Electrolyte and bipolar battery containing it

Abstract

The present invention provides an electrolyte and a bipolar battery containing the same. When the electrolyte containing the compound represented by formula I of the present invention is applied to a bipolar battery, the bipolar battery exhibits good high-temperature storage performance and high-temperature circulation performance. [Solution] The present invention provides an electrolyte and a bipolar battery containing the same. The electrolyte contains a first component, the first component being a compound represented by formula I, in which R1 and R2 are each independently selected from any one of an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, and a substituent having 1 to 3 heteroatoms. The heteroatoms are nitrogen atoms and / or sulfur atoms.

Description

Technical Field

[0001] The present invention specifically relates to an electrolyte and a bipolar battery containing the same.

Background Art

[0002] In a bipolar battery, a plurality of positive and negative electrode units are connected in series inside the battery, thereby effectively realizing voltage superposition, and thereby greatly improving the total output voltage of the battery. Due to its unique internal series design, the output voltage and output power of the battery are significantly improved. And, since the bipolar battery uses fewer tabs and a higher voltage, external connection components and the like can be reduced, further reducing the manufacturing cost and making the bipolar battery have a competitive advantage in terms of cost. This design can be applied in fields such as electric vehicles with high voltage and large power output, new energy storage systems, etc., showing excellent performance advantages.

[0003] Bipolar battery technology has significant advantages such as improving energy density and reducing manufacturing costs, but at the same time, it also faces technical problems and constraints such as the complexity of the manufacturing process and the high requirement for the consistency of battery cells. The consistency of battery cells and the synchronization problem of the battery state of charge (SOC) are particularly important in bipolar battery technology. Since the bipolar battery design adopts an internal series structure, that is, inside a single battery unit, a plurality of positive and negative electrodes are connected in series to form an integrated high-voltage battery. With this design, more battery cells are included inside a single battery unit, so the consistency between battery cells becomes particularly important. In a bipolar battery, due to the characteristics of the internal series structure, even if there are tiny performance differences between single battery cells, they will be amplified during the charge and discharge process of the battery, thereby affecting the performance and life of the entire battery. Specifically, when the parameter differences such as the capacity and internal resistance between battery cells are too large, during the charge and discharge of the battery, some battery cells reach the charge and discharge stop conditions early, while on the other hand, the remaining capacity of other battery cells may not be fully utilized, resulting in the inability to synchronize the SOC (battery state of charge).

Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of conventional bipolar batteries, namely poor cell matching and inability to synchronize State of Charge (SOC), which result in poor high-temperature storage and circulation performance. To this end, the present invention provides an electrolyte and a bipolar battery containing the same. When the electrolyte containing the compound represented by Formula I of the present invention is applied to a bipolar battery, the bipolar battery exhibits good high-temperature storage and circulation performance. [Means for solving the problem]

[0005] To solve the above-mentioned technical problems, the present invention provides the following solution. In a first embodiment, the present invention provides an electrolyte comprising a first component, wherein the first component is a compound represented by the following formula I. [ka]

[0006] In a second embodiment, the present invention provides a bipolar battery comprising a bipolar electrode, a separator, and an electrolyte, wherein the bipolar electrode comprises a bipolar current collector, a positive electrode active material layer, and a negative electrode active material layer, the positive electrode active material layer being located on one side of the bipolar current collector, and the negative electrode active material layer being located on the other side of the bipolar current collector.

[0007] Based on a foundation consistent with common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain each preferred example of the present invention.

