Electrolyte for alkali metal-thionyl chloride secondary battery and application thereof

Abstract

The invention belongs to the technical field of energy materials, further relates to the field of alkali metal batteries, and particularly relates to an electrolyte for an alkali metal-thionyl chloride secondary battery and application of the electrolyte. The electrolyte is salt capable of transmitting alkali metal ions, thionyl chloride and an additive; the additive is a salt of organic aniline cations. The additive is added into a basic electrolyte adopted by the alkali metal-thionyl chloride secondary battery. According to the present invention, with the introduced additive, the redox couple of the carbon positive electrode interface, which actually participates in the electrochemical reaction, can be changed, the potential and the capacity of the discharge platform under the large current density can be significantly improved, the voltage hysteresis phenomenon can be significantly improved, and the alkali metal-thionyl chloride secondary battery can obtain the excellent specific energy and the excellent energy efficiency. Compared with a comparison sample without addition of the additive, the battery using the additive provided by the invention has the advantages that the charge-discharge polarization is obviously reduced, and the discharge rate capability is improved. According to the battery using the additive provided by the invention, a primary battery is successfully converted into a secondary battery, and after 100 times of circulation, the cycle capacity retention rate of the secondary battery is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of energy materials, more specifically to the field of alkali metal batteries, and specifically relates to an electrolyte for an alkali metal-thionyl chloride secondary battery and an application thereof. Background Art

[0002] The rapid growth of the global economy has increased the demand for high-energy, high-safety and long-life batteries. However, the energy density of traditional lithium-ion battery systems has reached its limit, and the development of batteries has entered a bottleneck stage and cannot meet current needs. Therefore, the development of new batteries with high energy density, high safety and high stability will help to meet the growing challenge of large-scale energy storage. Looking back at past research on alkali metal ion batteries, mature primary batteries have gradually aroused strong interest, such as alkali metal-thionyl chloride primary batteries. This commercial primary battery has a specific energy of more than 700Wh / Kg, a wide operating temperature range (from -60°C to 150°C), is not easy to self-discharge during storage (shelf life can reach 10-20 years), and has stable voltage during the discharge process. It is widely used in military industry, oil and gas production, and big data infrastructure.

[0003] Regarding its mechanism, let’s take the lithium-thionyl chloride (Li-SOCl2) battery as an example. In the Li-SOCl2 battery, conductive carbon is the positive electrode, lithium metal is the negative electrode, and SOCl2 serves as both the electrolyte solvent and the discharge active substance. Its discharge reaction mechanism is: 4Li + +4e - +2SOCl2→4LiCl+S+SO2↑. As discharge products, some sulfur and sulfur dioxide can dissolve in the thionyl chloride electrolyte. However, lithium chloride is insoluble in the electrolyte and will deposit on the conductive carbon positive electrode to form a lithium chloride film, which will completely passivate the positive electrode and cause the battery to stop discharging. The charging reaction mechanism is: 2LiCl-2e - →2Li + +Cl2↑. That is, the lithium chloride deposited on the carbon decomposes into chlorine gas, which reacts with the aforementioned products of sulfur and sulfur dioxide, and further reacts and converts into thionyl chloride to achieve reversibility, but the conversion efficiency is low.

[0004] In terms of primary discharge, alkali metal-thionyl chloride batteries have problems with poor rate performance and voltage hysteresis. Since thionyl chloride reduction will produce thionyl chloride free radicals, which will dimerize and affect subsequent reduction, it is difficult to achieve high-rate discharge. The lithium chloride produced by decomposition will be over-densified, resulting in voltage hysteresis and thus shortened discharge life. At present, additives such as metal porphyrins are usually introduced, whose local conjugated system can enhance the electron reduction of SOCl2 and adsorb free radicals to avoid dimerization; at the same time, it can also adsorb lithium ions to avoid the passivation film being too dense and having a hysteresis voltage. However, metal porphyrin additives are expensive and difficult to synthesize.

