TWI813397B - Electrolyte composition and metal-ion battery of its application - Google Patents

Abstract

An electrolyte composition, which can be used in a metal ion battery, comprises: zinc chloride, group IA metal chloride and acetonitrile. This electrolyte composition is applied to the metal ion battery, and the metal ion battery comprises a positive electrode, a separator, a negative electrode and the aforementioned electrolyte composition, wherein the negative electrode is separated from the positive electrode by the separator, and the electrolyte composition is arranged between the positive electrode and the negative electrode.

Description

Electrolyte compositions and metal ion batteries with applications

The present invention relates to an electrolyte composition, and in particular to an electrolyte composition that can improve the performance and life of an aqueous zinc ion battery.

A lithium-ion battery is a rechargeable battery that relies primarily on the movement of lithium ions between the positive and negative electrodes to work. The lithium-ion battery uses an embedded lithium compound as an electrode material, and its research and development process was mainly carried out by John. Goodenough, Stanley. Whittingham, Ratched. Yazami and Akira Yoshino started it in the 1970s and developed into the 1980s. Then in 1991, Sony and Asahi Kasei reached a consensus on commercialization, and Goodenough, Whittingham and Akira Yoshino won the 2019 Nobel Prize in Chemistry for developing lithium-ion batteries. With the rapid growth of the consumer market for portable electronic devices, lithium-ion batteries have become the most popular rechargeable battery in today's portable electronic devices due to their high energy density, no memory effect, and only slow charge loss when not in use. mainstream type.

For more than 20 years, lithium batteries have been outstanding in the rechargeable battery market. However, safety concerns such as their inability to bend, high temperature resistance, and easy fire have always been the weaknesses of lithium batteries. Therefore, in 2018, American researchers combined traditional zinc battery technology with water battery technology to develop a water-based zinc-ion battery. Because the battery has a large capacity, is rechargeable, and is safer, there is no risk of explosion or fire. The performance, coupled with the abundant reserves of zinc, low cost, relatively low redox potential and compatibility with aqueous electrolytes, it is expected to become an ideal substitute for the currently widely used lithium batteries.

However, during the cyclic charge and discharge process of zinc-ion batteries, due to the lower concentration, there are too many free water molecules, which makes the zinc ions unstable during the deposition process. It is easy to generate zinc passivation and side reactions, and cannot be used during the discharge process. Dissolved and accumulated for a long time, the zinc passivation will pierce the isolation film and touch the cathode, causing short-circuit damage to the battery. Moreover, due to excessive free water, the cathode material is very easy to dissolve or cause the battery to produce gas, causing the battery capacity to rapidly decay. . Therefore, there are previous technologies, such as the US20210336293A1 patent, which mentions a method of mixing water-in-salt electrolyte (WiSE) to solve the above problems. However, the concentration ratio disclosed in this patent can only reach a maximum molar concentration by weight. 30m ZnCl ₂ and 10m LiCl are limited by the solubility of the single solvent water, so the concentration cannot continue to increase.

Therefore, in view of the deficiencies in the prior art, the applicant of this case finally conceived this case after careful research and experimentation, and in a spirit of perseverance, overcoming the deficiencies of the prior art. The following is a brief description of this case.

In order to solve the above problems, one object of the present invention is to provide an electrolyte composition for use in metal ion batteries, which includes: zinc chloride, a Group IA metal chloride and acetonitrile.

The above electrolyte composition, wherein the Group IA metal chloride is selected from one of lithium chloride, sodium chloride and potassium chloride or a combination thereof.

As in the above electrolyte composition, the weight molar concentration ratio of the zinc chloride, the Group IA metal chloride and the acetonitrile is 25:19:8, 30:19:8 or 30:22:8.

As the electrolyte composition mentioned above, the weight molar concentration ratio of the zinc chloride, the lithium chloride and the acetonitrile is 60: (4 to 33): (18 to 24).

The above electrolyte composition, wherein the electrolyte composition further contains hydrochloric acid.

As in the above electrolyte composition, the weight percentage concentration of the hydrochloric acid is 0.5wt% or 1wt%.

The above-mentioned electrolyte composition, wherein the weight percentage concentration of the hydrochloric acid is 0.1wt% to 5.0wt%.

Another object of the present invention is to provide a metal ion battery, including: a positive electrode; a separator; a negative electrode, wherein the negative electrode is separated from the positive electrode by the separator; and the electrolyte composition as described above is disposed on the positive electrode. between the negative electrode.

As the above metal ion battery, the metal ion battery is a zinc ion battery.

As in the above metal ion battery, the positive electrode is stainless steel, tungsten, zinc, copper, lead, indium, lithium iron phosphate, sodium vanadium phosphate, lithium vanadium phosphate, potassium vanadium phosphate or lithium manganese oxide, and the negative electrode is zinc , copper, lead, tungsten or indium.

The electrolyte composition provided by the invention has the following advantages:

1. The present invention can develop a new and highly safe battery system. Through the water-in-salt electrolyte composition of the present invention, the purpose of using a higher salt concentration can be achieved, thereby reducing the free water activity in the electrolyte. Improve the performance and life of aqueous zinc-ion batteries.

2. The present invention solves the problem that during the cyclic charge and discharge process of today's aqueous zinc ion batteries, due to the lower concentration, there are too many free water molecules, which makes the zinc ions unstable during the deposition process, and generates zinc passivation and side reactions, which cannot be used in the process. Dissolved during the discharge process and accumulated for a long time, it will pierce the isolation film and touch the cathode, causing short-circuit damage to the battery. Moreover, due to excessive free water, the cathode material is very easy to dissolve or the battery generates gas, causing the battery capacity to rapidly decay.

