JP2012094335A - Negative electrode plate for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, battery pack, manufacturing method of negative electrode plate for nonaqueous electrolyte secondary battery, and formation method of electrode active material layer for negative electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative electrode plate for a nonaqueous electrolyte secondary battery, a nonaqueous electrolyte secondary battery using the same, a battery pack, a manufacturing method of a negative electrode plate for a nonaqueous electrolyte secondary battery, and a formation method of an electrode active material layer for a negative electrode capable of relaxing drastic decrease of electrode capacitance even when a use environment temperature of the nonaqueous electrolyte secondary battery drastically lowers.SOLUTION: A negative electrode plate for a nonaqueous electrolyte secondary battery includes: a collector; and an electrode active material layer provided on at least part of the collector. The electrode active material layer contains negative electrode active material particles, metal and/or metal oxide, and resin.

Description

  The present invention relates to a negative electrode plate for a non-aqueous electrolyte secondary battery, a non-aqueous electrolyte secondary battery and a battery pack using the negative electrode plate for a non-aqueous electrolyte secondary battery, and a negative electrode for a non-aqueous electrolyte secondary battery. The present invention relates to a method for producing a plate and a method for forming a negative electrode active material layer.

  A non-aqueous electrolyte secondary battery represented by a lithium ion secondary battery has a high energy density and a high voltage, and has a memory effect during charging / discharging (when the battery is charged before it is completely discharged, Since there is no phenomenon in which the capacity decreases, it is used in various fields such as portable devices and large devices.

At present, efforts are being made to reduce CO ₂ emissions on a global scale. Plug-in hybrids that can greatly contribute to CO ₂ reduction by reducing the dependence on oil and enabling driving with low environmental impact. There is an urgent need to develop and spread next-generation clean energy vehicles such as automobiles and electric cars. Driving power that does not depend on gasoline is essential for the development and popularization of these next-generation clean energy vehicles. Non-aqueous electrolyte secondary batteries represented by lithium ion secondary batteries are expected as the driving force.

  The non-aqueous electrolyte secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and a non-aqueous electrolyte solution. Generally, a non-aqueous electrolyte secondary battery is configured such that a positive electrode plate and a negative electrode plate face each other with an electrode active material layer inside through a separator.

  The positive electrode plate and the negative electrode plate (hereinafter collectively referred to as “electrode plate”) include electrodes containing electrode active material particles bound only by a resin binder on a current collector such as a metal foil. Those having an active material layer are generally used (hereinafter referred to as “electrode plate having an electrode active material layer containing electrode active material particles bound only by a resin binder” as “conventional electrode body”. Also called). As a conventional method for producing an electrode plate, a method of forming an electrode active material layer by applying an electrode active material layer forming liquid on a current collector to form a coating film and drying the coating film is generally used. Is. The electrode active material layer forming liquid contains a resin binder in addition to the electrode active material particles, and the electrode active material particles are formed by the binding action of the resin binder when the coating film is dried. Is fixed on the current collector, and an electrode active material layer containing the electrode active material particles is completed (for example, Patent Document 1, paragraphs [0019] to [0026], Patent Document 2 [Claim 1], paragraph [ 0051] to [0055]).

JP 2006-310010 A JP 2006-107750 A

  When the non-aqueous electrolyte secondary battery is cooled to a temperature that is significantly lower than the environmental temperature that is expected to be used, the battery capacity that contributes to charge and discharge is reduced and the battery performance is lowered. Here, the non-aqueous electrolyte secondary battery provided with the above-described conventional electrode plate has a problem that the battery characteristics are also drastically lowered when the use environment temperature is drastically lowered.

  The cause of the rapid deterioration of the battery performance was considered as follows. That is, when the use environment temperature of the battery rapidly decreases, the temperature decreases from the outer wall surface of the current collector or the container housing the nonaqueous electrolyte secondary battery toward the electrode active material layer. At this time, in the conventional electrode plate, the current collector is generally composed of a member having good thermal conductivity such as a metal foil, and thus the temperature is quickly lowered. On the other hand, since the electrode active material layer in the conventional electrode plate includes the resin binder as described above, the thermal conductivity is smaller than that of the current collector, and thus the film thickness of the electrode active material layer. A temperature gradient occurs in the direction. Due to the occurrence of this temperature gradient, the electrode capacity shown in actual charge / discharge suddenly decreased, which was considered to cause a decrease in battery performance.

  Here, the present applicant has researched and developed an electrode plate in which active material particles are fixed on a current collector using a metal or metal oxide as a binder. The electrode plate developed by the present applicant is, for example, preparing an electrode active material layer forming solution by mixing at least electrode active material particles in a metal ion solution containing metal ions, and preparing an upper electrode active material layer forming solution. The active material particles are fixed to each other by a coating step of coating the current collector on the current collector to form a coating film, and a metal or metal oxide generated by the metal ions contained in the coating film or a reaction product thereof. Thus, an electrode active material layer can be formed, thereby obtaining the electrode plate.

  Using a battery manufactured using an electrode plate having the above-mentioned metal or metal oxide as a binder, and confirming the battery performance at a sudden drop in the operating environment temperature, the battery performance may also drop sharply. I understood. This is because the electrode active material layer mainly contains active material particles, metal or metal oxide, and optionally added conductive material, so that not only the current collector but also the electrode active material layer It was considered that the battery performance deteriorated due to a rapid decrease in temperature and a substantial decrease in the electrode capacity contributing to charging and discharging.

  As described above, the present inventors can use the non-aqueous electrolyte secondary battery regardless of whether the active material particles are fixed with a resin binder or a metal or metal oxide. It was confirmed that the electrode capacity that actually contributes to charging and discharging suddenly decreases as the operating environment temperature of the battery rapidly decreases, and as a result, the battery performance rapidly decreases.

  In view of the above problems, the present invention has been made by paying particular attention to a negative electrode plate used in a non-aqueous electrolyte secondary battery. That is, the present invention provides a negative electrode plate for a non-aqueous electrolyte secondary battery that can alleviate a rapid decrease in electrode capacity even when the operating environment temperature of the non-aqueous electrolyte secondary battery is rapidly reduced. , And a non-aqueous electrolyte secondary battery, a battery pack using the same, a method for producing the negative electrode plate for a non-aqueous electrolyte secondary battery, and a method for forming a negative electrode active material layer.

The present invention
(1) A negative electrode plate for a nonaqueous electrolyte secondary battery comprising a current collector and an electrode active material layer provided on at least a part of the current collector, wherein the electrode active material layer comprises a negative electrode active material layer. A negative electrode plate for a non-aqueous electrolyte secondary battery, comprising material particles, a metal and / or metal oxide, and a resin;
(2) The negative electrode for a non-aqueous electrolyte secondary battery according to (1), wherein the negative electrode active material particles are fixed to each other with the metal and / or metal oxide and the resin. Board,
(3) The negative electrode plate for a nonaqueous electrolyte secondary battery according to (1), wherein the negative electrode active material particles are fixed to each other with the metal and / or metal oxide,
(4) The negative electrode active material particles located in the vicinity of the current collector are directly fixed on the current collector by at least one of the metal and / or metal oxide or the resin. The negative electrode plate for a nonaqueous electrolyte secondary battery according to any one of (1) to (3) above,
(5) The electrode plate for a nonaqueous electrolyte secondary battery according to any one of (2) to (4), wherein the metal oxide exhibits an alkali metal ion insertion / release reaction ,
(6) A non-aqueous electrolyte secondary battery comprising at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and an electrolyte containing a non-aqueous solvent, The negative electrode plate is a negative electrode plate for a non-aqueous electrolyte secondary battery according to any one of (1) to (5),
(7) A storage case, a nonaqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal, and a protection circuit having an overcharge and overdischarge protection function are provided, and the storage case includes the nonaqueous electrolyte secondary battery. In the battery pack configured to house the battery and the protection circuit, the non-aqueous electrolyte secondary battery includes a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, A non-aqueous electrolyte secondary battery comprising at least an electrolyte solution containing a non-aqueous solvent, wherein the negative electrode plate is the non-aqueous electrolyte secondary battery according to any one of (1) or (5) above. A battery pack, characterized by being a negative electrode plate,
(8) At least negative electrode active material particles are mixed in a metal ion solution containing metal ions to prepare an electrode active material layer forming liquid, and the electrode active material layer forming liquid is applied onto the negative electrode current collector. A quasi-electrode active material layer is formed by adhering negative electrode active material particles to each other by a coating step for forming a coating film and a metal or metal oxide generated by a metal ion or a reaction product contained in the coating film. And forming the quasi-electrode active material layer forming step in this order, and then impregnating the quasi-electrode active material layer with the resin material-containing liquid, and then removing the solvent of the resin material-containing liquid, A non-aqueous electrolyte secondary characterized in that an electrode active material layer comprising a metal or metal oxide and negative electrode active material particles fixed to each other by the metal or metal oxide is directly formed on a current collector Manufacturing method for battery negative plate ,
(9) At least negative electrode active material particles are mixed in a metal ion solution containing metal ions to prepare an electrode active material layer forming solution, and the electrode active material layer forming solution is applied onto a substrate to form a coating film The quasi-electrode active material layer is formed by fixing the negative electrode active material particles to each other by a coating step for forming a metal, and a metal or metal oxide generated by a metal ion contained in the coating film or a reaction product thereof. The quasi-electrode active material layer forming step is performed in this order, and then the quasi-electrode active material layer is impregnated with the resin material-containing liquid, and then the solvent of the resin material-containing liquid is removed, and the resin and metal or A method of forming an electrode active material layer for a negative electrode, comprising forming an electrode active material layer comprising a metal oxide and negative electrode active material particles fixed to each other by the metal or metal oxide;
Is the gist.

  The negative electrode plate for a non-aqueous electrolyte secondary battery according to the present invention prevents the electrode capacity that actually contributes to charging / discharging from rapidly decreasing even when the operating environment temperature of the battery is rapidly decreased. . Therefore, the non-aqueous electrolyte secondary battery and the battery pack using the negative electrode plate for non-aqueous electrolyte secondary battery of the present invention have a rapid battery performance even when the operating environment temperature rapidly decreases. The decrease can be prevented.

