JP6859864B2 - Positive electrode, electrode element, non-aqueous electrolyte storage element - Google Patents

Description

The present invention includes a positive electrode, the electrode element, relates to a non-aqueous electrolyte energy storage device.

In a conventional thin laminated power storage element using lithium ions, when a high current rate is discharged, lithium ions in the electrolyte contained in the electrode are rapidly taken into the electrode active material and the lithium ion concentration in the electrode. When the value decreases, lithium ions are supplied from the electrolyte layer in the separator.

In such a high current rate discharge, since the solid content concentration is uniform in the electrode, it is difficult for lithium ions to diffuse to the electrode active material near the current collector, and the lithium ions are supplied from the electrolyte layer. Lithium ions are depleted without catching up, and the performance (battery life and output characteristics) of the power storage element is reduced.

Therefore, in order to improve the performance of the power storage element (battery life and output characteristics), a concentration gradient is provided so that the concentration of solids other than the electrolyte increases from the surface of the electrode active material layer of the power storage element toward the current collector side. A power storage element in which an electrolyte is filled in the voids of the solid minutes other than the electrolyte in the electrode active material layer has been proposed. This power storage element is characterized in that the pore ratio inside the electrode is distributed (see, for example, Patent Document 1).

However, in the above electrode, a concentration gradient is provided in the gel electrolyte salt in order to obtain a discharge at a high current rate. This technique is effective only for the electrodes of the power storage element using the gel electrolyte, and cannot be applied to the electrodes of the power storage element using the electrolytic solution. Therefore, it cannot contribute to the improvement of the performance (battery life and output characteristics) of the power storage element using the electrolytic solution.

The present invention has been made in view of the above, and an object thereof is to provide a positive electrode which can improve a performance of the power storage device using the electrolytic solution.

Tadashi Moto electrode, a positive electrode comprising a current collector and a front Symbol collector one multiple electrode material layers stacked on the side of the, among the plurality of electrode material layers, predetermined When the electrode material layer of No. 1 is used as the first electrode material layer and the predetermined electrode material layer arranged farther from the current collector than the first electrode material layer is used as the second electrode material layer, the above. The first electrode material layer and the second electrode material layer include a third material and a fourth material, and both the third material and the fourth material can store and release lithium ions. The fourth material has higher ion diffusivity than the third material, and the ratio of the weight of the fourth material to the total weight of the third material and the fourth material is higher than that of the first electrode material layer. Also requires that the second electrode material layer is smaller .

According to the disclosed technique, it is possible to provide a positive electrode which can improve a performance of the power storage device using the electrolytic solution.

It is sectional drawing which illustrates the non-aqueous electrolytic solution power storage element which concerns on 1st Embodiment. It is a figure explaining the manufacturing process of the non-aqueous electrolytic solution power storage element which concerns on 1st Embodiment. It is sectional drawing which illustrates the non-aqueous electrolytic solution power storage element which concerns on 2nd Embodiment. It is a figure explaining the manufacturing process of the non-aqueous electrolytic solution power storage element which concerns on 2nd Embodiment. It is sectional drawing which illustrates the non-aqueous electrolytic solution power storage element which concerns on the modification 1 of the 2nd Embodiment. It is sectional drawing which illustrates the non-aqueous electrolytic solution power storage element which concerns on the modification 2 of the 2nd Embodiment. It is a figure explaining the manufacturing process of the non-aqueous electrolytic solution power storage element which concerns on modification 2 of the 2nd Embodiment. It is sectional drawing which illustrates the non-aqueous electrolytic solution power storage element which concerns on 3rd Embodiment. It is a figure explaining the manufacturing process of the non-aqueous electrolytic solution power storage element which concerns on 3rd Embodiment. It is sectional drawing which illustrates the non-aqueous electrolyte storage element which concerns on the modification of the 3rd Embodiment.

Hereinafter, modes for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate description may be omitted.

<First Embodiment>
FIG. 1 is a cross-sectional view illustrating the non-aqueous electrolyte storage element according to the first embodiment. Referring to FIG. 1, the non-aqueous electrolyte storage element 1 has a structure in which the non-aqueous electrolyte 51 is injected into the electrode element 40 and sealed with an exterior 52. The non-aqueous electrolyte storage element 1 may have other members, if necessary. The non-aqueous electrolyte storage element 1 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte capacitor.

The electrode element 40 includes a negative electrode 10 in which the negative electrode material layers 12 and 13 are sequentially laminated on the negative electrode current collector 11, and a positive electrode 20 in which the positive electrode material layers 22 and 23 are sequentially laminated on the positive electrode current collector 21. The structure is such that the negative electrode current collector 11 and the positive electrode current collector 21 are laminated with the separator 30 facing outward. A negative electrode lead-out wire 41 is connected to the negative electrode current collector 11 and is led out to the outside of the exterior 52. A positive electrode lead-out wire 42 is connected to the positive electrode current collector 21 and is led out to the outside of the exterior 52.

In the electrode element 40, the area of the main surfaces of the negative electrode material layers 12 and 13 is larger than the area of the main surfaces of the positive electrode material layers 22 and 23. This is because the lithium ions emitted from the positive electrode material layers 22 and 23 are surely received by the negative electrode material layers 12 and 13. Here, the main surface is a surface substantially perpendicular to the stacking direction.

The shape of the non-aqueous electrolyte storage element 1 is not particularly limited, and can be appropriately selected from various generally adopted shapes according to the application. Examples thereof include a laminated type, a cylinder type in which a sheet electrode and a separator are spirally formed, a cylinder type having an inside-out structure in which a pellet electrode and a separator are combined, and a coin type in which a pellet electrode and a separator are laminated.

Hereinafter, the non-aqueous electrolyte storage element 1 will be described in detail. In the present embodiment, for convenience, the positive electrode current collector 21 side of the non-aqueous electrolyte current collector 1 is one surface side or upper side, and the negative electrode current collector 11 side is the other surface side or lower side. Further, the surface of each part on the positive electrode current collector 21 side is defined as one surface or upper surface, and the surface on the negative electrode current collector 11 side is defined as the other surface or lower surface. However, the non-aqueous electrolyte storage element 1 can be used in an upside-down state, or can be arranged at an arbitrary angle. Further, the negative electrode current collector and the positive electrode current collector may be referred to as an electrode current collector, and the negative electrode material layer and the positive electrode material layer may be referred to as an electrode material layer. Other embodiments are similar to these.
<Negative electrode>
The negative electrode 10 is not particularly limited as long as it contains the negative electrode active material, and can be appropriately selected depending on the intended purpose. However, in the present embodiment, the negative electrode material layers 12 and 13 are sequentially arranged on the negative electrode current collector 11. It is a laminated structure. The shape of the negative electrode 10 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape.
<< Negative electrode current collector >>
The material, shape, size, and structure of the negative electrode current collector 11 are not particularly limited and may be appropriately selected depending on the intended purpose.

The material of the negative electrode current collector 11 is not particularly limited as long as it is made of a conductive material, and can be appropriately selected depending on the intended purpose. For example, stainless steel, nickel, aluminum, copper and the like can be used. Can be mentioned. Of these, stainless steel and copper are particularly preferable.

The shape of the negative electrode current collector 11 is not particularly limited and can be appropriately selected depending on the intended purpose. The size of the negative electrode current collector 11 is not particularly limited as long as it can be used for the non-aqueous electrolyte storage element 1, and can be appropriately selected depending on the intended purpose.
<< Negative electrode material layer >>
The negative electrode material layers 12 and 13 are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the negative electrode active material may be contained at least, and a binder, a conductive agent and the like may be contained if necessary.

The average thickness of each of the negative electrode material layers 12 and 13 is not particularly limited and may be appropriately selected depending on the intended purpose, but the total average thickness of the negative electrode material layers 12 and 13 is preferably 10 μm or more and 450 μm or less, preferably 20 μm. More preferably 100 μm or less. If the total average thickness of the negative electrode material layers 12 and 13 is less than 10 μm, the energy density may decrease, and if it exceeds 450 μm, the cycle characteristics may deteriorate.
-Negative electrode active material-
The negative electrode active material contained in the negative electrode material layers 12 and 13 is not particularly limited as long as it can occlude and release lithium ions, and can be appropriately selected depending on the intended purpose. However, in the present embodiment, the negative electrode is used. The negative electrode active material contained in the material layers 12 and 13 includes a first material and a second material in which lithium ions are less likely to be deposited on the surface of the negative electrode 10 than the first material. For example, the carbonaceous material is used as the main material (first material), and another carbonaceous material is added as the second material. The surface of the negative electrode 10 on which lithium ions are deposited is specifically the interface between the negative electrode material layer 13 and the separator 30.

Examples of the carbonaceous material include graphite (graphite) such as coke, artificial graphite, and natural graphite, a pyrolyzed product of an organic substance under various pyrolysis conditions, and amorphous carbon. Among these, artificial graphite, natural graphite, and amorphous carbon are particularly preferable.

As the negative electrode active material contained in the negative electrode material layers 12 and 13, for example, artificial graphite or natural graphite can be used as the main material (first material), and amorphous carbon can be added as an additive (second material).