[0005] In terms of secondary reversibility, due to the difficulty in converting the reaction pathway mediated by chlorine, it cannot become a secondary battery, that is, it is not rechargeable. However, recently, based on the perspective of regulating the positive electrode structure, researchers (Nature 596, 525-530, 2021; JACS144, 22505-22513, 2022; Joule 7, 515-528, 2023) have successfully realized a reversible alkali metal-chlorine battery based on thionyl chloride (a reversible alkali metal-thionyl chloride battery in a non-traditional sense). Specifically, regardless of whether chlorine can be converted into thionyl chloride, the focus is on designing an ingenious positive electrode structure to store chlorine, directly using chlorine as a subsequent redox couple, and achieving reversibility through the conversion between chlorine and alkali metal chlorides.

[0006] At present, there is no research on developing electrolyte additives with redox mediators to improve discharge and reversibility at the same time, that is, introducing additives to achieve the development of high-power secondary batteries. Therefore, it is of great significance to develop new additives for alkali metal-thionyl chloride secondary batteries. Summary of the invention

[0007] In order to solve the problems of voltage hysteresis and difficulty in charging of alkali metal-thionyl chloride secondary batteries, the present invention provides an electrolyte for alkali metal-thionyl chloride secondary batteries and application thereof.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] An electrolyte for an alkali metal-thionyl chloride secondary battery comprises a salt capable of transmitting alkali metal ions, thionyl chloride and an additive; the additive is a salt of an organic aniline cation.

[0010] The concentration of the additive in the electrolyte is 0.05-1.0 mol / L, preferably 0.1-0.5 mol / L; the concentration of the salt in the electrolyte is 0.5-4 mol / L, preferably 1-2 mol / L.

[0011] The purity of the organic amine salt is ≥98%.

[0012] The organic aniline cation is one or more of aniline, benzylamine, phenethylamine, N-methylbenzylamine, N-ethylbenzylamine, and N-phenylaniline (diphenylamine) cations; the preferred additive is one or more of benzylamine, phenethylamine, and N-methylbenzylamine cations; and the anion coordinated by the organic aniline cation is a halogen ion or a tetrachloroaluminate ion.

[0013] The salt capable of transmitting alkali metal ions is an alkali metal salt and / or aluminum trichloride.

[0014] The purity of the salt capable of transporting alkali metal ions is ≥ 99%.

[0015] The anion of the alkali metal salt includes one or more of tetrachloroaluminate, tetrafluoroborate, dioxalatoborate, difluorooxalatoborate, bistrifluoromethylsulfonyl imide, trifluoromethylsulfonate, bisfluorosulfonyl imide, tetrachlorogallate, and perchlorate; the cation of the alkali metal salt is lithium ion, sodium ion, or potassium ion.

[0016] Preparation of the electrolyte:

[0017] (1) dissolving the desired transportable alkali metal ion salt in thionyl chloride to obtain a uniform solution;

[0018] (2) Dissolving the additive in the above solution and stirring evenly to obtain the desired electrolyte.

[0019] An application of the electrolyte is application of the electrolyte in an alkali metal-thionyl chloride secondary battery.

[0020] Furthermore, the electrolyte with the additive added is applied to the electrolyte of an alkali metal-thionyl chloride secondary battery with a carbon material as a positive electrode.

[0021] An alkali metal-thionyl chloride secondary battery comprises a positive electrode, a negative electrode and the electrolyte.