[0008] All reagents and raw materials used in this invention are commercially available. [Effects of the Invention]

[0009] The advantageous advancements of this invention are as follows: The present invention provides an electrolyte containing a compound represented by formula I. The addition of this compound allows for the consumption of excess charge within the battery during an overcharged state, improving the consistency of each battery unit and achieving a synchronous state of charge (SOC). Simultaneously, the compound represented by formula I exhibits stability under high voltage conditions, realizing an oxidation-reduction shuttle additive function while simultaneously reducing side reactions between the additive and the active material, thereby achieving excellent high-temperature storage and circulation performance. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of the structure of the bipolar battery manufactured in Example 1. [Figure 2] This is a schematic diagram of the process for assembling the bipolar battery in Example 1. [Modes for carrying out the invention]

[0011] electrolyte The electrolyte provided in a first aspect of the present invention comprises a first component, the first component being a compound represented by the following formula I. [ka]

[0012] The electrolyte of the present invention is applied to bipolar batteries and generally comprises an electrolyte, a solvent, and an additive. When the bipolar battery is a lithium-ion battery, the electrolyte is a lithium salt. When the bipolar battery is a sodium-ion battery, the electrolyte is a sodium salt.

[0013] In the present invention, in the compound represented by formula I, R1 and R2 may each be independently selected from one of the following: an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an amino group, an imidazolyl group, a thiazolyl group, and a pyridyl group.

[0014] In the present invention, the compound represented by formula I is selected from at least one of the following compounds. [Chemical formula]

[0015] In the present invention, the content of the first component may be 0.05 wt% to 10 wt%, preferably 0.1 to 3 wt%, more preferably 0.5 wt% to 1 wt%, and the wt% is the mass percentage of the first component in the mass of the electrolyte solution.

[0016] In some specific embodiments, the content of the first component is 0.05 wt%, 0.1 wt%, 0.5 wt%, 3 wt%, 10 wt%, and the wt% is the mass percentage of the first component in the mass of the electrolyte solution.

[0017] In the present invention, the electrolyte solution may further contain a second component, and the second component is one or two of vinylene carbonate and 1,3 - propane sultone.

[0018] In the present invention, the content of the second component may be 1 wt% to 10 wt%, for example, 1 wt%, 2.5 wt%, 5 wt% or 10 wt%, and the wt% is the mass percentage of the second component in the mass of the electrolyte solution.

[0019] In the present invention, the electrolyte solution further contains a third component, and the third component may be an organic solvent commonly used in this field, and the organic solvent may be any non - aqueous solvent previously used in non - aqueous electrolyte solutions. Examples of the third component include, but are not limited to, one or more of carbonate substances, carboxylic acid ester substances, and ether substances. The carbonate is one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, and trifluoroethyl methyl carbonate. The carboxylic acid ester is one or more of ethyl formate, ethyl acetate, propyl acetate, and ethyl propionate. The ether substances are one or more of ethylene glycol dimethyl ether, diethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether.

[0020] In some specific embodiments, the third component comprises at least component A and component B, wherein component A is fluoroethylene carbonate and / or trifluoroethyl methyl carbonate, and component B is one or more of ethylene glycol dimethyl ether, diethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether.

[0021] Here, the content of component A is preferably 40 wt% to 50 wt%, where wt% is the mass percentage of component A relative to the mass of the electrolyte, and the content of component B is preferably 20 wt% to 30 wt%, where wt% is the mass percentage of component B relative to the mass of the electrolyte.

[0022] In some specific embodiments, the mass content ratio of component A to component B is 7:3 to 8:2.

[0023] In some specific embodiments, the third component is trifluoroethylmethyl carbonate and tetraethylene glycol dimethyl ether in a mass ratio of 7:3.

[0024] In some specific embodiments, the third component is trifluoroethylmethyl carbonate and tetraethylene glycol dimethyl ether in a mass ratio of 8:2.

[0025] In some specific embodiments, the third component is fluoroethylene carbonate and tetraethylene glycol dimethyl ether in a mass ratio of 7:3.

[0026] In some specific embodiments, the third component is trifluoroethyl methyl carbonate and diethylene glycol diethyl ether in a mass ratio of 7:3.

[0027] In the present invention, the electrolyte contains a lithium salt, which may be a lithium salt commonly used in the art, and is preferably one or more selected from lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonylimide, lithium acetate, lithium methylsulfonate, and lithium trifluoromethylsulfonate.

