Negative electrode material, secondary battery and electrical equipment

Abstract

The present application provides a negative electrode material, a secondary battery, and an electrical device. The negative electrode material has a core-shell structure, comprising a core material and a shell layer, wherein the shell layer comprises an outer shell material, and the outer shell material comprises a cationic conductor material and a conductive sub-material; the cationic conductor material exists in a quasi-crystalline state. The presence of the cationic conductor material and the conductive sub-material can improve the electronic and electrical conductivity of the negative electrode material. The core-shell structure prevents direct contact between the electrolyte and the core material, thereby improving the battery's rate capability and cycle stability.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a negative electrode material, a secondary battery and an electrical device. Background Art

[0002] Secondary batteries, particularly sodium-ion batteries, not only offer the advantages of abundant sodium resources, widespread distribution, low cost, no development bottlenecks, environmental friendliness, and compatibility with existing lithium-ion battery production equipment, but also boast superior power characteristics, wide temperature adaptability, safety, and freedom from overdischarge. Furthermore, sodium-ion batteries share a similar structure to lithium-ion batteries, allowing for large-scale production that leverages the same production and testing equipment, process technologies, and manufacturing methods as lithium-ion batteries.

[0003] During the initial charge and discharge cycle of a battery, the negative electrode material and the electrolyte react at the solid-liquid interface to form an interfacial film. However, this interfacial film has poor chemical stability and poor ionic and electronic conductivity, increasing the battery's internal resistance and limiting its rate performance and cycling stability. Summary of the Invention

[0004] The technical problem to be solved by the present application is to overcome the defects of the negative electrode materials used in the prior art that lead to poor rate performance and cycle stability of the battery, thereby providing a negative electrode material, a secondary battery and an electrical device.

[0005] In view of this, the present application first provides a negative electrode material, which has a core-shell structure, wherein the core-shell structure includes a core material and a shell layer arranged on the surface of the core material, the shell layer includes an outer shell material, and the outer shell material includes a cationic conductor material and a conductive material; the existence form of the cationic conductor material includes a quasi-crystalline state.

[0006] Furthermore, the negative electrode material has a porous structure with a pore size of 0.1 nm to 50 nm.

[0007] Furthermore, the cation conductor material includes Na 1 / 2 La 1 / 2 One of TiO3, Na3PO4, NaAlO2 or Na2SiO3 or a combination of any of them, the particle size of the cationic conductor material is 20nm to 100nm.

[0008] Furthermore, the core material includes one or a combination of any of hard carbon, titanium dioxide, tin-containing alloy, tin-containing oxide and phosphorus-containing compound.

[0009] Furthermore, the particle size of the core material is 0.5um to 50um, and the core material has a non-porous structure.

[0010] Furthermore, the mass content of the shell material in the negative electrode material is 0.1% to 0.5%.

[0011] Furthermore, the thickness of the shell layer is 100nm to 500nm.

[0012] Furthermore, the Dv50 of the negative electrode material is 1 μm to 20 μm.

[0013] Furthermore, the conductive electronic material includes one or more of graphene, carbon nanotubes, carbon fibers and Ketjen black, and the structure of the conductive electronic material includes one or more of flocculent, sheet-like and honeycomb-like.

[0014] Furthermore, the shell layer satisfies any one of the following conditions:

[0015] a. The cationic conductor material and the conductive sub-material are combined to form the shell layer;

[0016] b. The shell layer includes a first shell and a second shell, the first shell is at least partially distributed on the surface of the core material, the second shell is at least partially distributed on the surface of the first shell, the cationic conductor material is distributed in the first shell, and the conductive material is distributed in the second shell.

[0017] The present application also provides a secondary battery, comprising a negative electrode plate, wherein the negative electrode plate comprises the above-mentioned negative electrode material.

[0018] The present application also provides an electrical device, comprising the above-mentioned secondary battery, wherein the secondary battery serves as a power supply for the electrical device.