[0022] The active material of the positive electrode is one or more of graphite, Super P, acetylene black, Ketjen black, carbon nanotubes, and carbon fibers; the current collector of the positive electrode is stainless steel; and the negative electrode is one or more of lithium metal, sodium metal, potassium metal, lithium silicon alloy, sodium silicon alloy, lithium tin alloy, sodium tin alloy, and lithium sodium alloy.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The organic amine salt additive proposed in the present invention can effectively increase the discharge voltage of the battery and can withstand high-rate discharge. In the process of preparing the electrolyte, the organic amine cation in the electrolyte will undergo an electrophilic aromatic substitution reaction with the solvent thionyl chloride, and the thionyl chloride group will be connected to the aniline structure. There are types of single-substituted and multi-substituted thionyl chloride groups; in the specific selection of anions, a diphenylamine sulfoxide cation structure can also be directly formed. Regarding its discharge reduction mechanism, specifically, for additives containing organic amine salts, the additive molecules adsorbed on carbon gain electrons and undergo reduction, decomposing into sulfoxyl radicals, chloride ions, and aniline anions containing thionyl chloride groups. The sulfoxyl radicals decompose into sulfur dioxide and sulfur through dimerization, the chloride ions directly combine with lithium ions and deposit on the carbon, and the aniline anions will attack the thionyl chloride solvent to reconnect the thionyl chloride group. In certain cases, the thionyl chloride groups on the aniline anions can also be completely detached and reconnected to the thionyl chloride groups. In short, the additive has the characteristics of a redox mediator during discharge reduction.

[0025] 2. The organic amine salt additive proposed by the present invention can realize the secondary use of the battery, and significantly reduce the charging voltage of the battery, thereby improving energy efficiency. The organic amine salt additive has the properties of a redox mediator for lithium oxygen batteries. Specifically, the polysubstituted thionyl chloride aniline cation will be oxidized at a lower potential, and the oxidized additive will directly decompose the alkali metal chloride (discharge product) to generate thionyl chloride and aniline cations that have lost a certain number of thionyl chloride groups. The aniline cation will react with sulfur and sulfur dioxide to regenerate the polysubstituted thionyl chloride aniline cation. Under certain circumstances, unsubstituted phenyl cations can also be directly formed, and the above-mentioned subsequent reactions will occur. In addition, the additive can achieve a cycle life with a relatively long stable time, which means that the additive does have the advantage of low cycle loss.

[0026] 3. The preparation process of the present invention by introducing additives into the alkali metal-thionyl chloride electrolyte is simple, the preparation cycle is short, the preparation equipment is simple and easy to operate, and it is convenient for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a charge and discharge curve diagram of the additive-free electrolyte provided in Example 1 of the present invention.

[0028] Figure 2 This is a charge and discharge curve diagram of the electrolyte with additives provided in Example 1 of the present invention.

[0029] Figure 3 This is a discharge curve diagram of the additive-free electrolyte provided in Example 1 of the present invention at different currents.

[0030] Figure 4This is a discharge curve diagram of the electrolyte with additives at different currents provided in Example 1 of the present invention.

[0031] Figure 5 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 1 of the present invention.

[0032] Figure 6 This is a charge and discharge curve diagram of the electrolyte with additives provided in Example 2 of the present invention.

[0033] Figure 7 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 2 of the present invention.

[0034] Figure 8 This is a charge and discharge curve diagram of the electrolyte with additives provided in Example 3 of the present invention.

[0035] Fig. 9 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 3 of the present invention.

[0036] Fig.10 This is a charge and discharge curve diagram of the additive-free electrolyte provided in Example 4 of the present invention.

[0037] Fig.11 This is a charge and discharge curve diagram of the electrolyte with additives provided in Example 4 of the present invention.

[0038] Fig.12 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 4 of the present invention.

[0039] Fig.13 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 5 of the present invention.

[0040] Fig.14 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 5 of the present invention.

[0041] Fig.15 The cycle diagram of the battery corresponding to the electrolyte with additives provided in Example 5 of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below in conjunction with the examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0043] The reagents used in the following examples are all commercially available products, wherein the purity of the organic amine salt is ≥98%; the purity of the salt capable of transmitting alkali metal ions is ≥99%; and the purity of SOCl2 is ≥99.5%.