[0028] Here, the lithium salt content is preferably 12 wt% to 16 wt%, for example 13 wt%, where wt% is the mass percentage of the lithium salt relative to the mass of the electrolyte.

[0029] In some specific embodiments, the lithium salt comprises lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, and the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide is (6-14):1, for example 6:1, 7:1, or 14:1.

[0030] In the present invention, the method for preparing the electrolyte may be a conventional method in the art, preferably obtained by mixing the first component, the second component, the third component and a lithium salt, and more preferably by adding the first component, the second component and the lithium salt to the third component.

[0031] bipolar battery A bipolar battery provided in a second aspect of the present invention comprises a bipolar electrode, a separator, and an electrolyte, wherein the bipolar electrode comprises a bipolar current collector, a positive electrode active material layer, and a negative electrode active material layer, the positive electrode active material layer being located on one side of the bipolar current collector, and the negative electrode active material layer being located on the other side of the bipolar current collector.

[0032] In the present invention, the bipolar battery may be any bipolar battery known in the art, such as a lithium-ion battery or a sodium-ion battery, and preferably a lithium-ion battery.

[0033] In the present invention, the structure of the bipolar battery is common in the art and includes a stacked electrode body, the stacked electrode body includes a negative electrode plate 100, a positive electrode plate 300, a bipolar electrode 200, a separator 40, and sealing adhesives 30a and 30b.

[0034] Here, the negative electrode plate 100 includes a negative electrode current collector 101 and a negative electrode active material layer 20 disposed on one side of the negative electrode current collector 101.

[0035] Here, the positive electrode plate 300 includes a positive electrode current collector 103 and a positive electrode active material layer 50 disposed on one side of the positive electrode current collector 103.

[0036] Here, the bipolar electrode 200 includes a bipolar current collector 102, a positive electrode active material layer 50 disposed on one side of the bipolar current collector 102, and a negative electrode active material layer 20 disposed on the other side of the bipolar current collector 102, and at least one bipolar electrode 200 is stacked and arranged between the positive electrode plate 300 and the negative electrode plate 100.

[0037] Here, the separator 40 is placed between adjacent bipolar electrodes 200 and between the bipolar electrodes 200 and the negative electrode plate 100 or the positive electrode plate 300.

[0038] In the present invention, the bipolar current collector may be a current collector commonly used in this field, for example, a copper-aluminum composite current collector. The copper-aluminum composite current collector is obtained by bonding two metals, copper foil and aluminum foil, with a connecting layer.

[0039] In the present invention, the positive electrode active material layer may contain a positive electrode active material, and a binder and a conductive agent may be further added as needed.

[0040] The positive electrode active material may be any positive electrode active material commonly used in lithium-ion battery positive electrodes in this field, and may include one or more of the following: lithium cobalt oxide (LCO), lithium nickel oxide (LNO), lithium manganese oxide (LMO), lithium nickel manganese oxide (LNMO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), and lithium-rich manganese oxide (LRMO), for example, LiNi 0.5 Mn 1.5 It is O4.

[0041] The binder may be a component that helps to bond the active material and the conductive agent, and also helps to bond the active material and the current collector. Typically, it may be selected from polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and various copolymers.

[0042] The conductive agent may be any of the following: graphite materials such as natural graphite and artificial graphite; carbon black materials such as Super P, carbon black, acetylene black, Ketjen black, channel carbon black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers and metal fibers; metal powders such as fluorocarbon powder, aluminum powder, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; and conductive metal oxides such as titanium dioxide or polyphenylene derivatives.

[0043] In the present invention, the negative electrode active material layer may contain a negative electrode active material, and a binder, a conductive agent, and a thickening agent may be further added as needed.

[0044] The aforementioned negative electrode active material may be any negative electrode active material that is common in this field, and may include graphite, but is not limited to graphite.

[0045] The aforementioned conductive agent may be a conductive agent commonly used in negative electrode plates in this field, and may include, but is not limited to, conductive carbon black.