1: Metal ion battery

11: Positive pole

12:Isolation film

13: Negative pole

14:Electrolyte composition

2: Metal ion battery

21:Nickel tab

22:Isolation film

23: Negative pole

24:Electrolyte composition

25:Fiberglass

26: Nickel tab

Figure 1 is a schematic cross-sectional view of the structure of the metal ion battery of the present invention.

Figure 2 is a schematic structural cross-sectional view of another metal ion battery of the present invention.

Figures 3A and 3B are Raman spectra of electrolyte solutions of zinc chloride, lithium chloride and acetonitrile of the present invention.

Figure 4A is a photo of a test sample without and with hydrochloric acid added to the electrolyte composition of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 according to the present invention.

Figure 4B is a photo of a test sample without and with hydrochloric acid added to the electrolyte composition of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 according to the present invention.

Figure 5 is a voltage-time diagram of the continuous deposition and dissolution results of the zinc/zinc symmetrical battery of the present invention under current density of 1 mA/cm ² and temperature of 40°C.

Figure 6A is a capacity-cycle number diagram of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 of the present invention under a current density of 0.5mA/ ^cm2 and a temperature of 40°C.

Figure 6B is a capacity-cycle number diagram of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 of the present invention under a current density of 0.5mA/ ^cm2 and a temperature of 40°C.

Figure 6C is a capacity-cycle number diagram of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 of the present invention under a current density of 0.5mA/ ^cm2 and a temperature of 30°C.

Figure 6D shows the coulombic efficiency and capacity results of the present invention with a weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile at a current density of 0.5mA/ ^cm2 and a temperature of 30°C.

Figure 6E is a capacity-cycle number diagram obtained by testing zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 according to the present invention after adding hydrochloric acid with a weight percentage concentration of 0.73wt%.

Figure 6F is a capacity-cycle number diagram obtained by testing zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:22:8 according to the present invention after adding hydrochloric acid with a weight percentage concentration of 0.73wt%.

Figure 6G shows an electrolyte composition with a weight molar concentration ratio of 30:19:8 according to the present invention without adding hydrochloric acid and SEM&EDS analysis results of the copper surface deposits obtained after adding 0.73wt% hydrochloric acid.

Figure 7A is the capacity-cycle number tested at a current density of 0.5 mA/cm ² using lead as the positive electrode of the present invention and using zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8. Figure.

Figure 7B is the capacity-cycle number tested by using lead as the positive electrode of the present invention and adding 0.73wt% hydrochloric acid to zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8. Figure.

Figure 8A is the capacity-cycle number tested at a current density of 0.5 mA/cm ² using indium as the positive electrode of the present invention, and using zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8. Figure.

Figure 8B is the capacity-cycle number tested at a current density of 0.5 mA/cm ² using indium as the positive electrode of the present invention, and using zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8. Figure.

Figure 8C is the capacity-cycle number obtained by adding 0.73wt% hydrochloric acid to zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 according to the present invention at a current density of 0.5mA/ ^cm2 . Figure.

Figure 9A is a capacity-cycle number diagram obtained by testing the present invention using lithium iron phosphate as the positive electrode and using zinc chloride, lithium chloride and acetonitrile at a molar weight ratio of 25:19:8 at a current density of 100mA/g. .

Figure 9B is a capacity-cycle number diagram obtained by testing the present invention using lithium iron phosphate as the positive electrode and using zinc chloride, lithium chloride and acetonitrile at a molar weight ratio of 30:19:8 at a current density of 100mA/g. .

Figure 9C shows the present invention using zinc chloride, lithium chloride and acetonitrile with weight molar concentration ratios of 30:19:8 and 30:22:8, after adding 0.73wt% hydrochloric acid, and testing the current density at 100mA/g The resulting capacity versus cycle number plot.

Figure 9D shows the current density test of the present invention at 100mA/g after adding 0.73wt% hydrochloric acid using zinc chloride, lithium chloride and acetonitrile with weight molar concentration ratios of 30:19:8 and 30:22:8. The resulting capacity versus cycle number plot.

Figure 10A is a capacity-cycle number diagram obtained by testing the present invention using sodium vanadium phosphate as the positive electrode and using zinc chloride, lithium chloride and acetonitrile at a molar weight ratio of 25:19:8 at a current density of 100mA/g. .

Figure 10B is a capacity-cycle number diagram obtained by testing the present invention using sodium vanadium phosphate as the positive electrode and using zinc chloride, lithium chloride and acetonitrile at a molar weight ratio of 30:19:8 at a current density of 100mA/g. .

Figure 10C shows the present invention using sodium vanadium phosphate as the positive electrode and adding zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8. After adding 0.73wt% hydrochloric acid, the current is 100mA/g. The capacity-cycle number graph obtained from testing under the condition of density.

Figure 10D shows the present invention using sodium vanadium phosphate as the positive electrode and adding zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:22:8. After adding 0.73wt% hydrochloric acid, the current is 100mA/g. The capacity-cycle number graph obtained from testing under the condition of density.

Figure 11 shows the present invention using lithium manganese oxide as the positive electrode and adding 0.73wt% hydrochloric acid to zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 at 500mA/g. Capacity-cycle number graph tested under conditions of current density.

Figure 12A shows the present invention using sodium vanadium phosphate as the positive electrode, copper as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 under the condition of 100mA/g current density. Capacity-cycle number graph obtained from the test.

Figure 12B shows the present invention using sodium vanadium phosphate as the positive electrode, copper as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 under the condition of 100mA/g current density. Capacity-cycle number graph obtained from the test.

Figure 12C shows the present invention using sodium vanadium phosphate as the positive electrode and copper as the negative electrode. The weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:19:8, and the weight percentage concentration is 0.73wt. % salt After acidification, the capacity-cycle number chart under the conditions of current density of 100mA/g and temperature of 30°C.

