A battery

Abstract

The application provides a battery, liquid electrolyte is used in the middle of the battery, solid electrolyte layers are used at two ends, the performance of the full solid-state battery is effectively prevented from sharply decreasing, and the performance requirement of the power battery is effectively met, the solid electrolyte is not prone to shrinkage, the positive plate and the negative plate are fixed at the solid electrolyte layers at two ends, direct contact of the positive plate and the negative plate caused by high temperature is effectively avoided, the short circuit condition is avoided, lithium is more prone to be deposited at the edge of the negative plate in the later stage of the battery cycle, the hard layer is arranged on the edge area of the diaphragm in the application, lithium dendrites are not prone to pierce the hard layer at the edge of the diaphragm, the technical problem that the deposited lithium dendrites pass through the diaphragm to reach the positive plate is avoided, and the thermal runaway is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a battery. BACKGROUND

[0002] In recent years, with the rapid development of new energy automobile industry, the power battery industry chain is also growing rapidly. Lithium ion battery is considered as one of the most competitive electrochemical energy storage technologies due to its light weight, high specific energy / specific power, low self-discharge, long service life and other characteristics. The current commercial lithium ion battery widely uses liquid electrolyte, which has the characteristics of high electrical conductivity and excellent electrochemical performance; but the flash point of liquid electrolyte is low, which may cause the electrolyte to heat and ignite under abnormal conditions such as large current discharge, overcharge, internal short circuit, etc., and even cause explosion and other safety problems. Therefore, as the core component of new energy vehicles, the thermal runaway safety performance of power battery pack restricts the development of new energy vehicles.

[0003] The separator in the lithium ion battery is an important component of the lithium ion battery, which is used to prevent the contact between the positive electrode and the negative electrode, while allowing the free migration of lithium ions in the electrolyte. When the thermal runaway critical point is reached, the internal temperature of the positive electrode and the negative electrode rises and a large amount of gas is generated. The high temperature causes the separator at the edge of the positive and negative electrode sheets to shrink, resulting in direct contact of the positive / negative electrode sheets. At this time, the generated gas cannot be discharged through the battery explosion-proof valve in time, and a large amount of heat is accumulated in the battery due to internal short circuit, which finally leads to explosion. At the same time, due to the larger current density at the edge of the electrode sheet, lithium is more likely to be precipitated at the edge of the electrode sheet in the later stage of battery cycle, and lithium dendrites will pierce the separator, leading to thermal runaway. The existing solid-state battery can solve the shrinkage or piercing of the separator, but the performance of the full solid-state battery will be sharply reduced, which cannot meet the performance requirements of the current power battery.

[0004] In summary, a new battery structure needs to be proposed to solve the above technical problems of battery safety problems caused by shrinkage or piercing of the separator at the edge of the electrode sheet and the stability problem of maintaining the performance of the battery. SUMMARY

[0005] The present application provides a battery, which can solve the technical problem that in the existing liquid battery, when the thermal runaway critical point is reached, the internal temperature of the positive electrode and the negative electrode rises and a large amount of gas is generated. The high temperature causes the separator at the edge of the positive and negative electrode sheets to shrink, resulting in direct contact of the positive / negative electrode sheets. At this time, the generated gas cannot be discharged through the battery explosion-proof valve in time, and a large amount of heat is accumulated in the battery due to internal short circuit, which finally leads to explosion. At the same time, due to the larger current density at the edge of the electrode sheet, lithium is more likely to be precipitated at the edge of the electrode sheet in the later stage of battery cycle, and lithium dendrites will pierce the separator, leading to thermal runaway. The existing solid-state battery can solve the shrinkage or piercing of the separator, but the performance of the full solid-state battery will be sharply reduced, which cannot meet the performance requirements of the current power battery.