[0046] The aforementioned thickener may be any thickener commonly used in negative electrode plates in this field, and may include, but is not limited to, sodium carboxymethylcellulose.

[0047] The aforementioned binder may be a binder commonly used in negative electrode plates in this field, and may include, but is not limited to, styrene-butadiene rubber.

[0048] In some specific embodiments, the mass ratio of the negative electrode active material, conductive agent, thickener, and binder is 96:1:1:2.

[0049] In the present invention, the separator may be a conventional separator in the art, including, but not limited to, a polypropylene film.

[0050] In the present invention, the method for preparing the bipolar battery may be common in the art. Generally, bipolar electrodes and separators are stacked sequentially, the separator is positioned midway between the positive and negative electrodes of adjacent bipolar electrodes, the positive electrode active material layer and the negative electrode active material layer of adjacent electrode plates are placed opposite each other, forming a stacked electrode body composed of bipolar electrodes connected in series. This is then enclosed in an aluminum plastic film, dried, an electrolyte is injected, the opening is sealed, and the electrolyte is converted to produce a bipolar battery.

[0051] The present invention will be further described below using the methods of the examples, but this does not limit the present invention to the scope of the above examples. Experimental methods in the following examples that do not specify concrete conditions should be selected according to the usual methods and conditions, or according to the product description.

[0052] The structures of the compounds involved in the examples and comparative examples are shown in Table 1 below.

[0053] [Table 1] JPEG2026067388000006.jpg225160

[0054] The above compounds are commercially available or can be synthesized by methods commonly used in this field.

[0055] Example 1 (1) Preparation of the electrolyte In a glove box under an argon gas atmosphere with a water content of <10 ppm, cell-grade trifluoroethyl methyl carbonate (FEMC) and tetraethylene glycol dimethyl ether were mixed in a mass ratio of 7:3 to form an organic solvent. Other components were then quantitatively added according to the electrolyte composition described in Table 2 below. In this mixture, the total mass of the electrolyte was 100 wt%, and the mass percentage of the lithium salt was 13 wt%.

[0056] (2) Preparation of the electrode plates Preparation of bipolar electrodes Cathode active material LiNi 0.5 Mn 1.5 O4, polyvinylidene fluoride as a binder, and Super P as a conductive agent were mixed in a weight ratio of 98:1:1. N-methylpyrrolidone (NMP) was added, and the mixture was stirred under the action of a vacuum stirrer until the system became uniformly transparent to obtain a positive electrode slurry. The positive electrode slurry was uniformly applied to one side of the aluminum foil of a copper-aluminum composite bipolar current collector. After drying at room temperature, it was transferred to a drying oven for further drying.

[0057] Artificial graphite was used as the negative electrode active material, Super P as the conductive agent, sodium carboxymethylcellulose (CMC-Na) as the thickener, and styrene-butadiene rubber (SBR) as the binder, all mixed in a mass ratio of 96:1:1:2. Deionized water was added, and a negative electrode slurry was obtained under the action of a vacuum stirrer. The negative electrode slurry was uniformly applied to one side of the copper foil of the copper-aluminum composite bipolar current collector described above. After drying at room temperature, it was transferred to a drying oven for drying, and then cold-rolled and slit to obtain a bipolar electrode.

[0058] Preparation of positive electrode plates Cathode active material LiNi 0.5 Mn 1.5 O4, polyvinylidene fluoride as a binder, and Super P as a conductive agent were mixed in a weight ratio of 98:1:1. N-methylpyrrolidone (NMP) was added, and the mixture was stirred under the action of a vacuum stirrer until the system became uniformly transparent to obtain a positive electrode slurry. The positive electrode slurry was uniformly applied to one side of the positive electrode current collector aluminum foil. After drying at room temperature, it was transferred to a drying oven for drying, and then cold-rolled and slit to obtain a positive electrode plate.

