JP2018190917A - Electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more rapidly facilitate the pre-doping.SOLUTION: An electrochemical device comprises: an electrode unit in which positive and negative electrodes are laminated so as to alternate with corresponding separators interposed therebetween; an electrolyte solution in which the electrode unit is immersed; and a lithium ion supply source having a piece of metal foil opposed to the electrode unit and electrically connected to the negative electrode and particles which are undissolving in the electrolyte solution, provided that the lithium ion supply source is immersed in the electrolyte solution together with the electrode unit. The negative electrode is pre-doped with lithium ions from a lithium metal layer provided on the piece of metal foil. The particles are dispersed in the lithium metal layer before the negative electrode is pre-doped with the lithium ions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrochemical device having a negative electrode, a positive electrode, and a current collector.

  As a large-capacity capacitor, a lithium ion capacitor having a high energy density has been studied. For example, in a lithium ion capacitor, a positive electrode, a negative electrode, a lithium ion supply source, and an electrolytic solution are sealed with a container, and lithium ions are pre-doped on the negative electrode from the lithium ion supply source in advance.

  For example, in pre-doping, when a lithium ion supply source is immersed in an electrolytic solution, metallic lithium contained in the lithium ion supply source dissolves into the electrolytic solution, and the dissolved lithium ions move to the negative electrode through the electrolytic solution. And the lithium ion which reached | attained the negative electrode vicinity is occluded by the negative electrode (for example, refer patent document 1).

JP 2009-059732 A

  However, the metallic lithium layer of the lithium ion source generally has a uniform thickness. Thereby, in pre-doping, lithium ions gradually dissolve into the electrolyte from the surface of the metal lithium layer in contact with the electrolyte. As a result, the progress of the pre-doping depends on the speed at which the metallic lithium layer immersed in the electrolytic solution becomes gradually thinner.

  In view of the circumstances as described above, an object of the present invention is to provide an electrochemical device in which pre-doping can proceed more rapidly.

In order to achieve the above object, an electrochemical device according to an embodiment of the present invention includes an electrode unit, an electrolytic solution, and a lithium ion supply source. In the electrode unit, the positive electrode and the negative electrode are alternately stacked via the separator. The electrode unit is immersed in the electrolytic solution. The lithium ion supply source includes a metal foil that faces the electrode unit and is electrically connected to the negative electrode, and particles that are insoluble in the electrolytic solution. Soaked. The negative electrode is pre-doped with lithium ions from a metal lithium layer provided on the metal foil. The particles are dispersed and arranged in the metal lithium layer before the lithium ions are pre-doped into the negative electrode.
In such an electrochemical device, the particles are dispersedly arranged in the metal lithium layer in the lithium ion supply source. Thereby, the area which contacts the said electrolyte solution of the said metal lithium layer increases, and the quantity which a lithium ion melt | dissolves from the said metal lithium layer increases. As a result, pre-doping proceeds more rapidly.

In order to achieve the above object, an electrochemical device according to an embodiment of the present invention includes an electrode unit, an electrolytic solution, and a lithium ion supply source. The electrode unit includes a positive electrode, a negative electrode, and a separator provided between the positive electrode and the negative electrode. The electrode unit is immersed in the electrolytic solution. The lithium ion supply source includes a metal foil that faces the electrode unit and is electrically connected to the negative electrode, and particles that are insoluble in the electrolytic solution. Soaked. The negative electrode is pre-doped with lithium ions from a metal lithium layer provided on the metal foil. The particles are dispersed and arranged in the metal lithium layer before the lithium ions are pre-doped into the negative electrode.
With such an electrochemical device, pre-doping proceeds more rapidly as described above.

In the above electrochemical device, the particles may be at least one of inorganic particles and organic particles.
With such an electrochemical device, at least one of inorganic particles and organic particles is dispersedly arranged in the metal lithium layer, and pre-doping proceeds more rapidly.

  As described above, according to the present invention, pre-doping proceeds more rapidly in an electrochemical device.

