JP2011023131A - Anode plate for nonaqueous secondary battery and nonaqueous secondary battery using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anode plate for a nonaqueous secondary battery and a nonaqueous secondary battery using the same, with a mass ratio of an anode active material and lithium at an inner winding side of the anode plate in an electrode group of the nonaqueous secondary battery made smaller than that of the anode active material and lithium at an outer winding side, without fear of buckling of the electrode group, and excellent in charge and discharge characteristics. <P>SOLUTION: In the anode plate 3 forming as an anode active material columnar particles 2a, 2b including a compound containing silicon and oxygen, or a compound containing tin and oxygen or the like, on a surface or a rear face of an anode collector 1 such as a copper foil having a number of protrusions 1a, 1b formed on the surface in an oblique direction and put under lithium filling treatment, a mass ratio of the anode active material of the columnar particle 2a at an inner winding side at spiral winding together with a cathode plate through a porous insulating layer and the lithium is to be smaller than that of the anode active material of the columnar particle 2b at an outer winding side and the lithium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a negative electrode plate for a non-aqueous secondary battery and a lithium secondary battery using the same, and in particular, a non-aqueous secondary battery containing a compound containing silicon and oxygen or a compound containing tin and oxygen as active materials. The present invention relates to a negative electrode plate.

  In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries as power sources has increased. A battery used for the above applications is required to have a high energy density and excellent cycle characteristics.

  In response to this requirement, a new high capacity active material has been developed for each of the positive electrode plate and the negative electrode plate, and the negative electrode active material can be solved by using an alloy or oxide containing silicon or tin that can provide a high capacity. It is about to be planned. However, silicon and tin, or their oxides and nitrides have a large irreversible capacity, and have a problem that the negative electrode active material has a large expansion and contraction. That is, since a large proportion of the lithium ions released from the positive electrode plate during the initial charge remains occluded in the negative electrode plate, the battery capacity becomes smaller than the theoretical capacity of these negative electrode plate materials. In addition, the insertion and removal of lithium ions during charging and discharging greatly expands and contracts the negative electrode active material, so that the negative electrode plate is greatly distorted, and this stress may cause the electrode plate of the electrode group to buckle.

  Therefore, in order to solve the problem of irreversible capacity, a technique has been proposed in which lithium corresponding to the irreversible capacity is occluded in advance in the negative electrode plate, and then the battery is assembled and charge / discharge is started. That is, as shown in FIG. 7, the negative electrode active material layer 52 including a negative electrode active material including at least one selected from the group consisting of silicon, tin, and a silicon-titanium alloy is provided on the negative electrode current collector 51, A lithium metal layer 53 is deposited or sputtered so as to cover the surface of the negative electrode active material layer 52 so that lithium ions released from the positive electrode plate at the first charge can be recovered from the negative electrode plate with a high probability and the battery capacity is increased. It is proposed to form by (for example, refer patent document 1).

  In order to suppress the buckling of the electrode plates of the electrode group, a method of providing a space inside the electrode group has been proposed. That is, as shown in FIG. 8, a space in a region other than the region A is obtained by applying lithium 63 having an electric quantity exceeding the irreversible capacity to a predetermined region A of the negative electrode active material layer 62 supported on the negative electrode current collector 61. There has been proposed a method of providing (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2005-063805 JP 2007-328932 A

  However, although the irreversible capacity can be reduced in the prior art disclosed in Patent Document 1 described above, there arises a problem that the electrode plates of the electrode group are bent due to deformation of the negative electrode plate during charging and discharging. Further, when a space is provided inside the electrode group in the conventional technique shown in Patent Document 2 described above, although there is an effect on the buckling of the electrode plate of the electrode group, there are two regions in the process of manufacturing the negative electrode plate Therefore, there is a problem that the production of the negative electrode plate becomes complicated because it is necessary to apply lithium under different conditions.

  The present invention has been made in view of the above-described conventional problems, and becomes an inside of the negative electrode plate in the electrode group with respect to the expansion amount of the negative electrode active material generated when lithium is supported on the negative electrode active material of the non-aqueous secondary battery. The negative electrode plate for a non-aqueous secondary battery has a configuration in which the amount of expansion of the negative electrode active material on the side is smaller than the amount of expansion of the negative electrode active material on the outer side, and the electrode plate of the electrode group does not buckle and is easily manufactured Another object is to provide a non-aqueous secondary battery using the same.

  In order to achieve the above object, the negative electrode plate for a non-aqueous secondary battery of the present invention is composed of a compound containing silicon and oxygen or a compound containing tin and oxygen on both sides of a negative electrode current collector made of a metal foil. A negative electrode plate for a non-aqueous secondary battery in which lithium is supported on the negative electrode active material, and when the negative electrode plate is spirally wound together with the positive electrode plate via the porous insulating layer It is characterized in that the amount of expansion of the negative electrode active material on the inner side is smaller than the amount of expansion of the negative electrode active material on the outer side.

