JP6287187B2 - Nonaqueous electrolyte secondary battery - Google Patents

Description

  The present invention relates to a non-aqueous electrolyte secondary battery.

  In recent years, non-aqueous electrolyte secondary batteries having a high energy density have been used for power sources for driving hybrid electric vehicles (PHEV, HEV), electric vehicles (EV), and the like. There is an increasing demand for higher performance of non-aqueous electrolyte secondary batteries used for such drive power sources.

  In the following Patent Document 1, as a technique for providing a non-aqueous electrolyte secondary battery with improved initial charge / discharge capacity, input / output characteristics, and impedance characteristics, a non-aqueous solvent contains a fluorosulfonate, Techniques for incorporating compounds have been proposed.

JP2013-152958A

  According to the technique disclosed in Patent Document 1, a non-aqueous electrolyte secondary battery having excellent battery characteristics can be obtained, but further improvement of battery characteristics is required. An object of the present invention is to provide a nonaqueous electrolyte secondary battery having higher battery characteristics, particularly a nonaqueous electrolyte secondary battery excellent in high temperature storage characteristics.

According to the nonaqueous electrolyte secondary battery of one embodiment of the present invention,
An electrode body having a positive electrode plate containing a lithium transition metal composite oxide as a positive electrode active material and a negative electrode plate containing a carbon material as a negative electrode active material;
A non-aqueous electrolyte,
An exterior body that houses the electrode body and the non-aqueous electrolyte;
A non-aqueous electrolyte secondary battery comprising:
The non-aqueous electrolyte contains lithium fluorosulfonate,
A nonaqueous electrolyte secondary battery in which the carbon material has a specific surface area of 6.7 to 8.1 m ² / g is provided.

The negative electrode plate is formed by forming a negative electrode mixture layer containing the carbon material on both surfaces of a negative electrode core,
The specific surface area of the negative electrode mixture layer is preferably 6.5 to 10.5 m ² / g.

The non-aqueous electrolyte contains ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate,
The content of diethyl carbonate in the non-aqueous electrolyte is preferably larger than the content of ethylene carbonate and larger than the content of ethyl methyl carbonate.

  The lithium transition metal composite oxide preferably contains nickel, cobalt, manganese, and zirconium.

The electrode body is a flat wound electrode body in which the positive electrode plate and the negative electrode plate are wound through a separator,
The exterior body is a bottomed cylindrical prismatic exterior body having an opening,
The wound electrode body is housed in the rectangular exterior body so that the winding axis of the wound electrode body is parallel to the bottom of the rectangular exterior body,
The opening is preferably sealed with a sealing body.

According to the nonaqueous electrolyte secondary battery of one embodiment of the present invention, the nonaqueous electrolyte contains lithium fluorosulfonate (FSO ₃ Li), and the specific surface area of the carbon material as the negative electrode active material is 6.7 to 8.1 m. ^Since it is ² / g, the nonaqueous electrolyte secondary battery excellent in the high temperature storage characteristic is provided.

FIG. 1 is a perspective view of a nonaqueous electrolyte secondary battery according to an embodiment. 2A is a partial cross-sectional view taken along line IIA-IIA in FIG. 1, and FIG. 2B is a partial cross-sectional view taken along line IIB-IIB in FIG. 2A. 3A is a plan view of a positive electrode plate used in the nonaqueous electrolyte secondary battery according to the embodiment, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A. 4A is a plan view of a negative electrode plate used in the nonaqueous electrolyte secondary battery according to the embodiment, and FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 4A.

  Hereinafter, embodiments of the present invention will be described in detail. However, each embodiment shown below is illustrated in order to understand the technical idea of the present invention, and the present invention is not intended to be specified in this embodiment.

  Initially, the structure of the nonaqueous electrolyte secondary battery which concerns on embodiment is demonstrated using FIGS. 1-3.

  As shown in FIG. 2, the nonaqueous electrolyte secondary battery has a flat wound electrode body 4 in which a positive electrode plate 1 and a negative electrode plate 2 are wound via a separator 3. The outermost peripheral surface of the flat wound electrode body 4 is covered with a separator 3.