Figure 12D shows the present invention using sodium vanadium phosphate as the positive electrode and copper as the negative electrode. The weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:22:8, and the weight percentage concentration is 0.73wt. % hydrochloric acid, the capacity-cycle number chart under the conditions of current density of 100mA/g and temperature of 30℃.

Figure 13A shows the present invention using sodium vanadium phosphate as the positive electrode, lead as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 at a current density of 100mA/g and a temperature of 30 Specific capacity-cycle number graph obtained under temperature conditions of ℃.

Figure 13B shows the present invention using sodium vanadium phosphate as the positive electrode, lead as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 at a current density of 100mA/g and a temperature of 30 The specific capacity-cycle number graph obtained under the temperature condition of ℃.

Figure 13C shows the present invention using sodium vanadium phosphate as the positive electrode and lead as the negative electrode. The weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:19:8, and the weight percentage concentration is 0.73wt. % hydrochloric acid, the specific capacity-cycle number chart under the conditions of 100mA/g current density and temperature 30℃.

Figure 13D shows the present invention using sodium vanadium phosphate as the positive electrode and lead as the negative electrode. The weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:22:8, and the weight percentage concentration is 0.73wt. % hydrochloric acid, the specific capacity-cycle number chart under the conditions of 100mA/g current density and temperature 30℃.

Figure 13E shows the present invention using sodium vanadium phosphate as the positive electrode and lead as the negative electrode. Zinc chloride, lithium chloride and acetonitrile are added with a weight molar concentration ratio of 30:10:8 and a weight percentage concentration of 1wt%. After adding hydrochloric acid, the specific capacity-cycle number diagram was obtained under the temperature conditions of 100mA/g current density and room temperature.

Figure 14A shows the present invention using sodium vanadium phosphate as the positive electrode, indium as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 25:19:8 at a current density of 100mA/g and a temperature of 30 ℃ temperature Specific capacity-cycle number graph obtained under high temperature conditions.

Figure 14B shows the present invention using sodium vanadium phosphate as the positive electrode, indium as the negative electrode, zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 at a current density of 100mA/g and a temperature of 30 Specific capacity-cycle number graph obtained under temperature conditions of ℃.

Figure 14C shows the present invention using sodium vanadium phosphate as the positive electrode and indium as the negative electrode. The molar weight ratios of zinc chloride, lithium chloride and acetonitrile are 30:19:8 and 30:22:8, adding 0.73 After adding wt% hydrochloric acid, the specific capacity-cycle number diagram was obtained under the current density of 100mA/g and the temperature of 30°C.

Figure 14D shows the present invention using sodium vanadium phosphate as the positive electrode and indium as the negative electrode. The weight molar concentration ratios of zinc chloride, lithium chloride and acetonitrile are 30:19:8 and 30:22:8, adding 0.73 After adding wt% hydrochloric acid, the specific capacity-cycle number diagram was obtained under the current density of 100mA/g and the temperature of 30°C.

Figure 15 shows the present invention using lithium iron phosphate as the positive electrode, copper as the negative electrode, and adding 0.73wt% hydrochloric acid to zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8. , specific capacity-cycle number chart under the conditions of current density of 100mA/g and temperature of 30℃.

Figure 16 is the specific capacity-cycle number tested at a current density of 100 mA/g using sodium vanadium phosphate as the positive electrode, zinc as the negative electrode, and zinc chloride, lithium chloride and acetonitrile at a concentration ratio of 30:5:0. Figure.

Figure 17 shows the specific capacity-cycle measured at a current density of 100 mA/g using sodium vanadium phosphate as the positive electrode, zinc as the negative electrode, and zinc chloride, lithium chloride and acetonitrile with a concentration ratio of 7.5:0:0. Times chart.

Figure 18 shows the specific capacity-cycle measured at a current density of 100 mA/g using sodium vanadium phosphate as the positive electrode, zinc as the negative electrode, and zinc chloride, lithium chloride and acetonitrile with a concentration ratio of 20:0:0. Times chart.

Figure 19 shows the specific capacity measured at a current density of 100 mA/g using sodium vanadium phosphate as the positive electrode, zinc as the negative electrode, and zinc chloride, lithium chloride and acetonitrile with a concentration ratio of 20:10:0. Cycle count graph.

The purpose and functional advantages of the present invention will be explained based on the information shown in the following figures and specific embodiments, so that the review committee can have a more in-depth and specific understanding of the present invention.

In order to achieve the above object, one embodiment of the present invention provides an electrolyte composition for use in metal ion batteries, such as zinc ion batteries, which contains: zinc monochloride (ZnCl ₂ ), lithium monochloride ( LiCl) and monoacetonitrile (ACN). In some embodiments, the weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 25:19:8. In some embodiments, the weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:19:8. In some embodiments, the weight molar concentration ratio of zinc chloride, lithium chloride and acetonitrile is 30:22:8. The preparation method of the electrolyte composition includes slowly adding a measured amount of zinc chloride salt to a fixed proportion of deionized water and slowly stirring. When the zinc chloride salt is completely dissolved, adding a fixed proportion of acetonitrile and continuing to stir for 30 minutes. , add lithium chloride salt, and continue stirring at 80°C until clear.

It is worth mentioning that in some embodiments, lithium chloride in the electrolyte composition can be replaced by sodium chloride or potassium chloride, and similar effects can be achieved. In other words, the present invention is not limited to lithium chloride. , all Group IA metal chlorides can be used in the present invention. In addition, the range of the weight molar concentration ratio of zinc chloride, Group IA metal chloride and acetonitrile is preferably between 60: (4 to 33): (18 to 24). If the concentration of the electrolyte composition is higher than Within this range, the concentration of the electrolyte will be too high and ions will not move smoothly. If the concentration is lower than this range, the concentration of the electrolyte will be too low, resulting in insignificant reactions and poor effects.