  According to the negative electrode plate for a non-aqueous secondary battery of the present invention, the negative electrode plate is spirally wound together with the positive electrode plate through the porous insulating layer with respect to the expansion amount of the negative electrode active material generated when lithium is supported on the negative electrode active material. When the amount of expansion of the negative electrode active material on the inner side when turned is smaller than the amount of expansion of the negative electrode active material on the outer side, the negative electrode plate is uniformly stressed in a certain direction. Therefore, it is possible to suppress the undulation of the negative electrode plate that occurs when the negative electrode plate receives uneven stress. In addition, it is possible to relieve the stress applied to the negative electrode active material on the inner side of the winding, which is subject to a greater compressive stress, during lithium supplementation in the manufacturing process of the negative electrode plate or when charging the battery, and cycle deterioration due to buckling of the electrode plate of the electrode group Can be suppressed.

The schematic diagram which shows the cross section of the negative electrode plate for non-aqueous secondary batteries in one Example of this invention. The schematic diagram which shows an example of the method for manufacturing the negative electrode plate for non-aqueous secondary batteries in one Example of this invention. The schematic diagram which shows the cross section of the negative electrode plate for non-aqueous secondary batteries in one Example of this invention. The schematic diagram which shows the cross section of the principal part of the electrode group of the non-aqueous secondary battery in one Example of this invention. The schematic diagram which shows the cross section of the non-aqueous secondary battery in one Example of this invention. (A) Schematic diagram showing a method for evaluating the curled state of the negatively curled negative electrode plate in the present invention, (b) Schematic diagram showing a method for evaluating the curled state of the negatively curled negative electrode plate, (c) Wave Schematic showing the method of evaluating the curl state of the negative electrode plate curled Schematic diagram showing a negative electrode plate for a non-aqueous secondary battery in a conventional example Schematic diagram showing a cross section of another negative electrode plate for a non-aqueous secondary battery in a conventional example

  In the first aspect of the present invention, a negative electrode active material consisting of a compound containing silicon and oxygen or a compound containing tin and oxygen on both sides of a negative electrode current collector made of metal foil, and lithium supported on the negative electrode active material A negative electrode plate for a non-aqueous secondary battery, wherein the amount of expansion of the negative electrode active material on the inner side when the negative electrode plate is spirally wound together with the positive electrode plate through the porous insulating layer becomes the outer side of the winding Since the negative electrode active material is configured so as to be smaller than the expansion amount of the negative electrode active material on the side, the negative electrode plate can be uniformly stressed in a certain direction and the undulation of the negative electrode plate can be suppressed.

In the second aspect of the present invention, a negative electrode active material consisting of a compound containing silicon and oxygen or a compound containing tin and oxygen on both sides of a negative electrode current collector made of metal foil, and lithium supported on the negative electrode active material A negative electrode plate for a non-aqueous secondary battery, wherein the negative electrode active material and lithium mass ratio on the inner side when the negative electrode plate is spirally wound together with the positive electrode plate through the porous insulating layer Is configured such that the amount of expansion of the negative electrode active material on the inner side of the winding becomes smaller than the amount of expansion of the negative electrode active material on the outer side of the negative electrode. It is possible to suppress the corrugation of the plate.

  In the third aspect of the present invention, the mass ratio between the negative electrode active material on the inner side and lithium is 5% to 10% less than the mass ratio between the negative electrode active material on the outer side and lithium. As a result, the amount of expansion of the negative electrode active material on the inner side of the winding becomes smaller than the amount of expansion of the negative electrode active material on the outer side of the winding, so that the undulation of the negative electrode plate can be suppressed and the curling amount can be reduced. .

  In the fourth aspect of the present invention, the amount of the negative electrode active material on the inner side and the outer side is the same, and the amount of lithium supported on the negative electrode active material on the inner side is supported on the negative electrode active material on the outer side. By configuring to be less than the amount of lithium applied, it is possible to generate the negative electrode active material layer on the inner side and the outer side on the same condition, and the generation of the negative electrode active material layer can be facilitated It becomes.

  In the fifth aspect of the present invention, since the amount of the negative electrode active material on the inner side becomes smaller than the amount of the negative electrode active material on the outer side, The volume and expansion amount are smaller than the volume and expansion amount of the negative electrode active material on the outer side of the winding, and the stress relaxation effect on the negative electrode active material on the inner side of the winding is increased, thereby effectively suppressing the undulation of the negative electrode plate. Is possible.

  In the sixth aspect of the present invention, the negative electrode active material layer on the inner side is made thinner than the negative electrode active material layer on the outer side. The thickness and expansion amount of the material is smaller than the thickness and expansion amount of the negative electrode active material on the outer side of the winding, and the stress relaxation effect on the negative electrode active material on the inner side of the winding is increased, thereby effectively suppressing the undulation of the negative electrode plate. It becomes possible to do.