  As shown in FIG. 3, the positive electrode plate 1 is a positive electrode core body in which the core body is exposed in a strip shape along the longitudinal direction at one end in the width direction on both surfaces of a positive electrode core body 1a made of aluminum or aluminum alloy. The positive electrode mixture layer 1c is formed so that the exposed portion 1b is formed on both sides. A positive electrode protective layer 1d is formed on the positive electrode core 1a near the end of the positive electrode mixture layer 1c. As shown in FIG. 4, the negative electrode plate 2 has negative electrode core exposed portions in which the core is exposed in a strip shape along the longitudinal direction at both ends in the width direction on both surfaces of the negative electrode core 2a made of copper or copper alloy. The negative electrode mixture layer 2c is formed so that 2b is formed on both sides. A negative electrode protective layer 2d is formed on the negative electrode mixture layer 2c. Here, the width of the negative electrode core exposed portion 2b provided at one end portion in the width direction of the negative electrode plate 2 is equal to that of the negative electrode core exposed portion 2b provided at the other end portion in the width direction of the negative electrode plate 2. Greater than width. Note that the negative electrode core exposed portion 2 b may be provided only at one end portion in the width direction of the negative electrode plate 2.

  The positive electrode plate 1 and the negative electrode plate 2 are wound through a separator 3 and formed into a flat shape, whereby a flat wound electrode body 4 is produced. At this time, the positive electrode core exposed portion 1b wound around one end of the flat wound electrode body 4 is formed, and the negative electrode core exposed portion 2b wound around the other end is formed. Like that.

As shown in FIG. 2, the wound positive electrode core exposed portion 1 b is electrically connected to the positive electrode terminal 6 through the positive electrode current collector 5. The wound negative electrode core exposed portion 2 b is electrically connected to the negative electrode terminal 8 through the negative electrode current collector 7. The positive electrode current collector 5 and the positive electrode terminal 6 are preferably made of aluminum or an aluminum alloy. The negative electrode current collector 7 and the negative electrode terminal 8 are preferably made of copper or a copper alloy. The positive electrode terminal 6 preferably includes a connecting portion 6a penetrating the metal sealing body 11, a plate-like portion 6b disposed on the outer surface side of the sealing body 11, and a bolt portion 6c provided on the plate-like portion 6b. The negative electrode terminal 8 preferably includes a connecting portion 8a penetrating the sealing body 11, a plate-like portion 8b disposed on the outer surface side of the sealing body 11, and a bolt portion 8c provided on the plate-like portion 8b.

  The conductive path between the positive electrode plate 1 and the positive electrode terminal 6 is provided with a current interrupting mechanism 16 that operates when the internal pressure of the battery exceeds a predetermined value and interrupts the conductive path between the positive electrode plate 1 and the positive electrode terminal 6. It has been.

  As shown in FIGS. 1 and 2A, the positive electrode terminal 6 is fixed to the sealing body 11 via an insulating member 9. The negative electrode terminal 8 is fixed to the sealing body 11 via the insulating member 10.

  The flat wound electrode body 4 is housed in a metal rectangular outer package 12 in a state of being covered with a resin insulating sheet 15. The sealing body 11 is brought into contact with the opening of the rectangular exterior body 12, and the contact portion between the sealing body 11 and the rectangular exterior body 12 is laser-welded.

  The rectangular exterior body 12 has a bottomed cylindrical shape, and includes a pair of large area side walls 12a, a pair of small area side walls 12b having a smaller area than the large area side wall 12a, and a bottom portion 12c. The flat portion of the flat wound electrode body 4 is disposed such that a pair of flat outer surfaces face the pair of large-area side walls 12a.

  The sealing body 11 has an electrolytic solution injection port 13 from which a nonaqueous electrolytic solution is injected, and then the electrolytic solution injection port 13 is sealed with a blind rivet or the like. The sealing body 11 is formed with a gas discharge valve 14 that breaks when the battery internal pressure becomes larger than the operating pressure of the current interrupt mechanism 16 and discharges the gas inside the battery to the outside of the battery.

  Next, the positive electrode plate 1, the negative electrode plate 2, the flat wound electrode body 4, and the method for producing the nonaqueous electrolyte solution as the nonaqueous electrolyte in the nonaqueous electrolyte secondary battery will be described.

[Production of positive electrode plate]
As the positive electrode active material, a lithium transition metal composite oxide represented by Li (Ni _0.35 Co _0.35 Mn _0.30 ) _0.95 Zr _0.05 O ₂ was used. This positive electrode active material, carbon powder as a conductive agent, and polyvinylidene fluoride (PVdF) as a binder are weighed so as to have a mass ratio of 91: 7: 2, and N as a dispersion medium. -Mix-2-pyrrolidone (NMP) was mixed to prepare a positive electrode mixture slurry.