  Moreover, if it is the manufacturing method of the electrode plate for nonaqueous electrolyte secondary batteries of this invention, the negative electrode plate for nonaqueous electrolyte secondary batteries which overcomes the subject mentioned above is easily manufactured using a general purpose material. be able to.

  Moreover, if it is the formation method of the electrode active material layer for negative electrodes of this invention, the electrode active material layer which can solve the subject mentioned above is formed as a film | membrane, Then, it laminates | stacks on a suitable electrical power collector, and an electrode A board can be manufactured and is applicable to various aspects. Or if it is the formation method of the electrode active material layer for negative electrodes of this invention, it can form easily on base materials other than a collector, and it can laminate | stack the said base material on a collector. It is possible to expand the design range of the electrode plate.

(1A) is a cross-sectional schematic diagram regarding an example of Embodiment 1 of the negative electrode plate of the present invention, and (1B) is a schematic cross-sectional diagram regarding a different example of Embodiment 2 of the negative electrode plate of the present invention. It is a cross-sectional schematic diagram regarding an example of Embodiment 5 of the negative electrode plate of the present invention. It is the cross-sectional schematic which shows the one aspect | mode of the nonaqueous electrolyte secondary battery of this invention. It is a disassembled perspective view which shows the one aspect | mode of the battery pack of this invention. It is a cycle voltammogram which shows the CV test result of graphite. It is a cycle voltammogram which shows the CV test result of the metal compound which does not show lithium ion insertion elimination reaction.

  A negative electrode plate for a non-aqueous electrolyte secondary battery according to the present invention (hereinafter also simply referred to as “negative electrode plate”) includes a current collector and an electrode active material layer provided on at least a part of the current collector. In the structure of a conventionally known general negative electrode plate, in particular, the electrode active material layer includes electrode active material particles, a metal and / or metal oxide, and a resin. is there. By adopting the above configuration, the present invention is able to generate a temperature gradient of the electrode active material layer, which has been a problem until now when the use environment temperature of the non-aqueous electrolyte secondary battery is reduced, and the electrode active material layer By preventing a rapid decrease in temperature, it is possible to satisfactorily prevent a rapid decrease in electrode capacity that actually contributes to charging and discharging.

  As described above, the negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention contains a metal or metal oxide as a material having good thermal conductivity in addition to the negative electrode active material particles in the electrode active material layer. By adopting the above-described configuration, the present inventors can prevent the non-aqueous electrolyte secondary battery from being added to the battery due to the presence of the metal or metal oxide even when the environment temperature of the non-aqueous electrolyte secondary battery is drastically decreased. It is presumed that generation of a temperature gradient in the film thickness direction of the electrode active material layer in the negative electrode plate to be used is well prevented.

  The negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention further contains a resin as a material having poor thermal conductivity in the electrode active material layer. By adopting the above configuration, the present inventors have used the negative electrode plate used in the battery due to the presence of the resin even when the use environment temperature of the non-aqueous electrolyte secondary battery is drastically decreased. It is presumed that the temperature of the electrode active material layer is prevented from rapidly decreasing.

  Note that the active material particles contained in the electrode active material layer generally do not have an action of adhering to each other or adhering to the current collector, so some kind of binder is necessary. And In the present invention, the binder is not particularly limited as long as the electrode active material particles can be fixed directly or indirectly on the current collector, thereby enabling the formation of the electrode active material layer. In particular, at least one of the metal and / or metal oxide and the resin in the present invention may act as a binder, and specific embodiments thereof will be described later.

  In the embodiments of the present invention to be described later, the negative electrode active material particles contained in the negative electrode plate of the present invention may be simply referred to as “active material particles”, and the current collector used in the negative electrode plate of the present invention is a negative electrode collector. In some cases, the current collector is simply referred to as a “current collector”.

[Embodiment 1]
The negative electrode plate of the present invention contains active material particles, metal and / or metal oxide, and resin in the electrode active material layer, and any of the metal and / or metal oxide and the resin is bonded. It may be a mode in which the active material particles adhere to each other by acting as a dressing (the above mode is also referred to as “embodiment 1”). Hereinafter, a metal and / or metal oxide that acts as a binder is referred to as a metal binder, and a resin that acts as a binder is referred to as a resin binder. In addition, Embodiment 1 shows an embodiment of the present invention in which a metal that does not show alkali metal ion insertion / release reaction or a metal oxide is selected as the metal binder.

  FIG. 1A schematically shows a cross section of a negative electrode plate 10 of the present invention as an example of Embodiment 1. FIG. The negative electrode plate 10 is formed by directly forming an electrode active material layer 21 on the current collector 1. The electrode active material layer 21 includes a plurality of negative electrode active material particles 3, and the active material particles 3 include a non-particulate metal binder 4 made of metal and / or metal oxide, and a resin binder. 5 are fixed to each other. Further, the active material particles 3 existing in the vicinity of the current collector 1 are directly fixed to the surface of the current collector 1 by the metal binder 4 and the resin binder 5, thereby the electrode active material layer 21. Is formed directly on the current collector 1. Further, in the electrode active material layer 21, there are gaps 6 in some places, whereby when the negative electrode plate 10 is used as the negative electrode plate of the non-aqueous electrolyte secondary battery, the electrode active material layer 21 has a non-aqueous solution. Electrolyte can penetrate. In addition, the resin binder 5 shown in FIG. 1A is the one in which the active material particles 3 or the active material particles 3 and the surface of the current collector 1 are directly bound, and the active material particles 3. Alternatively, any of those that indirectly cover the metal binding material 4 that directly binds the active material particles 3 and the surface of the current collector 1 to exert the binding action is included.

  The negative electrode plate 11 of the present invention shown in FIG. 1B is different from the negative electrode plate 10 in that the metal binder 4 ′ included in the electrode active material layer 22 is in the form of particles.

  The thickness of the electrode active material layer 21 can be appropriately designed in consideration of the electrode capacity and input / output characteristics required for the negative electrode plate 10. In particular, when the production method 1 of the negative electrode plate 10 of the present invention described later is adopted, the resin-containing liquid to be impregnated can sufficiently penetrate into the electrode active material layer in consideration of the size of the resin used. Furthermore, it is desirable to design the thickness of the electrode active material layer 21. In general, the electrode active material layer 21 is designed to have a thickness of 200 μm or less, more generally 30 μm or more and 150 μm or less. However, according to the manufacturing method of Embodiment 1 of the present invention described later, the thickness of the electrode active material layer 21 can be further reduced, and the input / output characteristics can be improved by thinning. is there. For example, from the viewpoint of improving the input / output characteristics, the thickness of the electrode active material layer 21 can be preferably 300 nm to 150 μm, and more preferably 500 nm to 100 μm. However, the above description does not limit the thickness of the electrode active material layer in the present invention.

Current collector 1:
The current collector 1 is not particularly limited as long as it is a negative electrode current collector that is generally used for a negative electrode plate for a nonaqueous electrolyte secondary battery. For example, the current collector 1 is preferably formed of a single element such as a copper foil or an alloy, but is not limited thereto. The current collector used in the present invention may be a current collector that has been subjected to surface processing on the surface on which the electrode active material layer is to be formed, if necessary. Examples of the current collector that has been subjected to surface processing treatment include those in which a conductive material is laminated, surface treatments such as chemical polishing treatment, corona treatment, and oxygen plasma treatment. Alternatively, the current collector may be physically provided with any unevenness on the surface.

  The negative electrode plate 10 or 11 shown in FIG. 1 is an example in which the electrode active material layer 21 or 22 is directly provided on the surface of the current collector 1. Thus, by providing the electrode and the material layer directly on the current collector, the distance between the current collector and the active material particles is reduced, and in particular, the active material particles in direct contact with the current collector surface Therefore, it is preferable that electrons move smoothly in the electrode active material layer and contribute to improvement of the input / output characteristics.

  The thickness of the current collector is not particularly limited as long as it is a thickness that can be used as a current collector generally used for a negative electrode plate for a nonaqueous electrolyte secondary battery, but is preferably 10 to 200 μm, and preferably 15 to 50 μm. It is more preferable that

Active material particles 3:
The active material particle 3 is not particularly limited as long as it is a compound that exhibits an alkali metal insertion / release reaction that contributes to charge / discharge in the negative electrode plate for a non-aqueous electrolyte secondary battery, and a conventionally known negative electrode active material is appropriately selected. Can be used. Specific examples of the active material particles 3 include, for example, a negative electrode active material exhibiting a lithium insertion / release reaction or an active material exhibiting a sodium insertion / release reaction such as natural graphite, artificial graphite, amorphous carbon, carbon black, or these A preferred example is a carbonaceous material obtained by adding a different element to these components. Among these, graphite is preferably used because of its large energy that can be taken out per weight, low discharge potential, and good flatness. In addition, lithium ions such as metallic lithium and its alloys, tin, silicon, and alloys thereof, oxides of silicon, titanium, cobalt, nitrides of manganese, iron, cobalt, and the like as negative electrode active materials that exhibit lithium insertion / extraction reaction in particular In general, materials that exhibit insertion and elimination reactions can be used. Among these, lithium titanate (Li ₄ Ti ₅ O ₁₂ ) is preferably used because of its high safety and excellent output characteristics and cycle characteristics.

  The particle diameter of the active material particles 3 is not particularly limited, and those having an arbitrary size can be appropriately selected and used. Specifically, the particle diameter of the active material particles used is generally about 0.1 μm to 30 μm.

  In the present invention, the average particle diameter of the active material particles 3 used is shown as an average particle diameter (volume median particle diameter: D50) measured by, for example, laser diffraction / scattering particle size distribution measurement. On the other hand, the particle diameter of the active material particles contained in the electrode active material layer was arbitrarily selected by using an electron microscope observation result using image analysis type particle size distribution measurement software (manufactured by Mount Tech Co., Ltd., MAC VIEW). It can be obtained by measuring the longest diameter of a plurality (for example, about 10) of active material particles and calculating an average value thereof.