  In the seventh invention of the present invention, a positive electrode plate having a positive electrode active material layer formed on both surfaces of the current collector, and a compound containing silicon and oxygen or a compound containing tin and oxygen on both surfaces of the current collector An electrode group comprising a negative electrode active material and a negative electrode plate carrying lithium on the negative electrode active material wound in a spiral shape through a porous insulating layer is enclosed in a battery case together with a non-aqueous electrolyte. In the non-aqueous secondary battery, by using any one of the first to sixth negative electrode plates of the present invention as the negative electrode plate, the amount of expansion of the negative electrode active material on the inner side of the winding is larger than the amount of expansion of the negative electrode active material on the outer side of the winding. It becomes possible to relieve the stress applied to the negative electrode active material on the inner side of the winding which is smaller and receives a larger compressive stress during lithium supplementation or charging, and the difference in curvature between the inner side and the outer side of the electrode plate when the electrode group is configured. Relieve stress difference caused by Since it is bets, it is possible to suppress breaking or buckling of the electrode plate, it is possible to provide a more secure non-aqueous secondary battery.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a negative electrode plate 3 for a non-aqueous secondary battery (hereinafter referred to as negative electrode plate 3) according to an embodiment of the present invention. In the figure, a negative electrode plate 3 according to the present invention is a compound containing silicon and oxygen as a negative electrode active material on the surface of a negative electrode current collector 1 such as a copper foil having a large number of protrusions 1a and 1b formed on the surface at a predetermined interval. Alternatively, the columnar particles 2a and 2b containing a compound containing tin and oxygen are formed in an oblique direction and then lithium-filled. At this time, when the negative electrode plate 3 is spirally wound together with the positive electrode plate through the porous insulating layer, the mass ratio between the negative electrode active material and lithium of the columnar particles 2a on the inner side is set as By making the mass ratio of the negative electrode active material and lithium of the columnar particle 2b on the side to be smaller, the expansion amount of the negative electrode active material on the inner side becomes smaller than the expansion amount of the negative electrode active material on the outer side, and the negative electrode plate Can be suppressed.

  First, an example of a method for producing the columnar particles 2a and 2b of the negative electrode active material on the surface of the negative electrode current collector 1 provided with the protrusions 1a and 1b will be described. FIG. 2 is a schematic view showing an example of a method for producing the negative electrode plate 3 in one embodiment of the present invention. In the figure, the inside of the vacuum chamber 103 is exhausted by an exhaust pump 113. In the vacuum chamber 103, the negative electrode current collector 1 provided with the protrusions 1 a and 1 b as the base material is sent out from the unwinding roll 110 through the transport roller 111 and travels along the can roll 105. In the meantime, the negative electrode active material vapor made of silicon or tin is supplied from the evaporation source 104 in an atmosphere containing oxygen, and the negative electrode current collector provided with the protrusions 1 a and 1 b by the negative electrode active material vapor that has passed through the opening of the mask 106. Columnar particles 2a and 2b of the negative electrode active material are formed on the surface of 1. The negative electrode plate 3 thus obtained is wound up on a winding roll 112.

  The atmosphere containing oxygen at this time can be created by blowing a certain amount of oxygen gas from the oxygen nozzle 107 through an orifice gas valve or a mass flow controller from an oxygen gas cylinder. For the evaporation source 104, a crucible or the like holding silicon or tin, which is a material of the negative electrode active material, is used. The higher the purity of silicon or tin, the better. As a method of heating the evaporation source 104, a resistance heating method or a heating method by irradiation with an electron beam can be used. Further, in order to adjust the thickness of the columnar particles 2a and 2b, for example, by making the heating amount of the evaporation source 104 constant, the evaporation rate of the material of the negative electrode active material is made constant, and the negative electrode current collector provided with the protrusions 1a and 1b This is possible by adjusting the traveling speed of the body 1. Further, the heating amount of the evaporation source 104 may be adjusted with the traveling speed of the negative electrode current collector 1 provided with the protrusions 1a and 1b being constant.

  Furthermore, in order to form the negative electrode active material columnar particles 2a and 2b by containing oxygen, the oxygen nozzle 107 is installed so that oxygen is distributed throughout the vapor of the negative electrode active material, and oxygen gas is introduced from the oxygen nozzle 107. . The method for forming the columnar particles 2a and 2b of the negative electrode active material is not particularly limited as long as the negative electrode plate 3 of the present invention can be obtained, but a dry process such as a vapor deposition method, a sputtering method, or a CVD method is used. It is preferable to use it. In particular, the vapor deposition method is a method with excellent productivity, and is preferable as a method for continuously and abundantly forming the columnar particles 2a and 2b of the negative electrode active material on the negative electrode current collector 1 provided with the moving protrusions 1a and 1b.

  After forming the columnar particles 2a of the negative electrode active material on the surface of the negative electrode current collector 1 provided with the protrusions 1a as described above, it is turned over and set in the apparatus, and the negative electrode current collector 1 provided with the protrusions 1b has a negative electrode on the surface thereof. After the columnar particles 2b of the active material are formed, a predetermined amount of lithium is vapor-deposited on both sides using a vacuum vapor deposition apparatus, and then slitted to a prescribed width and length to obtain a long strip negative electrode plate 3.

  So far, as a method of making the expansion amount of the negative electrode active material on the inner side of the negative electrode plate 3 smaller than the expansion amount of the negative electrode active material on the outer side of the winding, a method of changing the mass ratio between the negative electrode active material on the inner side and the outer side of the winding and lithium. As described above, even if the mass ratio between the negative electrode active material on the inner side and the outer side and lithium is the same as shown in FIG. 3, the thickness of the columnar particles 2a on the inner side becomes the thickness of the columnar particles 2b on the outer side. It is also possible to make the amount of expansion of the negative electrode active material on the inner side of the winding smaller than the amount of expansion of the negative electrode active material on the outer side of the winding even by making it thinner.

