CN220306301U

CN220306301U - Three-electrode battery and electric automobile

Info

Publication number: CN220306301U
Application number: CN202321792776.2U
Authority: CN
Inventors: 张云波
Original assignee: Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2024-01-05
Anticipated expiration: 2033-07-07

Abstract

The utility model discloses a three-electrode battery and an electric automobile. The three-electrode battery includes: the shell is an aluminum-plastic shell; the winding core structure is arranged in the shell and comprises a main winding part and a secondary winding part, wherein the main winding part comprises a positive pole piece, a first diaphragm, a negative pole piece and a second diaphragm which are sequentially stacked, the positive pole piece is arranged on a positive pole lug, and the negative pole piece is provided with a negative pole lug; the secondary winding part is arranged between the first diaphragm and the negative electrode plate and comprises a third diaphragm and a third electrode, and the third diaphragm is wrapped outside the third electrode; the positive electrode tab, the negative electrode tab and the third electrode are exposed relative to the shell. The three-electrode battery is convenient to package with the winding core structure in a hot-pressing mode because the shell is an aluminum plastic shell, and is convenient to prepare.

Description

Three-electrode battery and electric automobile

Technical Field

The utility model relates to the technical field of batteries, in particular to a three-electrode battery and an electric automobile.

Background

The lithium ion battery has the advantages of high energy density, quick charge and discharge, long cycle life, no pollution and the like, and is widely applied to the fields of portable electronic equipment, communication, energy storage and electric automobiles. With the technical development of lithium ion batteries, the performance requirements of various industries are higher and higher, so that the development test and evaluation of the electrochemical performance of new electrode materials and battery systems of the batteries are required.

The three-electrode technology is a means capable of testing the voltage working interval of the battery in situ, and analyzing the working potential of the positive electrode and the negative electrode and the polarization condition of the electrode of the battery, so that conditions can be created for the research of the attenuation mechanism of the battery and the optimization of a positive electrode material system and a negative electrode material system, and the three-electrode technology has very important guiding significance in the structural design of the battery, the pole piece design, the proportion of the positive electrode and the negative electrode, the material collocation, the optimization of the electrolyte components and the like.

In the traditional cylindrical battery, the battery shell is a steel shell, so that the hardness is high, and the three-electrode battery is difficult to prepare.

Disclosure of Invention

In order to solve at least one of the problems in the prior art, the present utility model provides a three-electrode battery, so that the three-electrode battery can be conveniently formed, and the condition of the battery can be conveniently analyzed.

According to an aspect of the present utility model, there is provided a three-electrode battery including: the shell is an aluminum-plastic shell; the winding core structure is arranged in the shell and comprises a main winding part and a secondary winding part, wherein the main winding part comprises a positive pole piece, a first diaphragm, a negative pole piece and a second diaphragm which are sequentially stacked, the positive pole piece is arranged on a positive pole lug, and the negative pole piece is provided with a negative pole lug; the secondary winding part is arranged between the first diaphragm and the negative electrode plate and comprises a third diaphragm and a third electrode, and the third diaphragm is wrapped outside the third electrode; the positive electrode tab, the negative electrode tab and the third electrode are exposed relative to the shell.

Thus, the third separator comprises a first wrapping portion and a second wrapping portion which are integrally arranged, and the third electrode is clamped between the first wrapping portion and the second wrapping portion.

In some embodiments, the total length of the first wrapper and the second wrapper is 15-25mm along the winding direction of the main roll portion.

In some embodiments, the first wrapper and the second wrapper are the same length along the winding direction of the main roll portion.

In some embodiments, the third electrode is buried in the third separator to a depth of 1/3 to 1/2 of the height of the third separator in the height direction of the main roll portion.

In some embodiments, the third electrode has a total length of between 90 and 150 mm.

In some embodiments, the third electrode is a copper wire.

In some embodiments, the copper wire has a diameter between 0.04 and 0.06 mm.

In some embodiments, the surface of the third electrode has protrusions.

In another aspect of the present utility model, an electric vehicle is provided.