Metal binder 4
The metal binder 4 may be any metal and / or metal oxide that does not show alkali metal ion insertion / extraction reaction and can at least fix the active material particles 3 to each other. Therefore, the shape and dimensions of the metal binder 4 are not particularly limited. For example, as shown in FIG. 1A, a non-particulate metal binder may be used, or as shown in FIG. 1B, particles may be formed like a metal binder 4 ′. The non-particulate metal binder 4 has an irregular shape, and may be any shape such as a film covering the surface of the active material particles or a continuous body filling the space between the active materials. . On the other hand, the term “particulate” means that, for example, when the electrode active material layer is observed with a scanning electron microscope of about 10,000 to 50,000 times, it is closed when the contour line or the extension of the contour line is traced. It is understood that it is.

  The metal oxide that may be contained in the electrode active material layer 21 as the metal binder 4 is not particularly limited as long as it is an oxide of an element that is generally understood to be a metal. In the present invention, the metal oxide means a compound having an oxygen element bonded to a metal element. Examples of the metal contained in the metal oxide include Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ga. , Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg , Tl, Pb, Bi, Fr, Ra, and Ce.

  Examples of metal oxides that can be contained as the metal binder 4 include oxides of copper, iron oxide, yttrium oxide, barium oxide, titanium oxide, aluminum oxide, zinc oxide, An example is nickel oxide. The metal oxide may be an oxide containing two or more metal elements, and examples thereof include composite metal oxides such as iron titanium oxide, lanthanum lithium titanium oxide, and lithium titanate. . However, these descriptions do not limit the present invention.

In particular, copper oxide can be given as one of preferable examples of the metal binder 4. When a metal oxide is contained in the electrode active material layer in the negative electrode plate, at least a part of the metal oxide may be reduced during the first charge. Here, when the copper oxide is reduced to copper in the electrode active material layer to form copper alone, it does not react with lithium ions (that is, does not exhibit lithium ion insertion / desorption reaction) and a current collector. This is preferable from the viewpoint of good electrical contact. Yttrium oxide is also more preferable as the metal binder 4 in the present invention because it contributes to the effect of improving the input / output characteristics of the electrode plate.

Another preferred example of the different metal binder 4 is a ternary composite metal oxide composed of three kinds of metal elements. Among these, La _X Li _Y TiO ₃ is preferable as the metal binder 4. By selecting La _X Li _Y TiO ₃ that is an oxide of lanthanum, lithium, and titanium as the metal binder 4, it is possible to particularly preferably improve the input / output characteristics of the negative electrode plate for a non-aqueous electrolyte secondary battery. it can. The element ratio of lanthanum and lithium in La _X Li _Y TiO ₃ is not limited, but is preferably in the range of 0 <X <1 and 0 <Y <1. The reason why the element ratio of La _X Li _Y TiO ₃ is preferably in the above range is not clear, but if it is in the above range, the lithium ion conductivity in the electrode is improved, which is a factor that improves the input / output characteristics. It is inferred that it is one. In addition, the above illustration does not limit the metal binder 4 in this invention at all.

Single metal:
The metal binder 4 may be a single metal. The metal simple substance that may be included in the electrode active material layer 21 as the metal binder 4 is a metal simple substance when the electrode active material layer is formed, and the metal oxide that is the metal binder 4 described above is an electrode active. Any of those reduced in the material layer 21 and having only a metal element may be used. In the present invention, the simple metal includes not only one composed of one metal element but also a composite metal composed of two or more metal elements. Specific examples of the simple metal include one metal such as copper, iron, yttrium, barium, titanium, aluminum, zinc and nickel, or a binary composite metal containing titanium and a ternary containing titanium. Examples of such composite metals. The element ratio of lanthanum and lithium in La _X Li _Y Ti, which is a preferable example of the ternary metal, is not limited, but in particular, it may be in the range of 0 <X <1, 0 <Y <1. preferable. The reason why the element ratio of La _X Li _Y Ti is preferably in the above range is not clear, but if it is in the above range, the lithium ion conductivity in the electrode is improved, and this is one of the factors that exert a favorable result. It is inferred that Note that the above specific examples do not limit the present invention.

Resin binder 5:
The resin used as the resin binder 5 is capable of exhibiting a binding action for directly or indirectly fixing the active material particles 3 or fixing the active material particles 3 and the current collector 1 together. I just need it. For example, a resin binder used in a conventional electrode plate may be included in the electrode active material layer 21 as the resin binder 5 in the present invention. Specifically, fluorinated polymers such as polytetrafluoroethylene and polyvinylidene fluoride; polyolefin polymers such as polyethylene and polypropylene; synthetic rubbers such as styrene butadiene rubber; methyl cellulose, carboxymethyl cellulose; polyester resins, polyamide resins, polyacrylic acid Although thermoplastic resins, such as ester resin, are mentioned, it is not limited to this.

  The content ratio of the metal binder 4 and the resin binder 5 contained in the electrode active material layer 21 is not particularly limited. The content ratio between the metal binder 4 and the resin binder 5 contained in the electrode active material layer 21 may be appropriately determined in consideration of the characteristics required for the negative electrode plate 10.

  That is, even when the metal binder 4 is contained in the electrode active material layer 21, quick thermal conductivity in the metal binder 4 is obtained, and the battery operating environment temperature rapidly decreases. Generation of a temperature gradient in the film thickness direction of the electrode active material layer can be prevented. In addition, as compared to the conventional electrode plate in which the active material particles are fixed only by the resin binder, a metal binder is contained in the electrode active material layer as an alternative to the resin binder, or the resin binder is bonded. It has been confirmed by the present inventors that the input / output characteristics of the negative electrode plate are improved by changing a part of the adhesive to a metal binder. In particular, the conductivity of the electrode active material layer can be improved by selecting a metal and / or metal oxide having good conductivity as the metal binder 4. Therefore, when the content ratio of the metal binder 4 is increased in the electrode active material layer 21, the above advantageous effect is remarkable.

  On the other hand, when the resin binder 5 is contained in the electrode active material layer 21, it is possible to prevent a rapid temperature drop of the electrode active material layer even when the battery operating environment temperature is rapidly decreased. . In addition, the flexibility of the resin binder 5 is advantageous, and the bending characteristics of the electrode active material layer 21 can be improved.

  Therefore, the content ratio of the metal binder 4 and the resin binder 5 contained in the electrode active material layer 21 takes into consideration the effects of the metal binder 4 and the resin binder 5 respectively. You may decide suitably. In particular, in order to satisfactorily solve the problems of the present invention, when the active material particles 3 are 100 parts by weight, the metal binder 4 is desirably contained in an amount of 1 part by weight or more, and the resin binder 5 is preferably contained in an amount of 1 part by weight or more.

  Further, the total amount of the metal binder 4 and the resin binder 5 in the electrode active material layer 21 and the mixing ratio of the active material particles 3 are not particularly specified, and the type and size of the active material particles 3 to be used, It can be determined as appropriate in consideration of the types of the metal binder 4 and the resin binder 5, functions required of the negative electrode, and the like. However, in general, the larger the amount of the active material particles 3 in the electrode active material layer 21, the greater the electric capacity of the electrode. From this viewpoint, the metal bond present in the electrode active material layer 21 is also increased. It can be said that it is preferable that the total amount of the adhesive 4 and the resin binder 5 is small. More specifically, in the electrode active material layer 21, when the weight ratio of the active material particles 3 is 100 parts by weight, the weight ratio of the total amount of the metal binder 4 and the resin binder 5 is 1 weight. Part to 30 parts by weight. If it is less than 1 part by weight, the active material particles 3 may not be satisfactorily fixed on the current collector. On the other hand, the description of the upper limit of the weight ratio of the total amount of the metal binder 4 and the resin binder 5 excludes that the total amount of the metal binder 4 and the resin binder 5 exceeds 50 parts by weight in the present invention. It is not the purpose. This shows that the active material particles 3 can be fixed on the current collector 1 with a smaller total amount of the metal binder 4 and the resin binder 5 in order to increase the electric capacity of the electrode. Therefore, the total amount of the active material particles 3, the metal binder 4, and the resin binder 5 blended in the electrode active material layer forming liquid is also the same as the metal binder 4 and the resin binder in the electrode active material layer 21. 5 can be determined in consideration of the total amount of 5 and the blending amount of the active material particles 3

Void 6:
The gap 6 is provided in order to allow the non-aqueous electrolyte to penetrate. The formation ratio (void ratio) of the voids 6 in the electrode active material layer 21 is not particularly limited. However, when the production method 1 of the negative electrode plate of the present invention described later is employed, the resin-containing liquid is sufficiently contained in the electrode active material layer. It is desirable to take care to ensure a porosity sufficient to penetrate the water. Generally, when the volume of the electrode active material layer 21 is 100%, it is designed to be about 15% to 45%. The porosity can be measured using, for example, a mercury porosimeter.

Conductive material:
The electrode active material layer 21 does not show conductive material particles or conductive material fibers, but in the negative electrode plate of the present invention, the electrode active material layer appropriately contains conductive material particles and / or conductive material fibers. May be. As the conductive material particles and the conductive material fibers, conventionally known ones may be appropriately selected and used. More specifically, examples thereof include carbon materials such as carbon black such as acetylene black and ketjen black, but are not limited thereto. In general, the average particle size of the conductive material particles is about 20 nm to 80 nm. Carbon fiber (VGCF) is known as the conductive material particles. The conductive agent may be included in the electrode active material layer by one type or a combination of two or more types. In the case where the conductive material is contained in the electrode active material layer, the content is not particularly limited, but in general, with respect to 100 parts by weight of the active material particles or 100 parts by weight of the total amount of the active material particles and the binding material. Thus, the proportion of the conductive material may be 0.1 parts by weight or more and 20 parts by weight or less. In addition, the negative electrode plate of this invention contains the aspect which does not use a electrically conductive material, and description of this paragraph does not exclude the aspect which uses a electrically conductive material.

  When the electrode active material layer 21 contains a conductive material, the conductive material is also fixed on the current collector by at least one of the metal binder 4 or 4 ′ and the resin binder 5. The

Example of manufacturing method of negative electrode plate 10 (manufacturing method 1):
Next, an example of a method for manufacturing the negative electrode plate 10 (hereinafter, also referred to as “manufacturing method 1”) will be described. The manufacturing method 1 of the negative electrode plate 10 includes an electrode active material that includes a metal binder precursor and active material particles that are precursors of a metal or metal oxide that is a metal binder 4, or an optional additive. A layer forming solution is prepared. And the said manufacturing method 1 apply | coats the said electrode active material layer forming liquid to the desired area | region of the collector surface, forms a coating film, and the quasi-electrode which forms a quasi-electrode active material layer from the said coating film An active material layer forming step is sequentially performed, and then a resin impregnation step of forming the electrode active material layer 21 by including the resin binder 5 in the formed quasi-electrode active material layer is provided. In addition, in the manufacturing method 1 demonstrated below, the electrode plate 10 in which the metal binder 4 contains a metal or a metal oxide in the electrode active material layer 21 is manufactured.