It is a typical sectional view showing the electrochemical device concerning this embodiment. Drawing (a) is a typical sectional view showing the electrochemical device sealed by the exterior film concerning this embodiment. FIG. (B) is a schematic perspective view showing an electrochemical device sealed with an exterior film according to the present embodiment. It is typical sectional drawing which shows the effect | action of the electrochemical device of this embodiment. It is a typical sectional view showing the electrochemical device concerning the 1st modification of this embodiment. It is a typical perspective view which shows the electrochemical device which concerns on the 2nd modification of this embodiment. It is a table | surface figure explaining the effect of the electrochemical device of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, XYZ axis coordinates may be introduced. The XYZ axes are orthogonal to each other.

[Configuration of electrochemical device]
The configuration of the electrochemical device 100A according to this embodiment will be described below. The electrochemical device 100A exemplified in this embodiment is, for example, a lithium ion capacitor.

  Fig.1 (a) and FIG.1 (b) are typical sectional drawings which show the electrochemical device which concerns on this embodiment. FIG. 1A shows an overall outline of the electrochemical device 100A, and FIG. 1B shows an outline of the electrode unit 101 of the electrochemical device 100A.

  An electrochemical device 100A shown in FIG. 1A includes an electrode unit 101, a lithium ion supply source 180, and a separator 152. FIG. 1A shows a state before lithium ions are pre-doped into the electrode unit 101. The electrode unit 101, the lithium ion supply source 180, and the separator 152 are immersed in the electrolytic solution.

  The electrode unit 101 and the lithium ion supply source 180 are arranged in the Z-axis direction (first direction). For example, the main surface (upper surface 101 u) where the electrode unit 101 faces the lithium ion supply source 180 overlaps with the main surface (lower surface 180 d) where the lithium ion supply source 180 faces the electrode unit 101 in the Z-axis direction. The electrode unit 101 and the lithium ion supply source 180 have, for example, a rectangular shape on the XY axis plane. The lithium ion supply source 180 has a sheet shape, for example. The electrode unit 101 has a stacked structure in which positive and negative electrodes are alternately stacked.

  In the present embodiment, for the sake of convenience, the direction from the electrode unit 101 toward the lithium ion supply source 180 is defined as upward, and the opposite direction is defined as downward. However, the direction is not ask | required depending on the use of the electrochemical device 100A. The number of electrode units 101 and lithium ion supply sources 180 arranged is not limited to the number shown.

  The lithium ion supply source 180 includes a metal foil 181 and a particle dispersion layer 184. The particle dispersion layer 184 includes a metal lithium layer 183 and particles 182 dispersed in the metal lithium layer 183. The particle dispersion layer 184 is provided between the upper surface 101 u of the electrode unit 101 and the lower surface 181 d of the metal foil 181. For example, in the example of FIG. 1A, the particle dispersion layer 184 is provided on the lower surface 181 d of the metal foil 181. The particle dispersion layer 184 has a uniform thickness along the main surface of the metal foil 181. For example, the thickness of the particle dispersion layer 184 is not less than 30 μm and not more than 300 μm.

  The particle dispersion layer 184 is formed into a sheet by extrusion molding to the metal foil 181, and is fixed to the metal foil 181 by pressure bonding or the like. For example, the procedure for forming the particle dispersion layer 184 on the metal foil 181 by extrusion molding is as follows. For example, after the particles 182 are kneaded with metal lithium, a metal lithium layer containing particles is extruded onto the metal foil 181 in a sheet form from a nozzle having a slit opening. Thereby, the metal lithium layer 183 in which the particles 182 are dispersed is formed on the metal foil 181. Note that the lithium ion supply source 180 and the electrode unit 101 are formed in separate steps.