In addition, in order to reduce the impedance of the electrolyte and expand its operating temperature range, hydrochloric acid (HCl) can be added to the above-mentioned electrolyte composition. In some embodiments, the weight percentage concentration of the hydrochloric acid added to the electrolyte composition is: 0.5wt%. In some embodiments, the weight percent of the hydrochloric acid is concentrated The degree can be 1wt%. Therefore, in the present invention, the weight percentage concentration of the hydrochloric acid can be between 0.1wt% and 5.0wt%. If the concentration of hydrochloric acid is higher than this range, the current collector will be corroded because it is too acidic. If the concentration of hydrochloric acid is lower than this range, the reaction will be insignificant and the effect will be poor because the concentration is too low.

Another embodiment of the present invention is to provide a metal ion battery 1, please refer to Figure 1, which includes a positive electrode 11, a separator 12, a negative electrode 13 and the above-mentioned electrolyte composition 14, wherein the negative electrode 13 uses the separator. 12 is separated from the positive electrode 11 , and the above-mentioned electrolyte composition 14 is disposed between the positive electrode 11 and the negative electrode 13 .

In some embodiments, another metal ion battery 2 of the present invention can also be presented in the form of a pouch battery. Please refer to Figure 2. It includes a positive electrode 21, a separator 22, a negative electrode 23, a glass fiber 25 and The above-mentioned electrolyte composition 24 is used, and the positive electrode 21, the negative electrode 23, the separator 22 and the nickel tab 26 are assembled in the form of a bagged battery.

The water-in-salt electrolyte composition designed by the present invention adds acetonitrile (ACN) as a diluent and a source of coordination ions, so the molar concentration of lithium chloride (LiCl) can be increased to 20m, and the The stability of the battery has been greatly improved, allowing it to reach concentrations beyond what was previously possible with mixed salt-in-water electrolytes. Please refer to Figures 3A and 3B, which are Raman spectra of electrolyte solutions of zinc chloride, lithium chloride and acetonitrile according to the present invention. From the figures, it can be seen that the ^CN- ions in acetonitrile coordinate with cations in the electrolyte. The interaction between water molecules can reduce the free water molecules in the electrolyte and increase the solubility of salts. Moreover, due to the strong coordination between CN ^- ions and zinc ions, the polarization potential is significantly increased, and the polarization potential can be effectively obtained. Stable and smooth zinc deposition. In addition, it can prevent the cathode material from dissolving due to high water activity and causing rapid capacity attenuation, so it can be used to solve the problems currently encountered in aqueous zinc-ion batteries.

Through the following specific examples, it can be further proved that the electrolyte composition of the present invention actually application scope and effects, but are not intended to limit the scope of the present invention in any way.

Experiment 1: Test by adding hydrochloric acid to the electrolyte composition

In order to verify the effect of adding hydrochloric acid on the electrolyte composition, this test uses two electrolyte compositions, namely zinc chloride and lithium chloride at a weight molar concentration ratio of 25:19:8 and 30:19:8 Hydrochloric acid with a weight percentage concentration of 0.5wt% and 1wt% was added to acetonitrile and acetonitrile respectively, and compared with the sample without adding hydrochloric acid. Please refer to Figures 4A and 4B for the test results. Figure 4A is a photo of the test sample without and with hydrochloric acid added to the electrolyte composition with a weight molar concentration ratio of 25:19:8. The results show that the electrolyte solution without hydrochloric acid is turbid. The electrolyte solution of hydrochloric acid appears clear, and the electrolyte solution adding 1wt% hydrochloric acid is clearer than the electrolyte solution adding 0.5wt% hydrochloric acid. Figure 4B is a photo of the test sample without and with hydrochloric acid added to the electrolyte composition with a weight molar concentration ratio of 30:19:8. The test results are the same as Figure 4A, showing that the electrolyte solution without hydrochloric acid is turbid, and the electrolyte solution without hydrochloric acid is turbid. The electrolyte solution appears clear, and the electrolyte solution adding 1wt% hydrochloric acid is the clearest. A clear electrolyte solution has a smaller impedance than a turbid electrolyte solution and is suitable for use in colder regions with lower temperatures. Therefore, a clear electrolyte solution can effectively expand the temperature range of its use.

Experiment 2: Zinc/Zinc Symmetric Battery Test

This test uses an electrolyte composition of zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 to conduct a zinc/zinc symmetrical battery test. Please refer to Figure 5 for the test results. The zinc/zinc symmetrical battery operates at 1mA /cm ² current density and a temperature of 40°C, the continuous deposition and dissolution results show that in the test using the electrolyte composition of the present invention, the continuous deposition and dissolution of the zinc negative electrode shows a very small overpotential and the Coulombic efficiency can be close to about 100%, meaning highly reversible zinc anode reaction and simultaneous suppression of water splitting.

Experiment 3: Zinc/Copper Half-Cell Test

In order to verify the impact of different concentration electrolyte compositions and different temperature conditions on the battery, confirm whether the battery can maintain stability and repeatability. This test uses copper as the positive electrode and zinc as the negative electrode, and uses zinc chloride, lithium chloride and acetonitrile with weight molar concentration ratios of 25:19:8 and 30:19:8 at temperatures of 40°C and 30°C. For the Coulombic efficiency and capacity results obtained under temperature conditions, please refer to Figures 6A and 6B. Figures 6A and 6B are electrolyte compositions with molar concentration ratios of 25:19:8 and 30:19:8 at 0.5mA/cm ² The Coulombic efficiency and capacity results obtained under current density and temperature conditions of 40°C show that regardless of the concentration of the electrolyte composition, after more than 1600 cycle tests, the Coulombic efficiency is almost 100%, and the capacity is almost no Reduction, the cycle life can be said to have been extended. Therefore, the use of the electrolyte composition of the present invention can effectively improve the cycle stability of zinc ion batteries, achieve rapid charging and zero waste of energy, even if there are differences in concentration. Same effect.