  Hereinafter, the non-aqueous secondary battery 27 of the present invention using the above-described negative electrode plate 3 will be described. FIG. 5 is a longitudinal sectional view of a cylindrical lithium secondary battery as an example of the non-aqueous secondary battery 27. In the cylindrical lithium secondary battery of FIG. 5, a positive electrode plate 6 using a composite lithium oxide as a positive electrode active material and a negative electrode plate 3 using a material capable of holding lithium as a negative electrode active material are used as a porous insulator layer. The electrode group 10 is produced by spirally winding the separator 7.

FIG. 4 is a cross-sectional view showing the main part of the electrode group 10 after winding. In the figure, an electrode group 10 for a non-aqueous secondary battery according to the present invention is formed by applying a positive electrode mixture paint on a positive electrode current collector 4 to form positive electrode mixture layers 5 a and 5 b on the positive electrode current collector 4. The positive electrode plate 6 and the negative electrode active material are vacuum-deposited on the negative electrode current collector 1 in an atmosphere containing oxygen to form columnar particles 2a and 2b of the negative electrode active material on the negative electrode current collector 1 to supplement lithium. The separator 7 is interposed between the treated negative electrode plate 3 and the negative electrode active material columnar particles 2a are wound inside, and the negative electrode active material columnar particles 2b are wound outside to form a spiral, The mass ratio of the negative electrode active material and lithium inside the winding is less than the mass ratio of the negative electrode active material and lithium outside the winding, and the amount of expansion of the negative electrode active material inside the winding is larger than the amount of expansion of the negative electrode active material outside the winding Make it smaller. Therefore, it is possible to relieve the stress applied to the negative electrode active material on the inner side that receives a larger compressive stress during lithium supplementation or charging, and the curvature of the inner side and the outer side of the electrode plate when the electrode group 10 is formed. Since the stress difference due to the difference can be alleviated and the electrode plate can be prevented from being broken or buckled, a highly safe non-aqueous secondary battery can be provided.

  Next, the electrode group 10 is housed inside the bottomed cylindrical battery case 21 while being insulated from the battery case 21 by the insulating plate 22, while the negative electrode lead 23 led out from the lower part of the electrode group 10 is the battery case 21. The positive electrode lead 24 led out from the upper part of the electrode group 10 is connected to the sealing plate 25. Further, after a predetermined amount of an electrolyte solution (not shown) made of a nonaqueous solvent is injected into the battery case 21, a sealing plate 25 with a sealing gasket 26 attached to the periphery is inserted into the opening, and the battery case 21 The opening is folded inward and caulked and sealed. Here, in the positive electrode plate 6, in order to form the positive electrode mixture layers 5a and 5b on the front surface or the back surface of the positive electrode current collector 4, the positive electrode active material, the conductive material, and the binder are put in an appropriate dispersion medium. A positive electrode mixture paint is prepared by mixing and dispersing with a disperser such as a Lee mixer, and kneading while adjusting the viscosity to be optimal for application to the positive electrode current collector 4 such as an aluminum foil. Here, as the positive electrode active material, for example, lithium cobaltate and modified products thereof (such as lithium cobaltate in which aluminum or magnesium is dissolved), lithium nickelate and modified products thereof (partially nickel is substituted with cobalt) Composite oxides such as lithium manganate and modified products thereof.

  As the conductive material at this time, for example, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black, and various graphites may be used alone or in combination. As the binder at this time, for example, polyvinylidene fluoride (PVdF), a modified polyvinylidene fluoride, polytetrafluoroethylene (PTFE), a rubber particle binder having an acrylate unit, and the like can be used. It is also possible to mix an acrylate monomer or an acrylate oligomer having a reactive functional group introduced into the binder.

  The positive electrode mixture paint prepared as described above is applied onto the positive electrode current collector 4 made of, for example, an aluminum foil using a die coater, dried, pressed to a predetermined thickness, and then a specified width. Then, a long belt-like positive electrode plate 6 is obtained by slit processing to a length. Here, the separator 7 may have any composition that can withstand the use range of the non-aqueous secondary battery, but it is preferable to use a microporous film of an olefin resin such as polyethylene or polypropylene, in particular, in a single or composite manner. . The thickness of the separator 7 is preferably 10 to 25 μm. Moreover, it is good also as a structure which formed the porous insulating layer containing the ceramic particle on the surface of the negative electrode plate 3 or the positive electrode plate 6 instead of the separator 7. FIG.

In the electrolytic solution at this time, various lithium compounds such as LiPF ₆ and LiBF ₄ can be used as an electrolyte salt. Further, ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC) can be used alone or in combination as a solvent. In addition, in order to form a good film on the positive electrode plate 6 or the negative electrode plate 3 and to ensure stability during overcharge, vinylene carbonate (VC) and cyclohexylbenzene (CHB), and modified products thereof are used. Is preferred. Moreover, although the shape of the negative electrode active material was described as columnar particles in the above, the effect of the present invention does not depend on the shape of the negative electrode active material. Therefore, for example, the effect of the present invention can be obtained even when the shape of the negative electrode active material is a laminate or a network. Hereinafter, specific examples will be described in more detail.