  The particles 182 are particles that are insoluble in the electrolytic solution. Here, the insolubility with respect to the electrolytic solution means substantially insoluble with respect to the electrolytic solution. For example, it does not dissolve in the electrolytic solution to the extent that the characteristics inherent to the electrolytic solution are not changed. For example, the reaction rate of the particles 182 with respect to the electrolytic solution is extremely slower than the reaction rate of the metallic lithium with respect to the electric field solution. Further, the particles 182 are particles that do not react or substantially do not react with metallic lithium. The material of the particles 182 is selected according to the electrolyte or lithium metal.

  The average particle diameter (measurement method: laser diffraction scattering method) of the particles 182 is, for example, 1 μm or more and 20 μm or less. If the average particle diameter of the particles 182 is smaller than 1 μm, the dispersion in lithium is not uniform, which is not preferable. If the average particle diameter of the particles 182 is larger than 20 μm, it is not preferable because the particles 182 cause damage such as scratches to the electrodes through the separator after the lithium is lost by pre-doping. The particles 182 may be porous particles or crystalline particles. The content of the particles 182 is 10 vol% or more and 40 vol% or less with respect to the metal lithium layer 183. When the content of the particles 182 is less than 10 vol%, the amount of addition is small and the pre-dope promoting effect is reduced, which is not preferable. When the content of the particles 182 is larger than 40 vol%, it is not preferable because lithium formation becomes difficult and production becomes difficult.

  The metal foil 181 faces the electrode unit 101 through the particle dispersion layer 184. The metal foil 181 is directly or indirectly electrically connected to the negative electrode of the electrode unit 101. The metal foil 181 may be provided with a plurality of through holes. In this case, the metal foil 181 is, for example, a porous metal foil.

  The separator 152 surrounds the electrode unit 101. For example, the separator 152 surrounds the electrode unit 101 in an arbitrary cross section in the XZ axis plane of the electrode unit 101. Thereby, the lithium ion supply source 180 does not directly contact the electrode unit 101. The separator 152 transmits ions contained in the electrolytic solution. In the example of FIG. 1, the side wall 101 e of the electrode unit 101 in the Y-axis direction (second direction) is opened from the separator 152. The electrode unit 101 can be electrically connected to the outside, such as the lithium ion supply source 180, other electrode units, and electrode terminals, through a side wall opened from the separator 152.

  Details of the electrode unit 101 will be described.

  As shown in FIG. 1B, the electrode unit 101 includes a negative electrode 130, a positive electrode 140, and a separator 151. Each of the negative electrode 130, the positive electrode 140, and the separator 151 is arranged in parallel in the XY plane. Each of the negative electrode 130, the positive electrode 140, and the separator 151 has a sheet shape, for example.

  In the electrode unit 101, the positive electrode 140 and the negative electrode 130 are alternately stacked in the Z-axis direction via the separator 151. The plurality of positive electrodes 140 are electrically connected directly or indirectly. The plurality of negative electrodes 130 are directly or indirectly electrically connected. The number of negative electrodes 130 and the number of positive electrodes 140 are not limited to the numbers shown.

  The negative electrode 130 includes a negative electrode current collector 132 and a negative electrode active material layer 133. The negative electrode active material layer 133 is provided on the main surfaces 132 a and 132 b of the negative electrode current collector 132. That is, the negative electrode current collector 132 is provided between adjacent negative electrode active material layers 133 in the Z-axis direction. An arbitrary negative electrode current collector 132 in the negative electrode 130 is electrically connected directly or indirectly to another negative electrode current collector 132, a metal foil 181, a negative electrode terminal, and the like.

  The negative electrode 130 is pre-doped with lithium ions from a metal lithium layer 183 provided on the metal foil 181. For example, when the metal lithium layer 183 electrically connected to the negative electrode 130 is immersed in the electrolytic solution, lithium ions are dissolved from the metal lithium layer 183 and the lithium ions are occluded in the negative electrode active material layer 133.

  The positive electrode 140 includes a positive electrode current collector 142 and a positive electrode active material layer 143. The positive electrode active material layer 143 is provided on the main surfaces 142 a and 142 b of the positive electrode current collector 142. That is, the positive electrode current collector 142 is provided between adjacent positive electrode active material layers 143 in the Z-axis direction. An arbitrary positive electrode current collector 142 in the positive electrode 140 is electrically connected directly or indirectly to another positive electrode current collector 142, a positive electrode terminal, or the like.