  A positive electrode protective layer slurry was prepared by mixing alumina powder, PVdF, carbon powder, and NMP as a dispersion medium at a mass ratio of 21: 4: 1: 74.

  The positive electrode mixture slurry produced by the above-described method was applied to both surfaces of a 15 μm-thick aluminum foil as the positive electrode core 1a by a die coater. Next, the positive electrode protective layer slurry produced by the above-described method was applied on the positive electrode core 1a at the end of the region where the positive electrode mixture slurry was applied. Thereafter, the electrode plate was dried to remove NMP as a dispersion medium, and compressed to a predetermined thickness by a roll press. And it cut | disconnects to a predetermined dimension so that the positive electrode core body exposure part 1b in which the positive mix layer 1c is not formed in both surfaces along the longitudinal direction may be formed in one edge part of the width direction of the positive electrode plate 1 may be positive electrode plate. It was set to 1.

[Production of negative electrode plate]
Mass ratio of graphite powder having a specific surface area of 7.46 m ² / g as a negative electrode active material, carboxymethyl cellulose (CMC) as a thickener, and styrene-butadiene rubber (SBR) as a binder. Was dispersed in water at a ratio of 98: 1: 1 to prepare a negative electrode mixture slurry.

  Negative electrode protective layer slurry in which alumina powder, binder (acrylic resin), and NMP as a dispersion medium are mixed at a mass ratio of 30: 0.9: 69.1 and mixed and dispersed by a bead mill. Was made.

  The negative electrode mixture slurry produced by the above-described method was applied to both surfaces of a copper foil having a thickness of 8 μm as the negative electrode core 2a by a die coater. Subsequently, it was dried to remove water as a dispersion medium, and compressed to a predetermined thickness by a roll press. Then, after apply | coating the negative electrode protective layer slurry produced by the above-mentioned method on the negative mix layer 2c, NMP used as a solvent was dried and removed and the negative electrode protective layer 2d was formed. And it cut | disconnected to the predetermined dimension so that the negative electrode core layer exposure part 2b in which the negative mix layer 2c was not formed in both surfaces along the longitudinal direction in the both ends of the width direction of a negative electrode plate was used as the negative electrode plate 2 .

The specific surface area of the negative electrode mixture layer 2c in the negative electrode plate 2 was 8.5 m ² / g. The measuring method of the negative electrode mixture layer 2c is as follows.

[Method for Measuring Specific Surface Area of Negative Electrode Mixture Layer]
In the negative electrode plate 2, three electrode plates for specific surface area measurement were prepared by cutting the areas where the negative electrode mixture layer 2c was formed on both surfaces of the negative electrode core 2a into a size of 2 cm × 5 cm in plan view, and MACSORB manufactured by Mountec Co., Ltd. The specific surface area was measured by HM model-1201. In calculating the specific surface area of the negative electrode mixture layer 2c, the surface area of the negative electrode core body 2a was sufficiently smaller than the surface area of the negative electrode mixture layer 2c. Therefore, the surface area of the negative electrode core body 2a was set to 0 m ² / g. Moreover, it calculated by remove | excluding the weight of the negative electrode core 2a from the weight of the electrode plate for a specific surface area measurement. When the negative electrode protective layer is formed on the surface of the negative electrode mixture layer, the specific surface area of the negative electrode mixture layer including the negative electrode protective layer is set.

[Production of flat wound electrode body]
The positive electrode plate 1 and the negative electrode plate 2 produced by the above-described method were wound through a polypropylene separator 3 and then formed into a flat shape to produce a flat wound electrode body 4. The wound positive electrode core exposed portion 1b is formed at one end in the winding axis direction of the flat wound electrode body 4, and the wound negative electrode core exposed portion 2b is formed at the other end. It is formed. The separator 3 is located on the outermost periphery of the flat wound electrode body 4. Further, the end of winding of the negative electrode plate 2 is located on the outer peripheral side of the end of winding of the positive electrode plate 1.