Please refer to Figures 6C and 6D. Figures 6C and 6D show zinc chloride, lithium chloride and acetonitrile with weight molar concentration ratios of 25:19:8 and 30:19:8 at a current density of 0.5mA/ ^cm2 and 30°C. The Coulombic efficiency and capacity results obtained under the temperature conditions show that no matter what the concentration of the electrolyte composition is, after 375 cycles of testing, the Coulombic efficiency is almost 100%, and the capacity is almost not reduced, which is Therefore, the electrolyte composition of the present invention can effectively improve the cycle stability of zinc ion batteries. In addition, please refer to Figures 6A and 6C or Figures 6B and 6D at the same time, which is to compare the Coulombic efficiency and capacity results of the same concentration but different temperature conditions at the same time. It shows that regardless of the concentration of the electrolyte composition, under different temperature conditions The Coulombic efficiency is almost 100%, and the capacity is almost not reduced. Therefore, even if the temperature differs by 10°C using the electrolyte composition of the present invention, it will not affect the stability of the charge and discharge cycle of the zinc ion battery.

Please refer to Figures 6E and 6F. Figures 6E and 6F show zinc chloride, lithium chloride and acetonitrile with molar weight ratios of 30:19:8 and 30:22:8 added to a solution with a weight percentage concentration of 0.73wt%. After hydrochloric acid, the Coulombic efficiency and capacity results obtained at a current density of 0.5mA/ ^cm2 and a temperature of 30°C show that regardless of the concentration of the electrolyte composition, after 375 cycles of testing, its Coulombic efficiency It is also almost 100%, and the capacity is almost not reduced. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect the stability of the charge and discharge cycle of the zinc ion battery.

Please refer to Figure 6G, which is a molar concentration ratio of zinc chloride, lithium chloride and acetonitrile of 30:19:8 without adding hydrochloric acid and adding hydrochloric acid with a weight percentage concentration of 0.73wt%. At 0.5mA/cm ^2. SEM&EDS analysis results of the deposits remaining on the copper surface obtained under current density and temperature conditions of 30°C. It shows that the surface without adding hydrochloric acid is less flat, and Cl and O can be clearly analyzed from the EDS without adding hydrochloric acid. and other elements (circled in Figure 6G), which indicates that the by-product contains Zn(OH)Cl, while the addition of hydrochloric acid is pure zinc metal residue. In addition, the efficiency of a zinc//copper (Zn//Cu) asymmetric cell is: peeling amount/deposition amount × 100%. The higher the efficiency, the better the reversibility of zinc on the copper surface. Adding hydrochloric acid is more reversible and more stable than not adding hydrochloric acid. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention can effectively improve the charge-discharge cycle performance of the zinc-ion battery.

Experiment 4: Zinc/Lead Half Cell Test

In order to verify the impact of the electrolyte composition of the present invention on the battery when used with different electrode materials, it is confirmed whether the battery can maintain stability and repeatability. This test uses lead as the positive electrode and zinc as the negative electrode, and uses zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 at a current density of 0.5mA/ ^cm2 and a temperature of 30°C. The Coulombic efficiency and capacity results obtained under the conditions are shown in Figure 7A, which shows that after 375 cycles of testing, the Coulombic efficiency is nearly 100%, and the capacity is almost unchanged. Therefore, the electrolyte composition of the present invention is used in the positive electrode. When the material is lead, it can also effectively maintain the cycle stability of zinc-ion batteries.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery, this test used zinc chloride and lithium chloride with a weight molar concentration ratio of 30:19:8 and acetonitrile after adding hydrochloric acid with a concentration of 0.73wt%, the Coulombic efficiency and capacity results obtained at a current density of 0.5mA/ ^cm2 and a temperature of 30°C, please refer to Figure 7B, which shows that after 850 After several cycle tests, the Coulombic efficiency is almost 100%, and the capacity is almost unchanged. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery, even from the data In terms of stability, the results with hydrochloric acid added are better than those without hydrochloric acid.

Experiment 5: Zinc/Indium Half Cell Test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses indium as the positive electrode and zinc as the negative electrode, and uses zinc chloride, lithium chloride and acetonitrile at a molar weight ratio of 25:19:8 and 30:19:8 at a current density of 0.5mA/ ^cm2 For the Coulombic efficiency and capacity results obtained at a temperature of 30°C, please refer to Figures 8A and 8B, which show that after more than 450 and 150 cycle tests respectively, the Coulombic efficiency is almost 100%, and the capacity is almost It remains unchanged but does not decrease. Therefore, when the electrolyte composition of different concentrations of the present invention is used as the cathode material indium, it will not affect the cycle stability of the zinc-ion battery, so fast charging and zero waste of energy can be achieved.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery, this test used zinc chloride and lithium chloride with a weight molar concentration ratio of 30:19:8 and acetonitrile after adding hydrochloric acid with a concentration of 0.73wt%, the Coulombic efficiency and capacity results obtained at a current density of 0.5mA/ ^cm2 and a temperature of 30°C, please refer to Figure 8C, which shows that after 170 After several cycle tests, its Coulombic efficiency is also nearly 100%, and its capacity is almost unchanged. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery.