  The separator 151 insulates the negative electrode 130 and the positive electrode 140 from each other. The separator 151 separates the negative electrode 130 and the positive electrode 140 and transmits ions contained in the electrolytic solution. The plurality of negative electrodes 130 are pre-doped with lithium ions from metallic lithium provided in the lithium ion supply source 180.

  Fig.2 (a) is typical sectional drawing which shows the electrochemical device sealed by the exterior film which concerns on this embodiment. FIG. 2B is a schematic perspective view showing the electrochemical device sealed with the exterior film according to the present embodiment. FIG. 2A shows a cross section taken along line AA of FIG.

  In the electrochemical device 100 </ b> A, a plurality of electrode units 101 arranged in the Z-axis direction are sealed with an exterior film 106. A lithium ion supply source 180 is provided between the electrode units 101 adjacent in the Z-axis direction. In the example of FIG. 2A, particle dispersion layers 184 are provided on both main surfaces of the metal foil 181. The electrode unit 101 and the lithium ion supply source 180 in the exterior film 106 are immersed in the electrolytic solution 120. The negative electrode terminal 131 is electrically connected to the negative electrode of the electrode unit 101. The positive terminal 141 is electrically connected to the positive electrode of the electrode unit 101.

  The exterior film 106 includes an exterior film 106a and an exterior film 106b. The exterior film 106a and the exterior film 106b are joined on the outer periphery of the electrode unit 101 by, for example, thermocompression bonding.

  The material which comprises the electrochemical device 100A is demonstrated.

  The particles 182 are at least one of inorganic particles and organic particles. Examples of the inorganic particles include at least one of synthetic zeolite particles, alumina particles, barium sulfate particles, zirconium oxide particles, silica gel, alumina, and the like. The organic particles are at least one of polyacrylic resin particles, epoxy resin particles, polystyrene resin particles, polyurethane resin particles, polyolefin resin particles, and the like. The metal foil 181 is, for example, a copper foil. The amount of the metal lithium layer 183 (for example, the thickness of the metal lithium layer 183) is arbitrarily adjusted within a range in which the negative electrode active material layer 133 can be doped in the pre-doping of lithium ions.

  The negative electrode current collector 132 is, for example, a metal foil. The negative electrode current collector 132 may be, for example, a copper foil. The negative electrode active material included in the negative electrode active material layer 133 is a material capable of occluding and releasing lithium ions in the electrolyte solution. For example, carbon-based materials such as non-graphitizable carbon (hard carbon), graphite, and soft carbon Alloy materials such as silicon and silicon oxide, or composite materials thereof may be used. The negative electrode active material layer 133 may be a material in which a negative electrode active material is mixed with a binder resin, and may further include a conductive additive. For example, the negative electrode active material layer 133 is formed by applying a slurry-like mixture of the above-described active material, conductive additive, and synthetic resin into a sheet shape and cutting it.

  The binder resin may be a synthetic resin that joins the negative electrode active material. As the binder resin, for example, carboxymethyl cellulose, styrene butadiene rubber, polyethylene, polypropylene, aromatic polyamide, fluorine rubber, polyvinylidene fluoride, isoprene rubber, butadiene rubber, ethylene propylene rubber, and the like may be used.

  The conductive auxiliary agent is a particle made of a conductive material and may improve conductivity between the negative electrode active materials. Examples of the conductive assistant include carbon materials such as graphite and carbon black. These may be single and multiple types may be mixed. The conductive auxiliary agent may be a metal material or a conductive polymer as long as it is a conductive material.

  The material of the positive electrode current collector 142 is, for example, aluminum. The positive electrode active material included in the positive electrode active material layer 143 is, for example, activated carbon, PAS (Polyacenic Semiconductor), lithium cobaltate, lithium manganate, lithium nickelate, or lithium composed of a plurality of transition elements. It contains at least one of active materials such as active materials such as composite oxides. The positive electrode active material layer 143 is formed by applying a slurry-like mixture of the above active material, a conductive additive (for example, carbon black) and a synthetic resin (for example, PTFE), and cutting it. It is.

