A thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization and its application method

Abstract

This invention belongs to the field of thermoelectric conversion technology, specifically a rechargeable thermo-regenerative electrochemical cycle battery based on thermosensitive crystallization-enhanced thermoelectric potential and its usage method. It includes a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte, and a cation exchange membrane. The electrode potentials in the positive and negative electrolytes are equal at an intermediate temperature, and the battery voltage is 0V. The positive and / or negative electrolytes also contain additives that induce thermosensitive crystallization of oxide or reduced ions in the electrolyte. The additives induce the oxide or reduced ions to dissolve at a first temperature and crystallize at a second temperature. The battery thermoelectric potential is increased through this thermosensitive crystallization process. The proposed thermo-regenerative electrochemical cycle battery requires no electrical assistance and can discharge at both high and low temperatures. The high thermoelectric potential based on the thermosensitive crystallization effect improves the battery's operating voltage, capacity, and thermoelectric conversion efficiency, achieving efficient recovery and conversion of low-grade heat.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectrochemical conversion technology, specifically relating to a non-rechargeable thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization and its usage method. Background Technology

[0002] Low-grade waste heat (<100℃) is widely present in the environment, industrial power plants, solar energy, and geothermal energy fields. Recycling this type of low-grade heat energy helps reduce carbon emissions, but due to its dispersed distribution and small temperature difference with the environment, efficient recycling is very difficult. In recent years, electrochemical thermoelectric conversion devices with high ionic thermoelectric potentials, including thermally diffusing ion capacitors, thermochemical batteries, and thermal regenerative electrochemical cycles (TREC), have been proposed for recycling low-grade heat energy. Among these technologies, TREC batteries show great application potential due to their ability to achieve a relatively high Carnot efficiency exceeding 10%. A TREC battery is an isothermal device whose operating principle is based on the temperature dependence of the anodic and cathode redox couple reactions, and its open-circuit voltage V... oc The change in battery thermoelectric potential with temperature is defined as α. cell :

[0003]

[0004] Where E + and E - These are the potentials of the positive and negative electrode reaction couples, respectively; α + and α - These are the thermoelectric potentials of the positive and negative electrode reactions, respectively. Therefore, TREC batteries can convert temperature differences into electrical work output by charging and discharging at different temperatures. However, this process requires electrical assistance for battery regeneration; ideal TREC batteries for recovering low-grade heat regeneration rely solely on thermal energy. Rechargeable TREC batteries do not require electrical assistance. However, the operation of rechargeable TREC batteries is achieved by limiting the voltage and capacity range, thus limiting energy output. A higher battery thermoelectric potential is preferred for optimal energy output. However, the reported thermoelectric potentials of rechargeable TREC batteries are generally less than 2 mV / K. For example, the positive and negative electrode pairs use Fe(CN)6... 3- / Fe(CN)6 4- The thermoelectric potential of the Prussian blue, non-rechargeable TREC battery is only -1.45mV / K, based on I3 - / I - (+)||Fe(CN)6 3- / Fe(CN)6 4- The thermoelectric potential of the non-rechargeable TREC battery (-) is 1.8 mV / K. The recently proposed Fe(CN)6... 3 / Fe(CN)6 4-The thermoelectric potential of (+)||FePO4 / LiFePO4(-)-based rechargeable TREC batteries is only -1.84 mV / K, which results in low thermoelectric conversion efficiency in currently reported rechargeable devices. Therefore, developing rechargeable TREC batteries with high thermoelectric potential is key to improving battery energy output and thermoelectric conversion efficiency. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a rechargeable thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystal and its usage method, so as to solve the problems of low thermoelectric potential, low capacity utilization, limited energy output and low thermoelectric conversion efficiency of the current rechargeable thermo-regenerative electrochemical cycle battery, and achieve the technical effect of efficient recovery and conversion of low-grade heat without the need for power assistance.