(Preparation of electrode active material layer forming solution)
The electrode active material layer forming liquid used in the production method 1 contains the negative electrode active material particles described above and the metal binder precursor in the solvent, or may further optionally contain other additives.

Metal binder precursor:
The metal binder precursor is a material that is dissolved in the electrode active material layer forming liquid, is contained in the electrode active material layer 21, and fixes the active material particles 3 to each other as the metal binder 4. Further, it is a metal or metal oxide precursor that does not show alkali metal ion insertion / desorption reaction, and that can fix the active material particles 3 on the current collector 1. The metal binder precursor dissolved in the electrode active material layer forming liquid may be one or more kinds, and is applied on the substrate in a state dissolved in a solvent and heated at a temperature equal to or higher than the thermal decomposition start temperature. Any metal that can produce the metal or metal oxide described above can be used.

Specifically, the metal binder precursor includes Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ga. , Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg , Tl, Pb, Bi, Fr, Ra, and Ce, any compound selected from the group consisting of two or more metal elements may be used. Moreover, although the reason is not clear, the output / input characteristics of the electrode plate 10 to be generated are particularly when a metal binder precursor containing a metal element belonging to 3 to 5 cycles among the above metal elements is used. This is preferable because it tends to be good.

  As the metal binder precursor containing the metal element, for example, a metal salt is preferably used. Examples of the metal salt include chloride, nitrate, sulfate, perchlorate, acetate, phosphate, bromate, carbonate, and the like. Among them, in the present invention, chlorides, nitrates and acetates are easily available as general-purpose products, and these metal salts are dissolved in an organic solvent such as alcohol and applied to form a coating film. When heated, chlorine ions, nitrate ions, and acetate ions can be easily eliminated from the coating film, and thus are preferably used. Moreover, nitrate is preferable from the viewpoint of good coating properties on the current collector. In addition, what is necessary is just to melt | dissolve 2 or more types of metal salts in a solvent, when producing | generating the metal binder containing 2 or more types of metal elements in an electrode active material layer.

  As a specific example of the metal binder precursor, for example, when the metal element is copper, the metal element is iron such as copper chloride, copper nitrate, copper acetate, copper sulfate, copper acetylacetonate. In some cases, such as iron nitrate, iron acetate, iron acetylacetonate, etc., when the metal element is yttrium, yttrium chloride, yttrium nitrate, yttrium acetate, yttrium acetylacetonate, etc., when the metal element is titanium, When the metal element is aluminum, such as titanium acetylacetonate, titanium diisopropoxybisacetylacetonate, etc. When the metal element is barium, such as aluminum chloride, aluminum nitrate, aluminum acetylacetonate, barium chloride, acetic acid When the metal element is zinc, such as barium and barium nitrate When the metal element is nickel, such as zinc chloride, zinc acetate, zinc nitrate, zinc acetylacetonate, metal oxide precursors such as nickel chloride, nickel acetate, nickel nitrate, nickel acetylacetonate can be listed. .

Alternatively, when it is planned to include lanthanum, lithium and titanium oxide (La _X Li _Y TiO ₃ ) or a reduced product thereof in the electrode active material layer, titanium acetylacetonate or titanium diiso Any of propoxybisacetylacetonate, any of lanthanum chloride, lanthanum nitrate, lanthanum acetate, lanthanum acetylacetonate, lanthanum isopropoxide, etc., lithium chloride, lithium nitrate, lithium acetate, lithium carbonate, lithium acetylacetonate, etc. Either of them can be mixed with a solvent and used as a metal oxide precursor.

  In the electrode active material layer forming liquid described above, the ratio of the total amount of the one or more metal binder precursors added in the solvent is 0.01 to 5 mol / L, particularly 0. 1-2 mol / L is preferred. By the said density | concentration being 0.01 mol / L or more, the collector 1 and the electrode active material layer 21 produced | generated on this collector 1 surface adhere | attach favorably, and fixation of the active material particle 3 is achieved. . Further, when the concentration is 5 mol / L or less, the electrode active material layer forming liquid can maintain a good viscosity enough to be applied to the surface of the current collector 1, and a uniform coating film can be formed. It is formed.

(Other additives)
In addition to the active material particles 3 and the metal binder precursor described above, the electrode active material layer forming liquid may include a conductive material, a dispersant, a plasticizer, or other materials within the scope of the present invention. Additives may be added.

(solvent)
The solvent used for preparing the electrode active material layer forming liquid is not particularly limited. For example, water or a lower alcohol having a total carbon number of 5 or less, such as methanol, ethanol, isopropyl alcohol, propanol, and butanol. And diketones such as acetylacetone, diacetyl and benzoylacetone, ketoesters such as ethyl acetoacetate, ethyl pyruvate, ethyl benzoylacetate and ethyl benzoylformate, toluene, and a mixed solvent thereof.

  Note that the electrode active material layer forming liquid is the active material particles 3 in the electrode active material layer 21 scheduled to be formed on the current collector 1, the metal binder 4, or, if necessary, other materials such as a conductive material. The amount of these additives is determined in consideration of the required amount of the additive. At that time, the ratio of the solute added to the solvent (that is, active material particles, metal binder precursor, or further optional additive) is determined by the coating property on the current collector 1 in the coating step and the subsequent steps. Adjust as appropriate in consideration of removal of the solvent. Generally, when the electrode active material layer forming liquid is 100% by weight, the total amount of solutes contained is adjusted to be 30 to 70% by weight.

(Coating process)
Next, the application | coating process which apply | coats the electrode active material layer forming liquid prepared as mentioned above on the electrical power collector 1, and forms a coating film is implemented. In the coating step in production method 1, the method for applying the forming liquid can be selected as appropriate. For example, the electrode active material layer forming liquid can be applied to an arbitrary region on the surface of the current collector 1 by a printing method, spin coating, dip coating, bar coating, spray coating, or the like to form a coating film. Further, when the surface of the current collector 1 is porous, provided with a large number of irregularities, or has a three-dimensional structure, the coating method is other than the above method, and is manually applied, for example. A method is also possible. The current collector 1 is preferable because it can further improve the film forming property of the electrode active material layer 21 by performing corona treatment, oxygen plasma treatment, or the like in advance as necessary.

  The amount of the electrode active material layer forming liquid applied to the current collector 1 can be arbitrarily determined according to the application of the electrode plate 10 to be manufactured. Since the electrode active material layer 21 in the present invention can be formed very thin as described above, when it is desired to reduce the thickness, the final electrode active material layer 21 has a thickness of 300 nm to 150 μm, particularly May be thinly applied so as to be about 500 nm to 100 μm.

(Pressing process)
A press step may be optionally further performed between the coating step and the electrode active material layer forming step described later or after the electrode active material layer forming step described later. The said press process can be implemented by drying the said electrode active material layer forming coating film formed on the electrical power collector 1 as needed, removing a solvent, and pressing it after that. Therefore, when performing an electrode active material layer formation process after a press process, a part or all of the solvent in a coating film may be removed beforehand before this electrode active material layer formation process. The pressing method can be carried out in the same manner as the conventional pressing, in which a slurry-like electrode active material layer forming liquid containing a resin binder is applied on a current collector and dried. . Thus, the manufacturing method 1 can adjust the porosity of the electrode active material layer 21 in the electrode plate 10 finally manufactured by implementing a press process, and can increase a volume energy density.

(Quasi-electrode active material layer formation process)
In the quasi-electrode active material layer forming step, the metal binder precursor contained in the coating film is reacted to generate a metal or metal oxide, and the metal or metal oxide is used as the metal binder 4. This is a step of forming a quasi-electrode active material layer containing the metal binder 4 and the active material particles 3 on the current collector 1 by fixing the active material particles 3 on the current collector 1. In the quasi-electrode active material layer forming step, when a solvent is contained in the coating film, the solvent is removed. In this step, the metal binder precursor includes both those dissolved in a solvent and those precipitated by removal of the solvent.

  Examples of the quasi-electrode active material layer forming step include a heating step, a reduced-pressure drying step, a reduced-pressure heating step, or a combination thereof. However, the quasi-electrode active material layer forming step is not limited thereto, and the electrode active material applied on the current collector is exemplified. What is necessary is just the process of implementing the means which can form the coating film formed with the substance layer forming solution as a quasi-electrode active material layer. For example, the quasi-electrode active material layer forming step includes two or more means such as a means for removing the solvent contained in the coating film and then a means for reacting the metal binder precursor. May be included.

  Hereinafter, the case where the heating step is performed as the quasi-electrode active material layer forming step will be described in more detail. When the metal oxide is to be produced as the metal binder 4, the heating step is performed for the purpose of thermally decomposing and oxidizing the metal binder precursor present in the coating film. In addition, the heating step is performed for the purpose of thermally decomposing the metal binder precursor present in the coating film and precipitating the metal alone when a metal is to be produced as the metal binder 4. . At this time, when the solvent remains in the coating film, the solvent is removed by heating in the heating step.

The heating method is not particularly limited as long as it is a heating method or a heating apparatus capable of heating the coating film at a heating temperature described later, and can be appropriately selected and carried out. Specific examples include a method of using a hot plate, an oven, a heating furnace, an infrared heater, a halogen heater, a hot air blower, or the like, or a combination of two or more. When the current collector to be used is planar, it is preferable to use a hot plate or the like for the heating step. In addition, when heating using a hot plate, it is preferable to install and heat the coating film surface side in a direction not in contact with the hot plate surface. Although the said heating temperature changes with kinds of metal binder precursor used, the thermal decomposition of a metal binder precursor is performed favorably by heating the said coating film in the temperature range of 150 to 800 degreeC normally. A metal or metal oxide is rapidly generated.