Experiment 6: Zinc/lithium iron phosphate battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses lithium iron phosphate (LiFePO ₄ ) as the positive electrode and zinc as the negative electrode. The molar weight ratios of zinc chloride, lithium chloride and acetonitrile are 25:19:8 and 30:19:8 at 100mA. /g current density and temperature of 30°C, please refer to Figures 9A and 9B, which show that after about 140 cycles of testing, the Coulombic efficiency is nearly 100%, while the capacity is It is slightly more than 99%. Therefore, when the electrolyte compositions of different concentrations of the present invention are used as the cathode material lithium iron phosphate, the cycle stability of the zinc-ion battery will not be affected.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery, this test used chlorine with a weight molar concentration ratio of 30:19:8 and 30:22:8. For the Coulombic efficiency and capacity results of zinc chloride, lithium chloride and acetonitrile after adding hydrochloric acid with a concentration of 0.73wt% at a current density of 100mA/g and a temperature of 30°C, please refer to Figure 9C and 9D , which shows that after 140 and 70 cycle tests respectively, the Coulombic efficiency and capacity of the weight molar concentration ratio of 30:19:8 have slightly decreased and deviated from the initial amount, but are still close to 100%, and The Coulombic efficiency of another concentration ratio of 30:22:8 is nearly 100%, and the capacity is also close to the initial amount. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not actually affect the zinc ion battery. Cycling stability.

Experiment 7: Zinc/sodium vanadium phosphate battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode and zinc as the negative electrode. The weight molar concentration ratios of zinc chloride and zinc chloride are 25:19:8 and 30:19:8. The Coulombic efficiency and specific capacity results of lithium chloride and acetonitrile at a current density of 100mA/g and a temperature of 30°C are shown in Figures 10A and 10B, which show that after approximately 170 cycles of testing, the weight of The Coulombic efficiency of the molar concentration ratio of 25:19:8 dropped slightly but was still close to 100%, while the specific capacity was slightly higher than the initial amount. The Coulombic efficiency of the molar concentration ratio of 30:19:8 was close to 100%, and the specific capacity is slightly higher than the initial amount. Therefore, when the electrolyte compositions of different concentrations of the present invention are used in the positive electrode material lithium iron phosphate, the cycle stability of the zinc-ion battery will not be affected.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the zinc-ion battery, this test used chlorine with a weight molar concentration ratio of 30:19:8 and 30:22:8. For the Coulombic efficiency and capacity results of zinc chloride, lithium chloride and acetonitrile after adding hydrochloric acid with a concentration of 0.73wt% at a current density of 100mA/g and a temperature of 30°C, please refer to Figure 10C and 10D , which shows that after about 200 cycle tests, its Coulombic efficiency is nearly 100%, and the capacity is close to the initial amount without decreasing. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect to the cycling stability of zinc-ion batteries.

Experiment 8: Zinc/lithium manganese oxide battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses lithium manganese oxide (LiMn ₂ O ₄ ) as the positive electrode, and adds zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:19:8 and a weight percentage concentration of 0.73wt%. After adding hydrochloric acid, the Coulombic efficiency and specific capacity results obtained at a current density of 500mA/g and a temperature of 30°C are shown in Figure 11. It shows that after about 225 cycles of testing, the Coulombic efficiency will exceed is greater than 99%, and the capacity will be lower than the initial amount. Therefore, when the electrolyte composition of the present invention is used in the cathode material lithium manganese oxide, it will not affect the cycle charge and discharge stability of the zinc ion battery, but it will cause battery aging. phenomenon occurs.

In particular, in order to verify whether the electrolyte composition of the present invention can be applied to other metal ion batteries with different electrode materials when the anode does not use zinc (Anode-free zinc), the following experiments were conducted.

Experiment 9: Copper/sodium vanadium phosphate battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode, copper as the negative electrode, and zinc chloride and zinc chloride at molar weight ratios of 25:19:8 and 30:19:8. For the Coulombic efficiency and specific capacity results of lithium chloride and acetonitrile at a current density of 100mA/g and a temperature of 30°C, please refer to Figures 12A and 12B, which show that after approximately 325 and 280 cycles of testing, respectively, The Coulombic efficiency is close to 100%, but the capacity is lower than the initial amount. Therefore, when the electrolyte composition of different concentrations of the present invention is used as the positive electrode material is lithium iron phosphate and the negative electrode is copper, it will not affect the charge and discharge stability of the battery. , but there is battery aging phenomenon.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the battery, this test used zinc chloride with a weight molar concentration ratio of 30:19:8 and 30:22:8 , lithium chloride and acetonitrile after adding hydrochloric acid with a weight percentage concentration of 0.73wt%, the Coulombic efficiency and specific capacity results obtained at a current density of 100mA/g and a temperature of 30°C, please refer to Figure 12C and 12D. It shows that after about 275 and 350 cycle tests respectively, its Coulombic efficiency is also close to 100%, but the capacity is lower than the initial amount. After comparing the data of the same molar concentration ratio by weight, this capacity The situation that the amount is lower than the initial amount should not be caused by hydrochloric acid, but caused by the aging phenomenon of the battery itself. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the battery.

