Lithium-calcium fluoride battery electrolyte additive, electrolyte and battery

Abstract

This invention relates to the field of lithium fluorocarbon batteries, and particularly to an electrolyte additive, electrolyte, and battery for lithium fluorocarbon batteries. The lithium fluorocarbon battery electrolyte additive comprises inorganic salts of group VB elements; wherein the group VB elements are selected from one or more of V, Nb, and Ta. This invention utilizes a chemical reaction to trigger the pre-nucleation of LiF, enabling the lithium fluorocarbon battery to pre-generate some LiF crystal nuclei before discharge. This not only effectively reduces the heat generation of Li / CF batteries during discharge but also improves the battery's thermal stability and electrochemical performance. Through pre-nucleation technology, the heat release during battery discharge is significantly controlled, thereby reducing the risk of thermal runaway and improving the battery's safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of lithium fluorocarbon batteries, and particularly to a lithium fluorocarbon battery electrolyte additive, electrolyte, and battery. Background Technology

[0002] Lithium fluoride (Li / CF) x The battery has a capacity of 2180Wh·kg. -1 With its high theoretical energy density, high theoretical voltage, and high energy density, Li / CF3 distinguishes itself from other types of lithium batteries, making it an ideal energy storage solution for cutting-edge fields such as space missions, military technology, and medical devices. Compared to other types of lithium batteries, Li / CF3... x The battery offers significant performance advantages, providing longer lifespan and a wider operating temperature range. However, despite its high theoretical energy density, Li / CF... x Batteries still face significant safety concerns related to thermal runaway. Especially under high-power discharge conditions, an exothermic redox reaction related to the formation of lithium fluoride (LiF) may occur inside the battery, leading to a large release of heat and a rapid increase in battery temperature. If thermal runaway occurs, it could trigger a fire or explosion, severely impacting battery safety and application range.

[0003] Although existing research has focused on Li / CF x While the thermal runaway mechanism of batteries has been explored to some extent, this problem remains unresolved. Current technologies primarily improve battery thermal stability by optimizing battery design and materials, but these methods still fail to completely prevent thermal runaway under high power or extreme environments. How to better address the thermal runaway problem of lithium-fluoride batteries, reduce heat generation during discharge, and enhance battery safety remains a pressing technical challenge. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a lithium fluoride carbon battery electrolyte additive, an electrolyte, and a battery. This invention proposes a pre-nucleation strategy to solve the Li / CF... x The thermal runaway problem in batteries. Before discharge, a small number of LiF nuclei are pre-generated through a chemical reaction. These LiF nuclei act as seed crystals, promoting the crystallization and growth of newly formed LiF on their surface during discharge, thereby reducing the entropy increase associated with LiF nucleation. Guided by this pre-nucleation strategy, the Li / CF ratio can be reduced. x This invention addresses the dual objectives of reducing heat generation during battery discharge and improving battery electrochemical performance. Based on this strategy, inorganic salts of group VB elements (V, Nb, Ta) were selected as electrolyte additives to trigger LiF pre-nucleation through chemical reactions. This invention can effectively reduce the Li / CF ratio. xThe heat generated during battery discharge also increases the Li / CF ratio. x The thermal stability and electrochemical performance of the battery.

[0005] In a first aspect, this invention provides an electrolyte additive for lithium fluoride carbon batteries, comprising inorganic salts of group VB elements; wherein the group VB elements are selected from one or more of V, Nb, and Ta. In this invention, inorganic salts of group VB elements (V, Nb, Ta) are used as electrolyte additives, utilizing chemical reactions to trigger the pre-nucleation of LiF. By adding the additive to the electrolyte, some LiF crystal nuclei can be pre-generated in the battery before discharge. This not only effectively reduces the Li / CF ratio... x The heat generated during battery discharge can also improve the battery's thermal stability and electrochemical performance. Through pre-nucleation technology, heat release during discharge is significantly controlled, thereby reducing the risk of thermal runaway and improving battery safety and reliability.

[0006] Preferably, the inorganic salt of the group VB element is selected from one or more of the nitrates, chlorides, and sulfates of trivalent group VB elements.

[0007] According to the present invention, trivalent group VB elements can promote the pre-nucleation of lithium fluoride. Higher valence group VB elements have excessive oxidizing power, which damages the electrolyte composition and causes irreversible side reactions in the electrolyte. Lower valence group VB elements cannot catalyze the breaking of carbon-fluorine bonds and promote the pre-nucleation of lithium fluoride.