  The separators 151 and 152 may be a woven fabric, a nonwoven fabric, a synthetic resin microporous film, or the like. The separators 151 and 152 may be porous sheets made of plastic fibers such as glass fibers, cellulose fibers, and olefin resins.

The electrolytic solution can be arbitrarily selected. For example, in the electrolytic solution, the cation includes at least lithium ions. Examples of the anion BF ₄ ^- (tetrafluoroborate ion), PF ₆ ^- (hexafluorophosphate ^{_{ion), (CF 3 SO 2)}} 2 N - include anions such (TFSA ions), the solvent propylene Carbonate, ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, dimethyl carbonate, sulfolane, dimethyl sulfone, ethyl methyl sulfone, ethyl isopropyl sulfone, and the like can be included. Specifically, a lithium tetrafluoroborate (LiBF ₄ ) or a propylene carbonate solution of lithium hexafluorophosphate (LiPF ₆ ) may be used.

  [Action of electrochemical device]

  FIG. 3A and FIG. 3B are schematic cross-sectional views showing the operation of the electrochemical device of the present embodiment.

  FIGS. 3A and 3B show a state after pre-doping of lithium ions into the negative electrode 130 is started.

  First, FIG. 3A shows a pre-doping state of the electrochemical device 500 according to the comparative example. In the electrochemical device 500 according to the comparative example, the particles 182 are not dispersed in the metal lithium layer 183. In the electrochemical device 500, the metal lithium layer 183 has a layer structure with a uniform thickness.

  For example, when the electrode unit 101, the lithium ion supply source 180, and the separator 152 are immersed in the electrolytic solution 120, the surface of the metal lithium layer 183 on the side facing the electrode unit 101 is exposed to the electrolytic solution 120. Immediately after being exposed to the electrolytic solution 120, the surface where the metal lithium layer 183 contacts the electrolytic solution 120 is defined as a contact surface 183a.

  Thereafter, lithium ions dissolved from the contact surface 183 a move into the electrode unit 101 through the separator 152 and are occluded in the negative electrode active material layer 133 of the electrode unit 101. As the pre-doping progresses, the metallic lithium layer 183 having a uniform thickness gradually becomes thinner. The surface of the metal lithium layer 183 exposed to the electrolytic solution 120 when it becomes thin is referred to as a contact surface 183b.

  However, since the metal lithium layer 183 is a flat layer and gradually becomes thinner, there is a large difference in surface area between the contact surface 183a at the initial stage of dissolution and the contact surface 183b after the dissolution has progressed to some extent. Does not occur.

  Therefore, in the electrochemical device 500, the lithium ion concentration in the electrolytic solution 120 after the pre-doping has progressed to some extent is not significantly different from the lithium ion concentration in the electrolytic solution 120 immediately after the start of pre-doping, and the pre-doping speed reaches its peak. .

  In contrast, in the electrochemical device 100A shown in FIG. 3B, the particles 182 are dispersed in the metal lithium layer 183. For this reason, the contact surface 183 b of the metal lithium layer 183 is formed along the surface of each particle 182. Thereby, the surface area of the contact surface 183b is greatly increased as compared with the surface area of the contact surface 183a at the initial stage of dissolution.

  Thereby, in the electrochemical device 100A, the amount of lithium ions dissolved from the metal lithium layer 183 is increased, and the lithium ion concentration in the electrolytic solution 120 is higher when pre-doping than in the comparative example. As a result, pre-doping progresses more rapidly than in the comparative example.

  Further, in the electrochemical device 100A, since the particles 182 are dispersed in the metallic lithium layer 183, the “bulk” of metallic lithium occurs. As a result, even if the amount of metallic lithium is small, the particle dispersion layer 184 has a desired thickness and rigidity, breaks of the layer on the metal foil 181 at the time of layer formation, and the film to the rolling jig side. Sticking is suppressed. As a result, the electrode unit 101 is uniformly doped with lithium ions.