Embodiment 1 of the present invention will be described with reference to the drawings. As shown in FIG. 1, a negative electrode current collector 1 provided with protrusions 1a and 1b is formed by rolling a roll of 10 μm thick copper foil including protrusions 1a and 1b with surface roughness Ra = 0.8. 2 was set in the vacuum vapor deposition apparatus shown in FIG. 2 in such a direction that the columnar particles 2 a of the negative electrode active material were formed on the surface, and the inside of the vacuum chamber 103 was exhausted by the exhaust pump 113. Thereafter, in the vacuum chamber 103, the negative electrode current collector 1 provided with the protrusions 1 a from the unwinding roll 110 was sent through the transport roller 111 and was run along the can roll 105 at a constant speed. The crucible charged with silicon was heated as an evaporation source 104 using an electron beam, and at the same time, oxygen was introduced from an oxygen nozzle 107. The negative electrode active material vapor was supplied in an atmosphere containing oxygen, and the negative electrode current collector 1 provided with the protrusions 1a by the vapor of the negative electrode active material that passed through the opening of the mask 106 had a thickness of 10 μm and a basis weight of 16 g / Columnar particles 2a of m ² negative electrode active material were formed. The negative electrode plate 3 thus obtained was wound up on a winding roll 112. Next, the vacuum chamber 103 is returned to the atmospheric pressure, the negative electrode active material is set in the direction in which the columnar particles 2b of the negative electrode active material are formed on the surface of the negative electrode current collector 1 and the columnar particles 2a are formed. Columnar particles 2b were formed by the same method. The formed columnar particles 2b were the same as the columnar particles 2a and had a thickness of 10 μm and a basis weight of 16 g / m ² .

  The negative electrode plate 3 obtained in this way is set in another vacuum vapor deposition apparatus in which lithium is introduced into the vapor deposition source 104 in a direction in which the columnar particles 2a are supplemented with lithium, and vapor deposition is performed using resistance heating while the negative electrode plate 3 is running. The source was heated to supplement the columnar particles 2a with lithium by lithium vapor. At this time, the traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 19.0%. Next, this vacuum vapor deposition apparatus is returned to atmospheric pressure, and is reset so that lithium is filled in the columnar particles 2b, so that the mass ratio of lithium and the negative electrode active material filled in the columnar particles 2b becomes 20.0%. The traveling speed of the negative electrode plate 3 was set to the other, and lithium was supplemented to the columnar particles 2b under the same conditions as those for the columnar particles 2a.

  The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 18.6%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. Example 2 was adopted.

  The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 18.2%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. Example 3 was adopted.

  The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 18.0%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. Example 4 was adopted.

(Comparative Example 1)
The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 20.0%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. It was set as Comparative Example 1.

(Comparative Example 2)
The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 19.6%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. It was set as Comparative Example 2.

(Comparative Example 3)
The traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 17.8%, and other conditions were the same as for the negative electrode plate 3 produced in the same manner as in Example 1. It was set as Comparative Example 3.

  Next, the negative electrode plates 3 of Examples 1 to 4 and Comparative Examples 1 to 3 were slit to the width defined by the non-aqueous secondary battery 27 to form a negative electrode plate 3 for a non-aqueous secondary battery having a length of 1 m, respectively. Ten sheets were produced and evaluated according to the following contents.

  First, as shown in FIG. 6, a negative electrode plate was placed on the surface plate 41, and the presence or absence of undulation was observed and the curl amount h was measured. For example, in the case of the negative electrode plate 31 curled in a convex shape, the curl amount h was measured as shown in FIG. Similarly, in the case of the negatively curled negative electrode plate 32, the curl amount h was measured as shown in FIG. 6B, and in the case of the corrugated negative electrode plate 33 as shown in FIG. 6C. The occurrence rate of the negative electrode plate 3 and the average value of the curl amount h are shown in Table 1 for 10 sheets each.

  As shown in (Table 1), as the mass ratio difference (BA) / B between the negative electrode active material and lithium on the inner side and the outer side becomes larger, the occurrence rate of undulation decreases, and (B-A) / B Was 5% or more, the undulation was suppressed and the incidence was 0%. This is because the cause of the undulation is due to the difference in the expansion amount of the negative electrode active material layer formed on the inner side and the outer side of the negative electrode plate 3, and as the mass ratio of the negative electrode active material and lithium increases, This is because the amount of expansion of the negative electrode active material increases. Further, when the mass ratio difference (B−A) / B between the negative electrode active material and lithium on the inner side and the outer side is less than 5%, the mass ratio between the negative electrode active material on the inner side and the outer side of the negative electrode plate 3 and lithium is Due to the variation in the plane, the amount of expansion of the negative electrode active material on the inner side of the winding locally becomes larger than the amount of expansion of the negative electrode active material on the outer side of the winding, which may cause undulation.