Further, in the present embodiment, the negative electrode material layer 12 and the negative electrode material layer 13 have different concentrations of additives with respect to the main material (ratio of the weight of the second material to the total weight of the first material and the second material). Is formed in.

Specifically, the farther the negative electrode material layer is arranged in the negative electrode current collector 11, the higher the concentration of the additive with respect to the main material (the weight of the second material with respect to the total weight of the first material and the second material). (To increase the ratio of). That is, the concentration of the additive is higher in the negative electrode material layer 13 far from the negative electrode current collector 11 (close to the separator 30) than in the negative electrode material layer 12 close to the negative electrode current collector 11.

For example, when artificial graphite or natural graphite is used as the main material and amorphous carbon is added as an additive, it is farther from the negative electrode current collector 11 (closer to the separator 30) than the negative electrode material layer 12 which is closer to the negative electrode current collector 11. The negative electrode material layer 13 has a higher concentration of amorphous carbon added.

Although the present embodiment shows an example in which two negative electrode material layers are laminated on the negative electrode current collector 11, three or more negative electrode material layers may be laminated on the negative electrode current collector 11. In this case, the concentration of the additive in the negative electrode material layer closest to the negative electrode current collector 11 is the lowest, and the additive is added toward the negative electrode material layer farther from the negative electrode current collector 11 (closer to the separator 30). Try to increase the concentration.

As described above, in the present embodiment, a plurality of negative electrode material layers are laminated on the negative electrode current collector 11, and the concentration of the additive in the negative electrode material layer closest to the negative electrode current collector 11 is the lowest, and the negative electrode collection The concentration of the additive is increased toward the negative electrode material layer farther from the electric body 11 (closer to the separator 30).

In other words, the additive is added to the main material from the negative electrode current collector 11 side toward the separator 30 side so that the effect of preventing the precipitation of lithium ions increases from the negative electrode current collector 11 side toward the separator 30 side. The concentration is gradually increased in each layer.

As a result, it is possible to prevent lithium ions from being deposited on the surface of the negative electrode 10 while maintaining the performance of the non-aqueous electrolyte storage element 1. As a result, the life of the non-aqueous electrolyte storage element 1 can be extended.

In order to prevent lithium ions from precipitating on the surface of the negative electrode 10, the negative electrode material layer 12 on the negative electrode current collector 11 side is formed of graphite, and the negative electrode material layer 13 on the separator 30 side is precipitated with lithium ions. A method of forming from amorphous carbon having a large preventive effect is also conceivable. However, this method is not preferable because when layers of different materials are laminated, a voltage difference is generated between the layers.

In the present embodiment, instead of laminating layers of different materials, the material composition of each layer is the same, and the material ratio of each layer is changed to prevent the precipitation of lithium ions. This method is preferable in that no voltage difference is generated in each layer.
-Binder-
The binder contained in the negative electrode material layers 12 and 13 is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a fluorine-based binder such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE). , Ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), isoprene rubber, carboxymethyl cellulose (CMC) and the like.

These may be used alone or in combination of two or more. Among these, fluorine-based binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) are preferable, and the number of repeated charges and discharges is higher than that of other binders. PVDF and SBR are particularly preferable from the viewpoint of improvement.

Examples of the conductive agent contained in the negative electrode material layers 12 and 13 include metal materials such as copper and aluminum, and carbonaceous materials such as carbon black and acetylene black. These may be used alone or in combination of two or more.
<Positive electrode>
The positive electrode 20 is not particularly limited as long as it contains a positive electrode active material, and can be appropriately selected depending on the intended purpose. However, in the present embodiment, the positive electrode material layers 22 and 23 are sequentially arranged on the positive electrode current collector 21. It is a laminated structure. The shape of the positive electrode 20 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape.
<< Positive Electrode Current Collector >>
The material, shape, size, and structure of the positive electrode current collector 21 are not particularly limited and may be appropriately selected depending on the intended purpose.

The material of the positive electrode current collector 21 is not particularly limited as long as it is made of a conductive material, and can be appropriately selected depending on the intended purpose. For example, stainless steel, nickel, aluminum, copper, and titanium. , Tantalum and the like. Among these, stainless steel and aluminum are particularly preferable.
The shape of the positive electrode current collector 21 is not particularly limited and can be appropriately selected depending on the intended purpose. The size of the positive electrode current collector 21 is not particularly limited as long as it can be used for the non-aqueous electrolyte storage element 1, and can be appropriately selected depending on the intended purpose.
<< Positive electrode material layer >>
The positive electrode material layers 22 and 23 are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the positive electrode material layers 22 and 23 may contain at least a positive electrode active material and, if necessary, a binder, a thickener, a conductive agent and the like. Good.

The average thickness of each of the positive electrode material layers 22 and 23 is not particularly limited and may be appropriately selected depending on the intended purpose, but the total average thickness of the positive electrode material layers 22 and 23 is preferably 10 μm or more and 300 μm or less, preferably 40 μm. More preferably, it is 150 μm or less. If the total average thickness of the positive electrode material layers 22 and 23 is less than 20 μm, the energy density may decrease, and if it exceeds 300 μm, the load characteristics may deteriorate.
-Positive electrode active material-
The positive electrode active material contained in the positive electrode material layers 22 and 23 is not particularly limited as long as it can occlude and release lithium ions, and can be appropriately selected depending on the intended purpose. However, in the present embodiment, the positive electrode is used. The positive electrode active material contained in the material layers 22 and 23 includes a third material and a fourth material having higher diffusivity to lithium ions (promoting the diffusion of lithium ions) than the third material. For example, a third material capable of increasing the capacity of the non-aqueous electrolyte storage element 1 is selected as the main material, and a fourth material having high diffusibility to lithium ions is added to the selected third material. By increasing the ratio of the fourth material having high diffusivity to lithium ions, the output of the non-aqueous electrolyte storage element 1 can be improved.

For _{example, LiNi X Co Y Mn Z O} 2 (x + y + z = 1) Lithium Ni composite oxide is as a main material (third material), manganese spinel or _{Li X Me Y (PO 4)} Z (0.5 ≦ x A material containing a lithium phosphoric acid-based material having a basic skeleton of ≦ 4, Me = transition metal, 0.5 ≦ y ≦ 2.5, 0.5 ≦ x ≦ 3.5) as an additive (fourth material). Can be used.

_{Further, LiNi X Co Y Mn Z O} 2 (x + y + z = 1) Lithium Ni composite oxide is as a main material (third material), a small particle diameter than the main material _{LiNi X Co Y Mn Z O 2} (x + y + z A material containing the lithium Ni composite oxide of = 1) as an additive (fourth material) may be used.

In this case, it is preferable that the average particle size of the main material is, for example, about 5 to 10 μm, and the average particle size of the additive is, for example, about 1 to 8 μm. Here, the average particle size means a diameter in which the abundance ratio of particles is measured on a volume basis and the large side and the small side are equal in quantity, and can be measured by, for example, a particle size distribution meter by a laser diffraction / scattering method. it can.

_{LiNi X Co Y Mn Z O 2} (x + y + z = 1) The lithium Ni composite oxide is, for _{example, LiNi 0.33 Co 0.33 Mn 0.33 O} 2, LiNi 0.5 Co 0.2 Mn 0 _.3 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ , LiNi _0.8 Co _0.2 Mn ₀ O _{2 and the} like can be mentioned.

Lithium phosphorus whose basic skeleton is Li _X Me _Y (PO ₄ ) _Z (0.5 ≦ x ≦ 4, Me = transition metal, 0.5 ≦ y ≦ 2.5, 0.5 ≦ x ≦ 3.5) Examples of the acid-based material include lithium vanadium phosphate (Li ₃ V ₂ (PO ₄ ) ₃ ), olivine iron (LiFePO ₄ ), olibin manganese (LiMnPO ₄ ), olibin cobalt (LiCoPO ₄ ), and olibin nickel (LiNiPO _4). ), Olivin vanadium (LiVOPO ₄ ), and similar compounds with these as the basic skeleton and doped with different elements.

Further, in the present embodiment, the positive electrode material layer 22 and the positive electrode material layer 23 have different concentrations of additives with respect to the main material (ratio of the weight of the fourth material to the total weight of the third material and the fourth material). Is formed in.

Specifically, the farther the positive electrode material layer is arranged in the positive electrode current collector 21, the lower the concentration of the additive with respect to the main material (the weight of the fourth material with respect to the total weight of the third material and the fourth material). (So that the ratio of) becomes smaller.

That is, the positive electrode material layer 22 close to the positive electrode current collector 21 emphasizes ion diffusivity rather than capacity, and the concentration of the additive is set so as to improve the ion diffusivity. On the other hand, the positive electrode material layer 23, which is far from the positive electrode current collector 21 (close to the separator 30), emphasizes the capacity rather than the ion diffusivity, and the concentration of the additive is set so as to increase the capacity.

For example, when spinel manganese is added using a lithium nickel composite oxide as a main material, the concentration of spinel manganese added in the positive electrode material layer 22 close to the positive electrode current collector 21 is made higher than that in the positive electrode material layer 23, and the ion diffusibility To improve. On the other hand, in the positive electrode material layer 23 far from the positive electrode current collector 21, the concentration of spinel manganese added is lower than that of the positive electrode material layer 22 to increase the capacity.