[0006] According to a first aspect of the present invention, a rechargeable thermal regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization is provided. The thermal regenerative electrochemical cycle battery includes a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte, and a cation exchange membrane; the electrode potentials of the redox couple in the positive and negative electrolytes are at an intermediate temperature T. m The battery voltage is 0V, and the positive and / or negative electrolytes also contain additives that induce thermosensitive crystallization of oxidized or reduced ions in the electrolyte. The additives induce the oxidized or reduced ions to dissolve at a first temperature T1 and crystallize and precipitate at a second temperature T2. The battery thermoelectric potential is increased through the thermosensitive crystallization process.

[0007] The intermediate temperature T m The electrode potentials of the positive and negative electrolytes were calibrated at different temperatures, and the relationship curves between the positive and negative electrolyte electrode potentials and temperature were plotted. The temperature at the intersection of the positive and negative electrolyte electrode potential-temperature curves was recorded as the intermediate temperature T. m The temperature at which the crystalline precipitate completely dissolves is the first temperature T1; the temperature T... m Both T1 and T2, measured in degrees Celsius, satisfy the following condition: T1 > T2. m T2 = 2T m -T1.

[0008] Preferably, when the active material in the positive electrode electrolyte is K3Fe(CN)6 / K4Fe(CN)6, the active material in the negative electrode electrolyte is KFe Ⅱ Fe Ⅲ(CN)6 (Prussian Blue); when the active material in the positive electrode electrolyte is KI3 / KI, the active material in the negative electrode electrolyte is K3Fe(CN)6 / K4Fe(CN)6.

[0009] Preferably, when the active material in the positive electrode electrolyte is K3Fe(CN)6 / K4Fe(CN)6, the additive is a salt containing guanidine ions, tetraethylammonium ions or 1-ethyl-3-methylimidazolium cations, or an organic solvent such as ethanol, methanol or acetonitrile; when the active material in the positive electrode electrolyte is KI3 / KI, the additive is cesium chloride or α-cyclodextrin.

[0010] Preferably, the salt containing guanidine ions is guanidine hydrochloride, guanidine sulfate, or guanidine nitrate; the salt containing tetraethylammonium ions is tetraethylammonium chloride or tetraethylammonium bromide; and the salt containing 1-ethyl-3-methylimidazolium ions is 1-ethyl-3-methylimidazolium chloride.

[0011] Preferably, the battery is a static battery or a flow battery.

[0012] Preferably, when the battery is a flow battery, the positive electrode and the negative electrode are respectively provided with electrolyte channels, and the electrolyte channels are serpentine channels, comb-shaped channels, or spiral channels.

[0013] According to another aspect of the present invention, a method for using the recharge-free thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization is provided, the specific operation steps of which are as follows:

[0014] (1) The electrode potentials of the positive and negative electrolytes at different temperatures were calibrated respectively, and the relationship curves between the electrode potentials of the positive electrolyte and temperature and the electrode potentials of the negative electrolyte were plotted. The temperature at the intersection of the electrode potentials of the positive and negative electrolytes was recorded as the intermediate temperature T. m ;

[0015] (2) The temperature at which the crystal precipitate in the positive or negative electrolyte completely dissolves is denoted as the first temperature T1, and the temperature at which the crystal precipitate in the positive or negative electrolyte is denoted as the second temperature T2; the T... m Both T1 and T2, measured in degrees Celsius, satisfy the following condition: T1 > T2. m T2 = 2T m -T1, determining the operating temperature range of the battery as T2 to T1;

[0016] (3) The difference between the slope of the positive electrode potential versus temperature curve and the slope of the negative electrode potential versus temperature curve is the thermoelectric potential of the battery, and the battery is kept at the intermediate temperature T. mWhen the battery thermoelectric potential is greater than zero, the temperature is reduced to T2. At this time, the battery voltage is negative. The positive and negative terminals of the battery are switched, and then the battery is discharged until the battery voltage is 0V. After the discharge is completed, the battery is short-circuited.

[0017] (4) Switch the positive and negative terminals of the battery again, then heat the battery to T1, and discharge it again until the battery voltage is 0V. After the discharge is finished, short-circuit the battery. Repeat steps (3) and (4) in this way.