  In addition, the heating temperature in the heating step is preliminarily applied by applying a solution in which a metal binder precursor to be used is dissolved on an appropriate substrate and heating, and scraping the film laminated on the substrate. It is possible to determine whether a metal or a metal oxide is formed by conducting a composition analysis and measuring the content ratio of the metal or the content ratio of the metal element and oxygen. And when the metal or metal oxide was produced | generated, it was confirmed that the used metal binder precursor was heated at the temperature more than thermal decomposition start temperature on a board | substrate. The heating in the preliminary test is performed in an atmosphere similar to the heating atmosphere planned in the manufacturing method.

  In the heating step, when determining the heating temperature, it is desirable to further consider the heat resistance of the current collector, active material particles, conductive material, and the like used. In addition, regarding the method for producing the electrode plate of the present invention, “heating temperature” means the highest temperature in the heating step. The heating mode in the heating step may be arbitrarily determined, for example, by gradually increasing the temperature, heating at a constant temperature, or heating at a stepped temperature.

  The heating atmosphere in the heating step is not particularly limited, taking into consideration the type of metal binder 4 to be generated, the material used to manufacture the electrode plate, the heating temperature, the oxygen potential of the metal element, and the like. It can be determined as appropriate. For example, in the case of an air atmosphere, it is preferable in that a special atmosphere adjustment is not necessary and the heating process can be easily performed. In particular, when a copper foil is used as a current collector, it is not desirable because it is oxidized when the heating step is performed in an air atmosphere. Therefore, in such a case, it is preferable to heat in an inert gas atmosphere, a reducing gas atmosphere, or a mixed gas atmosphere of an inert gas and a reducing gas. In the heating step, when a metal is produced as the metal binder 4, the heating step is performed in a reducing atmosphere, and the metal binder precursor present in the coating film is pyrolyzed in a reducing atmosphere. It is desirable to deposit a single metal.

  In the production method of the present invention, the inert gas atmosphere or the reducing gas atmosphere is not particularly limited to a specific atmosphere, and the production method of the invention can be appropriately carried out in these conventionally known atmospheres. As the inert gas atmosphere, argon gas, nitrogen gas, and reducing gas atmosphere include hydrogen gas, carbon monoxide gas, or a gas atmosphere in which the inert gas and the reducing gas are mixed.

(Resin impregnation process)
In the resin impregnation step, the quasi-electrode active material layer manufactured as described above further contains a resin material, and the resin material is used as the resin binder 5 or between the active material particles 3 or the active material particles 3 and the current collector. In this process, the body 1 is fixed and the electrode active material layer 21 is formed.

  In order to perform the resin impregnation step, the resin material described above is used as the resin binder 5 and mixed with an appropriate solvent to prepare a resin-containing liquid. At this time, the solvent is not particularly limited. For example, lower alcohols having a total carbon number of 5 or less such as methanol, ethanol, isopropyl alcohol, propanol and butanol, diketones such as acetylacetone, diacetyl and benzoylacetone, ethyl acetoacetate, and pyrubin Ketoesters such as ethyl acid, ethyl benzoyl acetate, ethyl benzoylformate, pyrrolidones such as N-methylpyrrolidone (NMP), toluene, a mixed solvent thereof, water, and the like may be used. Note that the resin selected may be adjusted in molecular weight in consideration of the size of the pores forming the voids of the formed quasi-electrode active material layer.

  Next, the voids of the quasi-electrode active material layer are impregnated with the resin-containing liquid prepared as described above. The impregnation method is not particularly limited. For example, the resin-containing liquid may be applied to the surface of the quasi-electrode active material layer, or impregnated by a printing method, spin coating, dip coating, bar coating, spray coating, or the like. Alternatively, the quasi-electrode active material layer may be immersed in a resin-containing liquid tank so that the resin-containing liquid penetrates into the voids of the quasi-electrode active material layer.

  Next, the quasi-electrode active material layer is dried, the solvent of the resin-containing liquid impregnated in the quasi-electrode active material layer is removed, and the active material particles 3 are made by the resin material contained in the resin-containing liquid, Alternatively, the active material particles 3 and the current collector 1 are fixed directly or indirectly to form an electrode active material layer, and the electrode plate 10 is completed.

Example of production method of embodiment 1 (production method 1 ′)
A method different from the manufacturing method 1 will be described with respect to the manufacturing method of the negative electrode plate 10 of Embodiment 1 described above. The negative electrode plate 10 of Embodiment 1 can be manufactured by utilizing the so-called sol-gel method of generating metal particles or metal oxide particles, and further by carrying out the resin impregnation step described in Manufacturing Method 1 (hereinafter referred to as “the metal particles”). , Also referred to as “Production Method 1 ′”).

  That is, at present, a method for producing an electrode plate using a sol-gel method is being studied. For example, Japanese Patent Application No. 2007-537121 (Evonik Degussa Publication) proposes an invention of an electrode plate unit in which an electrode active material layer is formed using a sol-gel method and a separator is laminated on the electrode active material layer. ing. In the above publication, it is described that the inorganic metal particles formed by the sol-gel method are binders, but in reality, the binding property between the inorganic metal particles formed by the sol-gel method is weak, and the electrode It was insufficient to give sufficient film strength to the active material layer. However, by impregnating a film produced on the current collector using the sol-gel method (in the present invention, this is called a quasi-electrode active material layer) with a resin-containing liquid as shown in Production Method 1, An excellent electrode plate having good film strength and solving the problems of the present invention can be produced.

[Embodiment 2]
As Embodiment 2 of the negative electrode plate of the present invention, a metal oxide showing an alkali metal ion insertion / release reaction may be contained in the electrode active material layer as the metal binder 4. The configuration of the negative electrode plate of Embodiment 2 is the same as that described in Embodiment 1 with respect to the configuration other than the metal binder, that is, the active material particles, the resin binder, the current collector, the voids, and the conductive material. Because there is, explanation is omitted here.

  The effect of increasing the electrode capacity of the electrode plate can be obtained by selecting a metal binding material in the present invention that exhibits an alkali metal ion insertion / release reaction. That is, when compared with the conventional electrode plate in which the active material particles are fixed only by the conventional resin binder, the present invention shows a part of the resin binder exhibits an alkali metal ion insertion / release reaction. By replacing with a metal binder, the fixing action is maintained well, and since the metal binder can act as an active material, substantially per unit area in the electrode active material layer This is because the amount of the active material can be increased.

  However, in the case where the metal binder exhibits an alkali metal ion insertion / release reaction, it may electrochemically react with the compound constituting the negative electrode active material, leading to expansion or loss of the metal binder. As a result, the electrode plate may be deteriorated. Therefore, when selecting a metal and / or metal oxide exhibiting an alkali metal ion insertion / release reaction as the metal binder, it is desirable to pay attention to the combination with the compound constituting the negative electrode active material. In view of the above, it is desirable to select, for example, lithium titanate or a compound in which titanium of lithium titanate and any other element are substituted as the active material particles and the metal oxide particles.

  In other words, from the viewpoint that there is no risk of electrochemical reaction with the negative electrode active material particles, the metal binder in the present invention is a metal and / or metal oxide that does not exhibit an alkali metal ion insertion / release reaction. It is preferable to select a product.

  Metal oxides that exhibit alkali metal ion insertion / release reactions are particularly limited as long as they are oxides of elements that are generally understood as metals, and that exhibit alkali metal ion insertion / release reactions. is not. The gold oxide may be a metal oxide composed of one metal element or an alkali metal composite continuous oxide containing two or more metal oxides.

Among metal binders that exhibit alkali metal ion insertion / release reactions, metal oxides that exhibit lithium ion insertion / release reactions can include, but are not limited to, Li ₄ Ti ₅ O _12. .

  A method for confirming whether or not the metal binder in the present invention exhibits an alkali metal ion insertion / release reaction will be described by taking lithium ion insertion / release as an example.

Cyclic voltammetry test (CV test):
For example, in the electrode plate 10 of the present invention, when the production of Li ₄ Ti ₅ O ₁₂ in the electrode active material layer is planned as the metal binder 4, except that the active material particles 3 are not included, Similar to the electrode plate 10, a laminate is prepared. Then, a CV test is performed using the laminate. Specifically, the electrode potential is first swept from 2.0 V to 0.03 V, and then returned to 2.0 V again. The scanning speed may be 1 mV / second. In the cyclic voltammogram showing the cycle result, a redox peak corresponding to the lithium ion insertion / elimination reaction of Li ₄ Ti ₅ O ₁₂ can be confirmed in the vicinity of 1.5 _V. As a result, the Li ₄ Ti ₅ O ₁₂ contained in the layer equivalent to the electrode active material layer 21 except for the active material particles 3 provided in the laminate is certainly inserted into the lithium-on insertion / desorption. It can be confirmed that a separation reaction is exhibited. The CV test can be performed using, for example, VMP3 manufactured by Bio Logic. Further, the electrode potential and scanning speed in the CV test may be determined under conditions suitable for the metal oxide to be tested.

FIG. 5 is a cycle voltammogram showing the CV test result of graphite which is known to show a lithium insertion / elimination reaction. Except that graphite was used instead of Li ₄ Ti ₅ O ₁₂ , when the test was carried out under the same conditions as the CV test described above, as shown in FIG. A reduction peak can be confirmed. On the other hand, FIG. 6 is a CV test result using a metal compound that does not show any lithium insertion / extraction reaction, and it is confirmed that no lithium insertion / extraction reaction is shown by no peak appearing. On the other hand, when a CV test is performed using a metal oxide that does not exhibit lithium insertion / elimination reaction, no oxidation peak or reduction peak is confirmed from the cyclic voltammogram (see FIG. 6).

  In producing the negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention, whether or not to show alkali metal ion insertion / desorption of a metal oxide that is expected to be contained in the electrode active material layer is determined in advance as described above. Can be confirmed. On the other hand, whether or not the metal oxide or the metal simple substance contained in the electrode active material layer in the already completed negative electrode plate exhibits an alkali metal ion insertion / release reaction can be confirmed as follows, for example. . That is, it is possible to estimate what kind of metal oxide or simple metal is contained in a sample by cutting the electrode active material layer to prepare a sample and conducting composition analysis of the sample. And the coating film which consists of the estimated metal oxide or a metal simple substance is formed on arbitrary board | substrates, such as copper and aluminum, The said metal oxide or a metal simple substance becomes an alkali metal ion by using this for a CV test. It can be confirmed whether or not an insertion / elimination reaction is exhibited.