When lithium vanadium phosphate is added using lithium nickel composite oxide as the main material, the concentration of vanadium lithium phosphate added is higher in the positive electrode material layer 22 near the positive electrode current collector 21 than in the positive electrode material layer 23, and ions are added. Improves diffusivity. On the other hand, in the positive electrode material layer 23 far from the positive electrode current collector 21, the concentration of added vanadium lithium phosphate is lower than that of the positive electrode material layer 22 to increase the capacity.

When a lithium nickel composite oxide having a particle size smaller than that of the main material is added using the lithium nickel composite oxide as the main material, the particle size of the positive electrode material layer 22 close to the positive electrode current collector 21 is smaller than that of the main material. The concentration of the lithium nickel composite oxide added is made higher than that of the positive electrode material layer 23 to improve the ion diffusivity. On the other hand, in the positive electrode material layer 23 far from the positive electrode current collector 21, the addition concentration of the lithium nickel composite oxide having a particle size smaller than that of the main material is made lower than that of the positive electrode material layer 22 to increase the capacity.

Although the present embodiment shows an example in which two positive electrode material layers are laminated on the positive electrode current collector 21, three or more positive electrode material layers may be laminated on the positive electrode current collector 21. In this case, the ion diffusivity of the positive electrode material layer closest to the positive electrode current collector 21 becomes the best, and the ion diffusivity increases toward the positive electrode material layer farther from the positive electrode current collector 21 (closer to the separator 30). The addition concentration should be such that the amount is reduced and the volume is increased.

As described above, in the present embodiment, a plurality of positive electrode material layers are laminated on the positive electrode current collector 21, and the ion diffusivity of the positive electrode material layer closest to the positive electrode current collector 21 is improved, and the positive electrode collection is performed. The concentration of the additive is reduced so that the ion diffusivity decreases and the capacity increases toward the positive electrode material layer farther from the electric body 21 (closer to the separator 30).

In other words, the additive is added to the main material from the positive electrode current collector 21 side toward the separator 30 side so that the ion diffusivity decreases from the positive electrode current collector 21 side toward the separator 30 side and the capacity increases. The concentration is gradually reduced in each layer.

As a result, the capacity of the non-aqueous electrolyte storage element 1 can be improved, and the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1 can be promoted to improve the output performance.

In order to improve the capacity of the non-aqueous electrolyte storage element 1 and promote the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1 to improve the output performance, the positive electrode on the positive electrode current collector 21 side. A method is also conceivable in which the material layer 22 is formed of a material that promotes the diffusion of lithium ions, and the positive electrode material layer 23 on the separator 30 side is formed of a material that can increase the capacity of the non-aqueous electrolyte storage element 1. However, this method is not preferable because when layers of different materials are laminated, a voltage difference is generated between the layers.

In the present embodiment, instead of laminating layers of different materials, the material composition of each layer is the same, and the material ratio of each layer is changed to improve the capacity of the non-aqueous electrolyte storage element 1 and non-water. The diffusion of lithium ions inside the electrolytic solution storage element 1 is promoted to improve the output performance. This method is also suitable in that no voltage difference is generated in each layer.
-Binder-
The binder contained in the positive electrode material layers 22 and 23 is not particularly limited as long as it is a material that is stable to the solvent and electrolytic solution used in the electrode production, and can be appropriately selected depending on the intended purpose. Examples thereof include fluorine-based binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), and isoprene rubber. These may be used alone or in combination of two or more.
-Thickener-
Examples of the thickener contained in the positive electrode material layers 22 and 23 include carboxymethyl cellulose (CMC), methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxide starch, phosphate starch, casein and the like. These may be used alone or in combination of two or more. It is not necessary to use a thickener.
-Conducting agent-
Examples of the conductive agent contained in the positive electrode material layers 22 and 23 include metal materials such as copper and aluminum, and carbonaceous materials such as carbon black and acetylene black. These may be used alone or in combination of two or more.
<Non-aqueous electrolyte>
The non-aqueous electrolytic solution 51 is an electrolytic solution containing a non-aqueous solvent and an electrolyte salt.
<< Non-aqueous solvent >>
The non-aqueous solvent is not particularly limited and may be appropriately selected depending on the intended purpose, but an aprotic organic solvent is preferable. As the aprotic organic solvent, a carbonate-based organic solvent such as a chain carbonate or a cyclic carbonate is used. Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and methyl propionate (MP).

Examples of the cyclic carbonate include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC) and the like.

When a mixed solvent in which ethylene carbonate (EC) is used as the cyclic carbonate and dimethyl carbonate (DMC) is used as the chain carbonate, the mixing ratio of ethylene carbonate (EC) and dimethyl carbonate (DMC) is particularly limited. However, it can be appropriately selected according to the purpose.

As the non-aqueous solvent, an ester-based organic solvent such as a cyclic ester or a chain ester, an ether-based organic solvent such as a cyclic ether or a chain ether, or the like can be used, if necessary.

Examples of the cyclic ester include γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone and the like.

Examples of the chain ester include propionic acid alkyl ester, malonic acid dialkyl ester, acetate alkyl ester (methyl acetate (MA), ethyl acetate, etc.), formic acid alkyl ester (methyl formate (MF), ethyl formate, etc.) and the like. Be done.

Examples of the cyclic ether include tetrahydrofuran, alkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, 1,4-dioxolane and the like.

Examples of the chain ether include 1,2-dimethosicietan (DME), diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether and the like.
<< Electrolyte salt >>
As the electrolyte salt, a lithium salt can be used. The lithium salt is not particularly limited and may be appropriately selected depending on the intended purpose. For example, lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ), lithium chloride (LiCl), and phosphite. Lithium chloride (LiBF ₄ ), Lithium hexafluorophosphate (LiAsF ₆ ), Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), Lithimbistrifluoromethylsulfonylimide (LiN (C ₂ F ₅ SO ₂ ) ₂ ), Examples thereof include lithium bispherfluoroethylsulfonylimide (LiN (CF ₂ F ₅ SO ₂ ) _2). These may be used alone or in combination of two or more. _{Among these, LiPF 6} is particularly preferable from the viewpoint of the large amount of anions occluded into the carbon electrode.

The content of the electrolyte salt is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.7 mol / L or more and 4 mol / L or less, preferably 1.0 mol / L or more in a non-aqueous solvent. 3 mol / L or less is more preferable, and 1.0 mol / L or more and 2.5 mol / L or less is more preferable from the viewpoint of achieving both the capacity and output of the power storage element.
<Separator>
The separator 30 is provided between the negative electrode 10 and the positive electrode 20 in order to prevent a short circuit between the negative electrode 10 and the positive electrode 20. The separator 30 is an insulating layer having lithium ion permeability and no electron conductivity. The material, shape, size, and structure of the separator 30 are not particularly limited and can be appropriately selected depending on the intended purpose.

Examples of the material of the separator 30 include paper such as kraft paper, vinylon mixed paper, synthetic pulp mixed paper, polyolefin non-woven fabric such as cellophane, polyethylene graft film, polypropylene melt flow non-woven fabric, polyamide non-woven fabric, glass fiber non-woven fabric, and polyethylene-based microporous material. Examples include a film and a polypropylene-based microporous film. Among these, those having a porosity of 50% or more are preferable from the viewpoint of retaining the non-aqueous electrolytic solution 51.

As the separator 30, for example, a material obtained by mixing ceramic fine particles such as alumina and zirconia with a binder or a solvent may be used. In this case, the average particle size of the ceramic fine particles is preferably, for example, about 0.2 to 3.0 μm. Thereby, lithium ion permeability can be provided. Here, the meaning of the average particle size and the method for measuring the average particle size are as described above.

The average thickness of the separator 30 is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less.

When the average thickness of the separator 30 is 3 μm or more, the negative electrode 10 and the positive electrode 20 can be reliably prevented from being short-circuited. Further, when the average thickness of the separator 30 is 50 μm or less, it is possible to prevent an increase in electrical resistance between the negative electrode 10 and the positive electrode 20 due to the negative electrode 10 and the positive electrode 20 being too far apart.

When the average thickness of the separator 30 is 5 μm or more, the negative electrode 10 and the positive electrode 20 can be more reliably prevented from short-circuiting. Further, when the average thickness of the separator 30 is 30 μm or less, it is possible to further prevent an increase in electrical resistance between the negative electrode 10 and the positive electrode 20 due to the negative electrode 10 and the positive electrode 20 being too far apart.

Examples of the shape of the separator 30 include a sheet shape and the like. The size of the separator 30 is not particularly limited as long as it can be used for the non-aqueous electrolyte storage element 1, and can be appropriately selected depending on the intended purpose. The structure of the separator 30 may be a single-layer structure or a laminated structure.
<Manufacturing method of non-aqueous electrolyte power storage element>
-Manufacturing of negative electrode and separator-
First, as shown in FIG. 2A, the negative electrode 10 and the separator 30 are manufactured. Specifically, a negative electrode current collector 11 made of stainless steel, copper, or the like is prepared. Then, a binder, a conductive agent, a solvent, and the like are added to the negative electrode active material as necessary to prepare a slurry-like negative electrode material composition for the negative electrode material layer 12, which is applied onto the negative electrode current collector 11 and dried. The negative electrode material layer 12 is formed. The negative electrode current collector 11 and the negative electrode material layer 12 are bound together.