Drawings

Fig. 1 is a schematic structural view of a three-electrode battery according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of the main roll portion of an embodiment of the present utility model;

FIG. 3 is a schematic view of a secondary winding portion according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a winding core structure according to an embodiment of the present utility model;

FIG. 5 is a schematic view of the case of FIG. 1 before it is prepared into a three-electrode battery;

fig. 6 is a schematic flow chart of a method for manufacturing a three-electrode battery according to an embodiment of the utility model;

fig. 7 is a graph showing the voltage and the lithium plating time between the positive electrode tab and the third electrode of the three-electrode battery according to the embodiment of the present utility model;

fig. 8 is a graph showing a change in voltage and a lithium plating time between a negative electrode tab and a third electrode of a three-electrode battery according to an embodiment of the present utility model.

Wherein the reference numerals have the following meanings:

100-three-electrode battery, 10-shell, 20-roll core structure, 21-main roll part, 211-positive electrode plate, 212-first diaphragm, 213-negative electrode plate, 214-second diaphragm, 215-positive electrode tab, 216-negative electrode tab, 22-secondary roll part, 221-third diaphragm, 2211-first package part, 2212-second package part, 222-third electrode.

Detailed Description

For a better understanding and implementation, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model.

In the description of the present utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model.

The utility model is described in further detail below with reference to the accompanying drawings.

When the battery is charged at low temperature or high rate, there may be a problem that lithium ions cannot be timely intercalated between graphite layers after reaching the negative electrode, and lithium precipitation occurs, i.e., a polarization phenomenon caused by limited kinetics. Therefore, in order to better study various electrochemical performances of the battery, reference electrodes are often introduced, and the potentials of the positive electrode and the negative electrode relative to the reference electrodes and the potential changes thereof under different test working conditions are tested respectively. The three electrodes can be used for comprehensive and in-situ Analysis on the aspects of film forming reaction, cyclic charge and discharge, multiplying power charge and discharge, high-low temperature charge and discharge, quantitative Analysis of lithium precipitation of the battery, positive and negative electrode impedance change, FA (Failure Analysis) and the like.

In the traditional cylindrical battery, the shell is a steel shell, so that the hardness is high, and the reference electrode is inconvenient to put into the battery, and therefore, the three-electrode battery provided by the utility model can be molded conveniently and rapidly.

Referring to fig. 1 to 5, a three-electrode battery 100 according to an embodiment of the present utility model includes a case 10 and a winding core structure 20.

The shell 10 is used for providing an accommodating space, and the shell 10 is an aluminum plastic shell; the winding core structure 20 is arranged in the shell 10 and comprises a main winding part 21 and a secondary winding part 22, wherein the main winding part 21 comprises a positive pole piece 211, a first diaphragm 212, a negative pole piece 213 and a second diaphragm 214 which are sequentially stacked, the positive pole piece 211 is arranged on a positive pole lug 215, and the negative pole piece 213 is provided with a negative pole lug 216; the secondary winding part 22 is arranged between the first diaphragm 212 and the negative electrode plate 213 and comprises a third diaphragm 221 and a third electrode 222, and the third diaphragm 221 is wrapped outside the third electrode 222; the positive electrode tab 215, the negative electrode tab 216 and the third electrode 222 are all exposed out of the case 10.

In the above three-electrode battery 100, the secondary winding portion 22 is placed in the main winding portion 21 to introduce the third electrode 222 through the secondary winding portion 22, and then the main winding portion 21 and the secondary winding portion 22 are packaged by the housing 10 to obtain the three-electrode battery 100, which is used for analyzing the service condition of the battery, for example, for judging the failure condition of the battery, and since the housing 10 adopts the aluminum plastic shell mode, after the winding core structure 20 is manufactured, the three-electrode battery 100 is conveniently packaged with the winding core structure 20 by hot pressing, thereby facilitating the manufacture of the three-electrode battery 100.

The three-electrode battery 100 in this example was prepared by disassembling a cylindrical battery sample at the time of preparation. Specifically, the cylindrical battery sample is discharged to 0% soc in the 1C state to ensure the test accuracy when the three-electrode battery 100 is manufactured, and then the steel case of the cylindrical battery sample and the winding core inside the steel case are split, and the winding core after the split is the main winding portion 21 in this embodiment.