Example of production method of embodiment 2 (production method 2):
In the production of Embodiment 2, an appropriate compound for producing a metal binder exhibiting an alkali metal ion insertion / release reaction is selected as the metal binder precursor, and a quasi-electrode active material layer forming step The electrode active material layer forming liquid is prepared in the same manner as in production method 1 except that the conditions are set so that the metal binder produced in step 1 becomes a metal binder exhibiting an alkali metal ion insertion / release reaction, A coating step and a quasi-electrode active material layer forming step can be performed, and a resin impregnation step can be further performed (hereinafter also referred to as “manufacturing method 2”).

That is, the metal binder precursor selected when preparing the electrode active material layer forming liquid is as follows. For example, when a metal oxide exhibiting a lithium ion insertion / release reaction is to be produced in the electrode active material layer as a metal binder, the metal binder precursor is selected from a lithium element-containing compound and titanium. Or a combination of one or more metal element-containing compounds containing any of the above metal elements. However, the example of the metal binder precursor selected in the manufacture of Embodiment 2 is not limited to the above.

  The metal binder precursor is a chloride, nitrate, sulfate, perchlorate, acetate, phosphate, bromate, carbonate, etc. of other metal elements such as lithium element or titanium. Good. Among them, in the present invention, chloride, nitrate, and acetate are preferably used because they are easily available as general-purpose products. In particular, nitrates are preferably used because they have good film forming properties over a wide variety of current collectors or arbitrary substrates.

For example, as a metal binder precursor for producing Li ₄ Ti ₅ O ₁₂ as a metal oxide on a current collector, a Li element-containing compound and a Ti element-containing compound are used in combination as main raw materials. In addition, other raw materials can be used in combination with the main raw material as required. Examples of the Li element-containing compound include lithium chloride, lithium nitrate, and lithium carbonate. Examples of the Ti element-containing compound include titanium tetrachloride and titanium acetylacetonate. The combination ratio (Li: Ti = X: 1) of the Li element-containing compound and the Ti element-containing compound used as the main raw material is not particularly limited, but is preferably 0.8 ≦ X <2, and 0.8 ≦ It is more preferable that X ≦ 1.

  In the manufacturing method of Embodiment 2, the change of the conditions in the quasi-electrode active material layer forming step in Manufacturing Method 1 is as follows. That is, it is understood that the metal binder in Embodiment 2 is a crystalline metal oxide because it is a metal oxide that exhibits an alkali metal ion insertion / release reaction. Therefore, care should be taken to set the conditions for the quasi-electrode active material layer formation step so that the crystallinity is shown to such an extent that the alkali metal ion insertion / elimination reaction is possible. For example, when the quasi-electrode active material layer forming step is a heating step, the heating temperature or the heating temperature and the heating atmosphere are appropriately adjusted. However, the range of adjustment can be set in the contents shown in the manufacturing method 1. That is, the heating temperature can be usually adjusted within a temperature range of 150 ° C. to 800 ° C., and the heating atmosphere may be any atmosphere such as an air atmosphere, a reducing atmosphere, or an inert atmosphere. Specific conditions may be appropriately determined while generating a metal oxide in a preliminary experiment and confirming whether or not the alkali metal ion insertion / elimination reaction is exhibited in the CV test.

[Embodiment 3]
The negative electrode plate of the present invention includes active material particles, metal and / or metal oxide, and resin in the electrode active material layer, and the metal and / or metal oxide acts as a binder, thereby The active material particles may be fixed to each other (the above aspect is also referred to as “embodiment 3”).

  The embodiment 3 is a binding property in which the resin contained in the electrode active material layer contributes to the adhesion between the active material particles or the adhesion between the active material particles and the current collector, as compared to the above-described embodiment 1 or 2. Is different in that it does not show.

  More specifically, the resin in Embodiment 3 is substantially not involved in the fixation between the active material particles or between the active material particles and the current collector, and the battery is operated. However, any resin such as a thermoplastic resin, a cellulosic resin, or a synthetic rubber may be used as long as it can remain in the electrode active material layer. The other configurations of the electrode plate, that is, the electrode active material, metal and / or metal oxide metal adhesive, conductive material, gap, and current collector are the same as those in the first or second embodiment. I will omit the explanation. Incidentally, in the electrode active material layer, the resin that does not substantially participate in the adhesion between the active material particles or the adhesion between the active material particles and the current collector is contained in the electrode active material layer, thereby binding the resin. Resin that can act as a material, and a resin that is not confirmed to act as a binder, and a resin that cannot function as a resin binder but can remain in the electrode active material layer Any of these are included.

  However, in Embodiment 3, since the resin contained in the electrode active material layer does not have a binding action as described above, the amount of the metal binder contained in the electrode active material layer is the amount of the electrode active material layer. It is desirable that the content of the metal binder in the first or second embodiment is equal to or higher than the level of film strength. Specifically, when the content of the active material particles contained in the electrode active material layer is 100 parts by weight, the content of the metal binder is preferably 1 part by weight or more and 30 parts by weight or less.

Example of production method of embodiment 3 (production method 3)
As an example of the manufacturing method of Embodiment 3, the resin material selected in the resin impregnation step is the same as the manufacturing method 1 or the manufacturing method 2 except that the resin material is selected from resins other than the resin binder. is there. Or it is the same as that of the said manufacturing method 1 or the said manufacturing method 2 except restraining the quantity of the resin binder to be used small and making it the resin quantity of the grade which does not act as a resin binder substantially.

[Embodiment 4]
In the electrode plate of the present invention, an electrode active material layer may be provided indirectly on the current collector. That is, in each of the negative electrode plates manufactured by the manufacturing methods 1 to 3 described above, the electrode active material layer is formed directly on the current collector. However, the electrode plate of the present invention is not limited to this, and an arbitrary intermediate layer 14 is provided between the current collector 1 and the electrode active material layer 23 as shown in FIG. It may be provided. For example, in the negative electrode plate 12, the electrode active material layer 23 is separately formed as a film, an adhesive layer is provided as the intermediate layer 14 on the current collector 1, and the electrode active material layer 23 formed as a film is pasted thereon. May be. Of course, an adhesive layer as the intermediate layer 14 may be provided on the electrode active material layer 23 side formed as a film, and the adhesive layer may be attached to the current collector 1 side. Alternatively, a conductive layer may be provided as the intermediate layer 14 between the electrode active material layer 23 and the current collector 1 as long as the movement of electrons between the two is not hindered.

  Embodiment 4 may be the same as the electrode plate shown in Embodiments 1 to 4 described above, except that the electrode active material layer 23 is not directly provided on the current collector 1. Since the structures of the electric conductor 1 and the electrode active material layer 23 are the same as those shown in any of Embodiments 1 to 4, detailed description thereof is omitted here.

Example of Production Method of Embodiment 4 (Production Method 4)
Embodiment 4 can be produced in the same manner as in Production Methods 1 to 5 except that an arbitrary substrate is used instead of the negative electrode current collector (hereinafter also referred to as “Production Method 4”). For example, the manufacturing method 4 uses a base material that is peelable from the electrode active material layer as the arbitrary base material, and the electrode active material layer is formed on the base material in the same manner as in the manufacturing methods 1 to 5. After that, the base material is peeled to form the electrode active material layer 23 as a film, and the electrode active material layer 23 is pasted on the current collector 1 through the adhesive layer that is the intermediate layer 14. Thus, the negative electrode plate 12 of Embodiment 4 can be manufactured.

  Alternatively, in the production method 4, the electrode active material layer 23 is formed on the base material that does not prevent the movement of electrons in the same manner as in the production methods 1 to 5, and then the electrode active material layer 23 of the base material is formed. The negative electrode plate 12 of Embodiment 5 can be manufactured by attaching the side surface opposite to the forming side onto the current collector 1 and using the base material as the intermediate layer 14.

  As described above, the negative electrode plate of the present invention may have an electrode active material layer formed directly on the current collector. In such a case, it is desirable from the viewpoint of thinning the electrode plate, and the electrode active material Since the distance between the active material particles contained in the layer and the current collector surface is shortened, it is preferable from the viewpoint of improving the input / output characteristics. On the other hand, in the negative electrode plate of the present invention, the electrode active material layer may be indirectly formed on the current collector. In such a case, the negative electrode current collector is not affected by the formation conditions in the electrode active material layer forming step. An electric body can be selected, and the design range of the electrode plate can be widened by providing an arbitrary functional layer between the electrode active material layer and the current collector.

[Nonaqueous electrolyte secondary battery]
In general, the non-aqueous electrolyte secondary battery of the present invention includes a negative electrode plate 10 of the present invention in which an electrode active material layer 21 is provided on one side of a current collector 1 as illustrated in FIG. And the positive electrode 50 by which the electrode active material layer 54 is provided in the one surface side of the collector 55 combined with this, and the separator 70 like a polyethylene-made porous film is provided among these. These are housed in the outer casings 81 and 82 and sealed and manufactured in a state where the outer casings 81 and 82 are filled with the non-aqueous electrolyte 90, thereby forming the non-aqueous electrolyte secondary battery 100. The

(Electrode plate)
The non-aqueous electrolyte secondary battery of the present invention is characterized by using the above-described negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention as the negative electrode plate. On the other hand, a conventionally known positive electrode plate can be used for the negative electrode plate.

  As a conventionally well-known positive electrode plate, in general, at least part of the current collector surface similar to the current collector used in the electrode plate of the present invention, positive electrode active material particles, conductive material, resin binder Although what was formed by apply | coating the positive electrode active material layer forming liquid to which etc. were added, drying and pressing as needed can be used, it is not limited to this.

(Non-aqueous electrolyte)
The non-aqueous electrolyte used in the present invention is not particularly limited as long as it is generally used as a non-aqueous electrolyte for a non-aqueous electrolyte secondary battery, but a lithium salt is dissolved in an organic solvent. A non-aqueous electrolyte is preferably used.