[0006] To solve the above problems, the technical scheme provided by the present application is as follows:

[0007] The present application provides a kind of battery, the battery includes shell, cavity is formed in the shell;The electrolyte layer is arranged in the cavity, and the electrolyte layer includes liquid electrolyte layer in the middle position of the cavity, first solid electrolyte layer and second solid electrolyte layer in the both ends position of the cavity;

[0008] The cavity is also provided with positive plate and negative plate, and one end of the positive plate and the negative plate is inserted into the first solid electrolyte layer, and the other end is passed through the second solid electrolyte layer and protrudes from the second solid electrolyte layer;

[0009] The positive plate and the negative plate are also provided with diaphragm, and the diaphragm includes ion permeable area corresponding to the positive plate and the negative plate, and edge area located in the periphery of the ion permeable area;Wherein, the diaphragm is provided with heat-resistant layer corresponding to the ion permeable area, and the diaphragm is provided with hard layer corresponding to the edge area.

[0010] According to an optional embodiment of the present application, the hard layer is a third solid electrolyte layer;Wherein, the width of the third solid electrolyte layer is n times of the width of the diaphragm, and n is 3, 4 or 5.

[0011] According to an optional embodiment of the present application, the edge surface of the positive plate is also provided with fourth solid electrolyte layer, and the edge surface of the negative plate is also provided with fifth solid electrolyte layer;

[0012] Wherein, the width of the fourth solid electrolyte layer is n times of the width of the positive plate, and the width of the fifth solid electrolyte layer is n times of the width of the negative plate, and n is 3, 4 or 5.

[0013] According to an optional embodiment of the present application, the material of the solid electrolyte layer is one of polymer electrolyte, inorganic oxide electrolyte and sulfide electrolyte.

[0014] According to an optional embodiment of the present application, the material of the heat-resistant layer is one of polyvinylidene fluoride and ceramic or two combined materials.

[0015] According to an optional embodiment of the present application, the material of the heat-resistant layer is graphite.

[0016] According to an optional embodiment of the present application, the diaphragm includes base film, and the heat-resistant layer and the hard layer are arranged on both sides of the base film, and the heat-resistant layer and the hard layer on the same side are arranged in the same layer, and the material of the base film is polyethylene, copper foil or graphite.

[0017] According to an optional embodiment of the present application, the diaphragm comprises micropores arranged in an array on the ion permeable region, and the micropores have a pore size of 0.01-0.05 microns.

[0018] According to an optional embodiment of the present application, the contact surface between the first and second solid electrolyte layers and the liquid electrolyte layer is a curved contact surface.

[0019] The first and second solid electrolyte layers are provided with a plurality of openings or protrusions on the side facing the liquid electrolyte layer.

[0020] According to an optional embodiment of the present application, the material of the positive electrode sheet is manganese dioxide, and the material of the negative electrode sheet is lithium metal and / or lithium alloy metal lithium.

[0021] The present application provides a battery, which comprises a shell, a cavity formed in the shell, an electrolyte layer arranged in the cavity, the electrolyte layer comprising a liquid electrolyte layer arranged at the middle position of the cavity, a first solid electrolyte layer and a second solid electrolyte layer arranged at the two ends of the cavity, a positive electrode sheet and a negative electrode sheet arranged in the cavity, one end of each of the positive electrode sheet and the negative electrode sheet inserted into the first solid electrolyte layer, the other end of each of the positive electrode sheet and the negative electrode sheet penetrating through the second solid electrolyte layer and protruding out of the second solid electrolyte layer, and a diaphragm arranged between the positive electrode sheet and the negative electrode sheet, the diaphragm comprising an ion permeable region corresponding to the positive electrode sheet and the negative electrode sheet, and a peripheral edge region arranged outside the ion permeable region, the diaphragm being provided with a heat-resistant layer corresponding to the ion permeable region and a hard layer corresponding to the peripheral edge region.

[0022] (1) The battery of the present application adopts liquid electrolyte at the middle position and solid electrolyte layers at the two ends, i.e. adopts a combination of liquid and solid electrolyte layers, which ensures high conductivity and low surface impedance of the electrolyte, greatly improves the safety of the battery system, and better adapts to high-energy positive and negative electrodes and reduces the weight of the system, realizes synchronous improvement of energy density, and effectively solves the problem that the performance of the all-solid-state battery will be sharply reduced, and meets the performance requirements of the current power battery.