Further, after the disassembly of the inner core and the outer steel can is completed, the end glue of the end of the core is disassembled, and a section of the positive electrode tab 211, the first separator 212, the negative electrode tab 213, and the second separator 214 at the tail of the core are partially unrolled to enable the placement of the sub-roll portion 22 in the subsequent process, for example as shown in fig. 2.

Specifically, referring to fig. 3, in the present embodiment, when the secondary winding portion 22 is prepared, the third separator 221 includes a first wrapping portion 2211 and a second wrapping portion 2212 that are integrally disposed, and the third electrode 222 is sandwiched between the first wrapping portion 2211 and the second wrapping portion 2212, specifically, the third separator 221 forms the first wrapping portion 2211 and the second wrapping portion 2212 in a doubling-up manner, so that wrapping of the third electrode 222 is achieved by doubling up the third separator 221, so that when the primary winding portion 21 is placed, it can be isolated from the positive electrode tab 211 and the negative electrode tab 213; while the separation of the third electrode 222 by doubling up is facilitated, and the entire sub-roll portion 22 is also facilitated to be placed in the main roll portion 21. In other embodiments, two separate diaphragms may be directly employed to sandwich the third electrode 222 between the two separate diaphragms.

The cylindrical battery to which the three-electrode battery 100 of the present embodiment is applied is 18650 or 21700, and the height of the third separator 221 of the embodiment corresponds to the height of 18650 or 21700, i.e., may be 65mm or 70mm, in order to correspond to the size of 18650 or 21700. In other embodiments, the height of the corresponding housing 10 and the size of the third membrane 221 may be prepared according to the size of the cylindrical battery sample to be prepared.

Further, the third separator 221 of the present embodiment has a length ranging from 15 to 25mm before being folded in half in the winding direction of the main winding portion 21, so that the first and second wrapping portions 2211 and 2212 after being folded in half can have a certain length to be effectively isolated from the pole piece in the main winding portion 21 when being wound back with the main winding portion 21, and the third electrode 222 can be stably wound inside the main winding portion 21.

Further, after the third separator 221 of the present embodiment is folded in half, the lengths of the first and second wrapping portions 2211 and 2212 are the same along the winding direction of the main roll portion 21, that is, when the first and second wrapping portions 2211 and 2212 are formed, both end portions of the third separator 221 are folded in half in a mutually adhering manner to form the first and second wrapping portions 2211 and 2212. In other embodiments, the first and second wrapping portions 2211 and 2212 may have different lengths along the winding direction of the main winding portion 21, as desired.

Referring to fig. 3, when the third electrode 222 is embedded in the third membrane 221, the third electrode 222 is embedded in the third membrane 221 along the height direction of the main winding portion 21 to a depth of 1/3-1/2 of the height of the third membrane 221, so that the embedded length of the third electrode 222 in the third membrane 221 is ensured, the third membrane 221 has a sufficient contact area, the stability of the clamping of the third electrode 222 in the main winding portion 21 is ensured, and the whole winding core structure 20 is prevented from falling out in the winding process. In some embodiments, for example, third electrode 222 is buried into third membrane 221 to a depth of 1/3, 2/5, or 1/2, etc. of the length of the membrane.

Further, to ensure that the third electrode 222 has a sufficient length to be exposed outside the housing 10 for measurement, the total length of the third electrode 222 is between 90-150mm, so that a sufficient contact area with the third membrane 221 can be ensured, and a sufficient reserved length outside the winding core structure 20 can be provided for use in a subsequent measurement process. In some embodiments, for example, corresponding to a 18650 model of cylindrical battery, the total length of the third electrode 222 may be set to a value of 90mm, 95mm, 100mm, etc., which is not limited herein; when corresponding to a 21700 model of cylindrical battery, the total length of the third electrode 222 may be set to a value of 100mm, 110mm, 120mm, or the like, which is not limited herein.

The third electrode 222 in the embodiment is a copper wire, and the copper material has a lower price and higher stability, so as to have the effects of saving cost and prolonging service life. Meanwhile, copper is more resistant to use than lithium materials, lithium is easily oxidized and consumed, and platinum is expensive, so the third electrode 222 in this embodiment is made of copper materials.