[0019] The negative electrode material, secondary battery, and electrical device provided herein include a shell material in the negative electrode material that can reduce the contact probability between the core material and the electrolyte and reduce the probability of passivation of particles in the core material. Furthermore, the cationic conductor material in the shell material is primarily used to conduct cations, and the conductive material is primarily used to conduct electrons, which can increase the transmission speed of cations and electrons, reduce the impedance of the negative electrode material, and thus improve the battery's charging rate and cycle life. Furthermore, the cationic conductor material can exist in a quasicrystalline state, which is an intermediate state between the crystalline and amorphous states. This state can enhance the structural stability of the cationic conductor material and further improve the battery's cycle life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 The microstructure of the negative electrode material of an embodiment is shown under a high-resolution transmission electron microscope. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described are only part of the embodiments of this application, not all of them.

[0023] In one embodiment, the present application provides a negative electrode material having a core-shell structure, wherein the core-shell structure includes a core material and a shell layer arranged on the surface of the core material, the shell layer includes an outer shell material, and the outer shell material includes a cationic conductor material and a conductive sub-material; the existence form of the cationic conductor material includes a quasi-crystalline state.

[0024] In this embodiment, the shell layer is at least partially distributed on the surface of the core material. The shell layer in the negative electrode material includes a shell material. The shell material can prevent the electrolyte from directly contacting the core material, thereby reducing the contact probability between the core material and the electrolyte and reducing the probability of the core material being passivated by the electrolyte. Secondly, the cationic conductor material in the shell material is mainly used to conduct cations, and the conductive material is mainly used to conduct electrons. Therefore, the ion conductivity and conductive properties of the negative electrode material can be improved, thereby reducing the impedance of the negative electrode material, thereby improving the charge and discharge rate and cycle stability of the battery. In addition, the existence form of the cationic conductor material includes a quasi-crystalline state, referring to Figure 1 As shown, the morphology of the material can be determined using high-resolution transmission electron microscopy (HRTEM). The quasicrystalline state is a state between the crystalline and amorphous states. This state can enhance the structural stability of the cationic conductor material, further improving the charge-discharge rate and cycle stability.

[0025] In some embodiments, the mass ratio of the cationic conductor material to the conductive sub-material is (1:2) to (3:1). Within the above ratio range, the negative electrode material can be guaranteed to have both suitable electrical conductivity and ion conductivity.

[0026] In one embodiment, the negative electrode material has a porous structure. The porous structure can improve the electrolyte's wetting effect on the negative electrode material, shorten the cation transport path, and increase the cation transport speed in the negative electrode sheet, which is beneficial for improving the battery's rate performance and cycle stability.

[0027] In one embodiment, the pore size of the negative electrode material is 0.1 nm to 50 nm, for example, in the range of one or both of 0.1 nm, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm. If the pore size is too small, it is not conducive to the electrolyte infiltration effect, resulting in increased interfacial impedance. If the pore size is too large, on the one hand, it will affect the compaction density of the negative electrode material and affect the specific capacity of the battery. On the other hand, it is easy to induce side reactions, which will deteriorate the cycle performance of the battery.

[0028] In one embodiment, the cation conductor material includes Na 1 / 2 La 1 / 2 One or a combination of any of TiO3, Na3PO4, NaAlO2 or Na2SiO3, wherein the above compounds have excellent sodium ion conductivity and improve the migration rate of sodium ions.

[0029] In one embodiment, the particle size of the cationic conductor material is 20 nm to 100 nm, for example, one or both of 20 nm, 40 nm, 60 nm, 80 nm, or 100 nm. A reasonable particle size range ensures a suitable porosity in the shell layer while also shortening the cation transport path, thereby increasing the migration rate of sodium ions.

[0030] In one embodiment, the specific surface area of ​​the cationic conductor material particles is 3 mm 2 / g~10mm 2 / g, for example 3mm 2 / g, 5mm 2 / g, 7mm 2 / g, 9mm 2 / g, or 10mm 2 / g. In this embodiment, the cationic conductor material with the above-mentioned particle size range of 20nm to 100nm is used, which can make the particles in the cationic conductor material have a suitable specific surface area, thereby improving the rate performance and cycle life of the battery. If the specific surface area of ​​the particles in the cationic conductor material is too large, the contact area between the negative electrode material and the electrolyte increases, which increases the side reactions and worsens the cycle life of the battery; if the specific surface area of ​​the particles in the cationic conductor material is too small, it causes the sodium ion transmission path to be too long and the reaction area to be too small, which is not conducive to improving the charge and discharge rate performance and cycle performance of the battery. Control the specific surface area of ​​the cationic conductor material to be 3mm 2 / g~10mm2 / g, which can achieve better battery charge and discharge rate and cycle stability.