[0023] (2) two ends of the solid electrolyte are not easy to shrink, which can effectively avoid the direct contact of the positive plate and the negative plate caused by high temperature, avoid the short circuit, and the edge of the negative plate is more prone to lithium precipitation in the later stage of battery cycle, since the hard layer is arranged on the edge area of the diaphragm in the application, the lithium dendrite is not easy to pierce the hard layer of the edge of the diaphragm, and the situation that the precipitated lithium dendrite passes through the diaphragm to reach the positive plate is avoided, that is, the technical problem of thermal runaway is avoided;In addition, the diaphragm is provided with a heat-resistant layer corresponding to the ion transmission area, and the heat-resistant layer and the hard layer can effectively avoid the thermal runaway safety problem caused by the shrinkage of the diaphragm, so it can be seen that the technical scheme of the application can fundamentally solve the technical defects in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiments or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0025] Figure 1 A structural schematic diagram of a battery is provided for the application.

[0026] Figure 2 A diaphragm structure schematic diagram in a battery is provided for the application.

[0027] Figure 3 A partial structure schematic diagram of a battery is provided for the application.

[0028] Figures 4 to 5 A specific structure schematic diagram of a diaphragm in a battery is provided for the application.

[0029] Figures 6 to 7 A specific structure schematic diagram of another diaphragm in a battery is provided for the application.

[0030] Figure 8 Another partial structure schematic diagram of a battery is provided for the application.

[0031] Figure 9 Still another partial structure schematic diagram of a battery is provided for the application. DETAILED DESCRIPTION

[0032] The technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the application.

[0033] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited. In the present application, " / " represents the meaning of "or". In the drawings, similar units are indicated by the same reference numerals, and the dashed lines in the drawings represent the absence of structure, and only illustrate the shape and position of the structure. The present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between the various embodiments and / or arrangements discussed.

[0034] With the growth of new energy vehicles worldwide and the rapid rise of energy storage market, the demand for lithium battery separator film will rapidly expand in the new energy market, and the market prospect is broad. It is estimated that by 2030, the proportion of new energy and clean energy powered vehicles will reach about 40%. In 2020, China's automobile sales reached 25,311,000, so by 2030, the number of new energy vehicles will reach 10 million. The high growth space of new energy vehicles plus the outbreak of the energy storage market, lithium ion batteries are considered one of the most competitive electrochemical energy storage technologies due to their light weight, high specific energy / specific power, low self-discharge, long service life, etc.

[0035] The present application is aimed at the existing liquid battery, when the thermal runaway critical point is reached, the temperature inside the positive and negative electrodes rises and a large amount of gas is generated, the high temperature causes the separator at the edge of the positive and negative electrode plates to shrink, resulting in direct contact between the positive / negative electrode plates, at this time the generated gas cannot be discharged through the battery explosion-proof valve, the battery generates a large amount of heat accumulation due to internal short circuit in an instant, and finally explodes. At the same time, due to the larger current density at the edge of the electrode plate, lithium is more likely to be precipitated at the edge of the battery in the later stage of the cycle, and lithium dendrites can pierce the separator to cause thermal runaway. The existing solid-state battery can solve the problem of shrinkage or piercing of the separator, but the performance of the all-solid-state battery will be sharply reduced, which cannot meet the performance requirements of the current power battery. The present embodiment can solve this defect.

[0036] To solve the above technical problems, the application provides a battery, which comprises a shell, wherein the shell is formed with a cavity; an electrolyte layer is arranged in the cavity, the electrolyte layer comprises a liquid electrolyte layer located at the middle position of the cavity, a first solid-state electrolyte layer and a second solid-state electrolyte layer located at both ends of the cavity; the cavity is further provided with a positive electrode sheet and a negative electrode sheet, one end of the positive electrode sheet and the negative electrode sheet is inserted into the first solid-state electrolyte layer, the other end of the positive electrode sheet and the negative electrode sheet passes through the second solid-state electrolyte layer and protrudes from the second solid-state electrolyte layer; a diaphragm is further arranged between the positive electrode sheet and the negative electrode sheet, the diaphragm comprises an ion permeable area corresponding to the positive electrode sheet and the negative electrode sheet, and an edge area located at the periphery of the ion permeable area; wherein the diaphragm is provided with a heat-resistant layer corresponding to the ion permeable area, and the diaphragm is provided with a hard layer corresponding to the edge area.