[Adjustment of non-aqueous electrolyte]
A mixed solvent was prepared by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) at a volume ratio (25 ° C., 1 atm) of 3: 3: 4. LiPF ₆ was added to this mixed solvent so as to be 1 mol / L, and vinylene carbonate (VC) was 0.3% by mass and lithium fluorosulfonate was 1.0% by mass with respect to the total non-aqueous electrolyte mass. % To make a non-aqueous electrolyte.

[Assembly of non-aqueous electrolyte secondary battery]
The positive electrode terminal 6 and the positive electrode current collector 5 are in an electrically connected state, and the positive electrode terminal 6 and the positive electrode current collector 5 are fixed to the aluminum sealing body 11 via the insulating member 9. It is preferable to provide a safety mechanism between the positive electrode terminal 6 and the positive electrode current collector 5 so that the conductive path between the positive electrode terminal 6 and the positive electrode current collector 5 is cut as the battery internal pressure increases. The negative electrode terminal 8 and the negative electrode current collector 7 are electrically connected, and the negative electrode terminal 8 and the negative electrode current collector 7 are fixed to the sealing body 11 via the insulating member 10. Thereafter, the positive electrode current collector 5 and the receiving component 5a are connected to the outermost surface of the wound positive electrode core exposed portion 1b, and the negative electrode current collector 7 and the receiving component are connected to the outermost surface of the negative electrode core exposed portion 2b. .

  Next, the flat wound electrode body 4 was covered with a polypropylene insulating sheet 15 bent into a box shape and inserted into the aluminum rectangular exterior body 12. And the contact part of the square exterior body 12 and the sealing body 11 was laser-welded, and the opening part of the square exterior body 12 was sealed.

  After injecting the nonaqueous electrolytic solution produced by the above-described method from the electrolytic solution injection port 13 of the sealing body 11, the electrolytic solution injection port 13 was sealed with a blind rivet. The nonaqueous electrolyte secondary battery according to this embodiment is referred to as a battery 1.

  A nonaqueous electrolyte secondary battery having the same configuration as that of the battery 1 was prepared except that lithium fluorosulfonate was not added to the nonaqueous electrolyte.

  About the battery 1 and the battery 2 produced by the above-mentioned method, the normal temperature resistance, the low temperature output, the low temperature regeneration, the initial capacity, and the capacity retention rate after storage were measured by the following methods.

[Measurement of room temperature resistance]
The battery was charged to a charge depth (SOC) of 79% at a constant current of 1 C under the condition of 25 ° C. After that, discharging was performed at a constant current of 7.5C, 15C, 22.5C, 30C, 37.5C, 45C, 52.5c and 60C for 10 seconds, and each battery voltage was measured. Each measurement result was plotted with the value as the x-axis, and the slope was taken as the normal temperature resistance value.

[Measurement of low-temperature output]
Under the condition of 25 ° C., constant current charging was performed at a constant current of 1 C so that the depth of charge (SOC) was 27%. Thereafter, these batteries were discharged at a constant current of 2.5C, 5C, 7.5C, 10C, 12.5C, 15C, 17.5C and 20C for 2 seconds at -30 ° C, respectively. The battery voltage was measured, and each current value and the battery voltage were plotted to obtain a low-temperature output (power (W) at 2.2 V discharge).

[Measurement of low temperature regeneration]
Under the condition of 25 ° C., constant current charging was performed at a constant current of 1 C so that the depth of charge (SOC) was 27%. After that, at −30 ° C., these batteries were charged for 5 seconds with constant currents of 0.75C, 1.5C, 2.25C, 3C, 3.75C, 4.5C, 5.25C and 6C, respectively. Each battery voltage was measured, and each current value and the battery voltage were plotted to obtain low-temperature regeneration (power (W) at 4.175 V charging).

[Measurement of initial capacity and capacity retention after storage]
The battery was charged to 4.1 V with a constant current of 1 C under the condition of 25 ° C., charged for 2 hours at 4.1 V, discharged to 3 V with a constant current of 1/2 C, and discharged at 3 V for 3 hours. The discharge capacity at this time was defined as the initial capacity. Then, it charged to SOC80% with the constant current of 1C, and preserve | saved at 60 degreeC for 40 days. After storage, the battery was charged to 4.1 V at a constant current of 1 C, charged at 4.1 V for 2 hours, discharged to 3 V at a constant current of 1/2 C, and discharged at 3 V for 3 hours. The discharge capacity at this time was defined as the capacity after storage. The capacity retention rate after storage was determined from the following formula.
Capacity retention after storage (%) = initial capacity / capacity before storage x 100

  The above measurement results are shown in Table 1. In Table 1, for the initial capacity, normal temperature resistance, low temperature output, and low temperature regeneration, the measurement result of the battery 2 is assumed to be 100%, and the measurement result of the battery 1 is shown as a relative value with respect to the measurement result of the battery 2.