On the other hand, when the mass ratio difference (BA) / B between the negative electrode active material and lithium on the inner side and the outer side is 5% or more, the expansion amount of the negative electrode active material on the inner side of the negative electrode plate 3 is always wound. Since it is smaller than the expansion amount of the negative electrode active material on the outer side, the deformation direction can be made constant. Further, when the mass ratio difference (BA) / B between the negative electrode active material and lithium on the inner side and the outer side of the winding is in the range of 0% to 5%, the curl amount h increases with an increase in (BA) / B. Diminished. This is because the curl amount h decreases with the decrease in the waviness described above.

  On the other hand, when (B−A) / B is in the range of 5% to 10%, the curl amount h increases with an increase in (B−A) / B. This is because the difference in the amount of expansion of the negative electrode active material between the inner side and the outer side becomes large. Further, when (B−A) / B is 11%, the curl amount increases, so that the workability when the negative electrode plate 3 is spirally wound together with the positive electrode plate via the separator 7 is deteriorated. Therefore, the mass ratio difference (B−A) / B between the negative electrode active material and lithium on the inner side and the outer side is in the range of 5% to 10%. It has been found that the effect of suppressing is great.

Another embodiment 5 of the present invention will be described with reference to the drawings. As shown in FIG. 3, the negative electrode current collector 1 provided with the protrusions 1a and 1b is a roll having a surface roughness Ra = 0.8 and a roll of 10 μm thick copper foil including the protrusions 1a and 1b. 2 was set in the vacuum vapor deposition apparatus shown in FIG. 2 in such a direction that the columnar particles 2 a of the negative electrode active material were formed on the surface, and the inside of the vacuum chamber 103 was exhausted by the exhaust pump 113. Thereafter, in the vacuum chamber 103, the negative electrode current collector 1 provided with the protrusions 1 a from the unwinding roll 110 was sent through the transport roller 111 and was run along the can roll 105 at a constant speed. A crucible containing silicon was used as an evaporation source 104 and heated using an electron beam, and oxygen was introduced from an oxygen nozzle 107 at the same time. The negative electrode active material vapor was supplied in an atmosphere containing oxygen, and the negative electrode current collector 1 provided with protrusions 1a by the vapor of the negative electrode active material passed through the opening of the mask 106 had a thickness of 9 μm and a basis weight of 15 g / Columnar particles 2a of m ² negative electrode active material were formed. The negative electrode plate 3 thus obtained was wound up on a winding roll 112.

Next, the vacuum chamber 103 is returned to atmospheric pressure, set in the direction in which the columnar particles 2b of the negative electrode active material are formed on the surface on the protrusion 1b side, and traveled at a speed slower than the traveling speed at which the columnar particles 2a were formed. As for other conditions, the columnar particles 2b were formed by the same method as the method for forming the columnar particles 2a. At this time, the thickness of the columnar particles 2b was 10 μm, and the basis weight was 16 g / m ² . The negative electrode plate 3 obtained in this way is set in another vacuum vapor deposition apparatus in which lithium is introduced into the vapor deposition source 104 in a direction in which the columnar particles 2a are supplemented with lithium, and vapor deposition is performed using resistance heating while the negative electrode plate 3 is running. The source was heated to supplement the columnar particles 2a with lithium by lithium vapor. At this time, the traveling speed of the negative electrode plate 3 was set so that the mass ratio of lithium supplemented in the columnar particles 2a and the negative electrode active material was 20.0%.

Next, this vacuum evaporation apparatus is returned to atmospheric pressure, and is reset so that lithium is filled in the columnar particles 2b, so that the mass ratio of lithium and the negative electrode active material filled in the columnar particles 2b becomes 20.0%. The traveling speed of the negative electrode plate 3 was set to the other, and lithium was supplemented to the columnar particles 2b under the same conditions as those for the columnar particles 2a. The negative electrode plate 3 obtained in this way was slit into the prescribed width of the non-aqueous secondary battery 27 to produce 10 negative electrode plates 3 for a non-aqueous secondary battery having a length of 1 m. The negative electrode plate 3 thus obtained was evaluated in the same manner as in Example 1. The occurrence probability of the negative electrode plate 3 and the average value of the curl amount h are shown in Table 2 for 10 sheets each.
For comparison, the evaluation results of Comparative Example 1 are also shown in (Table 2).

  As shown in Table 2, even if the mass ratio of the negative electrode active material and lithium on the inner side and the outer side is the same, the thickness of the negative electrode active material on the inner side is 9 μm, and the thickness of the negative electrode active material on the outer side is 10 μm. By making it smaller than this, the occurrence rate of the undulation of the negative electrode plate 3 can be reduced and the curl amount h can be reduced. This is because even if the mass ratio of the negative electrode active material and lithium on the inner side and the outer side is the same, the thickness of the negative electrode active material on the inner side is made smaller than the thickness of the negative electrode active material on the outer side. This is probably because the amount of expansion of the negative electrode active material was smaller than the amount of expansion of the negative electrode active material on the outside of the winding. Further, in addition to making the thickness of the negative electrode active material on the inner side smaller than the thickness of the negative electrode active material on the outer side, the mass ratio of the negative electrode active material on the inner side and lithium is wound as in Examples 1-4. By making it smaller than the mass ratio of the outer negative electrode active material and lithium, an effect can be further improved in improving the occurrence rate of waviness and the curl amount.