[0018] According to another aspect of the present invention, a method for using the recharge-free thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization is provided, the specific operation steps of which are as follows:

[0019] S1 calibrates the electrode potentials of the positive and negative electrolytes at different temperatures, and plots the relationship curves between the positive and negative electrolyte electrode potentials and temperature. The temperature at the intersection of these two curves is recorded as the intermediate temperature T. m ;

[0020] S2 is defined as the first temperature T1, where the temperature at which the crystal precipitate in the positive or negative electrolyte completely dissolves, and the second temperature T2, where the temperature at which the crystal precipitate in the positive or negative electrolyte crystallizes. m Both T1 and T2, measured in degrees Celsius, satisfy the following condition: T1 > T2. m T2 = 2T m -T1, determining the operating temperature range of the battery as T2 to T1;

[0021] S3. The difference between the slope of the positive electrode potential versus temperature curve and the slope of the negative electrode potential versus temperature curve is the thermoelectric potential of the battery, and the battery is kept at the intermediate temperature T. m When the battery thermoelectric potential is less than zero, the temperature is raised to the first temperature T1. At this time, the battery voltage is negative. The positive and negative terminals of the battery are switched, and then the battery is discharged until the battery voltage is 0V. After the discharge is completed, the battery is short-circuited.

[0022] S4 Then, after cooling the battery to the second temperature T2, discharge it again until the battery voltage is 0V. After the discharge is completed, short-circuit the battery. Repeat steps S3 and S4 in this way.

[0023] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0024] 1. The thermal regenerative electrochemical cycle battery proposed in this invention does not require electrical assistance. By matching the standard electrode potentials of the positive and negative redox couples, the voltage of the thermal regenerative electrochemical cycle battery is made to be 0V at the intermediate temperature. In this way, both heating and cooling will generate non-zero electromotive force, so that discharge can be achieved at both high and low temperatures, and the direction of the current is opposite. Thus, a regenerative electrochemical cycle without charging is realized.

[0025] 2. The positive and / or negative electrolytes of the present invention also contain additives, which can induce the oxidation or reduction ions in the positive and / or negative electrolytes to crystallize and precipitate at low temperatures and dissolve at high temperatures. This thermosensitive crystallization effect enhances the entropy change of the redox couple, resulting in a higher thermoelectric potential of the battery. This improves the battery's operating voltage and capacity, thereby improving the battery's energy output and thermoelectric conversion efficiency.

[0026] 3. The rechargeable thermo-regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization of the present invention has universality. In addition to being applied to static batteries, it can also be used to construct flow batteries, thereby further improving the power and efficiency of the thermo-regenerative electrochemical cycle battery. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the non-rechargeable thermal regeneration electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystals provided by the present invention.

[0028] Figure 2 These are the electrode potential-temperature curves of the positive and negative electrolytes of the non-rechargeable thermal regeneration electrochemical cycle battery provided by this invention.

[0029] Figure 3 This invention demonstrates the effect of the additive provided by the present invention on Fe(CN)6. 3- / Fe(CN)6 4- The effect of thermoelectric potential, where thermoelectric potential is the slope of the electrode potential-temperature curve.

[0030] Figure 4 These are images of the negative electrode electrolyte provided in Embodiment 1 of the present invention at 25°C and 55°C, wherein the precipitate is completely dissolved at 55°C.

[0031] Figure 5 (a) is a temperature-entropy diagram of the thermo-regenerative electrochemical cycle enhanced by thermosensitive crystallization; (b) is a comparison diagram of the regenerative electrochemical cycle of batteries with and without guanidine salts without charging.

[0032] Reference numerals: 1. Current collector; 2. Positive electrolyte; 3. Negative electrolyte; 4. Crystallization precipitate; 5. Positive electrode; 6. Negative electrode; 7. Storage tank; 8. Screw; 9. Cation exchange membrane. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0034] According to a first aspect of the present invention, a rechargeable thermal regenerative electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization is provided. The thermal regenerative electrochemical cycle battery includes a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte, and a cation exchange membrane; the electrode potentials of the redox couple in the positive and negative electrolytes are at an intermediate temperature T. m The battery voltage is 0V, and the positive and / or negative electrolytes also contain additives that induce thermosensitive crystallization of oxidized or reduced ions in the electrolyte. The additives induce the oxidized or reduced ions to dissolve at a first temperature T1 and crystallize and precipitate at a second temperature T2. The battery thermoelectric potential is increased through the thermosensitive crystallization process.