Specifically, when a copper wire is used as the third electrode 222, the copper wire has a diameter of between 0.04 and 0.06mm so as to be manually seen by naked eyes to be placed in the third membrane 221. For example, in some embodiments, the diameter of the copper wire is a value of 0.04mm, 0.05mm, 0.06mm, etc. In one specific implementation of the utility model, the diameter of the copper wire is 0.05mm, and in other embodiments, copper wires of other diameter values may be selected as desired.

In addition, in order to ensure the accuracy of the copper wire test, the surface of the third electrode 222 has protrusions, so that the surface of the copper wire is rugged, and the surface is in a rough state, so that lithium ions can adhere to the surface in the subsequent lithium plating process.

Specifically, in the present example, when forming protrusions on the surface of the copper wire, the copper wire was put into a 5% wt nitric acid solution and subjected to an ultrasonic environment to allow the oxide on the surface of the copper wire and nitric acid to react sufficiently to form protrusions on the surface of the copper wire.

Referring to fig. 1 and 5, in an embodiment of the present utility model, the housing 10 is an aluminum-plastic housing, and the aluminum-plastic housing is stamped into a cylindrical shape before being installed on the winding core structure 20, so as to adapt to the shape of the winding core structure 20, so that the housing 10 can be respectively connected with the positive electrode tab 215 and the negative electrode tab 216 by hot pressing. Specifically, during hot pressing, the positive electrode tab 215 and the negative electrode tab 216 are provided with tab glue corresponding to the welding area, the aluminum plastic shell is pressurized by the two semicircular sealing heads after heating on the upper side and the lower side of the tab area, so that the tab glue on the tab and the PP layer of the aluminum plastic shell are melted and adhered into a whole, meanwhile, other areas of the aluminum plastic shell are melted and flowed through polymers on the aluminum plastic shell to generate crosslinking, packaging effect is realized after cooling, and meanwhile, the positive electrode tab 215, the negative electrode tab 216 and the third electrode 222 are exposed relative to the aluminum plastic shell so as to facilitate subsequent test and use.

Specifically, the three-electrode battery 100 in the present embodiment assumes a cylindrical shape after the preparation is completed, the positive electrode tab 215 and the third electrode 222 are located at one end of the three-electrode battery 100, and the negative electrode tab 216 is located at the other end of the three-electrode battery 100.

Referring to fig. 6 to 8, the present utility model further provides a method 200 for preparing a three-electrode battery 100 according to a second embodiment, which includes the following steps:

s21, providing a main roll portion 21, where the main roll portion 21 includes a positive electrode plate 211, a first diaphragm 212, a negative electrode plate 213 and a second diaphragm 214 stacked in sequence, the positive electrode plate 211 is provided with a positive electrode tab 215, and the negative electrode plate 213 is provided with a negative electrode tab 216.

Specifically, the main roll portion 21 in this embodiment is provided in such a manner that a cylindrical battery sample using a steel can is disassembled.

The cylindrical battery sample was discharged to 0% soc prior to disassembly of the cylindrical battery sample. Specifically, the lithium ions intercalated in the negative electrode are returned to the positive electrode as much as possible by discharging to 0% soc at a discharge rate of 1C, reducing the amount of active lithium ions in the negative electrode.

After the discharge of the cylindrical battery sample is completed, the cylindrical battery sample is disassembled, and the case 10 and the inner winding core are detached, and the detached winding is the main winding part 21. As can be appreciated, the positive electrode tab 211 in the disassembled main roll portion 21 is provided with a positive electrode tab 215, the negative electrode tab 213 is provided with a negative electrode tab 216, and the positive electrode tab 215 and the negative electrode tab 216 have a certain length, specifically, the reserved lengths of the positive electrode tab 215 and the negative electrode tab 216 in the embodiment are 10mm, so as to be used for packaging in the subsequent steps; meanwhile, the termination adhesive at the tail end of the winding core is disassembled, and the positive electrode plate 211, the first diaphragm 212, the negative electrode plate 213 and the second diaphragm 214 which are part of the length of the tail end of the winding core are unfolded from the winding state.