[0044] The additive of the present invention is added to the basic electrolyte used in the alkali metal-thionyl chloride secondary battery. The additive introduced by the present invention changes the redox couple actually participating in the electrochemical reaction at the carbon positive electrode interface, can significantly improve the discharge platform potential and capacity at high current density, significantly improve the voltage hysteresis of the alkali metal-thionyl chloride secondary battery, and thus enable the alkali metal-thionyl chloride secondary battery to obtain a better specific energy and energy efficiency. Compared with the control sample without the additive, the battery using the additive provided by the present invention has a significantly reduced charge and discharge polarization, improved rate performance, and a greatly improved cycle stability. After 100 cycles, the cycle capacity retention rate is significant.

[0045] The electrochemical performance testing conditions in the following examples are:

[0046] (1) Single discharge rate test: discharge cut-off voltage is 2V, discharge current is 1A g -1 , 20A g -1 、30A g -1 .

[0047] (2) Cyclic test: using a high-load cathode (10 mg cm -2 ), the cycle data charge cut-off capacity is 6mA cm -2 , discharge cut-off voltage is 2V, discharge current is 5mA cm -2 The charge and discharge voltage curve is displayed by taking one circle.

[0048] Some cycle comparison data are for low-load cathode (1 mg cm -2 ), the charging cut-off capacity is 1000mAh g -1 , the discharge cut-off voltage is 2V, and the discharge current is 1A g -1 .

[0049] Example 1

[0050] Control group battery:

[0051] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain an electrolyte;

[0052] (2) Battery assembly: In a conventional manner, the Super P material was scraped onto a stainless steel foil as a working electrode, a metal lithium sheet was used as a counter electrode, and a battery was assembled with the above electrolyte as a control group, and its electrochemical performance was tested ( Figure 1 and Figure 3 ).

[0053] Experimental battery:

[0054] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution, and then 0.2 mol / L of phenylethylamine tetrachloroaluminate was added to the mixed solution to obtain an electrolyte.

[0055] (2) Battery assembly: In a conventional manner, the Super P material was scraped onto a stainless steel foil as a working electrode, a metal lithium sheet was used as a counter electrode, and the battery was assembled with the above electrolyte as an experimental group, and its electrochemical performance was tested ( Figure 2 , Figure 4 and Figure 5 ).

[0056] The electrochemical performance of the above experimental group and control group batteries were compared. Figure 1-2 It can be seen that due to the higher thermodynamic reduction potential of the additive and the improved voltage hysteresis phenomenon of the adsorption of lithium ions by the charge-rich π bond system, the discharge voltage of the battery is increased, and the energy density of the battery is increased. Figure 3-4 It can be seen that the preferential electron reduction can avoid the dimerization hindrance during the electrochemical reduction of thionyl chloride, which can improve the rate performance of the battery and facilitate the high-power operation of the battery. In the high-rate test, the discharge platform voltage is always higher than 3V (lower than 2.7V without additives), and the capacity is higher than 3000mAh / g (only about 1500mAh / g without additives). Figure 5 It can be seen that the additive can form thionyl chloride cations after oxidation, which can then directly react with lithium chloride to achieve stable decomposition of the passivation film and avoid the occurrence of inefficient conversion pathways mediated by chlorine. This improves the cycle stability of the battery and increases the battery life. It can be stably cycled for 100 times, and the cycle capacity retention rate can reach 99% ( Figure 5 ), while the high-load positive electrode without additives cannot be reversibly cycled ( Figure 1 ).

[0057] Example 2

[0058] Control group battery:

[0059] (1) Preparation of electrolyte: Add 29 g of aluminum chloride to 100 mL of distilled and purified SOCl2 and stir for 2 h to obtain an electrolyte;

[0060] (2) Battery assembly: In a conventional manner, acetylene black material was scraped onto a stainless steel foil as a working electrode, a metal lithium sheet was used as a counter electrode, and a battery was assembled with the above electrolyte as a control group, and its electrochemical performance was tested.

[0061] Experimental battery:

[0062] (1) Preparation of electrolyte: 29 g of aluminum chloride was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution, and then 0.2 mol / L of benzylamine chloride was added to the mixed solution to obtain an electrolyte.