[0031] In one embodiment, the mass content of the shell material in the negative electrode material is 0.1% to 0.5%, for example, 0.1%, 0.2%, 0.3%, 0.4%, or 0.5%. If the mass content of the shell material in the negative electrode material is too high, the energy density of the negative electrode material will be reduced; if the mass content of the shell material in the negative electrode material is too low, the improvement in the ionic and electronic conductivity of the negative electrode material will be limited. Within the above content range, the battery can ensure excellent rate performance and cycling stability.

[0032] In another embodiment, the shell layer has a thickness of 100 nm to 500 nm, for example, 100 nm, 200 nm, 300 nm, 400 nm, or 500 nm. Within the above thickness range, the negative electrode material can be ensured to have excellent ion conductivity and electronic conductivity while also ensuring the energy density of the negative electrode material.

[0033] In one embodiment, the core material includes one or a combination of any of hard carbon, titanium dioxide, tin-containing alloys, tin-containing oxides, and phosphorus-containing compounds.

[0034] In one embodiment, the core material has a particle size of 0.5 μm to 50 μm, for example, 0.5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm. A reasonable particle size range can improve the battery's charge and discharge rates. In some embodiments, the core material has a non-porous structure. This non-porous core material can increase the compaction density of the negative electrode material and thus increase the energy density of the negative electrode material.

[0035] In one embodiment, the Dv50 of the negative electrode material is 1μm to 20μm. The smaller the particles of the negative electrode material, the smaller the van der Waals force that needs to be overcome when sodium ions are intercalated, making intercalation easier. Furthermore, the smaller the particles, the shorter the channels for sodium ion intercalation and deintercalation, which is more conducive to quickly reaching a fully intercalated state, thereby achieving better charge and discharge performance. Graphite negative electrodes with smaller particles have a larger initial capacity, but also a larger irreversible capacity. As the particle size increases, the initial charge and discharge capacity decreases, and the irreversible capacity decreases. Furthermore, the smaller the graphite particles, the larger the specific surface area in contact with the electrolyte. The SEI film formed during the initial charge and discharge process consumes more charge, resulting in a greater loss of irreversible capacity. Using this particle size distribution can not only improve the initial capacity and initial efficiency of sodium ion batteries, but also improve the cycling performance of sodium ion batteries. Using this particle size distribution is beneficial for increasing the solid content of the negative electrode slurry and reducing the difficulty of coating.

[0036] In one embodiment, the conductive material includes one or more of graphene, carbon nanotubes, carbon fibers, and Ketjen black. The above conductive materials can further improve the conductivity of electrons.

[0037] In one embodiment, the structure of the conductive sub-material includes one or more of flocculent, sheet-like, and honeycomb-like structures. The structure of the conductive sub-material makes the conductive sub-material have a larger specific surface area, which is beneficial to enhancing the conductivity of electrons.

[0038] In some embodiments, the shell layer satisfies any one of the following conditions:

[0039] a. The cationic conductor material and the conductive sub-material are combined to form a shell layer;

[0040] b. The shell layer includes a first shell and a second shell, wherein the first shell is at least partially distributed on the surface of the core material, and the second shell is at least partially distributed on the surface of the first shell, the cationic conductor material is distributed in the first shell, and the conductive material is distributed in the second shell. Figure 1 The structure described.

[0041] In one embodiment, the mass specific capacity of the negative electrode material is greater than or equal to 260 mAh / g.

[0042] The present application also provides a secondary battery, which includes a negative electrode plate, wherein the negative electrode plate includes: a current collector; and a negative electrode material layer located on the surface of the current collector, wherein the negative electrode material layer includes the above-mentioned negative electrode material.