[0037] In the battery, the middle position is provided with a liquid electrolyte, and both ends are provided with solid-state electrolyte layers, so that the problem that the performance of the full solid-state battery is sharply reduced can be effectively solved, the performance demand of the power battery can be met, the solid-state electrolyte is not easy to shrink, and the two ends of the positive electrode sheet and the negative electrode sheet are fixed in the solid-state electrolyte layer, so that the positive electrode sheet and the negative electrode sheet can be effectively prevented from directly contacting each other, and the short circuit condition can be avoided; in the later stage of the battery cycle, the edge of the negative electrode sheet is more prone to lithium precipitation, the diaphragm is provided with a hard layer corresponding to the edge area, lithium dendrites cannot pierce the hard layer of the edge of the diaphragm, the condition that the precipitated lithium dendrites pass through the diaphragm to reach the positive electrode sheet is not easy to occur, and the technical problem that thermal runaway is caused can be avoided. The diaphragm is provided with a heat-resistant layer corresponding to the ion permeable area, and the heat-resistant layer and the hard layer can effectively avoid the thermal runaway safety problem caused by the shrinkage of the diaphragm, so it can be seen that the technical scheme of the application can fundamentally solve the technical defects in the prior art.

[0038] Preferably, the hard layer is a third solid-state electrolyte layer; wherein the width of the third solid-state electrolyte layer is n times of the width of the diaphragm, and n is 3, 4 or 5.

[0039] Preferably, the edge surface of the positive electrode sheet is further provided with a fourth solid-state electrolyte layer, and the edge surface of the negative electrode sheet is further provided with a fifth solid-state electrolyte layer.

[0040] Preferably, the width of the fourth solid-state electrolyte layer is n times of the width of the positive electrode sheet, and the width of the fifth solid-state electrolyte layer is n times of the width of the negative electrode sheet, and n is 3, 4 or 5. Preferably, the material of the solid-state electrolyte layer is one of a polymer electrolyte, an inorganic oxide electrolyte and a sulfide electrolyte.

[0041] Preferably, the material of the heat-resistant layer is one of polyvinylidene fluoride and ceramic or a combination of the two materials. Preferably, the material of the heat-resistant layer is graphite.

[0042] Preferably, the diaphragm comprises a base film, the heat-resistant layer and the hard layer are arranged on both sides of the base film, and the material of the base film is polyethylene or copper foil. Preferably, the diaphragm comprises an array of ion-permeable regions arranged corresponding to the positive electrode sheet and the negative electrode sheet, and the array is provided with micropores, and the pore size of the micropores is 0.01-0.05 microns.

[0043] Preferably, the contact surface of the first solid-state electrolyte layer and the second solid-state electrolyte layer with the liquid-state electrolyte layer is a bending contact surface; and the first solid-state electrolyte layer and the second solid-state electrolyte layer are provided with a plurality of openings or protrusions towards one side of the liquid-state electrolyte layer.

[0044] Preferably, the material of the positive electrode sheet is manganese dioxide, and the material of the negative electrode sheet is metal lithium or metal lithium alloy metal.

[0045] In detail, the diaphragm of the battery is a thin film with a microporous structure, which is the key inner layer component with the most technical barriers in the lithium ion battery industry chain, and the cost accounts for about 20% in the power battery. The diaphragm is located between the positive electrode sheet and the negative electrode sheet of the lithium battery, and mainly plays two roles: one is to separate the positive and negative active materials, and the other is to prevent the two poles from short-circuiting due to contact; in addition, during the electrochemical reaction, the diaphragm can also maintain the necessary electrolyte to form a channel for ion movement, and the types of lithium batteries are different, and the diaphragms used are also different.

[0046] As shown in Figure 1 The present application provides a structural diagram of a battery 10. The battery 10 comprises a shell 11, the shell 11 is formed with a cavity 111, the cavity 111 is filled with an electrolyte, the filled electrolyte forms an electrolyte layer for ion transfer, the electrolyte layer is provided with a positive electrode sheet 12 and a negative electrode sheet 13, the exposed terminals of the positive electrode sheet 12 and the negative electrode sheet 13 are protruded from the electrolyte layer and extend out of the shell 11, respectively forming a positive electrode exposed terminal 121 and a negative electrode exposed terminal 131, and a diaphragm 14 is arranged between the positive electrode sheet 12 and the negative electrode sheet 13. The diaphragm 14 is a thin film with a microporous structure, which is the key inner layer component with the most technical barriers in the lithium ion battery industry chain. The diaphragm 14 mainly plays two roles: one is to separate the positive and negative active materials, and the other is to prevent the two poles from short-circuiting due to contact; in addition, during the electrochemical reaction, the diaphragm can also maintain the necessary electrolyte to form a channel for ion movement. The shell 11 is also provided with a pressure relief valve 20, which can timely discharge the gas generated by the electrolyte layer due to high temperature, so as to avoid the overpressure of the cavity 111.