  Further, in the electrochemical device 100A, as illustrated in FIG. 2A, when a plurality of electrode units 101 are stacked, a lithium ion supply source 180 is disposed between the adjacent electrode units 101. Thereby, also in the electrode unit 101 located in the center part of the some electrode unit 101, pre dope advances rapidly.

  FIG. 4 is a schematic cross-sectional view showing an electrochemical device according to a first modification of the present embodiment.

  In the electrode unit 101, the positive electrode 140 and the negative electrode 130 do not have to be alternately stacked in the Z-axis direction. For example, in the electrochemical device 100 </ b> B illustrated in FIG. 4, the electrode unit 101 includes a pair of a positive electrode 140 and a negative electrode 130, and a separator 151 provided between the positive electrode 140 and the negative electrode 130.

  The electrochemical device 100B also has the same effects as the electrochemical device 100A.

  FIG. 5 is a schematic perspective view showing an electrochemical device according to a second modification of the present embodiment.

  The electrode unit 101 may have a structure wound around a wound core 112. For example, in the electrochemical device 100 </ b> C illustrated in FIG. 5, the positive electrode 140 and the negative electrode 130 are wound around the winding core 112 through the separator 151 and connected to the negative electrode 130 outside the electrode unit 101. A lithium ion supply source 180 is provided.

  The electrochemical device 100C also has the same effects as the electrochemical device 100A.

  FIG. 6A to FIG. 6B are table diagrams for explaining the effect of the electrochemical device of the present embodiment.

Non-graphitizable carbon having a charge capacity of 450 mAh / g was dispersed in water together with a binder resin and a conductive auxiliary agent to form a slurry. This slurry was applied to a metal foil, and the non-graphitizable carbon was applied at 50 g / m ² per area to form an active material layer. For the electrode area (4 cm × 5 cm), 0.01 g of metallic lithium was used for pre-doping.

  A metal lithium layer (thickness: 0.2 mmt) in which zeolite particles having an average particle diameter of 2 μm were dispersed was sandwiched between resin sheets, and the thickness of the particle dispersion layer was appropriately adjusted by roller pressing. A plurality of samples with varying amounts of added zeolite particles (vol%) were prepared.

  In FIG. 6A, in each symbol, “◯”: a particle dispersed layer having a uniform thickness is formed after rolling, “Δ”: minute discontinuity occurs in the particle dispersed layer after rolling, and “×”: It means that a clear break occurs in the particle dispersion layer after rolling.

  The amount of zeolite particles added in sample A is 10 vol%. The amount of zeolite particles added in sample B is 20 vol%. The amount of zeolite particles added in sample C is 30 vol%. The amount of zeolite particles added in sample D is 40 vol%. The amount of zeolite particles added in sample N is 0 vol%.

  As shown in FIG. 6 (a), in sample N in which the zeolite particles are not dispersed in the metal lithium layer, the particle dispersion layer becomes “◯” when the particle dispersion layer has a thickness of 200 μm and 100 μm. When the thickness of the layer was 50 μm, it became “Δ”, and when it was 25 μm, it became “x”.

  On the other hand, in Samples B, C, and D, the thickness of the particle dispersion layer was 200 μm, 100 μm, 50 μm, and 25 μm, and the particle dispersion layer was “◯”. However, in Samples B and C, when the thickness of the particle dispersion layer became 10 μm, the particle dispersion layer became “Δ”. In Sample D, when the thickness of the particle dispersion layer was 10 μm, the particle dispersion layer became “x”. On the other hand, in sample A, when the thickness of the particle dispersion layer is 200 μm, 100 μm, and 50 μm, the particle dispersion layer becomes “◯”, but at 25 μm, it becomes “Δ”, and when it becomes 10 μm, it becomes “x”. became.

