below 3.0V. Record the number of cycles.

[0099] (5) Lithium-ion battery hot box test method

[0100] The battery is fully charged at 20±5℃, the oven temperature is set to 25℃, and after standing for 30 minutes, the temperature is increased at a rate of 5±2℃ to the specified temperature of ℃±2℃, and maintained for 60 minutes. The temperature of the hot box is monitored during the process.

[0101] (6) Test method for battery cell liquid retention coefficient

[0102] The battery cell was disassembled and immersed in DMC solution for several times to wash out the electrolyte and lithium salt. All solids were dried and weighed. The electrolyte retention volume / battery cell capacity was measured by differential weight method to obtain the value of the liquid retention coefficient.

[0103] The results are shown in Table 2, Figures 4 and 5. Table 2 shows the performance parameters of the lithium-ion batteries provided in Examples 1 to 8 and Comparative Examples 1 to 4 of the present application. Figure 4 shows the -20°C capacity retention rate of the batteries provided in Comparative Example 1 and Example 5, where Base is the battery in Comparative Example 1 and 1%A is the battery in Example 5. Figure 5 shows the SOC-RSS curves of the batteries provided in Comparative Example 1 and Example 5, where Base is the battery in Comparative Example 1 and 1%A is the battery in Example 5.

[0104] Table 2 Performance parameters of lithium-ion batteries provided in Examples 1 to 8 and Comparative Examples 1 to 4 of the present application

[0105] As shown in Table 2, doping 0.01 μm to 1 μm of solid electrolyte in the electrode can significantly improve the high-temperature cycle capacity retention rate, low-temperature capacity retention rate, low-temperature loading times, rate discharge performance and hot box temperature of lithium-ion batteries, and reduce the minimum liquid retention coefficient and high-temperature cycle expansion rate.

[0106] Examples 9 to 15 and Comparative Examples 5 to 8

[0107] (1) Preparation of electrolyte

[0108] In an argon atmosphere glove box with a water content of <10ppm, ethylene carbonate (EC), propylene carbonate (PC) and diethyl carbonate (DEC) were mixed in a mass ratio of 3:3:4 to obtain a non-aqueous solvent, and then fully dried lithium salt LiPF6 was dissolved in the above non-aqueous solvent to make the mass percentage of LiPF6 in the electrolyte reach 12.5%. The mixture was mixed evenly to obtain an electrolyte.

[0109] (2) Preparation of current collector

[0110] A Cu foil with a thickness of 8 μm was used as the negative electrode current collector, and an Al foil with a thickness of 8 μm was used as the positive electrode current collector.

[0111] (3) Preparation of negative electrode sheet

[0112] The negative electrode active material artificial graphite / Si composite material, the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethyl cellulose (CMC) were added to the solid electrolyte in a weight ratio of 97.4:1.2:1.4 according to the formula shown in Table 3, and the mixture was thoroughly stirred in an appropriate amount of deionized water to form a uniform negative electrode slurry; the slurry was coated on the negative electrode current collector, dried, and cold pressed to obtain a negative electrode sheet.

[0113] Table 3 Lithium ion battery negative electrode formulas provided by Examples 9 to 15 and Comparative Examples 5 to 8

[0114] (4) Preparation of positive electrode sheet

[0115] Lithium cobalt oxide (LiCoO2), conductive carbon black (Super P) and polyvinylidene fluoride were added in a mass ratio of 97:1.4:1.6, and a solid electrolyte (Li 1.4 Al 0.4 Ti 1.6 (PO4)3) was mixed, N-methylpyrrolidone (NMP) was added, and the mixture was stirred evenly using a vacuum mixer to prepare a positive electrode slurry having a solid content of 72 wt%. The positive electrode slurry was evenly coated on the positive electrode current collector to prepare a positive electrode film. The prepared positive electrode film was dried at 85°C, cold pressed, cut into pieces, and slit, and then dried under vacuum conditions at 85°C for 4 hours to obtain a positive electrode sheet.