[0008] Secondly, the present invention also provides a lithium fluoride carbon battery electrolyte, wherein the lithium fluoride carbon battery electrolyte comprises lithium salt, ester solvent, ether solvent and trivalent group B salt; wherein the trivalent group B salt is selected from the above-mentioned lithium fluoride carbon battery electrolyte additives, such as vanadium chloride (trivalent), tantalum chloride (trivalent), niobium chloride (trivalent), vanadium sulfate (trivalent), tantalum sulfate (trivalent), niobium sulfate (trivalent), vanadium nitrate (trivalent), tantalum nitrate (trivalent), niobium nitrate (trivalent), preferably trivalent vanadium salt.

[0009] This invention overcomes the problem of existing technologies being unable to pre-nucleate lithium fluoride before discharge. By utilizing the catalytic effect of high-valence vanadium, it promotes partial breaking of carbon-fluorine bonds and guides the pre-generation of a small number of lithium fluoride nuclei before discharge, thereby significantly reducing heat generation during battery discharge. Specifically, trivalent group B elements such as vanadium can effectively promote the pre-nucleation reaction of lithium fluoride. However, higher-valence vanadium, due to its strong oxidizing properties, can damage the electrolyte composition, leading to irreversible side reactions. This not only fails to achieve the pre-nucleation effect but may also cause a decline in battery performance. Meanwhile, lower-valence vanadium, due to its insufficient catalytic ability, cannot effectively promote the breaking of carbon-fluorine bonds, thus affecting the pre-nucleation of lithium fluoride. In particular, trivalent vanadium plays a crucial role in this process, better promoting the effective pre-generation of lithium fluoride nuclei without damaging the electrolyte composition, thereby reducing heat release during discharge and improving the overall safety and performance of the battery.

[0010] Preferably, the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxaborate, lithium difluorooxaborate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, and lithium hexafluoroarsenate.

[0011] Preferably, the ester solvent is selected from one or more of dimethyl carbonate, propylene carbonate, ethylene carbonate, diethyl carbonate, and methyl ethyl carbonate.

[0012] Preferably, the ether solvent is selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, 1,2-dimethoxyethylene, 1,4-dioxocyclohexane, diethylene glycol dimethyl ether, and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether.

[0013] Preferably, the trivalent group B salt accounts for 0.1% to 20% of the total mass of the lithium fluoride carbon battery electrolyte; for example, 0.1%, 0.5%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, etc.

[0014] More preferably, the trivalent vanadium salt accounts for 1-10% of the total mass of the lithium fluoride carbon battery electrolyte, and more preferably 2-6%. The preferred proportion of trivalent vanadium salt in this invention can effectively promote the pre-nucleation of lithium fluoride and better reduce the temperature rise, especially when the vanadium salt addition is 2-6%, the effect is optimal.

[0015] More preferably, the molar concentration of the lithium salt in the lithium fluoride carbon battery electrolyte is 0.01~10M.

[0016] Further preferably, the volume ratio of the ester solvent to the ether solvent is 0.01~100:1. This invention can more effectively improve the thermal stability of lithium-carbon fluoride batteries by optimizing the mass proportion of trivalent group B salts and the types and proportions of each component in the electrolyte system.

[0017] Thirdly, the present invention provides a lithium fluoride carbon battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte; the electrolyte is the aforementioned lithium fluoride carbon battery electrolyte. In the lithium fluoride carbon battery system of the present invention, the positive electrode, negative electrode, separator, and electrolyte interact, and in particular, the optimized lithium fluoride carbon battery electrolyte effectively solves the aforementioned technical problems and more effectively reduces the Li / CF ratio. x The heat generated during battery discharge significantly increases the Li / CF ratio. x The thermal stability and electrochemical performance of the battery.

[0018] The low-heat-generating lithium fluoride (LiF) battery technology based on a pre-nucleation strategy provided by this invention can effectively reduce the heat generated during the discharge process of LiF batteries, thereby significantly improving the battery's thermal stability. Existing technologies cannot induce the pre-generation of lithium fluoride (LiF) nuclei before discharge. This invention utilizes the catalytic effect of high-valence vanadium to promote partial breakage of carbon-fluorine bonds before discharge, further promoting the pre-generation of a small number of LiF nuclei. In this way, the LiF nuclei formed during battery discharge can effectively suppress thermal runaway and reduce heat release. Ultimately, this invention achieves high energy density while reducing battery heat generation and improving the battery's thermal management capabilities, thus solving the shortcomings of existing technologies in addressing the thermal runaway problem of lithium fluoride batteries.