[0035] The intermediate temperature T m The electrode potentials of the positive and negative electrolytes were calibrated at different temperatures, and the relationship curves between the positive and negative electrolyte electrode potentials and temperature were plotted. The temperature at the intersection of the positive and negative electrolyte electrode potential-temperature curves was recorded as the intermediate temperature T. m The temperature at which the crystalline precipitate completely dissolves is the first temperature T1; the temperature T... m Both T1 and T2, measured in degrees Celsius, satisfy the following condition: T1 > T2. m T2 = 2T m -T1.

[0036] In some embodiments, when the positive electrode electrolyte is a mixture of K3Fe(CN)6 and K4Fe(CN)6, the negative electrode electrolyte is KFe Ⅱ Fe Ⅲ (CN)6; when the positive electrode electrolyte is a mixture of KI3 and KI, the negative electrode electrolyte is a mixture of K3Fe(CN)6 and K4Fe(CN)6.

[0037] In some embodiments, the additive is a salt containing guanidine ions, tetraethylammonium ions, or 1-ethyl-3-methylimidazolium cations, or an organic solvent such as ethanol, methanol, or acetonitrile, cesium chloride, and α-cyclodextrin.

[0038] In some embodiments, the guanidine-containing salt is guanidine hydrochloride, guanidine sulfate, or guanidine nitrate; the tetraethylammonium ion salt is tetraethylammonium chloride or tetraethylammonium bromide; and the salt containing 1-ethyl-3-methylimidazolium ion is 1-ethyl-3-methylimidazolium chloride.

[0039] In some embodiments, the positive and negative electrolytes further contain KCl supporting electrolyte.

[0040] In some embodiments, the battery is a static battery or a flow battery.

[0041] In some embodiments, when the battery is a flow battery, the positive and negative electrodes of the battery are respectively provided with electrolyte flow channels to ensure efficient electrolyte flow.

[0042] In some embodiments, the electrolyte flow channel is a serpentine flow channel, a comb-shaped flow channel, or a spiral flow channel.

[0043] In some embodiments, the positive and negative electrodes are selected from platinum sheets, graphite felt, carbon paper, carbon cloth, carbon nanotubes, and Prussian blue.

[0044] In some embodiments, the cation exchange membrane is selected from the Nafion series, Fumasep series, and Selemion series.

[0045] Example 1

[0046] A rechargeable, thermally regenerating electrochemical cycle battery based on the thermoelectric potential enhancement of thermosensitive crystallization has the following structure: Figure 1 As shown. KI3 / KI and K3Fe(CN)6 / K4Fe(CN)6, with similar standard electrode potentials, were selected as the positive and negative electrode electrolytes, respectively. Guanidine hydrochloride (GdmCl) was added to the negative electrode electrolyte to induce the thermosensitive crystallization of K4Fe(CN)6, thereby enhancing the Fe(CN)6… 3- / Fe(CN)6 4- The thermoelectric potential is determined by adding guanidine hydrochloride to the positive electrode electrolyte at the same concentration as the negative electrode to balance the guanidine ion concentration. The concentrations of the positive and negative electrode electrolytes are determined according to... Figure 2 The temperature relationship between the electrode potentials of the two electrodes was determined. The positive electrode electrolytes were 0.1M KI3, 0.9M KI, and 2M GdmCl, while the negative electrode electrolytes were 0.3M K3Fe(CN)6, 0.3M K4Fe(CN)6, and 2M GdmCl, with a corresponding intermediate temperature of 40℃. The ion exchange membrane used was Nafion 115 (purchased from Suzhou Shengernuo Technology Co., Ltd.).