Next, a negative electrode material composition for the negative electrode material layer 13 was prepared by adding a binder, a conductive agent, a solvent, etc. to the negative electrode active material as necessary to form a slurry by changing the concentration of the additive to the main material. , Is applied onto the negative electrode material layer 12 and dried to form the negative electrode material layer 13. The negative electrode material layer 12 and the negative electrode material layer 13 are bound together.

Next, fine particles of ceramic such as alumina and zirconia are mixed with a binder and a solvent to prepare a composition for a separator 30 which is made into a slurry, which is applied onto the negative electrode material layer 13 and dried to form the separator 30. .. The negative electrode material layer 13 and the separator 30 are bound together.

For the coating of the negative electrode material composition and the composition for the separator 30, for example, an inkjet method can be used, but there is no particular limitation, and an appropriate selection can be made according to the purpose, and a die coating machine or a comma coating can be used. A machine, a gravure coating machine, screen printing, dry press coating, a dispenser method, or the like may be used.

The inkjet method is suitable in that the object can be applied to the target portion of the lower layer. Further, the inkjet method is preferable in that the surfaces in contact with each other above and below the negative electrode current collector 11, the negative electrode material layer 12, and the negative electrode material layer 13 can be bonded to each other. Further, the inkjet method is suitable in that the layer thickness can be made uniform in each layer.

The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an aqueous solvent and an organic solvent. Examples of the aqueous solvent include water, alcohol and the like. Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), toluene and the like.

Further, a negative electrode active material to which a binder, a conductive agent, etc. is added is directly rolled to form a sheet electrode, a pellet electrode is formed by compression molding, or a method such as vapor deposition, sputtering, or plating is performed on the negative electrode current collector 11. It is also possible to form a thin film of the negative electrode active material.
-Preparation of positive electrode-
Next, as shown in FIG. 2B, the positive electrode 20 is produced. Specifically, a positive electrode current collector 21 made of stainless steel, aluminum, or the like is prepared. Then, a binder, a thickener, a conductive agent, a solvent, and the like are added to the positive electrode active material as necessary to prepare a slurry-like positive electrode material composition for the positive electrode material layer 22, and the positive electrode material composition is prepared on the positive electrode current collector 21. It is applied and dried to form the positive electrode material layer 22. The positive electrode current collector 21 and the positive electrode material layer 22 are bound together.

Next, the positive electrode material composition for the positive electrode material layer 23, which is made into a slurry by adding a binder, a thickener, a conductive agent, a solvent, etc. to the positive electrode active material as necessary, is obtained by adjusting the concentration of the additive to the main material. It is produced differently, applied on the positive electrode material layer 22, and dried to form the positive electrode material layer 23. The positive electrode material layer 22 and the positive electrode material layer 23 are bound together.

For the coating of the positive electrode material composition, for example, an inkjet method can be used, but there is no particular limitation, and an appropriate selection can be made according to the purpose, such as a die coating machine, a comma coating machine, and a gravure coating machine. , Screen printing, dry press coating, dispenser method, etc. may be used.

As the solvent, the same solvent as in the method for producing the negative electrode 10 can be used. Further, the positive electrode active material can be roll-molded as it is to form a sheet electrode, or a pellet electrode can be formed by compression molding.
-Manufacture of electrode elements and non-aqueous electrolyte storage elements-
Next, as shown in FIG. 2C, the electrode element 40 is manufactured. Specifically, first, the negative electrode lead-out wire 41 is joined to the negative electrode current collector 11 by welding or the like. Further, the positive electrode lead-out wire 42 is joined to the positive electrode current collector 21 by welding or the like. Then, the positive electrode 20 is arranged on the negative electrode 10 so that the negative electrode material layer 13 of the negative electrode 10 and the positive electrode material layer 23 of the positive electrode 20 face each other via the separator 30 to manufacture the electrode element 40.

After the step shown in FIG. 2C, the non-aqueous electrolytic solution 51 is injected into the electrode element 40 and sealed with the exterior 52 to complete the non-aqueous electrolytic solution storage element 1 shown in FIG.

As described above, in the present embodiment, the performance (life, output characteristics, etc.) of the non-aqueous electrolyte storage element 1 can be improved.

That is, the concentration of the additive added to the main material from the negative electrode current collector 11 side to the separator 30 side so that the effect of preventing the precipitation of lithium ions increases from the negative electrode current collector 11 side to the separator 30 side. Is gradually increased in each layer. As a result, it is possible to prevent lithium ions from being deposited on the surface of the negative electrode 10 while maintaining the performance of the non-aqueous electrolyte storage element 1. As a result, the life of the non-aqueous electrolyte storage element 1 can be extended.

Further, the concentration of the additive added to the main material from the positive electrode current collector 21 side toward the separator 30 side so that the ion diffusivity decreases from the positive electrode current collector 21 side toward the separator 30 side and the capacity increases. Is gradually reduced in each layer. As a result, the capacity of the non-aqueous electrolyte storage element 1 can be improved, and the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1 can be promoted to improve the output performance.

Further, when the inkjet method is used, each layer can be easily laminated, so that the manufacturing process can be simplified and the manufacturing time can be shortened.

In the method shown in FIG. 2, the separator 30 and the positive electrode material layer 23 are not bonded to each other, but a binder or the like is interposed between the separator 30 and the positive electrode material layer 23 to separate the separator 30 and the positive electrode material layer 23. You may bind them. In this case, the relative misalignment between the negative electrode material layer and the positive electrode material layer does not occur between the adjacent electrode current collectors.

As a result, it is possible to prevent lithium ions from being deposited on the surface of the negative electrode due to the relative positional deviation between the negative electrode material layer and the positive electrode material layer caused by vibration or bending. As a result, the life of the non-aqueous electrolyte storage element 1 can be extended. Moreover, a stable output can always be obtained.

Further, it is possible to prevent the negative electrode and the positive electrode from being short-circuited due to the relative positional deviation between the negative electrode material layer and the positive electrode material layer caused by vibration or bending, and the safety of the non-aqueous electrolyte storage element 1 is improved. can do. As a result, the non-aqueous electrolyte storage element 1 can be suitably used for devices such as wearable devices, mobile bodies, and robots that are prone to vibration and bending.

In the above, an example in which the additive concentration is changed stepwise in each layer in both the negative electrode 10 and the positive electrode 20, but the additive concentration is changed in each layer only in one of the negative electrode 10 and the positive electrode 20. May be changed stepwise in. In this case, the above effect can be obtained with an electrode in which the addition concentration of the additive is changed stepwise in each layer.

<Second Embodiment>
FIG. 3 is a cross-sectional view illustrating the non-aqueous electrolyte storage element according to the second embodiment. Referring to FIG. 3, the non-aqueous electrolyte storage element 2 has a structure in which the non-aqueous electrolyte 51 is injected into the electrode element 60 and sealed with an exterior 52. The non-aqueous electrolyte storage element 2 may have other members, if necessary. The non-aqueous electrolyte storage element 2 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte capacitor.

The electrode element 60 has a negative electrode material layer 62, a separator 63, a positive electrode material layer 64, a positive electrode current collector 65, a positive electrode material layer 66, a separator 67, a negative electrode material layer 68, and a negative electrode current collector on the negative electrode current collector 61. It has a structure in which the bodies 69 are sequentially laminated. The negative electrode current collector 61, the negative electrode material layer 62, the separator 63, and the positive electrode material layer 64 are bound together. Further, the positive electrode current collector 65, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68 are bound together.

The negative electrode material layers 62 and 68 are electrode material layers for the negative electrode capable of occluding and releasing lithium ions. Separators 63 and 67 are insulating layers having lithium ion permeability and no electron conductivity. The positive electrode material layers 64 and 66 are electrode material layers for the positive electrode capable of occluding and releasing lithium ions.

A negative electrode lead-out wire 41 is connected to the negative electrode current collectors 61 and 69 and is led out to the outside of the exterior 52. A positive electrode lead-out wire 42 is connected to the positive electrode current collector 65 and is led out to the outside of the exterior 52.

The materials and thicknesses of the negative electrode current collectors 61 and 69 and the positive electrode current collector 65 can be, for example, the same as those of the negative electrode current collector 11 and the positive electrode current collector 21.

The configurations of the negative electrode material layers 62 and 68 can be the same as those of the negative electrode material layers 12 and 13, for example. However, it is not necessary to add additives to the negative electrode active material, and the negative electrode active material includes, for example, coke, artificial graphite, graphite such as natural graphite (graphite), and thermal decomposition products of organic substances under various thermal decomposition conditions. , Carbon materials such as amorphous carbon can be used.

However, the negative electrode material layers 62 and 68 each have a laminated structure of a plurality of layers, and as in the first embodiment, in the laminated structure of the negative electrode material layer 62, additives to the main material are added as the distance from the negative electrode current collector 61 side increases. The addition concentration may be gradually increased in each layer, and in the laminated structure of the negative electrode material layer 68, the addition concentration of the additive to the main material may be gradually increased in each layer as the distance from the negative electrode current collector 69 side increases. As a result, the same effect as that of the first embodiment is obtained.

