Sumitomo Chemical Company, Limited

Ichiro Arise

Chikara Murakami

Toshihiko Ogata

Kosuke Kurakane

Chikae Yoshimaru

Junji Suzuki

Eiko Kashiwazaki

Hiroki Hashiwaki

Saki Morizane

Syusaku Hara

A nonaqueous electrolyte secondary battery separator has a short circuit prevention effect improved by controlling the shape of a dendrite. In the nonaqueous electrolyte secondary battery separator, when unevenness data of at least one surface of the separator is analyzed, kurtosis of a data group of heights from a reference level is not less than 5, and standard deviation of the data group of the heights from the reference level is not more than 12.

Separator and nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery laminate is provided which has a short circuit prevention effect improved by controlling the shape of a dendrite. The nonaqueous electrolyte secondary battery laminate in accordance with an aspect of the disclosure includes a separator and a graphite negative electrode. The graphite negative electrode has a non-reactivity parameter of not less than 230%. The separator has a surface that faces the graphite negative electrode and has an average void volume, obtained by analyzing a microscopic image of the surface, of not more than 0.015 μm.

Nonaqueous electrolyte secondary battery laminate, nonaqueous electrolyte secondary battery member, and nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery includes: a separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; and a positive electrode plate and a negative electrode plate for each of which the result of a scratch test in the width direction and the result of a scratch test in the flow direction are each within a predetermined range, the polyvinylidene fluoride-based resin containing an &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

Nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery includes: a separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; a positive electrode plate having a capacitance falling within a specific range; and a negative electrode plate having a capacitance falling within a specific range. The polyolefin porous film has a given piercing strength, having a value of not less than 0.00 and not more than 0.54, the value being represented by the following expression: |1&#x2212;T/M|, where T and M are distances at which a critical load is reached in a scratch test in which the polyolefin porous film is moved in transverse and machine directions, respectively, under a constant load of 0.1N. The polyvinylidene fluoride-based resin contains an &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

A nonaqueous electrolyte secondary battery which satisfies four requirements is provided. A porous layer contains &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol % with respect to 100 mol % of a total amount of (i) the &#x3b1;-form polyvinylidene fluoride-based resin and (ii) &#x3b2;-form polyvinylidene fluoride-based resin. A porous film has a temperature rise ending period of 2.9 sec&#xb7;m/g to 5.7 sec&#xb7;m/g with respect to an amount of a resin per unit area when the porous film is impregnated with N-methylpyrrolidone containing water in an amount of 3% by weight and then (ii) irradiated, at an output of 1,800 W, with a microwave having a frequency of 2,455 MHz. A positive electrode plate has a capacitance of 1 nF to 1000 nF per measurement area of 900 mm. A negative electrode plate has a capacitance of 4 nF to 8500 nF per measurement area of 900 mm.

A nonaqueous electrolyte secondary battery including: a nonaqueous electrolyte secondary battery separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; a positive electrode plate having a capacitance falling within a specific range; and a negative electrode plate having a capacitance falling within a specific range, wherein: the polyolefin porous film has a given rate of diminution of diethyl carbonate and a given spot diameter of the diethyl carbonate; the porous layer is provided between the nonaqueous electrolyte secondary battery separator and at least one of the positive electrode plate and the negative electrode plate; and the polyvinylidene fluoride-based resin contained in the porous layer contains an &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

The present invention provides a nonaqueous electrolyte secondary battery insulating porous layer having an excellent withstand voltage property and an excellent leakage resistance characteristic. The nonaqueous electrolyte secondary battery insulating porous layer having a trabecular structure including voids, which trabecular structure has an anisotropy value of 1.30 to 2.10, the anisotropy value being calculated from a three-dimensional image showing a void part and a solid content part on respective two gradation levels, the three-dimensional image being prepared by analyzing images of cross sections obtained by making observation at intervals of 20 nm in a thickness direction from a surface of the nonaqueous electrolyte secondary battery insulating porous layer with use of a FIB-SEM having a magnification of 6500 times.