Experiment 9: Lead/sodium vanadium phosphate battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode and lead as the negative electrode. The weight molar concentration ratios of zinc chloride and zinc chloride are 25:19:8 and 30:19:8. Please refer to Figures 13A and 13B for the Coulombic efficiency and specific capacity results of lithium chloride and acetonitrile at a current density of 100mA/g and a temperature of 30°C. They show that after approximately 300 and 375 cycles of testing respectively, Among them, the Coulombic efficiency with a weight molar concentration ratio of 25:19:8 is close to 100%, and the capacity is close to the initial amount without decreasing. The Coulombic efficiency with a weight molar concentration ratio of 30:19:8 is also close to 100%. , and the specific capacity is lower than the initial amount. Therefore, when the electrolyte compositions of different concentrations of the present invention are used as the positive electrode material is lithium iron phosphate and the negative electrode is lead, although it will not affect the charge and discharge stability of the battery, the concentration ratio is 30:19:8 will cause battery aging.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the battery, this test used zinc chloride with a weight molar concentration ratio of 30:19:8 and 30:22:8 After adding hydrochloric acid with a concentration of 0.73wt% to lithium chloride and acetonitrile, the Coulombic efficiency and specific capacity results obtained at a current density of 100mA/g and a temperature of 30°C are shown in Figures 13C and 13D. ; And the Coulomb obtained by using zinc chloride, lithium chloride and acetonitrile with a weight molar concentration ratio of 30:10:8 and adding hydrochloric acid with a weight percentage concentration of 1wt% at a current density of 100mA/g and room temperature. The efficiency and specific capacity results are shown in Figure 13E. Please refer to Figures 13C, 13D and 13E, which show that after approximately 360, 350 and 550 cycle tests respectively, the Coulombic efficiencies are all close to 100%, of which the weight The specific capacities of the molar concentration ratios of 30:19:8 and 30:22:8 are slightly lower than the initial amount, but very close to the initial amount, while the specific capacity of the molar concentration ratio of 30:10:8 is Lower than the initial amount, after comparing the data of the same weight molar concentration ratio of 30:19:8, the specific capacity with hydrochloric acid added will be much better than the specific capacity without hydrochloric acid, so hydrochloric acid is added to the present invention. The electrolyte composition does not affect the cycle stability of the battery.

Experiment 10: Indium/sodium vanadium phosphate battery half-cell test

In order to verify the impact of using different concentrations of electrolyte compositions on different electrode materials on the battery, and to confirm whether the battery can maintain stability and repeatability. This test uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode and indium as the negative electrode. The weight molar concentration ratios of zinc chloride and zinc chloride are 25:19:8 and 30:19:8. For the Coulombic efficiency and specific capacity results of lithium chloride and acetonitrile at a current density of 100mA/g and a temperature of 30°C, please refer to Figures 14A and 14B, which show that after approximately 400 and 415 cycles of testing, respectively, The Coulombic efficiency is close to 100%, and the specific capacity is lower than the initial amount. Therefore, when the electrolyte composition of different concentrations of the present invention is used as the positive electrode material is sodium vanadium phosphate and the negative electrode is indium, it will not affect the charge and discharge of the battery. Stability, but battery aging occurs.

In addition, in order to verify that adding hydrochloric acid to the electrolyte composition of the present invention will not affect the cycle stability of the battery, this test used zinc chloride with a weight molar concentration ratio of 30:19:8 and 30:22:8 After adding hydrochloric acid with a concentration of 0.73wt% to lithium chloride and acetonitrile, the Coulombic efficiency and specific capacity results obtained at a current density of 100mA/g and a temperature of 30°C are shown in Figures 14C and 14D. It shows that after about 300 and 400 cycle tests, the Coulombic efficiencies are all close to 100%. The specific capacities with molar weight ratio of 30:19:8 are slightly lower than the initial amount, but very close. is lower than the initial amount, and the specific capacity with a weight molar concentration ratio of 30:22:8 is lower than the initial amount. After comparison After describing the data of the same weight molar concentration ratio of 30:19:8, the specific capacity with the addition of hydrochloric acid will be much better than the specific capacity without the addition of hydrochloric acid. Therefore, adding hydrochloric acid to the electrolyte composition of the present invention will not affect to the cycle stability of the battery.

Experiment 11: Copper/lithium iron phosphate battery half-cell test

In order to verify the impact of the electrolyte composition of the present invention on the battery when used with different electrode materials, it is confirmed whether the battery can maintain stability and repeatability. This test uses lithium iron phosphate (LiFePO ₄ ) as the positive electrode and copper as the negative electrode. Zinc chloride, lithium chloride and acetonitrile are added with a weight molar concentration ratio of 30:19:8 and a weight percentage concentration of 0.73. After adding wt% hydrochloric acid, the Coulombic efficiency and specific capacity results were obtained at a current density of 100mA/g and a temperature of 30°C. Please refer to Figure 15. It shows that after approximately 135 cycle tests, the Coulombic efficiency is almost is 100%, and the specific capacity is lower than the initial amount. Therefore, when the electrolyte composition of the present invention is used when the positive electrode material is lithium iron phosphate and the negative electrode is copper, although it will not affect the charge and discharge stability of the battery, there are some problems with the battery. Aging occurs.

The above experiments are organized into the following table 1. From the results in table 1, it can be concluded that using zinc as the negative electrode and copper as the positive electrode, the weight molar concentration ratios are 25:19:8, 30:19:8 and 30:22 : Under the concentration conditions of zinc chloride, lithium chloride and acetonitrile of 8, the Coulombic efficiency obtained is almost 100%, and the capacity is almost not reduced, and the addition of hydrochloric acid will not affect the cycle stability of the battery. . In particular, when the electrolyte composition of the present invention is applied to zinc-ion batteries, the Coulombic efficiency and capacity obtained are basically close to 100% and are not reduced for the most part, while when used in non-zinc-ion batteries, Although the Coulombic efficiency obtained can reach close to 100%, most of them have a decrease in capacity, which means that the battery is aging.