[0059] Preparation of the negative electrode plate Artificial graphite was used as the negative electrode active material, Super P as the conductive agent, sodium carboxymethylcellulose (CMC-Na) as the thickener, and styrene-butadiene rubber (SBR) as the binder, all mixed in a mass ratio of 96:1:1:2. Deionized water was added, and a negative electrode slurry was obtained under the action of a vacuum stirrer. The negative electrode slurry was uniformly applied to one side of the copper foil of the negative electrode current collector. After drying at room temperature, it was transferred to a drying oven for drying, and then cold-rolled and slit to obtain a negative electrode plate.

[0060] (3) Preparation of separators A polypropylene film is used as a separator.

[0061] (4) Assembly of bipolar battery The electrode plates manufactured in step (2) and the separators from step (3) were sequentially stacked so that the separators were positioned between the positive and negative electrodes of adjacent bipolar electrodes to provide isolation. The positive electrode active material layer and the negative electrode active material layer of adjacent electrode plates were placed facing each other, forming a stacked electrode body consisting of bipolar electrodes connected in series. The specific assembly process is shown in Figure 2. Subsequently, the assembly was enclosed in an aluminum plastic film, transferred to a vacuum drying oven and dried at 120°C, injected with 3.0 g / Ah of the electrolyte manufactured in step (1), sealed, and subjected to electrolyte conversion to finally obtain a 1 Ah soft pack bipolar battery. The schematic diagram of the structure of the laminated electrode body manufactured in Example 1 is shown in Figure 1, and includes a positive electrode plate 300 composed of a positive electrode active material 50 and a positive electrode current collector 103, a negative electrode plate 100 composed of a negative electrode active material 20 and a negative electrode current collector 101, a bipolar electrode 200 composed of a positive electrode active material 50, a bipolar current collector 102 and a negative electrode active material 20 stacked in sequence, a separator 40 and sealing adhesives 30a and 30b.

[0062] Example 2 The difference from Example 1 is that the amount of compound 1 used is 0.5 wt%.

[0063] Example 3 The difference from Example 1 is that the amount of compound 1 used is 1 wt%.

[0064] Example 4 The difference from Example 1 is that the amount of compound 1 used is 3 wt%.

[0065] Example 5 The difference from Example 3 is that the amount of compound 1 used is 0.05 wt%.

[0066] Example 6 The difference from Example 3 is that the amount of compound 1 used is 10 wt%.

[0067] Example 7 The difference from Example 3 is that Compound 2 is used instead of Compound 1.

[0068] Example 8 The difference from Example 3 is that compound 3 is used instead of compound 1.

[0069] Example 9 The difference from Example 3 is that compound 4 is used instead of compound 1.

[0070] Example 10 The difference from Example 3 is that compound 5 is used instead of compound 1.

[0071] Example 11 The difference from Example 3 is that compound 6 is used instead of compound 1.

[0072] Example 12 The difference from Example 3 is that an additional 5 wt% of vinylene carbonate was added to the electrolyte.

[0073] Example 13 The difference from Example 3 is that an additional 5 wt% of 1,3-propanesultone was added to the electrolyte.

[0074] Example 14 The difference from Example 3 is that an additional 2.5 wt% of vinylene carbonate and 2.5 wt% of 1,3-propanesultone were added to the electrolyte.

[0075] Example 15 The difference from Example 3 is that an additional 1 wt% of 1,3-propanesultone was added to the electrolyte.

[0076] Example 16 The difference from Example 3 is that an additional 10 wt% of 1,3-propanesultone was added to the electrolyte.

[0077] Example 17 The difference from Example 3 is that instead of lithium hexafluorophosphate, a combination of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide is used, and in this combination, the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide is 6:1.

[0078] Example 18 The difference from Example 3 is that instead of lithium hexafluorophosphate, a combination of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide is used, and in this combination, the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide is 7:1.

[0079] Example 19 The difference from Example 3 is that instead of lithium hexafluorophosphate, a combination of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide is used, and in this combination, the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide is 14:1.