[0047] As shown in Figure 2As shown, the diaphragm 14 includes ion permeable regions 14-1 corresponding to the positive electrode sheet 12 and the negative electrode sheet 13, and edge regions 14-2 and 14-3 located at the periphery of the ion permeable regions 14-1; the ion permeable regions 14-1 are arrayed with micropores for forming channels for ion movement, and the pore size of the micropores is preferably 0.01-0.05 microns. The edge regions 14-2 and 14-3 at the periphery of the ion permeable regions 14-1 are respectively for the edge positions on both sides of the positive electrode sheet 12 and the negative electrode sheet 13, and due to long-term operation of the battery 10, lithium material can be precipitated at the edge positions on both sides of the negative electrode sheet 13, and the lithium material forms crystals with sharp corners that can easily pierce a conventional diaphragm. Therefore, the diaphragm 14 in the present embodiment is provided with a heat-resistant layer corresponding to the ion permeable regions 14-1, and the diaphragm 14 is provided with a hard layer corresponding to the edge regions 14-2 and 14-3, and the lithium material formed into crystals with sharp corners is not easy to pierce the hard layer, and the precipitated lithium dendrites are not easy to pass through the diaphragm to reach the positive electrode sheet, thereby avoiding the technical problem of causing thermal runaway.

[0048] As shown in the design scheme, Figure 3 The present application provides a partial structure diagram of a battery 10. The structure diagram of the battery 10. The battery 10 includes a shell 111, and the shell 111 is filled with an electrolyte, and the filled electrolyte forms an electrolyte layer 15 for ion transmission, and the electrolyte layer 15 includes a liquid electrolyte layer 151 located at the middle position of the cavity, a first solid-state electrolyte layer 152 and a second solid-state electrolyte layer 153 located at both ends of the cavity; Figure 3 In combination with Figure 1 , one end of the positive electrode sheet 12 and the negative electrode sheet 13 is inserted into the first solid-state electrolyte layer 152, and the other end passes through the second solid-state electrolyte layer 153 and protrudes from the second solid-state electrolyte layer 153, and the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 effectively fix the positive electrode sheet 12 and the negative electrode sheet 13, avoiding the positive electrode sheet 12 and the negative electrode sheet 13 from shaking in the liquid electrolyte layer 151 under high-temperature conditions. From the design scheme, it can be clearly seen that the middle position of the battery 10 uses a liquid electrolyte, and the two ends use a solid-state electrolyte layer, and the mixed liquid and solid electrolyte ensures high conductivity and low surface impedance of the electrolyte, greatly improves the safety of the battery system, and can better adapt to high-energy positive and negative electrodes and reduce the weight of the system, realizes synchronous improvement of energy density, effectively solves the problem that the performance of the all-solid-state battery will be sharply reduced, and meets the performance requirements of the current power battery; and the solid-state electrolyte is not easy to shrink, and can fix the two ends of the positive electrode sheet 12 and the negative electrode sheet 13, which can effectively avoid direct contact between the positive electrode sheet 12 and the negative electrode sheet 13, and avoid short circuit.