[0063] (2) Battery assembly: According to the conventional method, acetylene black material was scraped onto stainless steel foil as the working electrode, and the metal lithium sheet was used as the counter electrode. The battery was assembled with the above electrolyte as the experimental group, and its electrochemical performance was tested ( Figure 6 , Figure 7 ).

[0064] The experimental group also achieved a significant reduction in charge and discharge voltage polarization, and its cycle stability was also greatly improved. After 100 cycles, the cycle capacity retention rate could reach 99%.

[0065] Example 3

[0066] Control group battery:

[0067] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate and 29 g of aluminum trichloride were added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain an electrolyte;

[0068] (2) Battery assembly: In a conventional manner, the Ketjen black material was scraped onto a stainless steel foil as a working electrode, a metal lithium sheet was used as a counter electrode, and a battery was assembled with the above-mentioned electrolyte as a control group, and its electrochemical performance was tested.

[0069] Experimental battery:

[0070] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate and 42 g of aluminum trichloride were added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution, and then 0.2 mol / L of phenethylamine iodine was added to the mixed solution to obtain an electrolyte.

[0071] (2) Battery assembly: In a conventional manner, the Ketjen black material was scraped onto a stainless steel foil as a working electrode, a metal lithium sheet was used as a counter electrode, and the battery was assembled with the above electrolyte to form an experimental group, and its electrochemical performance was tested ( Figure 8 , Fig. 9 ).

[0072] The improvement effect of organic amine salts with iodine anions in secondary batteries is equivalent to the effect of adding inorganic iodine as an additive on the basis of the effect of organic amine cations (iodine anions will react with solvents to transform into iodine molecules). Therefore, compared with inorganic iodine additives, while ensuring the advantage of reversible sequence, it can further improve energy efficiency. Figure 8The first high potential platform is derived from the improvement of organic amine cations. The latter low potential platform is the result of the interaction between iodine and thionyl chloride at the interface to form a complex discharge with faster kinetics. The cycle stability of the experimental group is also improved. After 100 cycles, the cycle capacity retention rate can reach 99.2%.

[0073] Example 4

[0074] Control group battery:

[0075] (1) Preparation of electrolyte: 42 g of sodium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain an electrolyte;

[0076] (2) Battery assembly: According to the conventional method, acetylene black material was scraped onto stainless steel foil as the working electrode, and the metal sodium sheet was used as the counter electrode. The battery was assembled with the above electrolyte as the control group, and its electrochemical performance was tested ( Fig.10 ).

[0077] Experimental battery:

[0078] (1) Preparation of electrolyte: 42 g of sodium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution, and then 0.2 mol / L of benzylamine chloride was added to the mixed solution to obtain an electrolyte.

[0079] (2) Battery assembly: According to the conventional method, acetylene black material was scraped onto stainless steel foil as the working electrode, and the metal sodium sheet was used as the counter electrode. The battery was assembled with the above electrolyte as the experimental group, and its electrochemical performance was tested ( Fig.11 , Fig.12 ).

[0080] The experimental group also achieved a significant reduction in charge and discharge voltage polarization, and its cycle stability was greatly improved. After 100 cycles, the cycle capacity retention rate reached 99.1%.

[0081] Example 5

[0082] Control group battery:

[0083] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution, and then 0.2 mol / L of iodine was added to the mixed solution to obtain an electrolyte;

[0084] (2) Battery assembly: According to the conventional method, acetylene black material was scraped onto stainless steel foil as the working electrode, and the metal lithium sheet was used as the counter electrode. The battery was assembled with the above electrolyte as the control group, and its electrochemical performance was tested ( Fig.13 ).

[0085] Experimental battery:

[0086] (1) Preparation of electrolyte: 42 g of lithium tetrachloroaluminate was added to 100 mL of distilled and purified SOCl2 and stirred for 2 h to obtain a mixed solution; 0.2 mol / L of phenethylamine chloride was added to the mixed solution to obtain electrolyte No. 1; 0.2 mol / L of phenethylamine iodine was added to the mixed solution to obtain electrolyte No. 2.