In summary, in the metal ion battery of the present invention, in addition to zinc, copper, lead, indium, lithium iron phosphate, sodium vanadium phosphate or lithium manganese oxide, the positive electrode is made of other materials such as stainless steel, tungsten, lithium vanadium phosphate, and vanadium phosphate. Potassium, etc. can also be used in the positive electrode of the present invention, and in addition to zinc, copper, lead or indium, tungsten can also be used in the negative electrode of the present invention.

The present invention also conducts tests on the electrolyte composition without adding acetonitrile to compare with the above experimental results, and the comparative examples of the test results are described below.

Comparative Example: Zinc/Sodium Vanadium Phosphate Battery Half Cell Test

In order to verify the impact of the electrolyte composition without added acetonitrile on the battery, and to confirm that the electrolyte composition with added acetonitrile does significantly improve the performance of the battery. This test uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode, zinc as the negative electrode, and zinc chloride, lithium chloride and acetonitrile in a molar weight ratio of 30:5:0. Please refer to Figure 16 for the Coulombic efficiency and specific capacity results obtained under the condition of 100mA/g current density. It shows that after about 250 cycle tests, although the Coulombic efficiency is still close to 100%, the specific capacity has increased significantly. dropped to about 67% of the initial amount. Compared with the experimental results of adding acetonitrile in Experiment 7, not only the Coulombic efficiency of adding acetonitrile is close to 100%, but its specific capacity is also close to the initial amount. Therefore, the electrolyte composition of adding acetonitrile It has a significant inhibitory effect on battery aging, so acetonitrile can effectively extend the life of the battery and improve its performance.

In addition, in order to verify the impact of the electrolyte composition without adding acetonitrile and lithium chloride on the battery, and to confirm that the electrolyte composition with acetonitrile and lithium chloride added has indeed significantly improved the performance of the battery. This test also uses sodium vanadium phosphate (Na ₃ V ₂ (PO ₄ ) ₃ ) as the positive electrode and zinc as the negative electrode, and the weight molar concentration ratio is 7.5:0:0, 20:0:0, 20: For the Coulombic efficiency and specific capacity results of 10:0 zinc chloride, lithium chloride and acetonitrile under the condition of 100mA/g current density, please refer to Figure 17-19, which shows that after about 250 cycles of testing, The capacity dropped significantly to about 20%, 78%, and 65% of the initial amount respectively. This result once again confirmed that batteries without acetonitrile are very prone to aging, while lithium chloride not added seems to have little impact on the battery. In addition to the Coulombic efficiency falling to 70% at the weight molar concentration ratio of 7.5:0:0, the Coulombic efficiency of the other two concentrations is close to 100%. From this, it can be seen that the weight molar concentration of zinc chloride has a significant impact on the Coulombic efficiency. It has an important impact on the improvement and battery cycle stability.

The electrolyte composition designed by the present invention adds acetonitrile as a diluent and coordination As a source of ions, higher salt concentrations can be used to achieve concentrations beyond what previous technologies could achieve, thereby reducing the free water activity in the electrolyte to improve the performance and life of aqueous zinc-ion batteries.

The invention solves the problem that during the cyclic charge and discharge process of today's zinc ion batteries, due to the lower concentration, there are too many free water molecules, which makes the zinc ions unstable during the deposition process, generates zinc passivation and side reactions, and cannot be used during the discharge process. Dissolution, if accumulated for a long time, will pierce the isolation film and touch the cathode, causing the battery to short-circuit and die. Moreover, due to excessive free water, the cathode material is very easy to dissolve or the battery generates gas, causing the battery capacity to rapidly decay.

The concentration of the electrolyte composition used in the present invention and the battery system used are higher than those used in the prior art, and can be more widely used in various systems such as anode-free and cathode intercalation materials. Through the CN ^- ions and zinc ions in acetonitrile, The unique interaction and interaction can reduce the water activity in the electrolyte and at the same time have stable and efficient deposition/dissolution performance on different anode metal surfaces or ion intercalation anodes, and can also prevent general cathode materials from dissolving in aqueous electrolytes. phenomenon.

It should be understood that the foregoing description of the embodiments is given by way of example only, and various modifications may be made by those skilled in the art. The above specification and examples provide a complete description of the procedures and uses of illustrative embodiments of the invention. Although the above embodiments disclose specific examples of the present invention, they are not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can, without departing from the principles and spirit of the present invention, Various changes and modifications can be made to it, so the protection scope of the present invention shall be defined by the appended patent application scope.

1: Metal ion battery

11: Positive pole

12: Isolation film

13: Negative pole

14: Electrolyte composition

Claims (7)

An electrolyte composition for metal ion batteries, which includes: zinc chloride, a group IA metal chloride, acetonitrile and hydrochloric acid, wherein the group IA metal chloride is lithium chloride. The electrolyte composition as described in claim 1, wherein the weight molar concentration ratio of the zinc chloride, the Group IA metal chloride and the acetonitrile is 25:19:8, 30:19:8 or 30:22:8 . The electrolyte composition as described in claim 1, wherein the weight percentage concentration of the hydrochloric acid is 0.5wt% or 1wt%. The electrolyte composition according to claim 1, wherein the weight percentage concentration of the hydrochloric acid is 0.5wt% to 1wt%. A metal ion battery, including: a positive electrode; a separator; a negative electrode, wherein the negative electrode is separated from the positive electrode by the separator; and the electrolyte composition as described in any one of claims 1-4, disposed on the between the positive electrode and the negative electrode. The metal ion battery as claimed in claim 5, wherein the metal ion battery is a zinc ion battery. The metal ion battery as described in claim 5, wherein the positive electrode is stainless steel, tungsten, zinc, copper, lead, indium, lithium iron phosphate, sodium vanadium phosphate, lithium vanadium phosphate, potassium vanadium phosphate or lithium manganese oxide, and the The negative electrode is zinc, copper, lead, tungsten or indium.