Examples of the lithium salt include inorganic lithium salts such as LiClO ₄ , LiBF ₄ , LiPF ₆ , LiAsF ₆ , LiCl, and LiBr; LiB (C ₆ H ₅ ) ₄ , LiN (SO ₂ CF ₃ ) ₂ , LiC ( Organic compounds such as SO ₂ CF ₃ ) ₃ , LiOSO ₂ CF ₃ , LiOSO ₂ C ₂ F ₅ , LiOSO ₂ C ₄ F ₉ , LiOSO ₂ C ₅ F ₁₁ , LiOSO ₂ C ₆ F ₁₃ , and LiOSO ₂ C ₇ F ₁₅ Typical examples include lithium salts.

  Examples of the organic solvent used for dissolving the lithium salt include cyclic esters such as propylene carbonate and butylene carbonate, chain esters such as dimethyl carbonate and diethyl carbonate, cyclic ethers such as tetrahydrofuran and alkyltetrahydrofuran, and 1,2- Examples include, but are not limited to, chain ethers such as dimethoxyethane and 1,2-diethoxyethane.

  As the structure of the battery manufactured using the positive electrode plate, the negative electrode plate, the separator, and the nonaqueous electrolytic solution, a conventionally known structure can be appropriately selected and employed. For example, the structure which winds a positive electrode plate and a negative electrode plate in the shape of a spiral via the separator like a polyethylene porous film, and accommodates in a battery container is mentioned. As another aspect, a structure may be employed in which a positive electrode plate and a negative electrode plate cut into a predetermined shape are stacked and fixed via a separator, and are accommodated in a battery container. In any structure, after the positive electrode plate and the negative electrode plate are stored in the battery container, the lead wire attached to the positive electrode plate is connected to the positive electrode terminal provided in the outer container, while the lead wire attached to the negative electrode plate Is connected to a negative electrode terminal provided in the outer container, and the battery container is further filled with a nonaqueous electrification solution and then sealed to produce a nonaqueous electrolyte secondary battery.

[Battery pack]
The non-aqueous electrolyte secondary battery using the electrode plate of the present invention as a negative electrode plate can be used as a so-called non-aqueous electrolyte secondary battery used in a battery pack. That is, the battery pack of the present invention uses the electrode plate of the present invention as a negative electrode plate, and a non-aqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal and a protection circuit having an overdischarge protection function in a storage case. Contained and configured. The battery pack of the present invention is equipped with a protection function for protecting the battery from, for example, overcharge, overdischarge, overcurrent, a short circuit of the battery peripheral circuit, a short circuit between the positive and negative electrodes, etc., in the nonaqueous electrolyte secondary battery itself. In addition, it may be a battery pack in which a protection circuit for preventing overcharge and overdischarge is housed and integrated in a storage case together with the non-aqueous electrolyte secondary battery. The battery pack of the present invention can be suitably used as a battery power supply device for a device that consumes a large amount of power relative to the scale of the device, such as a portable device such as a notebook computer, a camera, or a mobile phone.

  FIG. 4 shows a schematic exploded view of a battery pack 30 of the present invention using a lithium ion secondary battery 31 configured using the negative electrode plate of the present invention as one embodiment of the battery pack of the present invention. The battery pack 30 includes a lithium ion secondary battery 31 housed in a resin container 36a, a resin container 36b, and an end case 37. At this time, a protection circuit for preventing overcharge and overdischarge between one end face of the lithium ion secondary battery 31 and a face including the positive electrode terminal 32 and the negative electrode terminal 33 and the end case 37. A substrate 34 is provided. The protection circuit board 34 includes an external connection connector 35. The external connection connector 35 is inserted into an external connection window 38a provided in the resin container 36a and an external connection window 38b provided in the end case 37. Connected to an external terminal. The protection circuit board 34 includes a charge / discharge safety circuit (not shown) for controlling charge / discharge, a wiring circuit for connecting the external connection terminal and the lithium ion secondary battery 31, and the like. In addition, the battery pack 30 can employ | adopt the structure of a conventionally well-known battery pack suitably except using the lithium ion secondary battery 31 in which the electrode plate of this invention was used. Although not shown, the battery pack 30 includes a positive electrode lead plate connected to the positive electrode terminal 32, a negative electrode lead plate connected to the negative electrode terminal 33, an insulator, and the like between the lithium ion secondary battery 31 and the end case 37. , May be provided as appropriate.

  In addition, the nonaqueous electrolyte secondary battery of the present invention using the negative electrode plate of the present invention has functions such as overcurrent blocking and battery temperature monitoring in addition to the above-described protection circuit, in addition to the usage mode for battery packs. And the protection circuit may be used by being integrated with the secondary battery itself. In such an embodiment, the battery pack can be used as a secondary battery having a protection function and a protection circuit without constituting a battery pack, and is highly versatile. In addition, the several aspects mentioned above are only illustrations, and do not limit the use of the negative electrode plate of this invention or the nonaqueous electrolyte secondary battery of this invention at all.

Example 1
Production of negative electrode plate:
A negative electrode active material layer forming solution for forming an electrode active material layer in a negative electrode plate for a non-aqueous electrolyte secondary battery was prepared as follows. As a metal binder precursor, 40 g of copper chloride is added to 40 g of methanol, and 20 g of artificial graphite having an average particle size of 10 μm is mixed as negative electrode active material particles, and rotated at 8000 rpm with an Excel auto homogenizer (Nippon Seiki Seisakusho Co., Ltd.). The electrode active material layer forming liquid for negative electrodes was prepared by stirring for 15 minutes.

  Next, an electrolytic copper foil having a thickness of 10 μm which is a negative electrode current collector is placed, and the electrode active material layer forming liquid prepared above is applied to one surface side of the negative electrode current collector with an applicator (2 mil). A coating film was formed. The coating amount is shown in Table 2. Then, the negative electrode current collector on which the coating film was formed was placed in an electric furnace and heated in an air atmosphere at 250 ° C. for 1 hour to form an electrode active material layer having a thickness of 20 μm on the current collector. . Next, as a resin binder, a solution obtained by dissolving 5 g of ethyl cellulose in 95 g in ethanol was applied on the electrode active material layer with a Miya bar (No. 6), and dried at 130 ° C. for 10 minutes in an air atmosphere. A negative electrode plate containing ethyl cellulose as a resin binder and copper oxide as a metal binder was formed in the electrode active material layer. Next, the negative electrode plate was cut into a predetermined size (a circle having a diameter of 15 mm) to obtain Example 1. The thickness of the electrode active material layer was determined by measuring 10 points at any location using a micrometer and calculating the average value.

Film formation evaluation:
In preparing Example 1, the negative electrode plate obtained above was processed into a disk shape of a desired size, but in the processing operation, there was no problem such as peeling of the electrode active material layer. We were able to. From this, it was confirmed that the film forming property of the electrode active material layer was good. Also in the following examples and comparative examples, as described above, when the electrode plate can be pulled out into a disk shape without any defects, it is evaluated that the film forming property of the electrode active material layer is good. . On the other hand, part of the electrode active material layer is peeled off in the above-mentioned punching process, or the active material particles fall from the current collector, etc., and the processing is poor, and it is used as a working electrode of a tripolar coin cell to be described later In the case where a disk that can withstand the above is not formed, it is evaluated that the film forming property of the electrode active material layer is poor.

Cyclic voltammetry test (CV test):
In order to confirm in advance whether or not the metal binder contained in the electrode active material layer in Example 1 exhibits a lithium ion insertion / release reaction, the following test was performed. That is, except that artificial graphite which is a negative electrode active material particle is not used, a forming liquid is prepared in the same manner as the above-described electrode active material layer forming liquid used in Example 1, and this is used to prepare the production method of Example 1. A laminate was prepared in the same manner. And the CV test was done using the said laminated body. Specifically, the operation of first sweeping the electrode potential from 2.0 V to 0.3 V and then returning it to 2.0 V was repeated twice. The scanning speed was 1 mV / sec. In the first cycle, current is detected by various decomposition reactions. In the cyclic voltammogram showing the result of the second cycle, no cyclic peak was confirmed, and it was confirmed that the copper oxide produced in the laminate does not undergo lithium ion insertion / release reaction. In Table 2, the results are shown as lithium ion insertion / elimination reaction, “None”. In this example, the CV test was conducted using VMP3 manufactured by Bio Logic.

Tripolar coin cell production:
Lithium hexafluorophosphate (LiPF ₆ ) is added as a solute to a mixed solvent of ethylene carbonate (EC) / dimethyl carbonate (DMC) (volume ratio = 1: 1), and the concentration of LiPF _{6 as} the solute is 1 mol. The non-aqueous electrolyte was prepared by adjusting the concentration to be / L. A negative electrode plate (circle with a diameter of 15 mm, weight of negative electrode active material layer: 16.7 g / m ² ) of Example 1 prepared as above as a working electrode, and a metal lithium foil is crimped onto a nickel mesh as a counter electrode and a reference electrode The lead metal (nickel wire) was previously attached to each electrode plate (negative electrode plate, counter electrode, reference electrode) using a spot welder, using the non-aqueous electrolyte prepared above as the electrolytic lithium solution After that, a tripolar coin cell was assembled, a test cell of Example 1 was produced, and subjected to the following charge / discharge test.

Charge / discharge test:
In Example Test Cell 1, which is a tripolar coin cell created as described above, first, the working electrode was subjected to a full charge according to the following charging test of Example Test Cell 1 in order to perform a discharge test of the working electrode.
(Charge test)
Example Test cell 1 was charged at a constant current (811 μA) under a 25 ° C. environment until the voltage reached 0.03 V. After the voltage reached 0.03 V, the voltage was 0.03 V. The current (discharge rate: 1C) was reduced until it became 5% or less so as not to fall below, and the battery was charged at a constant voltage, fully charged, and then suspended for 10 minutes. Here, the “1C” means a current value (current value reaching the discharge end voltage) at which constant current discharge is performed using the tripolar coin cell and discharge is completed in one hour.
(Discharge test)
Thereafter, the fully charged example test cell 1 was subjected to a constant current (811 μA) (discharge) in an environment of 25 ° C. until the voltage was changed from 0.03 V (full charge voltage) to 2.0 V (discharge end voltage). A constant current discharge at a rate of 1 C), the cell voltage (V) on the vertical axis, the discharge time (h) on the horizontal axis, a discharge curve is created, and the discharge capacity of the working electrode (the negative electrode plate of Example 1) (MAh) was determined and converted to a discharge capacity (mAh / g) per unit active material weight of the working electrode to obtain a 25 ° C. discharge capacity.