[0043] The current collector is a copper foil current collector, a copper alloy foil current collector or a carbon-based current collector. The carbon-based current collector is a carbon sheet current collector, a carbon nanotube current collector or a graphene current collector.

[0044] In one embodiment, the thickness of the negative electrode plate is 10 um to 200 um, for example, 10 um, 50 um, 100 um, 150 um or 200 um.

[0045] In one embodiment, for a mass of 1.5 g and a tiled area of ​​1.33 cm 2 The negative electrode material layer has a compaction density of 0.5 g / cm3 under a pressure of 30 t. 3 -1.5g / cm 3 , with a surface density of 1 mg / cm 2 -20mg / cm 2 .

[0046] The secondary battery also includes a positive electrode sheet and a separator. The positive electrode sheet and the negative electrode sheet are respectively arranged on both sides of the separator, and are placed in the order of positive electrode sheet, separator and negative electrode sheet. The positive electrode sheet and the negative electrode sheet are wound around each other to form a battery cell; electrolyte is injected into the battery cell to form a secondary battery.

[0047] In one embodiment, the first coulombic efficiency of the secondary battery is 80% to 90%, for example, 80%, 82%, 84%, 86%, 88% or 90%.

[0048] The present application also provides an electrical device, which includes the above-mentioned secondary battery, and the secondary battery serves as a power supply for the electrical device.

[0049] The negative electrode material, secondary battery, and electrical device provided herein include a shell material in the negative electrode material that can reduce the contact probability between the core material and the electrolyte and reduce the probability of passivation of particles in the core material. Furthermore, the cationic conductor material in the shell material is primarily used to conduct cations, and the conductive material is primarily used to conduct electrons, which can increase the transmission speed of cations and electrons, reduce the impedance of the negative electrode material, and thus improve the battery's charging rate and cycle life. Furthermore, the cationic conductor material can exist in a quasicrystalline state, which is an intermediate state between the crystalline and amorphous states. This state can enhance the structural stability of the cationic conductor material and further improve the battery's cycle life.

[0050] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0051] Example 1

[0052] Preparation of negative electrode materials

[0053] 1) At room temperature, 100 g of hard carbon (particle Dv50: 10 μm) was added to 1 L of deionized water, followed by the addition of sodium nitrate, lanthanum nitrate, and titanium nitrate, and the mixture was stirred until completely dispersed and dissolved to obtain a mixed solution having concentrations of 0.25 mol / L, 0.25 mol / L, and 0.5 mol / L, respectively, of sodium nitrate, lanthanum nitrate, and titanium nitrate.

[0054] 2) 10 mL of acetylacetone was slowly added and stirred at room temperature. The reaction product was then allowed to stand for 24 hours to obtain a gel-like substance.

[0055] 3) The gel-like substance was calcined at 800°C for 4 hours to obtain Na 1 / 2 La 1 / 2 TiO3 coated hard carbon material.

[0056] 4) Argon gas was introduced into the high temperature reaction furnace to exhaust the air in the chamber, and the Na 1 / 2 La 1 / 2 TiO3 coated hard carbon material was mixed with graphene and dispersed on the chamber substrate. The chamber temperature was maintained at 700 ° C, and a mixed gas of acetylene and nitrogen with a volume ratio of 1:1 was introduced. The reaction lasted for 1.5 hours, and then cooled to room temperature under a protective atmosphere to obtain a negative electrode material with an average pore size of 25 nm. The core of the negative electrode material was hard carbon, and the shell was graphene and Na 1 / 2 La 1 / 2 Composite material of TiO3, with a shell thickness of 300nm.

[0057] Example 2

[0058] The process is the same as that of Example 1, except that in step 4), the chamber temperature is maintained at 550° C., and a negative electrode material with an average pore size of 0.1 nm is obtained.

[0059] Example 3

[0060] The same as Example 1, except that in step 4), the chamber temperature is maintained at 600° C., and a negative electrode material with an average pore size of 5 nm is obtained.

[0061] Example 4

[0062] The process is the same as that of Example 1, except that in step 4), the chamber temperature is maintained at 650° C., and a negative electrode material with an average pore size of 10 nm is obtained.