[0116] (5) Preparation of diaphragm

[0117] Polyethylene (PE) with a thickness of 9 μm was used as the separator;

[0118] (6) Preparation of lithium-ion batteries

[0119] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, with the separator being placed between the positive electrode sheet and the negative electrode sheet to serve as an isolation, and then wound to obtain an electrode assembly; the electrode assembly is placed in an outer packaging aluminum-plastic film, and the electrolyte prepared in step (1) is injected into the dried battery. After vacuum packaging, standing, forming, shaping and other processes, the preparation of the lithium-ion battery is completed.

[0120] The performance of the lithium-ion batteries prepared in the above embodiments and comparative examples was tested using the test method described above. The results are shown in Table 4, which shows the performance parameters of the lithium-ion batteries provided in Examples 9 to 15 and Comparative Examples 5 to 8 of the present application.

[0121] Table 4 Performance parameters of lithium-ion batteries provided in Examples 9 to 15 and Comparative Examples 5 to 8 of the present application

[0122] As can be seen from Table 4, doping 0.01μm to 1μm solid electrolyte in both the positive and negative electrodes can significantly improve the high-temperature cycle capacity retention rate, low-temperature capacity retention rate, low-temperature loading times, rate discharge performance and hot box temperature of lithium-ion batteries, and reduce the minimum liquid retention coefficient and high-temperature cycle expansion rate.

[0123] Examples 16 to 21 and Comparative Example 9

[0124] (1) Preparation of electrolyte

[0125] In an argon atmosphere glove box with a water content of <10ppm, ethylene carbonate (EC), propylene carbonate (PC) and diethyl carbonate (DEC) were mixed in a mass ratio of 3:3:4 to obtain a non-aqueous solvent, and then fully dried lithium salt LiPF6 was dissolved in the above non-aqueous solvent to make the mass percentage of LiPF6 in the electrolyte reach 12.5%. The mixture was mixed evenly to obtain an electrolyte.

[0126] (2) Preparation of current collector

[0127] A Cu foil with a thickness of 8 μm was used as the negative electrode current collector, and an Al foil with a thickness of 8 μm was used as the positive electrode current collector.

[0128] (3) Preparation of negative electrode sheet

[0129] The negative electrode active material artificial graphite / Si composite material, binder styrene butadiene rubber (abbreviated as SBR), thickener sodium carboxymethyl cellulose (abbreviated as CMC) were prepared in a weight ratio of 97.4:1.2:1.4, and 0.5 wt% solid electrolyte (Li 1.4 Al 0.4 Ti 1.6 (PO4)3) are mixed and fully stirred in an appropriate amount of deionized water to form a uniform negative electrode slurry; the slurry is coated on the negative electrode collector, dried, and cold pressed to obtain a negative electrode sheet.

[0130] (4) Preparation of positive electrode sheet

[0131] Lithium cobalt oxide (LiCoO2), conductive carbon black (Super P) and polyvinylidene fluoride were added in a mass ratio of 97:1.4:1.6, and a solid electrolyte (Li 1.4 Al 0.4 Ti 1.6(PO4)3) was mixed, N-methylpyrrolidone (NMP) was added, and the mixture was stirred evenly using a vacuum mixer to prepare a positive electrode slurry having a solid content of 72 wt%. The positive electrode slurry was evenly coated on the positive electrode current collector to prepare a positive electrode film. The prepared positive electrode film was dried at 85°C, cold pressed, cut into pieces, and slit, and then dried under vacuum conditions at 85°C for 4 hours to obtain a positive electrode sheet.

[0132] (5) Preparation of diaphragm

[0133] A polyethylene (PE) with a thickness of 9 μm was used as a separator. The slurry shown in Table 5 was sprayed on the side of the separator close to the positive electrode. The slurry used NMP as a solvent and included 0.1 wt% of a binder SBR and 10 wt% of a solid electrolyte with a D50 of 0.5 μm. The slurry shown in Table 5 was sprayed on the side of the separator close to the negative electrode. The slurry used water as a solvent and included 0.1 wt% of a binder SBR and 10 wt% of a solid electrolyte. After drying, a solid electrolyte coating with a thickness of 1 μm was formed on both sides of the separator.