Nonaqueous elctrolyte secondary battery insulating porous layer

The present invention provides a nonaqueous electrolyte secondary battery containing (i) a separator containing a polyolefin porous film, (ii) a porous layer containing a polyvinylidene fluoride-based resin, (iii) a positive electrode plate having a capacitance falling within a certain range, and (iv) a negative electrode plate having a capacitance falling within a certain range, the polyvinylidene fluoride-based resin containing an &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

A nonaqueous electrolyte secondary battery includes: a separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; a positive electrode plate; and a negative electrode plate, wherein a sum of interface barrier energies being a predetermined value, the polyolefin porous film having a puncture strength of a predetermined value, the value represented by Formula (1) below being not less than 0.00 and not more than 0.54,|1&#x2212;&#x2003;&#x2003;Formula (1),and the polyvinylidene fluoride-based resin containing an &#x3b1;-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

As a nonaqueous electrolyte secondary battery whose battery performance is prevented from being deteriorated by charge and discharge, provided is a nonaqueous electrolyte secondary battery including: a nonaqueous electrolyte secondary battery separator having ion permeability barrier energy of not less than 300 J/mol/&#x3bc;m and not more than 900 J/mol/&#x3bc;m per unit film thickness; and a nonaqueous electrolyte containing a given additive in an amount of not less than 0.5 ppm and not more than 300 ppm.

A nonaqueous electrolyte secondary battery in accordance with an embodiment of the present invention includes: a separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; and a positive electrode plate and a negative electrode plate each of which has a capacitance in a specific range, the polyolefin porous film having a parameter X of not more than 20, and the polyvinylidene fluoride-based resin containing not less than 35.0 mol % of an &#x3b1;-form polyvinylidene fluoride-based resin.

As a nonaqueous electrolyte secondary battery separator used to produce a nonaqueous electrolyte secondary battery which is low in resistance increasing rate in a case where the nonaqueous electrolyte secondary battery is repeatedly subjected to a charge-discharge cycle, the present invention provides a nonaqueous electrolyte secondary battery separator which includes a polyolefin porous film, the nonaqueous electrolyte secondary battery separator having ion permeability barrier energy of not less than 300 J/mol/&#x3bc;m and not more than 900 J/mol/&#x3bc;m.

Nonaqueous electrolyte secondary battery separator

An insulating porous layer for a nonaqueous electrolyte secondary battery having excellent separator resistance is provided. The porous layer contains an inorganic filler and a resin, a central particle diameter of the inorganic filler is in a range of 0.1 &#x3bc;m to 11 &#x3bc;m, a BET specific surface area per unit area of the inorganic filler is not greater than 100 m/g, and the value of formula (1) is in a range of 0.10 to 0.40:[1&#x2212;T/M]&#x2003;&#x2003;(1)In formula (1), T and M respectively represent a distance by which the insulating porous layer moves in a traverse direction or a machine direction from a starting point of measurement to a point where a critical load is obtained in a scratch test under a constant load of 0.1 N.

Nonaqueous electrolyte secondary battery insulating porous layer

Provided as a nonaqueous electrolyte secondary battery insulating porous layer that allows a nonaqueous electrolyte secondary battery to have an improved discharge output characteristic is a nonaqueous electrolyte secondary battery insulating porous layer containing fine particles of a metal salt having a Lewis acid peak area within a range of not less than 0.2 gand not more than 3.6 gper unit weight, the Lewis acid peak area being measured by an infrared spectroscopy-based acid nature evaluation method for a solid surface, the Lewis acid peak area of a metal salt per unit weight being defined as a value resulting from dividing (i) the area of a peak present in a region of 1447 cmto 1460 cmof an infrared absorption spectrum measured of a sample on which pyridine was adsorbed and from which the pyridine has then been desorbed by (ii) the weight of the metal salt.

Nonaqueous electrolyte secondary battery insulating porous layer and nonaqueous electrolyte secondary battery laminated separator

A nonaqueous electrolyte secondary battery insulating porous layer which has an excellent discharge output characteristic is provided. The insulating porous layer is arranged such that an aspect ratio of a projection image of an inorganic filler at a surface of the insulating porous layer is in a range of 1.4 to 4.0 and respective peak intensities Iand Iof any diffraction planes (hkl) and (abc) of the insulating porous layer satisfy the following Formula (1). The peak intensities obtained from the diffraction planes (hkl) and (abc) orthogonal to each other are measured using a wide-angle X-ray diffraction method, and a maximum value of the peak intensity ratio is in a range of 1.5 to 300 when calculated by the following Formula (2):&#x2003;&#x2003;(1)&#x2003;&#x2003;(2).

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Osaka, Japan

Ichiro Arise