NEGATIVE ELECTRODE MATERIAL FOR LITHIUM-ION SECONDARY BATTERY, NEGATIVE ELECTRODE MATERIAL COMPOSITION FOR LITHIUM-ION SECONDARY BATTERY, NEGATIVE ELECTRODE FOR LITHIUM-ION SECONDARY BATTERY, AND LITHIUM-ION SECONDARY BATTERY
A negative electrode material for a lithium-ion secondary battery comprising graphite particles satisfying x≥2.0 when a compressive load required to consolidate to 1.7 g/cm 3 in autograph measurement is x (kN/cm 2 ), 5.0≤y≤20.0 when, a particle size at which a cumulative volume from a small diameter side of a volume-based particle size distribution measured by a laser diffraction method reaches 50% is y, the above mentioned x and y satisfy the following Formula (1), and a degree of graphitization satisfies 90.0% or more: 11.3 x −0.66 y +1.4≥14.5 (1).
1 . A negative electrode material for a lithium-ion secondary battery comprising graphite particles satisfying x≥2.0 when a compressive load required to consolidate to 1.7 g/cm 3 in autograph measurement is x (kN/cm 2 ), 5.0≤y≤20.0 when, a particle size at which a cumulative volume from a small diameter side of a volume-based particle size distribution measured by a laser diffraction method reaches 50% is y, wherein the above mentioned x and y satisfy the following Formula (1), and a degree of graphitization satisfies 90.0% or more:
11.3 x− 0.66 y+ 1.4≥14.5 (1).
2 . A negative electrode material for a lithium-ion secondary battery comprising graphite particles satisfying, when the negative electrode material for a lithium-ion secondary battery is used to form a negative electrode material layer, a ratio L/T between a curved path length L (μm), which is a distance from one face to the other face in a thickness direction through a void inside the negative electrode material layer and a thickness T (μm) of the negative electrode material layer, of 1.7 or less.
3 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a ratio I 002 /I 110 between a peak intensity (I 002 ) of a 002 diffraction line and a peak intensity (I 110 ) of a 110 diffraction line, which are obtained when the negative electrode material for a lithium-ion secondary battery is used to form a negative electrode and the negative electrode pressed under 0.8 t/cm is subject to an X-ray diffraction measurement, is 350 or less.
4 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a face of the graphite particles is not coated with a low crystalline carbon.
5 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein when a ratio I D /I G between a peak intensity (I D ) in a range of 1300 cm −1 to 1400 cm −1 and a peak intensity (I G ) in a range of 1580 cm −1 to 1620 cm −1 is a R value, the R value of the graphite particles is from 0.10 to 0.40.
6 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a face of the graphite particles is coated with a low crystalline carbon,
wherein when a ratio I D /I G between a peak intensity (I D ) in a range of 1300 cm −1 to 1400 cm −1 and a peak intensity (I G ) in a range of 1580 cm −1 to 1620 cm −1 is a R value, the R value of the graphite particles is from 0.20 to 0.60.
7 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a particle size of the graphite particles at which the cumulative volume from the small diameter side of the volume-based particle size distribution measured by a laser diffraction method reaches 10% is from 0.1 μm to 7.0 μm.
8 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a 0 times tap density of the graphite particles is from 0.3 g/cm 3 to 0.6 g/cm 3 .
9 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a 30 times tap density of the graphite particles is from 0.4 g/cm 3 to 0.7 g/cm 3 .
10 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a 250 times tap density of the graphite particles is from 0.7 g/cm 3 to 1.1 g/cm 3 .
11 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a specific surface area of the graphite particles measured by a nitrogen adsorption measurement at 77K is from 0.2 m 2 /g to 6.0 m 2 /g.
12 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a particle size distribution D90/D10 of the graphite particles is from 3.0 to 7.0.
13 . The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein the graphite particles comprises composite particles in which a plurality of graphite particles are gathered or bound together.
14 . A negative electrode material composition for a lithium-ion secondary battery, comprising: the negative electrode material for a lithium-ion secondary battery according to claim 1 , a binder, and a solvent.
15 . A negative electrode for a lithium-ion secondary battery, comprising: a negative electrode material layer comprising the negative electrode material for a lithium-ion secondary battery according to claim 1 , and a current collector.
16 . A lithium-ion secondary battery, comprising: the negative electrode for a lithium-ion secondary battery according to claim 15 ; a positive electrode; and an electrolytic solution.