[0134] Table 5 Coating formula of the separator provided in the examples and comparative examples close to the positive electrode

[0135] (6) Preparation of lithium-ion batteries

[0136] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, with the separator being placed between the positive electrode sheet and the negative electrode sheet to serve as an isolation, and then wound to obtain an electrode assembly; the electrode assembly is placed in an outer packaging aluminum-plastic film, and the electrolyte prepared in step (1) is injected into the dried battery. After vacuum packaging, standing, forming, shaping and other processes, the preparation of the lithium-ion battery is completed.

[0137] The performance of the lithium-ion batteries prepared in the above embodiments and comparative examples was tested using the same test methods as above. The results are shown in Table 6, which shows the performance parameters of the lithium-ion batteries provided in Examples 16 to 21 and Comparative Example 9 of the present application.

[0138] Table 6 Performance parameters of the lithium-ion batteries provided in Examples 16 to 21 of the present application and Comparative Example 9

[0139] It can be seen from Table 6 that doping 0.01μm to 1μm solid electrolyte in the positive and negative electrodes at the same time and forming a solid electrolyte layer on both sides of the separator can significantly improve the high-temperature cycle capacity retention rate, low-temperature capacity retention rate, low-temperature loading times, rate discharge performance and hot box temperature of lithium-ion batteries, and reduce the minimum liquid retention coefficient and high-temperature cycle expansion rate.

[0140] Examples 22-23 and Comparative Example 10

[0141] (1) Preparation of electrolyte

[0142] In an argon atmosphere glove box with a water content of <10ppm, ethylene carbonate (EC), propylene carbonate (PC) and diethyl carbonate (DEC) were mixed in a mass ratio of 3:3:4 to obtain a non-aqueous solvent, and then fully dried lithium salt LiPF6 was dissolved in the above non-aqueous solvent to make the mass percentage of LiPF6 in the electrolyte reach 12.5%. The mixture was mixed evenly to obtain an electrolyte.

[0143] (2) Preparation of current collector

[0144] A Cu foil with a thickness of 8 μm was used as the negative electrode current collector, and an Al foil with a thickness of 8 μm was used as the positive electrode current collector. According to the formula shown in Table 1, the slurry with the formula shown in Table 7 was sprayed on the surface of the negative electrode current collector and the positive electrode current collector, respectively. The slurry used NMP as a solvent and included 0.1 wt% of a binder SBR and 10 wt% of a solid electrolyte with a D50 of 0.5 μm. After drying, a 1 μm thick solid electrolyte coating was formed on the surface of the negative electrode current collector and the positive electrode current collector, respectively.

[0145] Table 7 Lithium ion battery current collector coating formulas provided in the examples and comparative examples

[0146] (3) Preparation of negative electrode sheet

[0147] The negative electrode active material artificial graphite / Si composite material, binder styrene butadiene rubber (abbreviated as SBR), thickener sodium carboxymethyl cellulose (abbreviated as CMC) were prepared in a weight ratio of 97.4:1.2:1.4, and 0.5 wt% solid electrolyte (Li 1.4 Al 0.4 Ti 1.6 (PO4)3) are mixed, and fully stirred and mixed in an appropriate amount of deionized water to form a uniform negative electrode slurry; the slurry is coated on the negative electrode collector, dried, and cold pressed to obtain a negative electrode sheet.

[0148] (4) Preparation of positive electrode sheet

[0149] Lithium cobalt oxide (LiCoO2), conductive carbon black (Super P) and polyvinylidene fluoride were added in a mass ratio of 97:1.4:1.6, and a solid electrolyte (Li 1.4 Al 0.4 Ti 1.6(PO4)3) was mixed, N-methylpyrrolidone (NMP) was added, and the mixture was stirred evenly using a vacuum mixer to prepare a positive electrode slurry having a solid content of 72 wt%. The positive electrode slurry was evenly coated on the positive electrode current collector to prepare a positive electrode film. The prepared positive electrode film was dried at 85°C, cold pressed, cut into pieces, and slit, and then dried under vacuum conditions at 85°C for 4 hours to obtain a positive electrode sheet.