[0063] Example 5

[0064] The process is the same as that of Example 1, except that in step 4), the chamber temperature is maintained at 750° C., and a negative electrode material with an average pore size of 40 nm is obtained.

[0065] Example 6

[0066] The same as Example 1, except that in step 4), the chamber temperature is maintained at 800° C., and a negative electrode material with an average pore size of 50 nm is obtained.

[0067] Example 7

[0068] The same as Example 1, except that in step 1), the Dv50 of the hard carbon is 1 μm.

[0069] Example 8

[0070] The same as Example 1, except that in step 1), the Dv50 of the hard carbon is 5 μm.

[0071] Example 9

[0072] The same as Example 1, except that in step 1), the Dv50 of the hard carbon is 15 μm.

[0073] Example 10

[0074] The same as Example 1, except that in step 1), the Dv50 of the hard carbon is 20 μm.

[0075] Example 11

[0076] The same as Example 1, except that the volume of acetylacetone added in step 2) is 3 mL.

[0077] Example 12

[0078] The same as Example 1, except that the volume of acetylacetone added in step 2) is 6 mL.

[0079] Example 13

[0080] The same as Example 1, except that the volume of acetylacetone added in step 2) is 12 mL.

[0081] Example 14

[0082] The same as Example 1, except that the volume of acetylacetone added in step 2) is 15 mL.

[0083] Example 15

[0084] The same as Example 1, except that in step 1), the concentrations of sodium nitrate, lanthanum nitrate, and titanium nitrate in the mixed solution are 0.08, 0.08, and 0.16 mol / L, respectively, to obtain a negative electrode material with a shell thickness of 100 nm.

[0085] Example 16

[0086] The same as Example 1, except that in step 1), the concentrations of sodium nitrate, lanthanum nitrate, and titanium nitrate in the mixed solution are 0.16, 0.16, and 0.32 mol / L, respectively, to obtain a negative electrode material with a shell thickness of 200 nm.

[0087] Example 17

[0088] The same as Example 1, except that in step 1), the concentrations of sodium nitrate, lanthanum nitrate, and titanium nitrate in the mixed solution are 0.32, 0.32, and 0.64 mol / L, respectively, to obtain a negative electrode material with a shell thickness of 400 nm.

[0089] Example 18

[0090] The same as Example 1, except that in step 1), the concentrations of sodium nitrate, lanthanum nitrate, and titanium nitrate in the mixed solution are 0.4, 0.4, and 0.8 mol / L, respectively, to obtain a negative electrode material with a shell thickness of 500 nm.

[0091] Example 19

[0092] The same as Example 1, except that in step 4), the reaction time is 2 h.

[0093] Example 20

[0094] The same as Example 1, except that in step 4), the reaction time is 1.5 h.

[0095] Example 21

[0096] The same as Example 1, except that in step 4), the reaction time is 1 h.

[0097] Example 22

[0098] The same as Example 1, except that in step 1), lanthanum nitrate and titanium nitrate were replaced by aluminum nitrate. The concentrations of sodium nitrate and aluminum nitrate were 0.5 mol / L and 0.5 mol / L, respectively.

[0099] Example 23

[0100] The method is the same as Example 1, except that in step 1), sodium nitrate, lanthanum nitrate and titanium nitrate are replaced by sodium silicate with a concentration of 1 mol / L.

[0101] Example 24

[0102] The same as Example 1, except that in step 1), sodium nitrate, lanthanum nitrate, and titanium nitrate were replaced by sodium phosphate with a concentration of 1 mol / L. In step 4), graphene was replaced by carbon nanotubes.

[0103] Comparative Example 1

[0104] Hard carbon without coating treatment is used as the negative electrode material.