[0019] Preferably, the lithium fluoride carbon battery operates at a temperature of -40 to 150°C.

[0020] Preferably, the lithium fluoride carbon battery is allowed to discharge at a rate of 0.01 to 10C during operation.

[0021] Preferably, the positive electrode contains fluorinated carbon.

[0022] Preferably, the negative electrode is a lithium negative electrode.

[0023] Preferably, the diaphragm includes any one of modified polypropylene diaphragm, modified polyethylene diaphragm, polyethylene diaphragm, polypropylene diaphragm, polytetrafluoroethylene diaphragm, and organic-inorganic composite diaphragm.

[0024] The beneficial effects of this invention are at least as follows: By adding specific additives to the electrolyte, the invention utilizes their catalytic effect to promote the partial breakage of carbon-fluorine bonds before discharge, thereby inducing the formation of a small number of lithium fluoride (LiF) crystal nuclei. This allows for the pre-generation of some lithium fluoride crystal nuclei at the positive electrode before discharge, significantly reducing the heat generated during battery discharge. This invention enables lithium-carbon fluoride batteries to achieve better thermal stability, reduces the risk of thermal runaway, and has significant advantages in improving battery thermal stability and electrochemical performance. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0027] Unless otherwise specified, specific techniques or conditions in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., used without a specified manufacturer are all conventional products that can be purchased through legitimate channels. The raw materials and reagents in the embodiments of this invention were all purchased commercially.

[0028] The analytical method in the embodiments of the present invention is as follows: Electrochemical testing of the assembled flow-type supercapacitor is performed using a Landian constant current charge-discharge instrument. The equipment used is a CT2001A battery testing system, manufactured by Wuhan Landian Electronics Co., Ltd.

[0029] Example 1 This embodiment provides a lithium fluoride carbon battery electrolyte additive, wherein the lithium fluoride carbon battery electrolyte additive is vanadium chloride (trivalent).

[0030] This embodiment also provides a lithium fluoride carbon battery electrolyte, comprising lithium salt (LiClO4), ester solvents (dimethyl carbonate and propylene carbonate), ether solvents (ethylene glycol dimethyl ether), and vanadium chloride (trivalent). The ester solvent and ether solvent are a mixture of dimethyl carbonate, propylene carbonate, and ethylene glycol dimethyl ether in a volume ratio of 1:1:1. The ratio of LiClO4 to the mixed solvent is 1 mol:1 L. The preparation process of the lithium fluoride carbon battery electrolyte includes: mixing dimethyl carbonate, propylene carbonate, and ethylene glycol dimethyl ether evenly in a volume ratio of 1:1:1; weighing 1 L of the mixed solvent; adding 1 mol of LiClO4 and stirring to dissolve; then adding vanadium chloride (trivalent) to the mixture at 2.5% of the electrolyte mass; and continuing to stir to dissolve, thus obtaining the lithium fluoride carbon battery electrolyte.

[0031] This embodiment also provides a lithium fluoride carbon battery, using the aforementioned lithium fluoride carbon battery electrolyte, with a lithium sheet as the negative electrode and Celgard 2500 as the separator. The assembly process of the lithium fluoride carbon battery is as follows: fluoride carbon, conductive carbon black, and PVDF (polyvinylidene fluoride) are dissolved in N-methylpyrrolidone at a mass ratio of 8:1:1 and mixed evenly. The mixture is then coated into an electrode film with a thickness of 0.15 mm using a wet film preparation device, vacuum dried, and cut into electrode sheets with a diameter of 14 mm using a slicer. A lithium sheet is used as the negative electrode, Celgard 2500 is used as the separator, and 70 μL of electrolyte is added. The battery is then assembled into a button cell in an argon-filled glove box. A lithium fluoride carbon button cell is prepared using the aforementioned lithium fluoride carbon battery electrolyte, and electrochemical and temperature tests are performed on the battery. The battery is discharged at a 5C rate to 1V. A temperature sensor is attached to the center of the positive electrode side of the coin cell to detect changes in battery temperature. During the test, the battery's discharge capacity and the surface temperature of the positive electrode casing at the moment of discharge completion are recorded. The assembled coin cell has a discharge capacity of 778 mAh / g and a positive electrode casing temperature of 50.4℃.

[0032] Example 2 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with vanadium nitrate (trivalent). The assembled coin cell has a discharge capacity of 776 mAh / g and a positive electrode casing temperature of 55.7°C.

[0033] Example 3 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with vanadium sulfate (trivalent). The assembled button cell has a discharge capacity of 773 mAh / g and a positive electrode casing temperature of 56.0°C.