[0047] To demonstrate the effect of thermosensitive crystallization on Fe(CN)6 3- / Fe(CN)6 4- The increase in thermoelectric potential, Figure 3The temperature dependence of the electrode potential of K3Fe(CN)6 / K4Fe(CN)6 with and without GdmCl was compared. Linear fitting revealed that the thermoelectric potential of the baseline system without guanidine salt was only -1.29 mV / K, while that of Fe(CN)6 with guanidine salt was significantly higher. 3- / Fe(CN)6 4- The average thermoelectric potential can reach as high as -3.41 mV / K, and particularly, it can even reach -4.13 mV / K in the temperature range below 20-40 °C. Furthermore, we observed that the K4Fe(CN)6 precipitate can completely dissolve at 55 °C, achieving regeneration. Figure 4 Based on this and referencing an intermediate temperature of 40℃, an operating temperature range of 25 to 55℃ was used to conduct a recharge-free thermal regeneration electrochemical cycle on the thermosensitive crystallization-enhanced battery, and the results were compared with those of a reference system without guanidine salts. The working process of the recharge-free thermal regeneration electrochemical cycle battery is as follows: from the battery thermoelectric potential α... cell If the voltage is >0, first cool the battery to 25℃. At this point, the battery voltage is negative. Switch the positive and negative terminals of the battery, then discharge until the battery voltage reaches 0V. After discharging, short-circuit the battery for a period of time until the battery voltage approaches 0V. Switch the positive and negative terminals of the battery again. Then heat the battery to 55℃ until the voltage stabilizes, and discharge it again until the battery voltage reaches 0V. After discharging, short-circuit the battery for a period of time until the battery voltage approaches 0V. Repeat this cycle. The working principle and process of the non-rechargeable thermal regeneration electrochemical cycle are as follows: Figure 5 As shown in (a), the additional entropy change contributed by the dissolution and cooling of K4Fe(CN)6 during heating and the precipitation of K4Fe(CN)6 during charging increases the battery's electrical work output, where the total electrical work output by the battery is... Figure 5 (b) The area enclosed by the discharge curve and the x-axis. The total energy density of the non-rechargeable thermal regenerative electrochemical cycle battery in Example 1 was calculated to be 3.3 J / mL. According to the battery's thermal-electric conversion efficiency formula, the Carnot relative efficiency of the battery was calculated to be 26.9%, of which the thermal recovery efficiency was 70%, which are 4.6 times that of the baseline system without guanidine salt.

[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A charge-free, thermally regenerative electrochemical cyclic cell based on thermosensitive crystallization of thermoelectric potential increase, characterized in that, The thermal regeneration electrochemical cyclic battery comprises a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte and a cation exchange membrane; the electrode potential of a redox couple in the positive electrolyte and the negative electrolyte is equal at the intermediate temperature T m 0 V; the positive electrolyte and / or the negative electrolyte further contains an additive for inducing thermal sensitive crystallization of oxidizing ions or reducing ions in the electrolyte, the additive induces the oxidizing ions or the reducing ions to dissolve at the first temperature T1 and to crystallize and precipitate at the second temperature T2; the battery thermal potential is improved through the thermal sensitive crystallization process. The intermediate temperature T m is the temperature at the intersection of the curve of the electrode potential of the positive electrolyte versus temperature and the curve of the electrode potential of the negative electrolyte versus temperature. m The temperature at which the crystal precipitate is completely dissolved is the first temperature T1; the T m , T1, T2 all satisfy T1>T m , T2=2T m -T1 in units of degrees Celsius; the active substance in the positive electrolyte and the negative electrolyte is selected from K3Fe(CN)6 / K4Fe(CN)6(+)||KFe Ⅱ Fe Ⅲ (CN)6(-) or KI3 / KI(+)||K3Fe(CN)6 / K4Fe(CN)6(-); the additive is a salt containing guanidinium ion, tetraethylammonium ion or 1-ethyl-3-methylimidazolium ion, or an organic solvent of ethanol, methanol or acetonitrile, cesium chloride or α-cyclodextrin.