[0150] (5) Preparation of diaphragm

[0151] Polyethylene (PE) with a thickness of 9 μm was used as the diaphragm, and the slurry with the formula shown in Table 8 was sprayed on both sides of the diaphragm. The slurry used NMP as a solvent and included 0.1 wt% of a binder SBR and 10 wt% of a solid electrolyte with a D50 of 0.5 μm. After drying, a solid electrolyte coating with a thickness of 1 μm was formed on both sides of the diaphragm.

[0152] Table 8 Lithium ion separator coating formulas provided in the examples and comparative examples

[0153] (6) Preparation of lithium-ion batteries

[0154] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, with the separator being placed between the positive electrode sheet and the negative electrode sheet to serve as an isolation, and then wound to obtain an electrode assembly; the electrode assembly is placed in an outer packaging aluminum-plastic film, and the electrolyte prepared in step (1) is injected into the dried battery. After vacuum packaging, standing, forming, shaping and other processes, the preparation of the lithium-ion battery is completed.

[0155] The performance of the lithium-ion batteries prepared in the above embodiments and comparative examples was tested using the same test methods as above. The results are shown in Table 9, which shows the performance parameters of the lithium-ion batteries provided in Examples 22 to 23 and Comparative Example 10 of the present application.

[0156] Table 9 Performance parameters of the lithium-ion batteries provided in Examples 22-23 and Comparative Example 10 of the present application

[0157] It can be seen from Table 9 that forming a solid electrolyte layer on the current collector can significantly improve the puncture safety and extrusion safety performance of the battery.

[0158] The lithium-ion battery provided by the present invention can be used in consumer products, such as terminals, including mobile phones, watches, tablets and other devices; it can also be used in power products, such as automobiles, etc., to improve the product's performance and battery life at low or high temperatures.

[0159] The above is only a specific embodiment of the present application, but the scope of protection of this application is not limited to this. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A semi-solid lithium battery, comprising: Electrolyte; a diaphragm disposed in the electrolyte; A positive electrode sheet and a negative electrode sheet are respectively arranged on both sides of the diaphragm; The positive electrode plate comprises a positive electrode current collector and a positive electrode active layer disposed on the positive electrode current collector; the positive electrode active layer is doped with 0.1 wt% to 5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1.2 μm; The negative electrode plate includes a negative electrode current collector and a negative electrode active layer disposed on the negative electrode current collector.

2. The semi-solid lithium battery according to claim 1, characterized in that: The negative electrode active layer is doped with 0.1 wt% to 5 wt% of an oxide electrolyte, and the D50 of the oxide electrolyte is 0.05 μm to 1.2 μm.

3. The semi-solid lithium battery according to claim 1 or 2, characterized in that: At least one side of the separator is provided with a coating layer, the coating layer comprising an oxide electrolyte.

4. The semi-solid lithium battery according to claim 3, characterized in that: The separator is provided with a first coating on the side facing the positive electrode plate, and a second coating on the side facing the negative electrode plate.

5. The semi-solid lithium battery according to claim 4, characterized in that: The thickness of the first coating layer and the second coating layer are independently 0.5 μm-5 μm; In the first coating layer and the second coating layer, D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm.

6. The semi-solid lithium battery according to any one of claims 1 to 2, characterized in that: In the positive electrode sheet, a third coating is provided between the positive electrode current collector and the positive electrode active layer, and the third coating includes an oxide electrolyte.

7. The semi-solid lithium battery according to claim 6, characterized in that: A fourth coating is disposed on a side of the positive electrode current collector away from the positive electrode active layer, and the fourth coating includes an oxide electrolyte.

8. The semi-solid lithium battery according to claim 7, characterized in that: The thickness of the third coating layer and the fourth coating layer is independently 0.5 μm-5 μm; In the third coating layer and the fourth coating layer, D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm.