The configurations of the positive electrode material layers 64 and 66 can be the same as those of the positive electrode material layers 22 and 23, for example. However, it is not necessary to add an additive to the positive electrode active material, and as the positive electrode active material, for example, lithium nickel composite oxide, spinel manganese, lithium phosphoric acid-based material, or the like can be used.

However, the positive electrode material layers 64 and 66 each have a laminated structure of a plurality of layers, and as in the first embodiment, the concentration of the additive added to the main material is gradually increased in each layer as the distance from the positive electrode current collector 65 side increases. It may be lowered. As a result, the same effect as that of the first embodiment is obtained.

As the separators 63 and 67, for example, fine particles of ceramic such as alumina, zirconia, and silica can be used. In this case, the average particle size of the ceramic fine particles is preferably, for example, about 0.2 to 3.0 μm. Thereby, lithium ion permeability can be provided. Here, the meaning of the average particle size and the method for measuring the average particle size are as described above. A material obtained by mixing the ceramic fine particles with the binder or solvent shown in the first embodiment can be used. By using the fine particles of ceramic, the separators 63 and 67 can be formed on the lower layer by the inkjet method, so that the separators 63 and 67 can be bonded to the lower layer.

The average thickness of the separators 63 and 67 is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 10 μm or less. When the average thickness of the separators 63 and 67 is 1 μm or more and 10 μm or less, a short circuit between the negative electrode material layer 62 and the positive electrode material layer 64, and the positive electrode material layer 66 and the negative electrode material layer 68 can be prevented.

In order to manufacture the non-aqueous electrolytic solution power storage element 2, first, as shown in FIG. 4A, the negative electrode material layer 62 and the separator 63 are placed on the negative electrode current collector 61 in the same manner as in the first embodiment. , And the positive electrode material layer 64 are sequentially laminated. The negative electrode current collector 61, the negative electrode material layer 62, the separator 63, and the positive electrode material layer 64 are bound together.

Next, as shown in FIG. 4B, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68 are sequentially laminated on the positive electrode current collector 65 in the same manner as in the first embodiment. The positive electrode current collector 65, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68 are bound together.

The layers in FIGS. 4 (a) and 4 (b) can be produced by any method exemplified in the first embodiment, but it is preferably performed by an inkjet method capable of binding adjacent layers. .. When each layer is produced by the inkjet method, the slurry is applied onto the lower layer by the inkjet method and then heated to a predetermined temperature to remove the solvent.

Next, as shown in FIG. 4C, the electrode element 60 is manufactured. Specifically, first, the negative electrode lead-out wire 41 is joined to the negative electrode current collectors 61 and 69 by welding or the like. Further, the positive electrode lead-out wire 42 is joined to the positive electrode current collector 65 by welding or the like. Then, on the laminated body of the negative electrode current collector 61, the negative electrode material layer 62, the separator 63, and the positive electrode material layer 64, the laminated body of the positive electrode current collector 65, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68 is placed. The electrode element 60 is manufactured by arranging the negative electrode current collector 69 and further arranging the negative electrode current collector 69 on the negative electrode material layer 68.

In this method, the positive electrode material layer 64 and the positive electrode current collector 65 are not bonded to each other, but a binder or the like is interposed between the positive electrode material layer 64 and the positive electrode current collector 65, and the positive electrode material layer 64 and the positive electrode current collector are collected. It may be bound to the electric body 65. Similarly, although the negative electrode material layer 68 and the negative electrode current collector 69 are not bonded to each other, a binder or the like is interposed between the negative electrode material layer 68 and the negative electrode current collector 69, and the negative electrode material layer 68 and the negative electrode current collector 69 are interposed. And may be bound.

After the step shown in FIG. 4C, the non-aqueous electrolytic solution 51 is injected into the electrode element 60 and sealed with the exterior 52 to complete the non-aqueous electrolytic solution storage element 2 shown in FIG.

As described above, in the non-aqueous electrolytic solution power storage element 2, adjacent layers of the negative electrode current collector 61, the negative electrode material layer 62, the separator 63, and the positive electrode material layer 64 are bound to each other. Further, in the positive electrode current collector 65, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68, adjacent layers are bound to each other. That is, the relative positional deviation between the negative electrode material layer and the positive electrode material layer does not occur between the adjacent electrode current collectors.

As a result, it is possible to prevent lithium ions from being deposited on the surface of the negative electrode due to the relative positional deviation between the negative electrode material layer and the positive electrode material layer caused by vibration or bending. As a result, the life of the non-aqueous electrolyte storage element 2 can be extended. Moreover, a stable output can always be obtained.

Further, it is possible to prevent the negative electrode and the positive electrode from being short-circuited due to the relative positional deviation between the negative electrode material layer and the positive electrode material layer caused by vibration or bending, and the safety of the non-aqueous electrolyte storage element 2 is improved. can do. As a result, the non-aqueous electrolyte storage element 2 can be suitably used for devices such as wearable devices, mobile bodies, and robots that are prone to vibration and bending.

Further, since each layer can be easily laminated by the inkjet method, the manufacturing process can be simplified and the manufacturing time can be shortened.

It is also possible to deform as shown in FIG. In the non-aqueous electrolyte storage element 3 shown in FIG. 5, the electrode element 60 of the non-aqueous electrolyte storage element 2 is replaced with the electrode element 60A.

The electrode element 60A is different from the electrode element 60 in the order of laminating each layer. That is, the electrode element 60A has a positive electrode material layer 66, a separator 67, a negative electrode material layer 68, a negative electrode current collector 61, a negative electrode material layer 62, a separator 63, a positive electrode material layer 64, and a positive electrode current collector on the positive electrode current collector 65. The structure is such that the bodies 69A are sequentially laminated. The negative electrode current collector 61, the negative electrode material layer 62, the separator 63, and the positive electrode material layer 64 are bound together. Further, the positive electrode current collector 65, the positive electrode material layer 66, the separator 67, and the negative electrode material layer 68 are bound together.

A negative electrode lead-out wire 41 is connected to the negative electrode current collector 61 and is led out to the outside of the exterior 52. A positive electrode lead-out wire 42 is connected to the positive electrode current collectors 65 and 69A and is led out to the outside of the exterior 52.

The non-aqueous electrolyte storage element 3 can be manufactured by the same method as the non-aqueous electrolyte storage element 2. In the non-aqueous electrolyte storage element 3, similarly to the non-aqueous electrolyte storage element 2, there is no relative misalignment between the negative electrode material layer and the positive electrode material layer between adjacent electrode current collectors. As a result, the same effect as that of the non-aqueous electrolyte storage element 2 is obtained.

It can also be deformed as shown in FIG. In the non-aqueous electrolyte storage element 4 shown in FIG. 6, the electrode element 60 of the non-aqueous electrolyte storage element 2 is replaced with the electrode element 60B.

In the electrode element 60B, the separator 163 is laminated between the separator 63 and the positive electrode material layer 64, and the separator 167 is laminated between the separator 67 and the negative electrode material layer 68. The separators 63 and 67 may be referred to as a first separator, and the separators 163 and 167 may be referred to as a second separator.

In the electrode element 60B, examples of the separators 163 and 167 include polyvinylidene fluoride, polytetrafluoroethylene, polyacrylate, 6 nylon (registered trademark), 66 nylon, polycarbonate, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, acrylic, and phenol. Resin materials such as resin, melamine resin, epoxy resin, silicon resin, and polyurethane can be used. Among these, those having a porosity of 50% or more are preferable from the viewpoint of retaining the non-aqueous electrolytic solution 51.

The average thickness of the separators 163 and 167 is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less. When the average thickness of the separators 163 and 167 is 5 μm or more, the negative electrode material layer 62 and the positive electrode material layer 64, and the positive electrode material layer 66 and the negative electrode material layer 68 can be more reliably prevented from short-circuiting. Further, when the average thickness of the separators 163 and 167 is 30 μm or less, it is possible to further prevent an increase in electrical resistance between the negative electrode material layer 62 and the positive electrode material layer 64, and between the positive electrode material layer 66 and the negative electrode material layer 68.

In order to manufacture the non-aqueous electrolytic solution power storage element 4, first, as shown in FIG. 7A, the negative electrode material layer 62 and the separator 63 are placed on the negative electrode current collector 61 in the same manner as in the first embodiment. , Separator 163, and positive electrode material layer 64 are sequentially laminated. The negative electrode current collector 61, the negative electrode material layer 62, the separator 63, the separator 163, and the positive electrode material layer 64 are bound together.

Next, as shown in FIG. 7B, the positive electrode material layer 66, the separator 67, the separator 167, and the negative electrode material layer 68 are sequentially laminated on the positive electrode current collector 65 in the same manner as in the first embodiment. To do. The positive electrode current collector 65, the positive electrode material layer 66, the separator 67, the separator 167, and the negative electrode material layer 68 are bound together. Note that FIG. 7C is an example of a perspective view of the structure shown in FIG. 7A.