[0034] Example 4 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with niobium chloride (trivalent). The assembled coin cell has a discharge capacity of 757 mAh / g and a positive electrode casing temperature of 54.9°C.

[0035] Example 5 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with tantalum chloride (trivalent). The assembled coin cell has a discharge capacity of 762 mAh / g and a positive electrode casing temperature of 56.3°C.

[0036] Example 6 Following the method and requirements of Example 1, without changing other conditions, the only difference is that the amount of vanadium chloride (trivalent) added is changed from 2.5% to 10%. The assembled button cell has a discharge capacity of 770 mAh / g and a positive electrode casing temperature of 61.3°C.

[0037] Example 7 Following the method and requirements of Example 1, without changing other conditions, the only difference is that the amount of vanadium chloride (trivalent) added is changed from 2.5% to 1%. The assembled button cell has a discharge capacity of 768 mAh / g and a positive electrode casing temperature of 61.9°C.

[0038] Example 8 Following the method and requirements of Example 1, without changing other conditions, the only difference is that the amount of vanadium chloride (trivalent) added is changed from 2.5% to 0.1%. The assembled button cell has a discharge capacity of 765 mAh / g and a positive electrode casing temperature of 66.2°C.

[0039] Example 9 Following the method and requirements of Example 1, without changing other conditions, the only difference is that the amount of vanadium chloride (trivalent) added is changed from 2.5% to 20%. The assembled button cell has a discharge capacity of 762 mAh / g and a positive electrode casing temperature of 65.9°C.

[0040] Comparative Example 1 Following the requirements of Example 1, without changing other conditions or adding vanadium chloride (trivalent), the assembled button cell has a discharge capacity of 623 mAh / g and a positive electrode casing temperature of 86.2°C.

[0041] Comparing Example 1 with Comparative Example 1, it can be found that without adding group VB element electrolyte additives, it is impossible to achieve the purpose of promoting LiF prenucleation and reduce battery heat generation.

[0042] Comparative Example 2 Following the method and requirements of Example 1, without changing other conditions, the only difference is that the amount of vanadium chloride (trivalent) added is changed from 2.5% to 25%. The assembled button cell has a discharge capacity of 627 mAh / g and a positive electrode casing temperature of 79.8°C.

[0043] Comparing Example 1 and Comparative Example 2, it can be found that due to the excessive addition of vanadium chloride (trivalent), the impedance of the electrolyte increases, the Joule heat of the battery increases, and the heat generated during battery discharge increases.

[0044] Comparative Example 3 Following the method and requirements of Example 1, without changing other conditions, the only difference was that the amount of vanadium chloride (trivalent) added was changed from 2.5% to 0.05%. The assembled button cell had a discharge capacity of 616 mAh / g and a positive electrode casing temperature of 81.8°C.

[0045] Comparing Example 1 with Comparative Example 3, it can be found that due to the low amount of vanadium chloride (trivalent), the pre-nucleation process cannot be fully promoted, and the purpose of effectively reducing battery heat generation cannot be achieved.

[0046] Comparative Example 4 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with vanadium chloride (tetravalent). The assembled button cell has a discharge capacity of 635 mAh / g and a positive electrode casing temperature of 80.1°C.

[0047] Comparing Example 1 with Comparative Example 4, it can be found that due to the excessive oxidizing power of vanadium chloride (tetravalent), the structure of the electrolyte and electrode active materials is damaged, the internal resistance of the battery increases, the Joule heat of the battery increases, and the purpose of reducing battery heat generation cannot be achieved.

[0048] Comparative Example 5 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with vanadium chloride (divalent). The assembled button cell has a discharge capacity of 642 mAh / g and a positive electrode casing temperature of 80.4°C.

[0049] Comparing Example 1 with Comparative Example 5, it can be found that because the vanadium element in vanadium chloride (divalent) has too low a valence state, it cannot play a role in promoting the pre-nucleation process, resulting in no significant reduction in battery heat generation.

[0050] Comparative Example 6 Following the method and requirements of Example 1, without changing other conditions, the only difference is that vanadium chloride (trivalent) is replaced with vanadium acetate (trivalent). The assembled button cell has a discharge capacity of 651 mAh / g and a positive electrode casing temperature of 83.7°C.

[0051] Comparing Example 1 with Comparative Example 6, it can be found that since the anion of vanadium acetate (trivalent) is an organic anionic group, this group cannot exist stably in the electrolyte, which affects the performance of vanadium (trivalent) and cannot promote the LiF pre-nucleation process, thus failing to effectively solve the problem of excessive heat generation in the battery.