S22, a third electrode 222 and a third separator 221 are provided, and the third separator 221 is wrapped around the third electrode 222 to constitute a sub-roll portion 22.

The third electrode 222 in the embodiment is a copper wire, and the copper material has a lower price and higher stability, so as to have the effects of saving cost and prolonging service life. Meanwhile, copper is more resistant to use than lithium materials, lithium is easily oxidized and consumed, and platinum is expensive, so the third electrode 222 in this embodiment is made of copper materials. Specifically, when a copper wire is used as the third electrode 222, the copper wire has a diameter of between 0.04 and 0.06mm so as to be easily seen by human eyes, thereby being easily inserted into the third membrane 221.

The third separator 221 wraps the third electrode 222 in such a manner that the third separator 221 is folded in half to form a first wrapping portion 2211 and a second wrapping portion 2212, and the third electrode 222 is sandwiched between the first wrapping portion 2211 and the second wrapping portion 2212, so that the third separator 221 is folded in half to wrap the third electrode 222, so that the third separator can be isolated from the positive electrode tab 211 and the negative electrode tab 213 when the main winding portion 21 is placed; while the separation of the third electrode 222 by doubling up is facilitated, and the entire sub-roll portion 22 is also facilitated to be placed in the main roll portion 21. In other embodiments, two separate diaphragms may be directly employed to sandwich the third electrode 222 between the two separate diaphragms.

In addition, before the step of providing the sub-rolled portion 22, the manufacturing method of the three-electrode battery 100 further includes:

s221, the third electrode 222 is reacted for 30-60min in an ultrasonic environment by using 5% wt nitric acid.

In this step, the third electrode 222 is placed in 5% wt nitric acid under an ultrasonic environment, so that the oxide on the surface of the third electrode 222 and nitric acid are fully reacted and completely oxidized, the copper wire is exposed outside, and after being fully reacted with nitric acid, the surface of the third electrode 222 has rugged protrusions, so that lithium ions can be plated in the subsequent process.

And S222, cleaning the third electrode 222 by adopting ethanol in an ultrasonic environment for 30-60min.

After the reaction in the above step is completed, the third electrode 222 is cleaned by using ethanol in an ultrasonic environment in this step to clean the nitric acid on the surface of the third electrode 222.

S23, the sub-winding portion 22 is placed between the first separator 212 of the main winding portion 21 and the negative electrode sheet 213, and the main winding portion 21 and the sub-winding portion 22 are wound and restored to the winding core structure.

In this step, after the secondary winding portion 22 is placed on the primary winding portion 21, the whole is rewound and wound into a cylindrical shape, thereby obtaining a new winding core structure 20.

S24, providing the housing 10 formed by an aluminum plastic housing, and packaging the housing 10 with the main roll portion 21 and the sub roll portion 22.

Specifically, the casing 10 of this embodiment is an aluminum-plastic casing, the aluminum-plastic casing is first stamped to be circular, the recovered winding core structure 20 is put into the aluminum-plastic casing, then the aluminum-plastic casing is subjected to hot-pressing encapsulation through two semicircular sealing heads, after encapsulation is completed, the positive electrode tab 215 and the third electrode 222 are located at one end of the three-electrode battery 100, and the negative electrode tab 216 is located at the other end of the three-electrode battery 100.

S25, an electrolyte is injected into the case 10.

After the encapsulation of the housing 10 and the winding core structure 20 is completed, a liquid injection process is performed in this step, and an electrolyte is injected into the housing 10.

In addition, in order to allow the electrolyte to be sufficiently impregnated in the jelly-roll structure 20, the manufacturing method of the three-electrode battery 100 further includes, after injecting the electrolyte into the case 10:

three-electrode cell 100 was left to stand in an oven for 12-24H.

That is, at a higher temperature of the oven, the mobility of the liquid molecules in the electrolyte increases, the mobility of the electrolyte increases, and during this period of 12-24H, the electrolyte molecules infiltrate into the interior of the jellyroll structure 20 sufficiently, ensuring the accuracy of the subsequent testing of the three-electrode battery 100.