Hereinafter, the electrode element 60B is manufactured in the same manner as in FIG. 4C, the non-aqueous electrolytic solution 51 is injected into the electrode element 60B, and the non-aqueous electrolytic solution 51 is sealed with the exterior 52. 4 is completed.

Like the non-aqueous electrolyte storage element 4, the second separator (separators 163, 167) may be laminated on the first separator (separators 63, 67). The non-aqueous electrolyte storage element 4 further exerts the following effects in addition to the effects described in the non-aqueous electrolyte storage element 2. That is, when the first separator (separator 63, 67) is made of a ceramic material and the second separator (separator 163, 167) is made of a resin material, a short circuit between the positive electrode layer and the negative electrode layer accompanied by heat generation occurs. It is possible to safely shut down the battery.

That is, conventionally, when the battery is composed of a resin separator corresponding to the second separator (separators 163 and 167), the positive electrode and the negative electrode are short-circuited, and when heat is generated, the resin shrinks and the positive electrode and the negative electrode are generated. The number of places where the resin separator does not exist increases between the two. Therefore, the number of short-circuited points increases, and as a result, heat generation due to the short-circuit does not stop.

On the other hand, by using the first separators (separators 63 and 67) as the ceramic material, heat generation due to a short circuit of the battery can be tolerated up to the melting temperature of the ceramic material. As a result, even if heat is generated such that the second separators (separators 163 and 167) which are resins are melted due to the short circuit, the presence of the first separators (separators 63 and 67) causes the positive electrode and the negative electrode to melt. The number of short circuits between them does not increase. As a result, the battery can be safely shut down when a short circuit between the positive electrode layer and the negative electrode layer accompanied by heat generation occurs.

In addition, in FIG. 3, FIG. 5, and FIG. 7, one or more sets of the positive electrode material layer, the separator, and the negative electrode material layer may be further laminated. For example, in FIG. 3, the negative electrode material layer, the separator, the positive electrode material layer, and the positive electrode current collector are sequentially laminated on the negative electrode current collector 69, and the laminated positive electrode current collector is passed through the positive electrode lead-out wire 42 to the positive electrode. It may be connected to the current collector 65. Further, the negative electrode material layer, the separator, the positive electrode material layer, and the positive electrode current collector are sequentially laminated under the negative electrode current collector 61, and the laminated positive electrode current collector is passed through the positive electrode lead-out wire 42 to the positive electrode current collector 65. May be connected with. Thereby, the energy density can be improved.

Further, in the cases of FIGS. 1, 5, and 8 and 10 described later, the separator is a first separator made of a ceramic material and a second separator made of a resin material, as in the case of FIG. May be a laminated structure of.

<Third embodiment>
FIG. 8 is a cross-sectional view illustrating the non-aqueous electrolyte storage element according to the third embodiment. Referring to FIG. 8, the non-aqueous electrolyte storage element 5 has a structure in which the non-aqueous electrolyte 51 is injected into the electrode element 70 and sealed with an exterior 52. The non-aqueous electrolyte storage element 5 may have other members, if necessary. The non-aqueous electrolyte storage element 5 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte capacitor.

The electrode element 70 has a positive electrode material layer 74, a separator 73, a negative electrode material layer 72, a negative electrode current collector 71, a negative electrode material layer 76, a separator 77, a positive electrode material layer 78, and a positive electrode current collector 79 on the positive electrode current collector 75. Is a structure in which is sequentially laminated. A negative electrode material layer 72, a separator 73, and a positive electrode material layer 74 are bonded to the lower side of the negative electrode current collector 71. Further, a negative electrode material layer 76, a separator 77, and a positive electrode material layer 78 are bonded to the upper side of the negative electrode current collector 71. That is, the negative electrode current collector 71 is bound to both the negative electrode material layer 72 and the negative electrode material layer 76.

A negative electrode lead-out wire 41 is connected to the negative electrode current collector 71 and is led out to the outside of the exterior 52. A positive electrode lead-out wire 42 is connected to the positive electrode current collectors 75 and 79 and is led out to the outside of the exterior 52.

The materials and thicknesses of the negative electrode current collector 71, the positive electrode current collector 75, and the positive electrode current collector 79 can be, for example, the same as those of the negative electrode current collector 11 and the positive electrode current collector 21.

The configurations of the negative electrode material layers 72 and 76 can be the same as those of the negative electrode material layers 12 and 13, for example. However, it is not necessary to add additives to the negative electrode active material, and the negative electrode active material includes, for example, coke, artificial graphite, graphite such as natural graphite (graphite), and thermal decomposition products of organic substances under various thermal decomposition conditions. , A carbonaceous material such as amorphous carbon can be used.

However, the negative electrode material layers 72 and 76 each have a laminated structure of a plurality of layers, and as in the first embodiment, the concentration of the additive added to the main material is gradually increased in each layer as the distance from the negative electrode current collector 71 side increases. It may be increased. As a result, the same effect as that of the first embodiment is obtained.

The configurations of the positive electrode material layers 74 and 78 can be the same as those of the positive electrode material layers 22 and 23, for example. However, it is not necessary to add an additive to the positive electrode active material, and as the positive electrode active material, for example, lithium nickel composite oxide, spinel manganese, lithium phosphoric acid-based material, or the like can be used.

However, the positive electrode material layers 74 and 78 each have a laminated structure of a plurality of layers, and as in the first embodiment, in the laminated structure of the positive electrode material layer 74, additives to the main material are added as the distance from the positive electrode current collector 75 side increases. The additive concentration may be gradually decreased in each layer, and in the laminated structure of the positive electrode material layer 78, the additive concentration to the main material may be gradually decreased as the distance from the positive electrode current collector 79 side increases. As a result, the same effect as that of the first embodiment is obtained.

The separators 73 and 77 can have the same composition as the separators 63 and 67, for example.

In order to manufacture the non-aqueous electrolytic solution power storage element 5, first, as shown in FIG. 9A, the negative electrode material layer 72 and the separator 73 are placed on the negative electrode current collector 71 in the same manner as in the first embodiment. , And the positive electrode material layer 74 are sequentially laminated. The negative electrode current collector 71, the negative electrode material layer 72, the separator 73, and the positive electrode material layer 74 are bound together.

Next, as shown in FIG. 9B, the laminated body shown in FIG. 9A is turned upside down, and the negative electrode material layer 72 and the like of the negative electrode current collector 71 are formed in the same manner as in the first embodiment. The negative electrode material layer 76, the separator 77, and the positive electrode material layer 78 are sequentially laminated on the opposite surface. The negative electrode current collector 71, the negative electrode material layer 76, the separator 77, and the positive electrode material layer 78 are bound together.

The layers in FIGS. 9 (a) and 9 (b) can be produced by any method exemplified in the first embodiment, but it is preferably performed by an inkjet method capable of binding adjacent layers. .. When each layer is produced by the inkjet method, the slurry is applied onto the lower layer by the inkjet method and then heated to a predetermined temperature to remove the solvent.

Next, as shown in FIG. 9C, the electrode element 70 is manufactured. Specifically, the positive electrode current collector 75 is arranged below the positive electrode material layer 74. Further, the positive electrode current collector 79 is arranged above the positive electrode material layer 78. Then, the negative electrode lead-out wire 41 is joined to the negative electrode current collector 71 by welding or the like, and the positive electrode lead-out wire 42 is joined to the positive electrode current collectors 75 and 79 by welding or the like to manufacture the electrode element 70. The electrode element 70 can also be regarded as a product obtained by manufacturing the electrode element 60A by a different manufacturing method.

In this method, the positive electrode material layer 74 and the positive electrode current collector 75 are not bonded to each other, but a binder or the like is interposed between the positive electrode material layer 74 and the positive electrode current collector 75, and the positive electrode material layer 74 and the positive electrode current collector are collected. It may be bound to the electric body 75. Similarly, although the positive electrode material layer 78 and the positive electrode current collector 79 are not bonded to each other, a binder or the like is interposed between the positive electrode material layer 78 and the positive electrode current collector 79, and the positive electrode material layer 78 and the positive electrode current collector 79 are interposed. And may be bound.

After the step shown in FIG. 9C, the non-aqueous electrolytic solution 51 is injected into the electrode element 70 and sealed with the exterior 52 to complete the non-aqueous electrolytic solution storage element 5 shown in FIG.

As described above, in the non-aqueous electrolyte storage element 5, adjacent layers of the negative electrode current collector 71, the negative electrode material layer 72, the separator 73, the positive electrode material layer 74, the negative electrode material layer 76, the separator 77, and the positive electrode material layer 78 are adjacent to each other. Is bound. Further, the negative electrode current collector 71 is bound to both the negative electrode material layer 72 and the negative electrode material layer 76. That is, the relative positional deviation between the negative electrode material layer and the positive electrode material layer does not occur between the adjacent electrode current collectors. As a result, the same effect as that of the second embodiment is obtained.

It is also possible to deform as shown in FIG. In the non-aqueous electrolyte storage element 6 shown in FIG. 10, the electrode element 70 of the non-aqueous electrolyte storage element 5 is replaced with the electrode element 70A.