As shown in Table 1, when the non-aqueous electrolyte contains lithium fluorosulfonate and the specific surface area of the carbon material as the negative electrode active material is 6.7 to 8.1 m ² / g, output characteristics and high temperature storage characteristics A non-aqueous electrolyte secondary battery excellent in the above can be obtained.

  The above effect can be obtained if the nonaqueous electrolyte contains lithium fluorosulfonate, but the content of lithium fluorosulfonate in the nonaqueous electrolyte should be 0.1 to 2.0% by mass. Is preferable, and it is more preferable to set it as 0.5-1.5 mass%. Further, as the negative electrode active material, graphite is preferable, and it is particularly preferable to use a material in which the surface of graphite is coated with an amorphous carbon material.

  In the solvent in the non-aqueous electrolyte, the EC content is preferably 20 to 40% by volume, the EMC content is 20 to 40% by volume, and the DEC content is preferably 30 to 50% by volume. The non-aqueous electrolyte may contain a solvent other than EC, EMC, and DEC.

<Other matters>
(Additions)
As the positive electrode active material, lithium cobaltate (LiCoO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium nickelate (LiNiO ₂ ), lithium nickel manganese composite oxide (LiNi _1-x Mn _x O ₂ (0 < x <1)), lithium nickel cobalt composite oxide (LiNi _1-x Co _x O ₂ (0 <x <1)), lithium nickel cobalt manganese composite oxide (LiNi _x Co _y Mn _z O ₂ (0 <x <1, 0 <y <1, 0 <z <1, x + y + z = 1)) and the like. Moreover, what added Al, Ti, Zr, Nb, B, W, Mg, Mo, etc. to said lithium transition metal complex oxide can also be used. For example, Li _{1 + a} Ni _x Co _y Mn _z M _b O ₂ (M = at least one element selected from Al, Ti, Zr, Nb, B, Mg, and Mo, 0 ≦ a ≦ 0.2, 0. 2 ≦ x ≦ 0.5, 0.2 ≦ y ≦ 0.5, 0.2 ≦ z ≦ 0.4, 0 ≦ b ≦ 0.02, a + b + x + y + z = 1) Is mentioned.

  As the negative electrode active material, a carbon material capable of occluding and releasing lithium ions can be used. Examples of the carbon material capable of occluding and releasing lithium ions include graphite, non-graphitizable carbon, graphitizable carbon, fibrous carbon, coke, and carbon black. Of these, graphite is particularly preferable.

As the nonaqueous solvent (organic solvent) of the nonaqueous electrolyte, carbonates, lactones, ethers, ketones, esters and the like can be used, and two or more of these solvents can be used in combination. it can. For example, cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate, and chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate can be used. In particular, it is preferable to use a mixed solvent of a cyclic carbonate and a chain carbonate. Moreover, unsaturated cyclic carbonates such as vinylene carbonate (VC) can also be added to the nonaqueous electrolyte.

As the electrolyte salt of the non-aqueous electrolyte, those generally used as the electrolyte salt in the conventional lithium ion secondary battery can be used. For example, LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ , LiAsF ₆ , LiClO ₄ , Li ₂ B ₁₀ Cl ₁₀ , Li ₂ B ₁₂ Cl ₁₂ , LiB (C ₂ O ₄ ) ₂ , LiB ( C ₂ O ₄ ) F ₂ , LiP (C ₂ O ₄ ) ₃ , LiP (C ₂ O ₄ ) ₂ F ₂ , LiP (C ₂ O ₄ ) F _{4 and the} like and mixtures thereof are used. Among these, LiPF ₆ is particularly preferable. The amount of electrolyte salt dissolved in the non-aqueous solvent is preferably 0.5 to 2.0 mol / L.

As the separator, it is preferable to use a porous separator made of polyolefin such as polypropylene (PP) or polyethylene (P E ). In particular, it is preferable to use a separator having a three-layer structure (PP / PE / PP or PE / PP / PE) of polypropylene (PP) and polyethylene (PE). Further, a polymer electrolyte may be used as a separator.