[0087] (2) Battery assembly: In a conventional manner, acetylene black material was scraped onto stainless steel foil as the working electrode, and the metal lithium sheet was used as the counter electrode. The battery was assembled with the above electrolyte as the experimental group, and its electrochemical performance was tested. The battery test results corresponding to electrolyte No. 1 are Fig.14 The battery test results corresponding to the No. 2 electrolyte are: Fig.15 .

[0088] In comparison, compared with inorganic iodine additives and phenylethylamine iodine additives, the battery cycle after the introduction of phenylethylamine chloride additives is more stable, and the capacity retention rate can reach 99% after 200 cycles. Iodine may be corrosive to the battery, so the battery cycle performance begins to deteriorate after 100 cycles. Specifically, organic aniline cations play a major role in improving the battery cycle.

[0089] As can be seen from the above embodiments, the introduction of the additive of the present invention changes the redox couple at the carbon positive electrode interface, can significantly improve the discharge platform at high current density and improve the battery polarization, so that the alkali metal-thionyl chloride secondary battery has a good discharge voltage and discharge capacity, and significantly improves the voltage hysteresis of the alkali metal-thionyl chloride secondary battery. The battery using the additive provided by the present invention has a significantly improved discharge voltage, improved rate performance, and greatly improved cycle stability compared to the control sample without the additive. After 100 cycles, the cycle capacity retention rate is significant.

[0090] The above are only preferred specific embodiments of the present invention, but the protection scope of the invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An electrolyte for an alkali metal-thionyl chloride secondary battery, characterized in that: The electrolyte comprises a salt capable of transmitting alkali metal ions, thionyl chloride and an additive; the additive is a salt of an organic aniline cation.

2. The electrolyte for alkali metal-thionyl chloride secondary battery according to claim 1, characterized in that: The concentration of the additive in the electrolyte is 0.05-1.0 mol / L; the concentration of the salt in the electrolyte is 0.5-4 mol / L.

3. The electrolyte for alkali metal-thionyl chloride secondary battery according to claim 1, characterized in that: The organic aniline cation is one or more of aniline, benzylamine, phenethylamine, N-methylbenzylamine, N-ethylbenzylamine, and N-phenylaniline (diphenylamine) cations; and the anion coordinated by the organic aniline cation is a halogen ion or a tetrachloroaluminate ion.

4. The electrolyte for alkali metal-thionyl chloride secondary battery according to claim 1, characterized in that: The salt capable of transmitting alkali metal ions is an alkali metal salt and / or aluminum trichloride.

5. The electrolyte for alkali metal-thionyl chloride secondary battery according to claim 4, characterized in that: The anion of the alkali metal salt includes one or more of tetrachloroaluminate, tetrafluoroborate, dioxalatoborate, difluorooxalatoborate, bistrifluoromethylsulfonyl imide, trifluoromethylsulfonate, bisfluorosulfonyl imide, tetrachlorogallate, and perchlorate; the cation of the alkali metal salt is lithium ion, sodium ion, or potassium ion.

6. An application of the electrolyte according to claim 1, characterized in that: Application of the electrolyte in an alkali metal-thionyl chloride secondary battery.

7. An alkali metal-thionyl chloride secondary battery, characterized in that: The battery comprises a positive electrode, a negative electrode and the electrolyte according to claim 1.

8. The alkali metal-thionyl chloride secondary battery according to claim 7, characterized in that: The active material of the positive electrode is one or more of graphite, Super P, acetylene black, Ketjen black, carbon nanotubes, and carbon fibers; the current collector of the positive electrode is stainless steel; and the negative electrode is one or more of lithium metal, sodium metal, potassium metal, lithium silicon alloy, sodium silicon alloy, lithium tin alloy, sodium tin alloy, and lithium sodium alloy.

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