And S26, lithium plating is performed on the third electrode 222.

After the injection of the electrolyte in the above steps is completed and after the electrolyte is sufficiently impregnated in the winding core structure 20, the third electrode 222 is subjected to lithium plating in this step.

Specifically, the third electrode 222 is subjected to lithium plating in the following manner: (1) Firstly, the positive electrode tab 215 is used for connecting an external positive electrode, the third electrode 222 is used for connecting an external negative electrode, and the 10uA current is used for charging 10H; (2) The external positive electrode is turned on with the negative tab 216, the external negative electrode is turned on with the third electrode 222, and the 10H is charged with 10uA current.

Wherein:

the graph of the voltage change with time corresponding to the step (1) is shown in fig. 7;

the graph of the voltage change with time corresponding to the step (2) is shown in fig. 8.

After the preparation of the three-electrode battery 100 and the lithium plating of the third electrode 222 are completed, the preparation method of the three-electrode battery 100 further includes a detection process for the three-electrode battery 100, specifically, the detection method is as follows:

s261, acquiring a first voltage between the positive electrode tab 215 and the third electrode 222;

s262, obtaining a second voltage between the negative electrode tab 216 and the third electrode 222;

s263, obtaining a difference value between the first voltage and the second voltage;

s264, judging whether the difference value is within a preset range;

s265, if yes, indicates that the three-electrode battery 100 is successfully manufactured.

Specifically, if the difference between the first voltage and the second voltage is less than or equal to 20mV, it indicates that the three-electrode battery 100 is successfully manufactured.

In the above method for manufacturing a three-electrode battery, the main winding portion 21 and the sub-winding portion 22 are manufactured, and the sub-winding portion 22 is placed between the first separator 212 and the negative electrode sheet 213 of the main winding portion 21 to obtain the winding core structure 20, the third electrode 222 is introduced from the sub-winding portion 22, and then the main winding portion 21 and the sub-winding portion 22 are packaged by the case 10 formed by the aluminum plastic shell, so as to manufacture the three-electrode battery 100.

In another aspect, the utility model also provides an electric automobile comprising the three-electrode battery.

The technical means disclosed by the scheme of the utility model is not limited to the technical means disclosed by the embodiment, and also comprises the technical scheme formed by any combination of the technical features. It should be noted that modifications and adaptations to the utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims

1. A three-electrode battery, comprising:

the shell is an aluminum-plastic shell;

the winding core structure is arranged in the shell and comprises a main winding part and a secondary winding part, wherein the main winding part comprises a positive pole piece, a first diaphragm, a negative pole piece and a second diaphragm which are sequentially stacked, the positive pole piece is arranged on a positive pole lug, and the negative pole piece is provided with a negative pole lug; the secondary winding part is arranged between the first diaphragm and the negative electrode plate and comprises a third diaphragm and a third electrode, and the third diaphragm is wrapped outside the third electrode;

the positive electrode tab, the negative electrode tab and the third electrode are exposed relative to the shell.

2. The three electrode battery of claim 1, wherein the third separator comprises a first wrap and a second wrap integrally disposed, the third electrode being sandwiched between the first wrap and the second wrap.

3. The three-electrode battery according to claim 2, wherein the total length of the first wrapping portion and the second wrapping portion in the winding direction of the main roll portion is 15-25mm.

4. The three-electrode battery according to claim 2 or 3, wherein the lengths of the first wrapping portion and the second wrapping portion are the same along the winding direction of the main roll portion.

5. A three-electrode battery according to any one of claims 1 to 3, wherein the third electrode is buried in the third separator to a depth of 1/3 to 1/2 of the height of the third separator in the height direction of the main roll portion.

6. A three electrode battery according to any one of claims 1-3, wherein the total length of the third electrode is between 90-150 mm.

7. A three electrode battery according to any one of claims 1-3, wherein the third electrode is a copper wire.

8. The three electrode battery of claim 7, wherein the copper wire has a diameter between 0.04-0.06 mm.

9. A three electrode battery according to any one of claims 1-3, wherein the surface of the third electrode has protrusions.

10. An electric vehicle comprising a three-electrode battery according to any one of claims 1 to 9.