2. A self-recharging, electrochemical cycled cell based on thermosensitive crystallization for thermoelectric potential enhancement according to claim 1, characterized in that, The guanidinium-containing salt is guanidine hydrochloride, guanidine sulfate or guanidine nitrate; the tetraethylammonium-containing salt is tetraethylammonium chloride or tetraethylammonium bromide; the 1-ethyl-3-methylimidazolium-containing salt is 1-ethyl-3-methylimidazolium chloride.

3. A self-recharging, electrochemical cycled cell based on thermosensitive crystallization for thermoelectric potential enhancement according to claim 1, characterized in that, The battery is a static battery or a flow battery.

4. A self-recharging, electrochemical cycled cell based on thermosensitive crystallization for thermoelectric potential enhancement according to claim 3, characterized in that, When the battery is a flow battery, the positive electrode and the negative electrode are respectively provided with electrolyte flow channels, and the electrolyte flow channels are serpentine flow channels, comb flow channels or spiral flow channels.

5. A method of using a self-recharging electrochemical cyclic cell based on thermosensitive crystallization for increasing thermoelectric potential according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: (1) calibrate the electrode potential of the positive electrolyte and the negative electrolyte at different temperatures respectively, draw the positive electrolyte electrode potential-temperature curve and the negative electrolyte electrode potential-temperature curve, and record the temperature at the intersection of the positive electrolyte electrode potential-temperature curve and the negative electrolyte electrode potential-temperature curve as the intermediate temperature T m ; (2) the temperature at which the crystalline precipitate in the positive electrolyte or the negative electrolyte is completely dissolved is the first temperature T1, and the temperature at which the crystalline precipitate in the positive electrolyte or the negative electrolyte is formed is the second temperature T2; the T m , T1, T2 all satisfy: T1>T m , T2=2T m -T1 in units of degrees Celsius; and the working temperature range of the battery is determined as T2 to T1. (3) the difference between the slope of the curve of the positive electrolyte electrode potential versus temperature and the slope of the curve of the negative electrolyte electrode potential versus temperature is the battery thermal potential; the battery is brought to the intermediate temperature T m when the battery thermal potential is greater than zero, the battery is cooled to a second temperature T2, at which time the battery voltage is negative, the positive and negative electrodes of the battery are switched, and then the battery is discharged to a battery voltage of 0 V, and after the discharge is complete, the battery is short-circuited; (4) Switching the positive electrode and the negative electrode again, then heating the battery to the first temperature T1, discharging again until the battery voltage is 0 V, and then short-circuiting the battery after the discharging is completed, and repeating the steps (3) and (4).

6. A method of using a self-recharging electrochemical cyclic cell based on thermosensitive crystallization for increasing thermoelectric potential according to any one of claims 1 to 4, characterized in that, The specific operation steps are as follows: S1 respectively calibrates the electrode potential of the positive electrolyte and the negative electrolyte at different temperatures, and draws the positive electrolyte electrode potential-temperature curve and the negative electrolyte electrode potential-temperature curve, and records the temperature at the intersection of the positive electrolyte electrode potential-temperature curve and the negative electrolyte electrode potential-temperature curve as the intermediate temperature T m ; S2 is the temperature at which the crystalline precipitate in the positive or negative electrolyte is completely dissolved, and T1 is the temperature at which the crystalline precipitate in the positive or negative electrolyte is formed; T m , T1, and T2 all satisfy: T1>T m , T2=2T m -T1, and the working temperature range of the battery is T2 to T1. S3 the difference between the slope of the positive electrolyte electrode potential versus temperature curve and the slope of the negative electrolyte electrode potential versus temperature curve is the battery thermovoltage; bringing the battery to the intermediate temperature T m when the battery thermovoltage is less than zero, heating to a first temperature T1 at which the battery voltage is negative, switching the positive and negative electrodes of the battery, and subsequently discharging to a battery voltage of 0 V, and after the end of the discharge, short-circuiting the battery; S4 Then cooling the battery to the second temperature T2, discharging again until the battery voltage is 0 V, and then short-circuiting the battery after the discharging is completed, and repeating the steps S3 and S4.

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