  In FIG. 6B, in each symbol, “◯” means that it was able to be crimped to the copper foil for the lithium supply source, and “×” was that it was not able to be crimped to the copper foil for the lithium supply source. . Here, the thickness of the particle dispersion layer in Samples A, B, C, D, and N is 50 μm.

  As shown in FIG. 6B, Samples A, B, C, and N all showed “◯”, but Sample D in which the amount of added particles was 40% became “X”. In Sample D, although a particle dispersion layer having a uniform thickness was formed, it can be inferred that the particle content was excessive and the adhesion of the particle dispersion layer to the copper foil was reduced.

  Thus, by adjusting the addition amount of the zeolite particles to 10 vol% or more and 40 vol% or less, preferably 20 vol% or more and 40 vol% or less, more preferably 20 vol% or more and 30 vol% or less, the thickness is uniform and extremely thin. It was found that a particle-dispersed layer having a particle size can be formed. For example, even when the electrochemical device is smaller and a smaller lithium ion source is required, a uniform and ultrathin metallic lithium layer can be placed on the electrochemical device.

Furthermore, 0.1 g of samples A, B, C, and N were rolled to a thickness of 0.05 mm, and each was attached to a copper foil, and each was individually opposed to the active material layer via a separator. Next, each of the opposed groups is placed in a laminate bag, the particle dispersion layer and the active material layer are electrically connected, and an electrolyte solution (PC / LiPF ₆ 1.0M) is placed in the laminate bag. Was injected. The laminating bag whose liquid inlet was sealed with heat was covered with a 1 mm thick silicon sheet so as to cover the electrode area, and further sandwiched with a 1 mm SUS plate so as to cover the silicon sheet, and a load of 100 g was applied to the cell. . The sample was allowed to stand for 7 days in an argon atmosphere at 30 ° C. and then decomposed to confirm the remaining of lithium. In Samples A, B, and C, no lithium remained, and in Sample N, lithium remained.

  As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, Of course, a various change can be added.

100A, 100B, 100C, 500 ... Electrochemical device 101 ... Electrode unit 101e ... Side wall 101u ... Upper surface 106, 106a, 106b ... Outer film 112 ... Winding core 120 ... Electrolytic solution 130 ... Negative electrode 130e ... End portion 131 ... Negative electrode terminal 132 ... Negative electrode current collector 132a, 132b, 142a, 142b ... Main surface 133 ... Negative electrode active material layer 140 ... Positive electrode 141 ... Positive electrode terminal 142 ... Positive electrode current collector 143 ... Positive electrode active material layer 151, 152 ... Separator 180 ... Lithium ion supply Source 180d, 181d ... Bottom 181 ... Metal foil 182 ... Particles 183 ... Metal lithium layer 183a, 183b ... Contact surface 184 ... Particle dispersion layer

Claims (3)

An electrode unit in which positive electrodes and negative electrodes are alternately stacked via separators;
An electrolyte in which the electrode unit is immersed;
A lithium ion supply source having a metal foil facing the electrode unit and electrically connected to the negative electrode, and particles insoluble in the electrolyte, and immersed in the electrolyte together with the electrode unit And
The negative electrode is pre-doped with lithium ions from a metal lithium layer provided on the metal foil,
The electrochemical device, wherein the particles are dispersed in the metallic lithium layer before the lithium ions are pre-doped into the negative electrode. An electrode unit having a positive electrode, a negative electrode, and a separator provided between the positive electrode and the negative electrode;
An electrolyte in which the electrode unit is immersed;
A lithium ion supply source having a metal foil facing the electrode unit and electrically connected to the negative electrode, and particles insoluble in the electrolyte, and immersed in the electrolyte together with the electrode unit And
The negative electrode is pre-doped with lithium ions from a metal lithium layer provided on the metal foil,
The electrochemical device, wherein the particles are dispersed in the metallic lithium layer before the lithium ions are pre-doped into the negative electrode. The electrochemical device according to claim 1 or 2,
The electrochemical device is at least one of inorganic particles and organic particles.