[0105] The relevant parameters of the negative electrode materials prepared in the above Examples 1 to 24 and Comparative Example 1 are recorded in Table 1 (the mass ratio A in Table 1 represents the mass ratio of the cationic conductor material to the electronic material), and the negative electrode material is used as the raw material to prepare a negative electrode plate. The negative electrode plate, the separator and the positive electrode plate are stacked in sequence. The separator adopts PP / PE / PP composite film. Then, the battery cell is wound into a battery cell and loaded into a soft-pack shell. After the top and side sealing and the injection of electrolyte, a soft-pack battery is made. The internal resistance, rate performance and cycle performance of the battery are tested. The test results are shown in Table 2. The preparation process of the above-mentioned negative electrode sheet is: after the negative electrode main material, binder, conductive agent and solvent are evenly mixed, they are evenly coated on the aluminum foil current collector, and after drying at 90°C, it becomes the negative electrode sheet; the production process of the positive electrode sheet is: after the positive electrode main material, binder, conductive agent and solvent are evenly mixed, they are evenly coated on the aluminum foil current collector, and after drying at 90°C, it becomes the positive electrode sheet; preparation of the electrolyte: 1M concentration of NaPF6 is mixed with a mixed solution of EC, DMC and EMC with a mass ratio of 1:1 to obtain the electrolyte.

[0106] The battery testing method is as follows:

[0107] 1) Battery internal resistance test: At room temperature, the battery state is 50% SOC, the open circuit voltage is V0, the 3C rate current is I0, and the voltage after charging for 30s is V1. DCR = (V1-V0) / I0.

[0108] 2) Battery rate performance and cycle performance test: The battery was subjected to cyclic charge and discharge tests at current densities of 1C / 1C, 2C / 2C, 3C / 3C, 4C / 4C, and 5C / 5C, with a voltage range of 3.9V to 1.5V, for 100 cycles, and the battery capacity retention rate at 100 cycles was recorded.

[0109] Table 1

[0110]

[0111]

[0112] Table 2

[0113]

[0114] According to the above data, when the hard carbon surface is coated with cationic conductor materials and conductive electronic materials, the internal resistance of the battery can be significantly reduced, which has a significant effect on improving the battery's rate performance and cycle stability.

[0115] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A negative electrode material, characterized in that The negative electrode material has a core-shell structure, the core-shell structure includes a core material and a shell layer arranged on the surface of the core material, the shell layer includes a shell material, and the shell material includes a cationic conductor material and a conductive electron material; The cation conductor material exists in a quasi-crystalline state, and the cation conductor material includes Na 1 / 2 La 1 / 2 One of TiO3, Na3PO4, NaAlO2 or Na2SiO3 or a combination of any of them.

2. The negative electrode material according to claim 1, characterized in that The negative electrode material has a porous structure with a pore diameter of 0.1 nm to 50 nm.

3. The negative electrode material according to claim 1, characterized in that The particle size of the cationic conductor material is 20nm to 100nm.

4. The negative electrode material according to any one of claims 1 to 3, characterized in that The core material includes one or a combination of any of hard carbon, titanium dioxide, tin-containing alloy, tin-containing oxide and phosphorus-containing compound.

5. The negative electrode material according to claim 1, characterized in that The mass content of the shell material in the negative electrode material is 0.1% to 0.5%.

6. The negative electrode material according to claim 1, characterized in that The thickness of the shell layer is 100nm to 500nm.

7. The negative electrode material according to claim 1, characterized in that The Dv50 of the negative electrode material is 1 μm to 20 μm.

8. The negative electrode material according to claim 1, characterized in that The conductive electronic material includes one or more of graphene, carbon nanotubes, carbon fibers and Ketjen black, and the structure of the conductive electronic material includes one or more of flocculent, sheet and honeycomb shapes.

9. The negative electrode material according to claim 1, characterized in that The shell layer satisfies any one of the following conditions: a. The cationic conductor material and the conductive sub-material are combined to form the shell layer; b. The shell layer includes a first shell and a second shell, the first shell is at least partially distributed on the surface of the core material, the second shell is at least partially distributed on the surface of the first shell, the cationic conductor material is distributed in the first shell, and the conductive material is distributed in the second shell.

10. A secondary battery, characterized in that: The invention comprises a negative electrode plate, wherein the negative electrode plate comprises the negative electrode material according to any one of claims 1 to 9.

11. An electrical device, characterized in that: The secondary battery according to claim 10 is included, and the secondary battery is used as a power supply for the electrical device.

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