The electrode element 70A is different from the electrode element 70 in the order of laminating each layer. That is, the electrode element 70A has a negative electrode material layer 76, a separator 77, a positive electrode material layer 78, a positive electrode current collector 75, a positive electrode material layer 74, a separator 73, a negative electrode material layer 72, and a negative electrode current collector on the negative electrode current collector 71. The structure is such that the bodies 79A are sequentially laminated.

A positive electrode material layer 78, a separator 77, and a negative electrode material layer 76 are bonded to the lower side of the positive electrode current collector 75. Further, a positive electrode material layer 74, a separator 73, and a negative electrode material layer 72 are bonded to the upper side of the positive electrode current collector 75.

A positive electrode lead-out wire 42 is connected to the positive electrode current collector 75 and is led out to the outside of the exterior 52. A negative electrode lead-out wire 41 is connected to the negative electrode current collectors 71 and 79A and is led out to the outside of the exterior 52. The electrode element 70A can also be regarded as a product obtained by manufacturing the electrode element 60 by a different manufacturing method.

The non-aqueous electrolyte storage element 6 can be manufactured by the same method as the non-aqueous electrolyte storage element 5. The separator 73 is formed so as to cover the side surface of the positive electrode material layer 74 in order to laminate the negative electrode material layer 72 wider than the positive electrode material layer 74. Similarly, the separator 77 is formed so as to cover the side surface of the positive electrode material layer 78 in order to laminate the negative electrode material layer 76 wider than the positive electrode material layer 78.

In the non-aqueous electrolyte storage element 6, the relative misalignment between the negative electrode material layer and the positive electrode material layer does not occur between the adjacent electrode current collectors as in the non-aqueous electrolyte storage element 5. As a result, the same effect as that of the non-aqueous electrolyte storage element 5 is obtained.

In addition, in FIG. 8 and FIG. 10, one or more sets of the positive electrode material layer, the separator, and the negative electrode material layer may be further laminated. For example, in FIG. 8, the positive electrode material layer, the separator, the negative electrode material layer, and the negative electrode current collector are sequentially laminated on the positive electrode current collector 79, and the laminated negative electrode current collector is passed through the negative electrode lead-out wire 41 to the negative electrode. It may be connected to the current collector 71. Further, the positive electrode material layer, the separator, the negative electrode material layer, and the negative electrode current collector are sequentially laminated under the positive electrode current collector 75, and the laminated negative electrode current collector is passed through the negative electrode lead-out wire 41 to the negative electrode current collector 71. May be connected with. Thereby, the energy density can be improved.

[Example 1]
In Example 1, the non-aqueous electrolyte storage element 1 shown in FIG. 1 was produced. However, the positive electrode material layer was one layer. That is, on the positive electrode 20 side, the addition concentration of the additive is not changed stepwise in each layer.

Specifically, first, a negative electrode active material in which amorphous carbon is added to graphite as a main material so that the weight ratio is graphite: amorphous carbon = 8: 2 is prepared, and the first embodiment A negative electrode material composition for the negative electrode material layer 12 was prepared by adding a binder, a conductive agent, and a solvent appropriately selected from the materials shown in (1) to form a slurry.

Further, a negative electrode active material was prepared by adding amorphous carbon to graphite, which is the main material, so that the weight ratio was graphite: amorphous carbon = 6: 4, and the material shown in the first embodiment was prepared. A negative electrode material composition for the negative electrode material layer 13 was prepared by adding a binder, a conductive agent, and a solvent appropriately selected from the above to form a slurry.

Next, a copper current collector base material having a thickness of 8 μm was prepared as the negative electrode current collector 11, and 5 mg / cm ² of the negative electrode material composition for the negative electrode material layer 12 was applied onto the negative electrode current collector 11 by an inkjet method. It was dried to bind the negative electrode material layer 12.

Next, the negative electrode material composition for the negative electrode material layer 13 was ^{applied to the negative electrode material layer 12 by an inkjet method at 5 mg / cm 2} and dried to bind the negative electrode material layer 13. As described above, the negative electrode 10 in which the negative electrode material layer 12 and the negative electrode material layer 13 are sequentially laminated on the negative electrode current collector 11 is produced.

Next, an aluminum current collector base material having a thickness of 15 μm was prepared as the positive electrode current collector 21, and a positive electrode material layer containing a nickel composite oxide of ^{15 mg / cm 2 as a main material was bonded onto the positive electrode current collector 21.} , A positive electrode 20 was produced. Then, the negative electrode 10 was opposed to the positive electrode 20 via a separator 30 made of a microporous film made of polypropylene having a thickness of 25 μm.

Then, the negative electrode lead-out wire 41 was joined to the negative electrode current collector 11 by welding, and the positive electrode lead-out wire 42 was joined to the positive electrode current collector 21 by welding to manufacture the electrode element 40. _{Then, 1.5M LiPF 6} EC: DMC = 1: 1 is injected into the electrode element 40 as the non-aqueous electrolyte solution 51, and the electrode element 40 is sealed with a laminated exterior material as the exterior 52 to form the non-aqueous electrolyte storage element 1. Made.

[Comparative Example 1]
First, a negative electrode active material was prepared by adding amorphous carbon to graphite, which is the main material, so that the weight ratio was graphite: amorphous carbon = 7: 3, and the same binder and conductive agent as in Example 1 were prepared. A solvent was added to prepare a slurry-like negative electrode material composition.

Next, a copper current collector base material having a thickness of 8 μm was prepared as the negative electrode current collector, and 10 mg / cm ² of the prepared negative electrode material composition was applied onto the negative electrode current collector by an inkjet method, dried, and the negative electrode material was dried. As a layer, a negative electrode was produced in which one negative electrode material layer was bonded on the negative electrode current collector.

A non-aqueous electrolytic solution power storage element according to Comparative Example 1 was produced in the same manner as in Example 1 except for this. For convenience, this non-aqueous electrolyte storage element is referred to as a non-aqueous electrolyte storage element 1X.

[Comparison of Example 1 / Comparative Example 1]
The non-aqueous electrolyte storage elements 1 and 1X were charged and discharged at 1C (current value that can be completely discharged in 1 hour), and the discharge capacity retention rates after 500 cycles were compared. As a result, the non-aqueous electrolyte storage element 1 (Example 1) was 87%, and the non-aqueous electrolyte storage element 1X (Comparative Example 1) was 82%.

Further, the non-aqueous electrolyte storage elements 1 and 1X were disassembled, and the thickness of the lithium ions deposited on the negative electrode was depth-analyzed using XPS (X-ray Photoelectron Spectroscopy). As a result, the amount of lithium ion deposited in the non-aqueous electrolyte storage element 1 (Example 1) was 12% smaller than the amount of lithium ion deposited in the non-aqueous electrolyte storage element 1X (Comparative Example 1).

In this way, in each layer of the negative electrode 10, amorphous carbon (additive), which is more difficult to precipitate lithium ions on the surface of the negative electrode 10 than graphite, is added to graphite (main material). Then, the concentration of the amorphous carbon (additive) added to the graphite (main material) is gradually increased in each layer from the negative electrode current collector 11 side to the separator 30 side. As a result, it was confirmed that it is possible to prevent lithium ions from being deposited on the surface of the negative electrode 10 while maintaining the performance of the non-aqueous electrolyte storage element 1.

[Example 2]
In Example 2, the non-aqueous electrolyte storage element 1 shown in FIG. 1 was produced. However, the negative electrode material layer was one layer. That is, on the negative electrode 10 side, the addition concentration of the additive is not changed stepwise in each layer.

Specifically, first, a positive electrode active material was prepared by adding spinel manganese to the main material lithium nickel composite oxide so that the weight ratio was lithium nickel composite oxide: spinel manganese = 6: 4. A negative electrode material composition for the positive electrode material layer 22 was prepared by adding a binder, a conductive agent, a thickener, and a solvent appropriately selected from the materials shown in the above embodiment to form a slurry.

Further, a positive electrode active material is prepared by adding spinel manganese to the main material lithium nickel composite oxide so that the weight ratio is lithium nickel composite oxide: spinel manganese = 8: 2, and in the first embodiment. A binder, a conductive agent, a thickener, and a solvent appropriately selected from the materials shown were added to prepare a slurry-like negative electrode material composition for the positive electrode material layer 23.

Next, an aluminum current collector base material having a thickness of 15 μm was prepared as the positive electrode current collector 21, and 7.5 mg / cm ^{2 of the positive electrode material composition for the positive electrode material layer 22 was applied onto the positive electrode current collector 21 by an inkjet method.} Then, it was dried to bind the positive electrode material layer 22.

^{Next, 7.5 mg / cm 2} of the positive electrode material composition for the positive electrode material layer 23 was applied onto the positive electrode material layer 22 by an inkjet method and dried to bind the positive electrode material layer 23. As described above, the positive electrode 20 in which the positive electrode material layer 22 and the positive electrode material layer 23 are sequentially laminated on the positive electrode current collector 21 is produced.

Next, a copper current collector base material having a thickness of 8 μm was prepared as the negative electrode current collector 11 ^{, and a negative electrode material layer containing 10 mg / cm 2} of graphite as a main material was bonded onto the negative electrode current collector 11, and the negative electrode 10 was used. Was produced. Then, the negative electrode 10 was opposed to the positive electrode 20 via a separator 30 made of a microporous film made of polypropylene having a thickness of 25 μm.