[0049] Figures 4 to 7This is a schematic diagram illustrating the specific structures of the two types of diaphragms in this invention. In one embodiment, as shown... Figure 4 As shown, this embodiment provides a top view of a separator structure in a battery. In the top view, the surface of the separator 14 includes a heat-resistant layer 141 and hard layers 142 located on both sides of the heat-resistant layer 141. In this embodiment, the heat-resistant layer 141 and... Figure 2 The ion-permeable region 14-1 is positioned in alignment. The heat-resistant layer 141 is preferably made of a combination of polyvinylidene fluoride (PVDF) and ceramic. In other embodiments, the heat-resistant layer 141 may also be made of either PVDF or ceramic. The hard layer 142 and... Figure 2 Edge regions 14-2 and 14-3 are aligned and disposed in the membrane. The material of the hard layer 142 is preferably a solid electrolyte. The hard layer 142 includes a third solid electrolyte layer 1421 and a third solid electrolyte layer 1422 located on both sides of the heat-resistant layer 141. The width of the third solid electrolyte layer 1421 and the third solid electrolyte layer 1422 is one-nth of the width of the separator 14, where n is preferably 3, 4, or 5. A fourth solid electrolyte thin layer is disposed on the edge surface of the positive electrode 12, and a fifth solid electrolyte thin layer is disposed on the edge surface of the negative electrode 13. The width of the fourth solid electrolyte layer is one-nth of the width of the positive electrode 12, and the width of the fifth solid electrolyte layer is one-nth of the width of the negative electrode 13, where n is preferably 3, 4, or 5. Both the fourth and fifth solid electrolyte thin layers are... Figure 2 The edge regions 14-2 and 14-3 in the above embodiment are aligned and arranged. The solid electrolyte layer is made of one of the following electrolytes: polymer electrolyte, inorganic oxide electrolyte, and sulfide electrolyte.

[0050] like Figure 5 As shown, this embodiment provides a schematic diagram of the membrane structure of a separator 14 in a battery. Figure 5 for Figure 4 A schematic diagram of the corresponding membrane layers is shown. In this embodiment, the separator 14 includes a base membrane 140. The heat-resistant layer and the rigid layer are disposed on both sides of the base membrane 140, and the heat-resistant layer and the rigid layer on the same side are disposed in the same layer. The base membrane 140 is made of one or more materials selected from polyethylene and copper foil. The heat-resistant layer is made of a combination of two materials selected from polyvinylidene fluoride and ceramic. The rigid layer is preferably made of a solid electrolyte. Specifically, the heat-resistant layer 141 and the rigid layer 142 are disposed on one side of the base membrane 140, and the heat-resistant layer 141 and the rigid layer 142 are located on the surface of the separator 14 facing the positive electrode 12. The heat-resistant layer 141' and the rigid layer 142' are disposed on the other side of the base membrane 140, and the heat-resistant layer 141' and the rigid layer 142' are located on the surface of the separator 14 facing the negative electrode 13.

[0051] In another embodiment, as shown in Figure 6 FIG. 6, the present embodiment provides another schematic diagram of the top view of the separator in a battery, in which the surface of the separator 14 includes a heat-resistant layer 144 and hard layers 145 located on both sides of the heat-resistant layer 144. The heat-resistant layer 144 in the present embodiment is arranged in register with the ion-permeable region 14-1 in Figure 2 FIG. 5, and the material of the heat-resistant layer 144 is graphite. The hard layers 145 are arranged in register with the edge regions edge region 14-2 and edge region 14-3 in Figure 2 FIG. 5, and the material of the hard layers 145 is preferably a solid-state electrolyte. The hard layers 145 include a third solid-state electrolyte layer 1451 and a third solid-state electrolyte layer 1452 located on both sides of the heat-resistant layer 144, and the width of the third solid-state electrolyte layer 1451 and the third solid-state electrolyte layer 1452 is n-th of the width of the separator 14, and n is preferably 3, 4 or 5. The edge surface of the positive electrode sheet 12 is provided with a fourth solid-state electrolyte layer, and the edge surface of the negative electrode sheet 13 is provided with a fifth solid-state electrolyte layer; wherein the width of the fourth solid-state electrolyte layer is n-th of the width of the positive electrode sheet, and the width of the fifth solid-state electrolyte layer is n-th of the width of the negative electrode sheet, and n is 3, 4 or 5. The fourth solid-state electrolyte layer and the fifth solid-state electrolyte layer are both arranged in register with the edge regions edge region 14-2 and edge region 14-3 in Figure 2 FIG. 5, and the material of the solid-state electrolyte layer in the above embodiment is one of a polymer electrolyte, an inorganic oxide electrolyte and a sulfide electrolyte.