  The electrode body may be a laminated electrode body in which a plurality of positive plates and a plurality of negative plates are laminated with separators.

DESCRIPTION OF SYMBOLS 1 Positive electrode plate 1a Positive electrode core body 1b Positive electrode core body exposed part 1c Positive electrode mixture layer 1d Positive electrode protective layer 2 Negative electrode plate 2a Negative electrode core body 2b Negative electrode core body exposed part 2c Negative electrode mixture layer 2d Negative electrode protective layer 3 Separator 4 Winding electrode Body 5 Positive electrode current collector 6 Positive electrode terminal 7 Negative electrode current collector 8 Negative electrode terminal 9, 10 Insulating member 11 Sealing body 12 Rectangular outer body 12a Large area side wall 12b Small area side wall 12c Bottom 13 Electrolyte injection port 14 Gas discharge valve 15 Insulation sheet 16 Current interruption mechanism

Claims (8)

An electrode body having a positive electrode plate containing a lithium transition metal composite oxide as a positive electrode active material and a negative electrode plate containing a carbon material as a negative electrode active material;
A non-aqueous electrolyte,
An exterior body that houses the electrode body and the non-aqueous electrolyte;
A non-aqueous electrolyte secondary battery comprising:
The non-aqueous electrolyte contains lithium fluorosulfonate,
The specific surface area of the carbon material Ri 6.7~8.1m ² / g der,
The negative electrode plate is formed by forming a negative electrode mixture layer containing the carbon material on both surfaces of a negative electrode core,
The specific surface area of the negative electrode mixture layer, 6.5~10.5m ² / g Der Ru nonaqueous electrolyte secondary battery. The non-aqueous electrolyte contains ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate,
The nonaqueous electrolyte secondary battery according to claim 1, wherein the content of diethyl carbonate in the nonaqueous electrolyte is larger than the content of ethylene carbonate and larger than the content of ethyl methyl carbonate. The lithium transition metal complex oxide, nickel, cobalt, manganese, and a non-aqueous electrolyte secondary battery according to claim 1 or 2 containing zirconium. The electrode body is a flat wound electrode body in which the positive electrode plate and the negative electrode plate are wound through a separator,
The exterior body is a bottomed cylindrical prismatic exterior body having an opening,
The wound electrode body is housed in the rectangular exterior body so that the winding axis of the wound electrode body is parallel to the bottom of the rectangular exterior body,
The non-aqueous electrolyte secondary battery according to any one of claims 1 to 3, wherein the openings are sealed by the sealing member. An electrode body having a positive electrode plate containing a lithium transition metal composite oxide as a positive electrode active material and a negative electrode plate containing a carbon material as a negative electrode active material;
A non-aqueous electrolyte,
An exterior body that houses the electrode body and the non-aqueous electrolyte;
With
The specific surface area of the carbon material is 6.7 to 8.1 m. ² / G,
The negative electrode plate is formed by forming a negative electrode mixture layer containing the carbon material on both surfaces of a negative electrode core,
The specific surface area of the negative electrode mixture layer is 6.5 to 10.5 m. ² / G of non-aqueous electrolyte secondary battery manufacturing method,
A method for producing a nonaqueous electrolyte secondary battery, comprising a step of disposing the nonaqueous electrolyte containing lithium fluorosulfonate in the outer package. The non-aqueous electrolyte contains ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate,
The method for producing a non-aqueous electrolyte secondary battery according to claim 5, wherein the content of diethyl carbonate in the non-aqueous electrolyte is larger than the content of ethylene carbonate and larger than the content of ethyl methyl carbonate. The method for producing a nonaqueous electrolyte secondary battery according to claim 5 or 6, wherein the lithium transition metal composite oxide contains nickel, cobalt, manganese, and zirconium. The electrode body is a flat wound electrode body in which the positive electrode plate and the negative electrode plate are wound through a separator,
The exterior body is a bottomed cylindrical prismatic exterior body having an opening,
The wound electrode body is housed in the rectangular exterior body so that the winding axis of the wound electrode body is parallel to the bottom of the rectangular exterior body,
The method for manufacturing a nonaqueous electrolyte secondary battery according to claim 5, wherein the opening is sealed with a sealing body.