[0080] Example 20 The distinguishing feature from Example 3 is that the mass ratio of trifluoroethyl methyl carbonate (FEMC) to tetraethylene glycol dimethyl ether is 8:2.

[0081] Example 21 The difference from Example 3 is that trifluoroethylmethyl carbonate (FEMC) is replaced with fluoroethylene carbonate.

[0082] Example 22 The difference from Example 3 is that the fluorotetraethylene glycol dimethyl ether is replaced with diethanol diethyl ether.

[0083] Comparative Example 1 The difference from Example 3 is that compound 1 is not added.

[0084] Comparative Example 2 The difference from Example 3 lies in the replacement of compound 1 with compound 7.

[0085] Comparative Example 3 The difference from Example 3 lies in replacing compound 1 with compound 8.

[0086] Examples of Effects 1. High-temperature circulation stability test Bipolar batteries manufactured in the examples and comparative examples were subjected to cyclic charging and discharging under a 45°C environment, and their capacity retention rate was measured. The voltage range was 3.4V to 4.85V, and the charge / discharge ratio was 0.5C / 1C. The results are recorded in Table 2. 2. High-temperature storage discharge capacity test The bipolar batteries manufactured in the examples and comparative examples were stored in a 60°C constant temperature bath for 15 days. After sufficient cooling, they were charged and discharged three times in the constant temperature bath at a 1C multiplier. The average discharge capacity of the three cycles was taken as the battery discharge capacity at that temperature, and the percentage relative to the discharge capacity at 25°C was calculated. For the lithium nickel-manganate / graphite batteries, the charge / discharge termination voltage was 3.4V to 4.85V. The results are recorded in Table 2.

[0087] Table 2 shows the electrolyte composition and effect data of the bipolar batteries prepared in the examples and comparative examples.

[0088] [Table 2] JPEG2026067388000008.jpg239160JPEG2026067388000009.jpg239160JPEG2026067388000010.jpg199160

[0089] When the electrolyte provided in this invention is applied to a bipolar battery, the presence of a compound with a specific structure in the electrolyte enables the bipolar battery to achieve good high-temperature storage performance and high-temperature circulation performance. In several specific implementations, the storage capacity retention rate at 60°C is 70.89% or higher, and the number of 45°C circulation cycles is 318 or higher. When the voltage is 4.80V, the compound represented by formula I initiates an oxidation reaction, consuming the overcharge amount inside the battery, improving the consistency of the electrocentric cores, and thereby improving the safety of the bipolar battery. Furthermore, the battery's circulation performance is also improved, extending the battery's service life.

[0090] Examples 1-6 examine the effects of adding the same type of compound but different amounts to the electrolyte and applying it to bipolar batteries. The results show that good performance can be achieved with any of the usual amounts of additive, but the effect is better when the amount is 0.1wt% to 3wt%, and even better when it is 0.5wt% to 1wt%.

[0091] Examples 3 and 7-11 involved adding different types of compounds, but using the same amount, to the electrolyte, and the effectiveness data when applied to bipolar batteries was verified. It was found that all bipolar batteries containing different compounds exhibited good high-temperature storage performance and high-temperature circulation performance, with compound 3 showing the best effect.

[0092] Examples 3 and 12-16 verified the addition of different types and amounts of additives, Examples 3 and 17-19 verified the addition of different types and amounts of lithium salts, and Examples 3 and 20-22 verified different types and amounts of organic solvents. It can be seen that changing only the type and amount of additives, the type and amount of lithium salts, or the type of organic solvent has a certain effect on the technical effect, but all of them can solve the technical problems of the present invention.

[0093] Comparative Example 1, which does not contain the compound of the present invention, shows that both the storage capacity retention rate at 60°C and the number of cycles at 45°C are significantly affected compared to the Example.