Then, the negative electrode lead-out wire 41 was joined to the negative electrode current collector 11 by welding, and the positive electrode lead-out wire 42 was joined to the positive electrode current collector 21 by welding to manufacture the electrode element 40. _{Then, 1.5M LiPF 6} EC: DMC = 1: 1 is injected into the electrode element 40 as the non-aqueous electrolyte solution 51, and the electrode element 40 is sealed with a laminated exterior material as the exterior 52 to form the non-aqueous electrolyte storage element 1. Made.

[Comparative Example 2]
First, a positive electrode active material was prepared by adding spinel manganese to the main material lithium nickel composite oxide so that the weight ratio was lithium nickel composite oxide: spinel manganese = 7: 3, and a binder similar to that in Example 2 was prepared. , A conductive agent, a thickener, and a solvent were added to prepare a slurry-like positive electrode material composition.

Next, an aluminum current collector base material having a thickness of 15 μm was prepared as the positive electrode current collector, and 15 mg / cm ² of the prepared positive electrode material composition was applied onto the positive electrode current collector by an inkjet method, dried, and the positive electrode material was dried. As a layer, a positive electrode was produced in which one positive electrode material layer was bonded on the positive electrode current collector.

A non-aqueous electrolyte storage device according to Comparative Example 1 was produced in the same manner as in Example 2 except for this. For convenience, this non-aqueous electrolyte storage element is referred to as a non-aqueous electrolyte storage element 1X.

[Comparison of Example 2 / Comparative Example 2]
For the non-aqueous electrolyte storage elements 1 and 1X, the discharge capacity retention rate when continuous load discharge was performed at 5C was measured and compared. The discharge capacity retention rate was calculated with the discharge capacity as 100% when evaluated at 0.2C. As a result, the non-aqueous electrolyte storage element 1 (Example 2) was 81%, and the non-aqueous electrolyte storage element 1X (Comparative Example 2) was 75%.

As described above, in each layer of the positive electrode 20, spinel manganese (additive) having higher diffusivity to lithium ions than the lithium nickel composite oxide is added to the lithium nickel composite oxide (main material). Then, the concentration of spinel manganese (additive) added to the lithium nickel composite oxide (main material) is gradually reduced in each layer from the positive electrode current collector 21 side toward the separator 30 side. As a result, it was confirmed that the output performance can be improved by promoting the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1.

[Example 3]
In Example 3, the non-aqueous electrolyte storage element 1 shown in FIG. 1 was produced. However, the negative electrode material layer was one layer. That is, on the negative electrode 10 side, the addition concentration of the additive is not changed stepwise in each layer.

Specifically, the non-aqueous electrolytic solution power storage element 1 was produced in the same manner as in Example 2 except that the additive was changed from spinel manganese to a lithium nickel composite oxide having a particle size smaller than that of the main material.

[Comparative Example 3]
A non-aqueous electrolytic solution power storage element 1X was produced in the same manner as in Comparative Example 2 except that the additive was changed from spinel manganese to a lithium nickel composite oxide having a particle size smaller than that of the main material.

[Comparison of Example 3 / Comparative Example 3]
For the non-aqueous electrolyte storage elements 1 and 1X, the discharge capacity retention rate when continuous load discharge was performed at 5C was measured and compared. The discharge capacity retention rate was calculated with the discharge capacity as 100% when evaluated at 0.2C. As a result, the non-aqueous electrolyte storage element 1 (Example 3) was 76%, and the non-aqueous electrolyte storage element 1X (Comparative Example 3) was 70%.

In this way, in each layer of the positive electrode 20, a lithium nickel composite oxide (additive) having a particle size smaller than that of the lithium nickel composite oxide (main material) is added to the lithium nickel composite oxide (main material). Then, from the positive electrode current collector 21 side toward the separator 30 side, the addition concentration of the lithium nickel composite oxide (additive) having a particle size smaller than that of the main material with respect to the lithium nickel composite oxide (main material) is stepped in each layer. Decrease. As a result, it was confirmed that the output performance can be improved by promoting the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1.

[Example 4]
In Example 4, the non-aqueous electrolyte storage element 1 shown in FIG. 1 was produced. However, the negative electrode material layer was one layer. That is, on the negative electrode 10 side, the addition concentration of the additive is not changed stepwise in each layer.

Specifically, the non-aqueous electrolyte storage element 1 was produced in the same manner as in Example 2 except that the additive was replaced with vanadium lithium phosphate from spinel manganese.

[Comparative Example 4]
A non-aqueous electrolyte storage element 1X was produced in the same manner as in Comparative Example 2 except that the additive was replaced with vanadium lithium phosphate from spinel manganese.

[Comparison of Example 4 / Comparative Example 4]
For the non-aqueous electrolyte storage elements 1 and 1X, the discharge capacity retention rate when continuous load discharge was performed at 5C was measured and compared. The discharge capacity retention rate was calculated with the discharge capacity as 100% when evaluated at 0.2C. As a result, the non-aqueous electrolyte storage element 1 (Example 4) was 86%, and the non-aqueous electrolyte storage element 1X (Comparative Example 4) was 79%.

As described above, in each layer of the positive electrode 20, vanadium lithium phosphate (additive) having higher diffusivity to lithium ions than the lithium nickel composite oxide is added to the lithium nickel composite oxide (main material). Then, the concentration of vanadium lithium phosphate (additive) added to the lithium nickel composite oxide (main material) is gradually reduced in each layer from the positive electrode current collector 21 side toward the separator 30 side. As a result, it was confirmed that the output performance can be improved by promoting the diffusion of lithium ions inside the non-aqueous electrolyte storage element 1.

Although the preferred embodiments and the like have been described in detail above, the embodiments are not limited to the above-described embodiments and the like, and various embodiments and the like described above are used without departing from the scope of the claims. Modifications and substitutions can be added.

For example, in the first embodiment, an example in which the negative electrode 10 and the positive electrode 20 are used for the non-aqueous electrolyte storage element 1 is shown, but the present invention is not limited to this, and the negative electrode 10 and the positive electrode 20 are storage elements using a gel electrolyte. In that case, the same effect as when used for the non-aqueous electrolyte storage element 1 is obtained.

1, 2, 3, 4, 5, 6 Non-aqueous electrolyte storage element 10 Negative electrode 11, 61, 69, 71, 79A Negative electrode current collector 12, 13, 62, 68, 72, 76 Negative electrode material layer 20 Positive electrode 21, 65, 69A, 75, 79 Positive electrode current collector 22, 23, 64, 66, 74, 78 Positive electrode material layer 30, 63, 67, 73, 77, 163, 167 Separator 40, 60, 60A, 70, 70A Electrode element 41 Negative electrode lead wire 42 Positive electrode lead wire 51 Non-aqueous electrolyte 52 Exterior

Patent No. 4055671

Claims (7)

A positive electrode comprising a current collector and a front Symbol collector one multiple electrode material layers stacked on the side of, the,
Among the plurality of electrode material layers, a predetermined electrode material layer is used as a first electrode material layer, and a predetermined electrode material layer arranged farther than the current collector than the first electrode material layer is a second electrode material layer. When used as the electrode material layer of
The first electrode material layer and the second electrode material layer include a third material and a fourth material.
Both the third material and the fourth material can occlude and release lithium ions.
The fourth material has higher ion diffusivity than the third material.
The ratio of the weight of the fourth material to the total weight of the third material and the fourth material is smaller in the second electrode material layer than in the first electrode material layer . The electrode material layer of each _{is, LiNi X Co y Mn z O} 2 (x + y + z = 1) the lithium nickel composite oxide is a spinel manganese, or _{Li X Me Y (PO 4)} Z (0.5 ≦ x ≦ 4, Me = transition metal, a positive electrode according to claim 1 comprising a lithium phosphate-based material and 0.5 ≦ y ≦ 2.5,0.5 ≦ z ≦ 3.5) the basic skeleton. A pre-Symbol lithium nickel composite oxide third material is _{LiNi X Co y Mn z O 2} (x + y + z = 1),
The fourth material is spinel manganese or Li _X Me _Y (PO ₄ ) _Z (0.5 ≦ x ≦ 4, Me = transition metal, 0.5 ≦ y ≦ 2.5, 0.5 ≦ z ≦ 3. the positive electrode of claim 2, 5) is a lithium phosphate-based material as a basic skeleton. A pre-Symbol lithium nickel composite oxide third material is _{LiNi X Co y Mn z O 2} (x + y + z = 1),
The _{LiNi X Co y Mn z O 2} (x + y + z = 1) a positive electrode of claim 2 wherein the lithium-nickel composite oxide is a small particle diameter than the fourth material said third material. A negative electrode that can occlude and release lithium ions,
The positive electrode according to any one of claims 1 to 4,
The negative electrode and the disposed between the positive electrode, the electrode elements to Yes and insulating layer, a having a permeability to lithium ions. The electrode element according to claim 5 , wherein the material of the insulating layer is particulate ceramic. The electrode element according to claim 5 or 6,
The non-aqueous electrolytic solution injected into the electrode element and
A non-aqueous electrolyte storage element having the electrode element and an exterior for sealing the non-aqueous electrolyte.

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