  First, in the same manner as in Example 5, the negative electrode active material columnar particles 2a on the inner side of the negative electrode current collector 1 provided with the protrusions 1a are 9 μm thick, and the negative electrode active material on the outer side of the negative electrode current collector 1 provided with the protrusions 1b. After the columnar particles 2b of the material are formed with a thickness of 10 μm, the difference (BA) / B between the mass ratio A of the negative electrode active material and lithium inside the roll and the mass ratio B of the negative electrode active material and lithium outside the roll is 5%. Lithium was vapor-deposited on both sides so as to form a negative electrode plate 3 by slit processing. Next, in the positive electrode plate 6, 100 parts by weight of lithium cobaltate as an active material, 2 parts by weight of acetylene black as a conductive material with respect to 100 parts by weight of the active material, and 100 parts by weight of polyvinylidene fluoride as a binder. A positive electrode mixture paint was prepared by stirring and kneading 2 parts by weight with an appropriate amount of N-methyl-2-pyrrolidone in a double-arm kneader.

  Next, as shown in FIG. 4, after this positive electrode mixture paint was applied to the surface of the positive electrode current collector 4 made of an aluminum foil having a thickness of 15 μm and dried, the thickness of the positive electrode mixture layers 5 a and 5 b on one side was reduced. Positive electrode plates 6 each having a thickness of 85 μm were prepared. Furthermore, by pressing this positive electrode plate 6 so that the total thickness becomes 140 μm, the thickness of the positive electrode mixture layers 5 a and 5 b on one side is set to 64 μm, and the width of the nonaqueous secondary battery 27 is specified. The positive electrode plate 6 was produced by slit processing.

  A nonaqueous secondary battery 27 as shown in FIG. 5 was produced using the negative electrode plate 3 and the positive electrode plate 6 produced as described above. More specifically, the positive electrode plate 6 and the negative electrode plate 3 were wound in a spiral shape through a separator 7 made of a polyethylene microporous film having a thickness of 20 μm to produce an electrode group 10. Next, the electrode group 10 is housed in the bottomed cylindrical battery case 21 while being insulated from the battery case 21 by the insulating plate 22, while the negative electrode lead 23 led out from the lower part of the electrode group 10 is placed in the battery case. The positive electrode lead 24 led out from the upper part of the electrode group 10 was connected to the sealing plate 25. Further, the battery case 21 is injected with an electrolyte solution (not shown) made of a predetermined amount of a non-aqueous solvent, and thereafter, a sealing plate 25 with a sealing gasket 26 attached to the periphery is inserted into the opening, and the battery case 21 is inserted. The 100 non-aqueous secondary batteries 27 produced by folding the opening of each of the two inwardly and caulking and sealing were used as Example 3.

(Comparative Example 4)
In the same manner as in Comparative Example 1, the negative electrode active material columnar particles 2a on the inner side of the negative electrode current collector 1 provided with the protrusions 1a have a thickness of 10 μm and a basis weight of 16 g / m ² . Similarly, the columnar particles 2b of the negative electrode active material on the outer side of the body 1 were formed to have a thickness of 10 μm and a basis weight of 16 g / m ^2, and then lithium was supplemented to the columnar particles 2a and 2b under the same conditions on both sides. Vapor deposition was performed so that the mass ratio of lithium to the negative electrode active material was 20.0%, and slit processing was performed to prepare the negative electrode plate 3. The positive electrode mixture paint used was the same as in Example 3. Next, using this positive electrode mixture paint, a positive electrode plate 6 having a thickness of 85 μm on one side of the positive electrode mixture layers 5a and 5b after being applied to a positive electrode current collector 4 made of an aluminum foil having a thickness of 15 μm and dried. did. Further, by pressing the positive electrode plate 6 so that the total thickness becomes 140 μm, the positive electrode plate 6 in which the thickness of the positive electrode mixture layers 5 a, 5 b on one side becomes 64 μm is prepared, and the non-aqueous secondary battery 27 It was used as the positive electrode plate 6 of Comparative Example 1 after slitting to a prescribed width. Further, a non-aqueous secondary battery 27 produced in the same manner as in Example 6 using these positive electrode plate 6 and negative electrode plate 3 was used as Comparative Example 4. Next, the battery performance of the non-aqueous secondary battery 27 of Example 6 and Comparative Example 4 wound in a spiral shape was evaluated. The characteristics of the negative electrode plate 3 of Example 6 and Comparative Example 4 are summarized in (Table 3).

  About the non-aqueous secondary battery 27 of Example 6 and Comparative Example 4, after evaluating 100 initial capacity | capacitance, respectively, the capacity | capacitance after repeating charging / discharging 500 cycles was evaluated. Furthermore, after repeating 500 cycles, the nonaqueous secondary battery 27 and the electrode group 10 were disassembled and observed. As a result of evaluating the capacity after 500 cycles of charge and discharge, the capacity maintenance ratio of Example 6 was about 1.7 times higher than the capacity maintenance ratio of Comparative Example 4. As a result of decomposition and observation after 500 cycles, in Example 6, no defects such as lithium precipitation, breakage of the negative electrode plate 3, buckling of the negative electrode plate 3, and loss of the negative electrode active material in the negative electrode plate 3 were observed. However, in Comparative Example 4, defects such as lithium deposition, breakage of the negative electrode plate 3, buckling of the negative electrode plate 3, and loss of the negative electrode active material in the negative electrode plate 3 were observed in 75 pieces out of 100 pieces.