[0094] Comparative Examples 2 and 3 differ from Example 3 in the type of compound used, and each exhibits a different degree of reduction in its effects. In Comparative Example 2, biphenyl, commonly used in this field, was added, and in Comparative Example 3, a substance structurally similar to the compound represented by Formula I of the present invention was added. Under all other conditions being the same, it can be seen that the effects on the 60°C storage capacity retention rate and the number of 45°C circulation cycles are clearly reduced.

[0095] The embodiments described above represent only a limited number of embodiments of the present invention and are provided to facilitate understanding and use of the invention for those skilled in the art. Clearly, those skilled in the art can apply these embodiments to other embodiments with some modifications or changes without requiring any creative work. Therefore, the present invention is not limited to the embodiments described above, and any equivalent changes, simple modifications and modifications made within the scope of the invention still fall within the scope of the invention. [Industrial applicability]

[0096] This invention specifically relates to an electrolyte and a bipolar battery containing the same. [Explanation of Symbols]

[0097] 101 Negative electrode current collector 102 Bipolar current collector 103 Positive electrode current collector 20 Negative electrode active material layer 50 Cathode active material layer 100 Negative electrode plate 300 Positive electrode plate 200 bipolar electrodes 40 Separators 30a, 30b Sealing adhesive

Claims

1. An electrolyte containing a first component, wherein the first component is a compound represented by the following formula I. 【Chemistry 1】

2. R １ and R ２ The electrolyte according to claim 1, characterized in that each of the following is independently selected from an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an amino group, an imidazolyl group, a thiazolyl group, and a pyridyl group.

3. The electrolyte according to claim 1, characterized in that the compound represented by formula I is selected from at least one of the following compounds. 【Chemistry 2】

4. The electrolyte according to claim 1, characterized in that the content of the first component is 0.1 wt% to 3 wt%, and the wt% is the mass percentage of the first component relative to the mass of the electrolyte.

5. The electrolyte according to claim 1, characterized in that the electrolyte contains a second component, and the second component is one or two of vinylene carbonate and 1,3-propanesultone.

6. The electrolyte according to claim 5, characterized in that the content of the second component is 1 wt% to 10 wt%, and the wt% is the mass percentage of the second component relative to the mass of the electrolyte.

7. The electrolyte according to claim 1, characterized in that the electrolyte satisfies one or two of the following conditions a to b. a. The electrolyte contains a third component, the third component being one or more carbonate esters, carboxylic acid esters, and ethers, the carbonate ester being one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, fluoroethylene carbonate, and trifluoroethyl methyl carbonate, the carboxylic acid ester being one or more of ethyl formate, ethyl acetate, propyl acetate, and ethyl propionate, and the ethers being one or more of ethylene glycol dimethyl ether, diethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether. b. The electrolyte contains a lithium salt, wherein the lithium salt includes one or more of the following: lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonylimide, lithium acetate, lithium methylsulfonate, and lithium trifluoromethylsulfonate. The lithium salt content is 12 wt% to 16 wt%, where wt% is the mass percentage of the lithium salt relative to the mass of the electrolyte.

8. The electrolyte according to claim 7, characterized in that the lithium salt comprises lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, and the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide is (6 to 14):

1.

9. The electrolyte according to claim 7, wherein the third component comprises at least component A and component B, wherein component A is fluoroethylene carbonate and / or trifluoroethyl methyl carbonate, and component B is one or more of ethylene glycol dimethyl ether, diethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether, the content of component A is 40 wt% to 50 wt%, where wt% is the mass percentage of component A relative to the mass of the electrolyte, and the content of component B is 20 wt% to 30 wt%, where wt% is the mass percentage of component B relative to the mass of the electrolyte.

10. A bipolar battery comprising a bipolar electrode, a separator, and an electrolyte according to any one of claims 1 to 9, wherein the bipolar electrode comprises a bipolar current collector, a positive electrode active material layer, and a negative electrode active material layer, the positive electrode active material layer being installed on one side of the bipolar current collector, and the negative electrode active material layer being installed on the other side of the bipolar current collector.

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