Negative electrode material for power storage device, manufacturing method thereof, and lithium ion power storage device

Patent metadata

Field	Value
Publication number	US-2017263386-A1
Application number	US-201515505818-A
Country	US
Kind code	A1
Filing date	Aug 28, 2015
Priority date	Aug 29, 2014
Publication date	Sep 14, 2017
Grant date	—

Abstract

A negative electrode material for a power storage device contains a single-phase porous carbon material capable of electrochemically occluding and releasing lithium ions, the single-phase porous carbon material has a BET specific surface area of not less than 100 m 2 /g, and a cumulative volume of pores having a pore diameter of 2 nm to 50 nm in a pore diameter distribution of the single-phase porous carbon material is not less than 25% of a total pore volume.

First claim

1 . A negative electrode material for a power storage device, containing a single-phase porous carbon material capable of electrochemically occluding and releasing lithium ions, wherein
the single-phase porous carbon material has a BET specific surface area of not less than 100 m 2 /g, and a cumulative volume of pores having a pore diameter of 2 nm to 50 nm in a pore diameter distribution of the single-phase porous carbon material is not less than 25% of a total pore volume.

2 . The negative electrode material for the power storage device according to claim 1 , wherein
an X-ray diffraction image of the single-phase porous carbon material has a peak ascribed to a (002) plane of graphite, a plane interval of the (002) plane obtained from a position of the peak is 0.340 nm to 0.370 nm, and a crystallite size of the graphite obtained from a half width of the peak is 1 nm to 20 nm.

3 . The negative electrode material for the power storage device according to claim 1 , wherein the total pore volume is 0.3 cm 3 /g to 1.2 cm 3 /g.

4 . The negative electrode material for the power storage device according to claim 1 , wherein the pore diameter distribution of the single-phase porous carbon material has at least one pore distribution peak in a region of 2 nm to 5 nm in pore distribution analysis in QSDFT analysis that assumes a carbon slit structure.

5 . A method for manufacturing a negative electrode material for a power storage device, the method comprising:
(i) a step of activating a carbon precursor in which a graphite structure grows at a temperature of not higher than 1500° C., into a porous structure; and (ii) heating the activated carbon precursor at a temperature at which the graphite structure grows, to cause the graphite structure to grow to generate a single-phase porous carbon material.

6 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein
the carbon precursor is easily-graphitizable carbon, and the activation includes a step of heating the carbon precursor at a temperature of lower than 1100° C. in an atmosphere containing water vapor and/or carbon dioxide.

7 . The method for manufacturing the negative electrode material for the power storage device according to claim 6 , wherein the easily-graphitizable carbon is generated by carbonizing a precursor at a temperature of lower than 1000° C.

8 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein
the carbon precursor is a metal carbide, and the activation includes a step of heating the metal carbide at a first temperature in an atmosphere containing chlorine.

9 . The method for manufacturing the negative electrode material for the power storage device according to claim 8 , wherein the step of causing the graphite structure to grow includes a step of heating the activated carbon precursor in a substantially oxygen-free atmosphere at a second temperature higher than the first temperature.

10 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein
the carbon precursor is a metal carbide, the activation includes heating the metal carbide in an atmosphere containing chlorine at a temperature at which the graphite structure grows, and the activation and the step of causing the graphite structure to grow are performed in parallel.

11 . The method for manufacturing the negative electrode material for the power storage device according to claim 8 , wherein the metal carbide is a carbide containing at least one metal of metals that belong to any of 4A, 5A, 6A, 7A, 8, and 3B groups in a short-form periodic table.

12 . The method for manufacturing the negative electrode material for the power storage device according to claim 11 , wherein the metal is at least any one of titanium, aluminum, and tungsten.

13 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein the activated carbon precursor has a BET specific surface area of not less than 1000 m 2 /g.

14 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein
the single-phase porous carbon material has a BET specific surface area of not less than 100 m 2 /g, and a cumulative volume of pores having a pore diameter of 2 nm to 50 nm in a pore diameter distribution of the single-phase porous carbon material is not less than 25% of a total pore volume.

15 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein
an X-ray diffraction image of the single-phase porous carbon material has a peak ascribed to a (002) plane of graphite, an average of a plane interval of the (002) plane obtained from a position of the peak is 0.340 nm to 0.370 nm, and a crystallite size of the graphite obtained from a half width of the peak is 1 nm to 20 nm.

16 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , wherein a total pore volume of the single-phase porous carbon material is 0.3 cm 3 /g to 1.2 cm 3 /g.

17 . The method for manufacturing the negative electrode material for the power storage device according to claim 14 , wherein the pore diameter distribution of the single-phase porous carbon material has at least one pore distribution peak in a region of 2 nm to 5 nm in pore distribution analysis in QSDFT analysis that assumes a carbon slit structure

18 . The method for manufacturing the negative electrode material for the power storage device according to claim 5 , further comprising a step of heating the single-phase porous carbon material in a temperature range of 500° C. to 800° C. in an atmosphere containing water vapor and/or hydrogen, after the step of causing the graphite structure to grow.

19 . A lithium ion power storage device comprising: a positive electrode containing a positive electrode active material; a negative electrode containing a negative electrode active material; a separator interposed between the positive electrode and the negative electrode;
and a nonaqueous electrolyte containing a salt of an anion and a lithium ion, wherein the negative electrode active material contains the negative electrode material for the power storage device according to claim 1 .

Assignees

• Sumitomo Electric Industries

Inventors

• Ishikawa Shinji
• Kuwahara Kazuya
• Saito Takahiro

Classifications

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01G11/32 Primary

  Carbon-based · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01G11/62

  characterised by the solute, e.g. salts, anions or cations therein · CPC title

• H01G11/26

  characterised by their structure, e.g. multi-layered, porosity or surface features · CPC title