  As a result of this evaluation, when the electrode group 10 was constructed in Example 6, the stress difference due to the difference in curvature between the inner side and the outer side of the electrode plate was alleviated, and the inner side that received a larger compressive stress during charging. By reducing the stress by reducing the thickness of the columnar particles of the negative electrode active material in the electrode, breakage or buckling of the electrode plate could be suppressed, and as a result, the capacity at 500 cycles could be maintained. Conceivable. From this, in order to relieve the stress of expansion and contraction during charging and discharging, it is necessary to provide a difference in the thickness of the columnar particles of the negative electrode active material and the mass ratio of the negative electrode active material and lithium on the front and back of the electrode plate. It can be said that the effect of preventing defects such as capacity deterioration in the case of the above and breakage of the negative electrode plate 3 is great.

  The negative electrode plate according to the present invention and a non-aqueous secondary battery using the same are broken by compressive force between columnar particles of the negative electrode active material when the negative electrode active material expands due to occlusion of lithium ions using a high capacity active material In particular, since it is possible to suppress the columnar particles of the negative electrode active material on the inner side of the winding which is easily affected by expansion and contraction due to charge and discharge and has a small expansion space and easily causes particle breakage, the negative electrode plate and the It is useful as the used non-aqueous secondary battery.

DESCRIPTION OF SYMBOLS 1 Negative electrode collector 1a, 1b Protrusion 2a, 2b Columnar particle of negative electrode active material 3 Negative electrode plate 4 Positive electrode collector 5 Positive electrode active material layer 6 Positive electrode plate 7 Separator 10 Electrode group 21 Battery case 22 Insulating plate 23 Negative electrode lead 24 Positive electrode Lead 25 Sealing plate 26 Sealing gasket 27 Non-aqueous secondary battery 31 Convex-curled negative electrode plate 32 Concave-curled negative electrode plate 33 Corrugated negative-electrode plate 41 Surface plate 103 Vacuum chamber 104 Evaporation source 105 Can roll 106 Mask 107 Oxygen nozzle 110 Unwinding roll 111 Conveying roller 112 Winding roll 113 Exhaust pump h Curling amount of negative electrode plate L Length of negative electrode plate

Claims (7)

  A negative electrode active material comprising a compound containing silicon and oxygen or a compound containing tin and oxygen on both sides of a negative electrode current collector made of metal foil, and a negative electrode plate for a non-aqueous secondary battery in which lithium is supported on the negative electrode active material The amount of expansion of the negative electrode active material on the inner side when the negative electrode plate is spirally wound with the positive electrode plate through the porous insulating layer is determined from the amount of expansion of the negative electrode active material on the outer side. A negative electrode plate for a non-aqueous secondary battery, characterized in that the negative electrode plate is configured to be reduced.   A negative electrode active material comprising a compound containing silicon and oxygen or a compound containing tin and oxygen on both sides of a negative electrode current collector made of metal foil, and a negative electrode plate for a non-aqueous secondary battery in which lithium is supported on the negative electrode active material And when the negative electrode plate is spirally wound together with the positive electrode plate through the porous insulating layer, the negative electrode active material on the outer side is determined by the mass ratio of the negative electrode active material on the inner side and lithium on the inner side. A negative electrode plate for a non-aqueous secondary battery, wherein the negative electrode plate is configured to be less than a mass ratio of a substance and lithium.   3. The non-aqueous system according to claim 2, wherein the mass ratio of the negative electrode active material on the inner side and lithium is 5% to 10% less than the mass ratio of the negative electrode active material and lithium on the outer side. Negative electrode for secondary battery.   The amount of the negative electrode active material on the inner side and the outer side of the winding is the same, and the amount of lithium carried on the negative electrode active material on the inner side is smaller than the amount of lithium carried on the negative electrode active material on the outer side of the winding The negative electrode plate for a non-aqueous secondary battery according to claim 2, which is configured as described above.   The negative electrode plate for a nonaqueous secondary battery according to claim 2, wherein the amount of the negative electrode active material on the inner side becomes smaller than the amount of the negative electrode active material on the outer side.   2. The negative electrode plate for a non-aqueous secondary battery according to claim 1, wherein the negative electrode active material layer on the inner side becomes thinner than the negative electrode active material layer on the outer side.   A positive electrode plate having a positive electrode active material layer formed on both surfaces of a current collector, a negative electrode active material comprising a compound containing silicon and oxygen or a compound containing tin and oxygen on both surfaces of the current collector, and the negative electrode active material In the non-aqueous secondary battery, in which a negative electrode plate carrying lithium is wound in a battery case together with a non-aqueous electrolyte, the negative electrode plate is wound in a spiral shape with a porous insulating layer interposed therebetween. A non-aqueous secondary battery using the negative electrode plate according to any one of claims 1 to 6.

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