[0052] Comparative Example 7 Following the method and requirements of Example 1, without changing other conditions, the only difference was replacing vanadium chloride (trivalent) with molybdenum chloride (trivalent). The assembled coin cell had a discharge capacity of 648 mAh / g and a positive electrode casing temperature of 81.0℃. As shown in Comparative Example 7, although Group VIB elements can play a certain catalytic role, they cannot achieve the excellent effect of Group VB elements.

[0053] Comparative Example 8 Following the requirements of Example 1, without changing other conditions, the only difference was that in the preparation of the fluorinated carbon electrode, the same amount of vanadium chloride (trivalent) was added to the positive electrode active material as in Example 1, and vanadium chloride (trivalent) was not added during the preparation of the electrolyte. The discharge specific capacity of the assembled coin cell was 651 mAh / g, and the positive electrode casing temperature was 81.6℃. As can be seen from Comparative Example 8, during the preparation of the fluorinated carbon electrode, the specific capacity of the assembled coin cell decreased significantly, and a large amount of heat was generated during discharge. This was because in the initial stage of discharge, vanadium chloride (trivalent) was not fully dissolved (the local concentration of vanadium chloride (trivalent) between the positive electrodes was too high, and the vanadium chloride (trivalent) solution was in a supersaturated state, etc.), which increased the internal resistance between the electrode active materials, ultimately leading to a large amount of heat generation during battery discharge.

[0054] Unless otherwise specified, all figures appearing in this application specification and claims, such as temperature and time values, should not be construed as absolutely precise values. Due to the standard deviation of measurement techniques, the measured values ​​inevitably contain a certain degree of experimental error.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium fluoride carbon battery electrolyte additive, characterized in that, Inorganic salts including elements of group VB; wherein the elements of group VB are selected from one or more of V, Nb and Ta.

2. The lithium fluoride carbon battery electrolyte additive according to claim 1, characterized in that, The inorganic salts of the group VB elements are selected from one or more of the nitrates, chlorides, and sulfates of trivalent group VB elements.

3. A lithium fluoride carbon battery electrolyte, characterized in that, The lithium fluoride carbon battery electrolyte comprises lithium salt, ester solvent, ether solvent and trivalent group B salt; wherein the trivalent group B salt is selected from the lithium fluoride carbon battery electrolyte additives according to claim 1 or 2.

4. The lithium fluoride carbon battery electrolyte according to claim 3, characterized in that, The lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxaborate, lithium difluorooxaborate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, and lithium hexafluoroarsenate. And / or, the ester solvent is selected from one or more of dimethyl carbonate, propylene carbonate, ethylene carbonate, diethyl carbonate, and methyl ethyl carbonate; And / or, the ether solvent is selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, 1,2-dimethoxyethylene, 1,4-dioxocyclohexane, diethylene glycol dimethyl ether, and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether.

5. The lithium fluoride carbon battery electrolyte according to claim 3 or 4, characterized in that, The trivalent vanadium salt accounts for 0.1% to 20% of the total mass of the lithium fluoride carbon battery electrolyte; Preferably, the trivalent B group salt accounts for 1 to 10% of the total mass of the lithium fluoride carbon battery electrolyte.

6. The lithium fluoride carbon battery electrolyte according to any one of claims 3 to 5, characterized in that, The molar concentration of the lithium salt in the lithium fluoride carbon battery electrolyte is 0.01~10M; And / or, the volume ratio of the ester solvent to the ether solvent is 0.01 to 100:

1.

7. A lithium fluoride carbon battery, characterized in that, The lithium fluoride carbon battery includes a positive electrode, a negative electrode, a separator, and an electrolyte; the electrolyte is the lithium fluoride carbon battery electrolyte according to any one of claims 3 to 6.

8. The lithium fluoride carbon battery according to claim 7, characterized in that, The operating temperature of the lithium fluoride carbon battery is -40~150℃.

9. The lithium fluoride carbon battery according to claim 7 or 8, characterized in that, The allowable discharge rate of the lithium fluoride carbon battery during operation is 0.01~10C.

10. The lithium fluoride carbon battery according to any one of claims 7 to 9, characterized in that, The positive electrode contains fluorinated carbon; And / or, the negative electrode is a lithium negative electrode; And / or, the diaphragm includes any one of modified polypropylene diaphragm, modified polyethylene diaphragm, polyethylene diaphragm, polypropylene diaphragm, polytetrafluoroethylene diaphragm, and organic-inorganic composite diaphragm.