[0052] As shown in Figure 7 FIG. 7, the present embodiment provides another schematic diagram of the film layer structure of the separator 14 in a battery, Figure 7 as shown in Figure 6 FIG. 8, a corresponding schematic diagram of the film layer. The separator 14 in the present embodiment includes a base film 140, and the heat-resistant layer and the hard layer are arranged on both sides of the base film 140, and the heat-resistant layer and the hard layer on the same side are arranged in the same layer, and the material of the base film 140 is one or more than one superimposed material of polyethylene and copper foil. The material of the heat-resistant layer is graphite. The material of the hard layer is preferably a solid-state electrolyte,

[0053] wherein the heat-resistant layer 144 and the hard layer 145 are arranged on one side of the base film 140, and the heat-resistant layer 144 and the hard layer 145 are located on the surface of the side of the separator 14 facing the positive electrode sheet 12, and the heat-resistant layer 144' and the hard layer 145' are arranged on the other side of the base film 140, and the heat-resistant layer 144' and the hard layer 145' are located on the surface of the side of the separator 14 facing the negative electrode sheet 13.

[0054] The material of the base film 140 in other embodiments can also be at least one of aluminum oxide, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethyl methacrylate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, and acrylonitrile-butadiene-styrene copolymer. The heat-resistant layer and the hard layer surface are also preferably provided with recesses, and the two adjacent recesses are arranged in a two-dimensional array.

[0055] In Figure 3 , the contact surface between the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 and the liquid-state electrolyte layer 151 is a flat contact surface, which is easy to manufacture. In actual cases, when the thermal runaway critical point is reached, the temperature inside the positive electrode and the negative electrode rises and a large amount of gas is generated. The high temperature causes the separator at the edge of the electrode sheet to shrink, and the volume of the liquid-state electrolyte layer 151 also expands correspondingly. In order to reduce the tension caused by the volume expansion of the liquid-state electrolyte layer 151, the inventors further improved the structure of the contact surface between the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 and the liquid-state electrolyte layer 151, and designed the contact surface between the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 and the liquid-state electrolyte layer 151 as a bending contact surface; the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 are provided with a plurality of openings or protrusions on the side facing the liquid-state electrolyte layer 151. When the electrolyte of the liquid-state electrolyte layer 151 expands along the opening or protrusion surface, this distribution effectively avoids the "climbing" phenomenon caused by the surface tension of the liquid, thereby improving the stability of the surface of the liquid-state electrolyte layer 151, effectively solving the problem that the performance of the all-solid-state battery will be sharply reduced, and meeting the performance requirements of the current power battery.

[0056] As Figure 8 shown, the present application provides another partial structure diagram of a battery 10. The battery 10 comprises a shell, and the shell is filled with an electrolyte, and the filled electrolyte forms an electrolyte layer 15 for ion transmission, the electrolyte layer 15 comprises a liquid-state electrolyte layer 151 located at the middle position of the cavity, a first solid-state electrolyte layer 152 and a second solid-state electrolyte layer 153 located at both ends of the cavity; the first solid-state electrolyte layer 152 is provided with a plurality of openings 1521 facing the liquid-state electrolyte layer 151, and the second solid-state electrolyte layer 153 is provided with a plurality of openings 1531 facing the liquid-state electrolyte layer 151, and the other structures are the same as Figure 3 similar, which will not be repeated here.

[0057] As Figure 8As shown, the present application provides another partial structural schematic diagram of a battery 10. The battery 10 comprises a shell, and the shell is filled with an electrolyte, and the filled electrolyte forms an electrolyte layer 15 for ion transmission, which comprises a liquid electrolyte layer 151 located at the middle position of the cavity, a first solid-state electrolyte layer 152 and a second solid-state electrolyte layer 153 located at both ends of the cavity; the first solid-state electrolyte layer 152 is provided with a plurality of protrusions 1521 towards the liquid electrolyte layer 151, and the second solid-state electrolyte layer 153 is provided with a plurality of protrusions 1531 towards the liquid electrolyte layer 151, and other structures are the same as Figure 3 Similarly, details are not repeated here.

