Patent ID: 11967720
Assignee: KABUSHIKI KAISHA TOSHIBA
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. An electrode comprising:
an electrode mixture layer containing an active material and a conductive assistant,
the conductive assistant contains particles of a first carbon material and particles of a second carbon material,
the particles of the first carbon material having an average particle size d1 within a range of 4 μm or more and less than 7 μm and being flat particles having an aspect ratio within a range of 1.5 to 2,
the particles of the second carbon material having an average particle size d2 within a range of 0.5 μm or more and less than 2 μm,
the particles of the first carbon material satisfying an intensity ratio G1/D1 within a range of 2 or more and less than 4 in a Raman spectrum of the electrode mixture layer, where G1 is an intensity of a G1 band whose peak top appears in a range of 1550 cm−1 to 1650 cm−1, and D1 is an intensity of a D1 band whose peak top appears in a range of 1300 cm−1 to 1400 cm−1 in the Raman spectrum,
the particles of the second carbon material satisfying an intensity ratio G2/D2 within a range of 1 or more and less than 1.5 in the Raman spectrum, where G2 is an intensity of a G2 band whose peak top appears in a range of 1550 cm−1 to 1650 cm−1 in the Raman spectrum, and D2 is an intensity of a D2 band whose peak top appears in a range of 1300 cm−1 to 1400 cm−1,
an average particle size ratio d1/d2 being within a range of 2 or more and 14 or less, and
a weight ratio C1/C2 being within a range of 0.2 or more and less than 1, where C1 is a weight of the particles of the first carbon material contained in the electrode mixture layer, and C2 is a weight of the particles of the second carbon material contained in the electrode mixture layer,
wherein, in a logarithmic differential pore volume distribution by a mercury intrusion method, the electrode mixture layer satisfies:
a ratio P1/P2 within a range of 2 or more and less than 8, and
a ratio S1/S2 within a range of 3 or more and less than 10,
where P1 is a value [mL/g] of a maximum logarithmic differential pore volume in a pore diameter range of 0.1 μm or more and 1 μm or less in the logarithmic differential pore volume distribution and P2 is a value [mL/g] of a logarithmic differential pore volume for a pore diameter of 0.03 μm in the logarithmic differential pore volume distribution, and, S1 is an integrated value in a pore diameter range of 0.1 μm or more and 1 μm or less in the logarithmic differential pore volume distribution and S2 is an integrated value in a pore diameter range of more than 0 μm and less than 0.1 μm in the logarithmic differential pore volume distribution, and
wherein an area ratio A2/A1 is within a range of 0.1 or more and 0.4 or less, where A1 is an area [μm2] of the active material contained in 1 μm2 of a cross-section of the electrode mixture layer, and A2 is an area [μm2] of the conductive assistant contained in 1 μm2 of the cross-section.