9. The semi-solid lithium battery according to any one of claims 1 to 2, characterized in that: In the negative electrode sheet, a fifth coating is disposed between the negative electrode current collector and the negative electrode active layer, and the fifth coating includes an oxide electrolyte.

10. The semi-solid lithium battery according to claim 9, characterized in that: A sixth coating layer is disposed on a side of the negative electrode current collector away from the negative electrode active layer, and the sixth coating layer includes an oxide electrolyte.

11. The semi-solid lithium battery according to claim 9, characterized in that: The thickness of the fifth coating layer and the sixth coating layer is independently 0.5 μm-5 μm; In the fifth coating layer and the sixth coating layer, D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm.

12. The semi-solid lithium battery according to any one of claims 1 to 2, characterized in that: The oxide electrolyte is selected from one or more of NASICON structure materials, perovskite structure materials, antiperovskite structure materials, LISICON structure materials and garnet structure materials.

13. The semi-solid lithium battery according to claim 12, characterized in that: The oxide electrolyte is selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li7La3Zr2O 12 , Li 6.4 La3Zr2Ta 0.6 O 12 and La 0.56 Li 0.33 One or more of TiO3.

14. The semi-solid lithium battery according to claim 13, characterized in that: The positive electrode active material in the positive electrode active layer is selected from one or more of lithium cobalt oxide, manganese-rich lithium, nickel manganese spinel, lithium iron phosphate, lithium iron manganese phosphate, and lithium manganese oxide; The negative electrode active material in the negative electrode active layer is selected from one or more of carbon materials, silicon-based materials, metallic lithium, and lithium alloys.

15. The semi-solid lithium battery according to claim 14, characterized in that: The positive electrode active layer is doped with 0.15wt% to 3.5wt% of an oxide electrolyte, wherein the D50 of the oxide electrolyte is 0.05μm to 1μm; the oxide electrolyte is selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

16. The semi-solid lithium battery according to claim 15, characterized in that: The negative electrode active layer is doped with 0.15wt% to 3.5wt% of an oxide electrolyte, wherein the D50 of the oxide electrolyte is 0.05μm to 1μm; the oxide electrolyte is selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3.

17. The semi-solid lithium battery according to claim 16, characterized in that: The separator is provided with a first coating on one side facing the positive electrode sheet, and a second coating on one side facing the negative electrode sheet, wherein the first coating includes an oxide electrolyte, and the second coating includes an oxide electrolyte; In the first coating and the second coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

18. The semi-solid lithium battery according to claim 17, characterized in that: In the positive electrode sheet, a third coating is provided between the positive electrode collector and the positive electrode active layer, and the third coating includes an oxide electrolyte; a fourth coating is provided on the side of the positive electrode collector away from the positive electrode active layer, and the fourth coating includes an oxide electrolyte; In the third coating and the fourth coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

19. The semi-solid lithium battery according to claim 18, characterized in that: In the negative electrode sheet, a fifth coating is provided between the negative electrode current collector and the negative electrode active layer, and the fifth coating includes an oxide electrolyte; a sixth coating is provided on the side of the negative electrode current collector away from the negative electrode active layer, and the sixth coating includes an oxide electrolyte; In the fifth coating and the sixth coating, the D50 of the oxide electrolyte is independently 0.05 μm to 1.2 μm; the oxide electrolyte is independently selected from Li 1.4 Al 0.4 Ti 1.6 (PO4)3 or Li7La3Zr2O 12 .

20. The semi-solid lithium battery according to claim 19, characterized in that: Its minimum liquid retention coefficient is 1.25-1.45g / Ah; its high temperature cycle 1000cls capacity retention rate is more than 65%; its high temperature cycle 1000cls expansion rate is less than 14%; its -20℃ capacity retention rate is more than 55%; its -20℃ loading times is more than 45 times; its 2C / 0.2C rate discharge capacity is more than 92%; The hot box temperature is above 130°C.

21. A terminal comprising the semi-solid lithium battery according to any one of claims 1 to 20.

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