[0058] In other embodiments, the contact surface of the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 with the liquid electrolyte layer 151 is designed as a bending contact surface; the first solid-state electrolyte layer 152 and the second solid-state electrolyte layer 153 are arranged in a wave shape or a zigzag shape towards one side of the liquid electrolyte layer 151.

[0059] In the above, in the battery of the embodiment, liquid electrolyte is used at the middle position, and solid-state electrolyte layers are used at both ends, that is, a combination of liquid and solid electrolyte layers is used, which ensures high conductivity and low surface impedance of the electrolyte, greatly improves the safety of the battery system, and can better adapt to high-energy positive and negative electrodes and reduce the weight of the system, realize synchronous improvement of energy density, effectively solve the problem that the performance of the all-solid-state battery will be sharply reduced, and meet the performance requirements of the current power battery; the solid-state electrolyte is not easy to shrink, and the positive plate and the negative plate are fixed at the solid-state electrolyte layer at both ends, which can effectively avoid direct contact between the positive plate and the negative plate, and avoid short circuit; in the later stage of battery circulation, the edge of the negative plate is more prone to lithium precipitation, and the separator is provided with a hard layer corresponding to the edge area, so that lithium dendrites cannot pierce the hard layer at the edge of the separator, and the lithium dendrites are not easy to pass through the separator to reach the positive plate, thereby avoiding the technical problem of thermal runaway. The separator is provided with a heat-resistant layer corresponding to the ion transmission area, and the heat-resistant layer and the hard layer can effectively avoid the thermal runaway safety problem caused by the shrinkage of the separator. Therefore, the technical solution of the present application can fundamentally solve the technical defects in the prior art.

[0060] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application, and those skilled in the art can make various modifications and decorations without departing from the spirit and scope of the present application, therefore the protection scope of the present application is subject to the scope defined by the claims.

Claims

1. A battery, characterized by, The shell is provided with an explosion-proof valve, and a cavity is formed in the shell; an electrolyte layer is arranged in the cavity, which includes a liquid electrolyte layer at the middle position of the cavity, a first solid-state electrolyte layer and a second solid-state electrolyte layer at both ends of the cavity; The cavity is also provided with a positive plate and a negative plate, one end of each of the positive plate and the negative plate is inserted into the first solid-state electrolyte layer, the other end of each of the positive plate and the negative plate passes through the second solid-state electrolyte layer and protrudes from the second solid-state electrolyte layer; A separator is also arranged between the positive plate and the negative plate, the separator includes an ion permeable area corresponding to the positive plate and the negative plate, and an edge area at the periphery of the ion permeable area; the separator is provided with a heat-resistant layer corresponding to the ion permeable area, and a hard layer corresponding to the edge area; the material of the heat-resistant layer is graphite, and the hard layer is a third solid-state electrolyte layer.

2. The battery of claim 1, wherein, The width of the third solid-state electrolyte layer is n times of the width of the separator, and n is 3, 4 or 5.

3. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. The edge surface of the positive plate is also provided with a fourth solid-state electrolyte layer, and the edge surface of the negative plate is also provided with a fifth solid-state electrolyte layer; The width of the fourth solid-state electrolyte layer is n times of the width of the positive plate, and the width of the fifth solid-state electrolyte layer is n times of the width of the negative plate, and n is 3, 4 or 5.

4. The battery of any one of claims 1-3, wherein the cathode comprises a lithium metal oxide. The material of the solid-state electrolyte layer is one of a polymer electrolyte, an inorganic oxide electrolyte and a sulfide electrolyte.

5. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. The separator includes a base film, the heat-resistant layer and the hard layer are arranged on both sides of the base film, and the heat-resistant layer and the hard layer on the same side are arranged in the same layer, and the material of the base film is polyethylene, copper foil or graphite.

6. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. The separator includes a plurality of micropores arranged in an array corresponding to the ion permeable area, and the pore size of the micropores is 0.01-0.05 μm.

7. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. The contact surface of the first solid-state electrolyte layer and the second solid-state electrolyte layer with the liquid electrolyte layer is a bending contact surface; The side of the first solid-state electrolyte layer and the second solid-state electrolyte layer facing the liquid electrolyte layer is provided with a plurality of openings or protrusions.

8. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. The material of the positive plate is manganese dioxide, and the material of the negative plate is lithium metal and / or lithium alloy.

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