  Subsequently, except that the test environment temperature was changed to −20 ° C., the charge test and the discharge test were performed in the same manner as described above to obtain the −20 ° C. discharge capacity. The charge / discharge test at −20 ° C. was carried out promptly after placing the example test cell in a −20 ° C. environment.

Evaluation of discharge capacity maintenance rate under rapid cooling:
The −20 ° C. discharge capacity value determined in the charge / discharge test was divided by the 25 ° C. discharge capacity value and multiplied by 100 to determine the discharge capacity retention rate under rapid cooling. The results are shown in Table 3.

(Comparative Example 1)
Comparative Example 1 in which an electrode plate was produced in the same manner as in Example 1 except that the resin impregnation step was not performed, and the electrode active material layer had a metal binder made of copper chloride and contained no resin. It was.

(Comparative Example 2)
41 g of artificial graphite having an average particle size of 10 μm as a raw material for the negative electrode active material, 46 g of N-methyl-2-pyrrolidone as a solvent, and 4 g of polyvinylidene fluoride as a resin binder were mixed together, and an Excel auto homogenizer (Nippon Seiki Seisakusho Co., Ltd.) ) To obtain a slurry-like electrode active material layer forming solution by kneading for 15 minutes at a rotational speed of 8000 rpm. Next, the obtained slurry-like electrode active material layer forming liquid was coated on a 10 μm-thick copper foil as a negative electrode current collector with an applicator (1 mil), and dried in hot air at 130 ° C. for 10 minutes in an air atmosphere. (Primary drying) was performed to form a negative electrode active material layer having a thickness of 25 μm.

Furthermore, after pressing using a roll press machine so that the coating density of the formed negative electrode active material layer is 1.0 g / cm ³ , it is cut into a predetermined size (a circle having a diameter of 15 mm), and 120 A negative electrode plate was produced by vacuum drying (secondary drying) at 12 ° C. for 12 hours.

(Comparative Example 3)
100 g of artificial graphite having an average particle diameter of 10 μm as a raw material for the negative electrode active material, 95 g of ethanol as a solvent, and 5 g of ethyl cellulose as a resin binder are mixed, and 15 rpm at a rotation speed of 8000 rpm with an Excel auto homogenizer (Nippon Seiki Seisakusho). By kneading for a minute, a slurry-like electrode active material layer forming liquid was obtained. Next, the obtained slurry-like electrode active material layer forming liquid was coated on a 10 μm-thick copper foil as a negative electrode current collector with an applicator (1 mil), and dried in hot air at 130 ° C. for 10 minutes in an air atmosphere. (Primary drying) was performed to form a negative electrode active material layer having a thickness of 25 μm.

Furthermore, after pressing using a roll press machine so that the coating density of the formed negative electrode active material layer is 1.0 g / cm ³ , it is cut into a predetermined size (a circle having a diameter of 15 mm), and 120 A negative electrode plate was produced by vacuum drying (secondary drying) at 12 ° C. for 12 hours.

(Examples 2 to 4)
In Example 1, the concentration of ethyl cellulose dissolved in ethanol was 5%, but a negative electrode plate was formed in the same manner as in Example 1 except that this was changed to 4%, 3%, and 6%. 2-4. About Examples 2-4 created as mentioned above, the tripolar coin cell was created and it was set as Example test cells 2-4, respectively.

(Example 5)
Except for changing the materials and heating conditions shown in Table 1 and changing the coating amount and heating conditions shown in Table 2, an electrode plate was created in the same manner as in Example 1, and in the electrode active material layer, Example 5 containing nickel as a metal binder and polyvinylidene fluoride as a resin binder was obtained.

(Comparative Example 4)
Except that the resin impregnation step was not carried out, an electrode plate was produced in the same manner as in Example 5, and the electrode active material layer contained nickel as a metal binder and did not contain a resin. .

(Comparative Example 5)
An electrode plate was prepared in the same manner as in Comparative Example 2 except that the material and heating conditions shown in Table 1 were changed and the coating amount shown in Table 2 was changed, and metal and / or in the electrode active material layer was formed. The comparative example 4 which does not contain a metal oxide was created.

(Example 6)
Conductive material (Denka Black 2g) was added to the materials shown in Table 1, the heating conditions were changed to the contents shown in Table 1, and the current collector was changed to 15 μm-thick aluminum, and the coating shown in Table 2 was applied. Except for changing the amount and heating conditions, an electrode plate was prepared in the same manner as in Example 1, and in the electrode active material layer, lithium titanate as the metal binder and polyfluoride as the resin binder were used. Example 6 containing vinylidene was obtained.

(Comparative Example 6)
Comparative Example 6 in which an electrode plate was produced in the same manner as in Example 6 except that the resin impregnation step was not performed, lithium titanate was contained as a metal binder in the electrode active material layer, and no resin was contained. It was.

  About Examples 2-6 and Comparative Examples 2-6, similarly to Example 1, the measurement of the film thickness of an electrode active material layer, film formation property evaluation, and the CV test were implemented. The results are shown in Table 2. Moreover, about Examples 2-6 and Comparative Examples 2-6, the charging / discharging test in 25 degreeC and -20 degreeC was implemented similarly to Example 1, and the discharge capacity maintenance factor under rapid cooling was calculated | required. However, for Example 5, Comparative Example 4, and Comparative Example 5, the discharge rate during the discharge test was changed to 5C. The results are shown in Table 3.

  In the combination of the examples in which the weight of the active material particles per unit and the comparative examples were combined, the discharge capacity retention rate of the examples was high, and the metal and / or metal oxide in the electrode active material layer, It has been confirmed that when the resin is contained, the electrode performance is improved with respect to the rapid temperature drop in the surrounding area.

  Further, from the above results, the nonaqueous electrolyte secondary battery or battery pack using the electrode plate of the present invention as the positive electrode plate has a sudden drop in battery performance even when the use environment temperature is drastically lowered. It was suggested that this problem was avoided and that the desired task was successfully achieved.

DESCRIPTION OF SYMBOLS 1,55 Current collector 3 Active material particle 4, 4 'Metal binder 5 Resin binder 6 Void 10, 11, 12 Negative electrode plate 14 Intermediate layers 21, 22, 23, 54 Electrode active material layer 30 Battery pack 31 Lithium ion secondary battery 32 Positive electrode terminal 33 Negative electrode terminal 34 Protective circuit board 35 External connector 36a, 36b Resin container 37 End case 38a, 38b External connection window 50 Positive electrode plate 70 Separator 81, 82 Exterior 90 Nonaqueous electrolyte 100 Lithium ion secondary battery

Claims (9)

A negative electrode plate for a non-aqueous electrolyte secondary battery comprising a current collector and an electrode active material layer provided on at least a part of the current collector,
The negative electrode plate for a non-aqueous electrolyte secondary battery, wherein the electrode active material layer includes negative electrode active material particles, a metal and / or a metal oxide, and a resin. 2. The negative electrode plate for a non-aqueous electrolyte secondary battery according to claim 1, wherein the negative electrode active material particles are fixed to each other with the metal and / or metal oxide and the resin. 2. The negative electrode plate for a non-aqueous electrolyte secondary battery according to claim 1, wherein the negative electrode active material particles are fixed to each other by the metal and / or metal oxide. 2. The negative electrode active material particles located in the vicinity of the current collector are directly fixed on the current collector by at least one of the metal and / or metal oxide or the resin. 4. The negative electrode plate for a nonaqueous electrolyte secondary battery according to any one of items 1 to 3. The electrode plate for a non-aqueous electrolyte secondary battery according to any one of claims 2 to 4, wherein the metal oxide exhibits an alkali metal ion insertion / release reaction. A non-aqueous electrolyte secondary battery comprising at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and an electrolyte containing a non-aqueous solvent,
The said negative electrode plate is a negative electrode plate for nonaqueous electrolyte secondary batteries of any one of Claim 1 to 5, The nonaqueous electrolyte secondary battery characterized by the above-mentioned. A storage case; a non-aqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal; and a protection circuit having an overcharge and over-discharge protection function, wherein the storage case includes the non-aqueous electrolyte secondary battery and the In a battery pack configured to contain a protection circuit,
The non-aqueous electrolyte secondary battery includes at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and an electrolyte solution containing a non-aqueous solvent. A secondary battery,
A battery pack, wherein the negative electrode plate is the negative electrode plate for a non-aqueous electrolyte secondary battery according to any one of claims 1 and 5. An electrode active material layer forming liquid is prepared by mixing at least negative electrode active material particles in a metal ion solution containing metal ions,
A coating step of coating the electrode active material layer forming liquid on the negative electrode current collector to form a coating film;
A quasi-electrode active material layer forming step of forming a quasi-electrode active material layer by fixing negative electrode active material particles to each other with a metal ion or metal oxide generated by a metal ion contained in the coating film or a reaction product thereof When,
In this order, then
After impregnating the quasi-electrode active material layer with the resin material-containing liquid, the solvent of the resin material-containing liquid is removed, and the resin, the metal or metal oxide, and the negative electrode fixed to each other by the metal or metal oxide An electrode active material layer containing active material particles is directly formed on a current collector. A method for producing a negative electrode plate for a non-aqueous electrolyte secondary battery. An electrode active material layer forming liquid is prepared by mixing at least negative electrode active material particles in a metal ion solution containing metal ions,
An application step of applying the electrode active material layer forming liquid on a substrate to form a coating film;
A quasi-electrode active material layer forming step of forming a quasi-electrode active material layer by fixing negative electrode active material particles to each other with a metal ion or metal oxide generated by a metal ion contained in the coating film or a reaction product thereof When,
In this order, then
After impregnating the quasi-electrode active material layer with the resin material-containing liquid, the solvent of the resin material-containing liquid is removed, and the resin, the metal or metal oxide, and the negative electrode fixed to each other by the metal or metal oxide A method for forming an electrode active material layer for a negative electrode, comprising forming an electrode active material layer containing active material particles.