Positive electrode for all-solid-state battery, and all-solid-state battery comprising same

Patent metadata

Field	Value
Publication number	US-2025293255-A1
Application number	US-202318858672-A
Country	US
Kind code	A1
Filing date	Dec 13, 2023
Priority date	Dec 27, 2022
Publication date	Sep 18, 2025
Grant date	—

Abstract

A positive electrode for an all-solid-state battery having adjusted properties of a composition related to a carbon-based conductive material, and an all-solid-state battery including the same is provided. The positive electrode for an all-solid-state battery includes a positive-electrode active material, a carbon-based conductive material, a binder, and an inorganic solid electrolyte, wherein the carbon-based conductive material is a fibrous carbon-based conductive material having a length from 1 μm to 100 μm. The fibrous carbon-based conductive material can improve the initial discharge efficiency of the all-solid-state battery when mixed with the positive-electrode active material in an appropriate ratio, as well as improve the capacity retention rate at a high-rate discharge above 0.5 C.

First claim

1 . A positive electrode, comprising:
a positive-electrode active material, a carbon-based conductive material, and an inorganic solid electrolyte, wherein the carbon-based conductive material is a fibrous carbon-based conductive material having a length from 1 μm to 100 μm.

2 . The positive electrode of claim 1 , wherein the carbon-based conductive material is a fibrous carbon-based conductive material having a diameter from 50 nm to 500 nm.

3 . The positive electrode of claim 1 , wherein the carbon-based conductive material has a BET specific surface area from 1 m 2 /g to 20 m 2 /g.

4 . The positive electrode of claim 1 , wherein a powder resistivity of the carbon-based conductive material is equal to or less than 0.025 ohm-cm under 196 MPa pressure.

5 . The positive electrode of claim 1 , wherein the carbon-based conductive material has a density from 1 g/cm 3 to 5 g/cm 3 .

6 . The positive electrode of claim 1 , wherein the carbon-based conductive material has an A value from 100 to 500, wherein the A value is calculated by Equation 1:

A
=

specific
⁢

surface
⁢

area
×
length
×
density

wherein the specific surface area is a BET specific surface area of the conductive material (m 2 /g), the length is a length of the conductive material (μm), and the density is a density of the conductive material (g/cm 3 ).

7 . The positive electrode of claim 1 , wherein the carbon-based conductive material has a difference of 0.3 to 0.7 in I D /I G values before and after graphitization in a Raman spectral analysis.

8 . The positive electrode of claim 1 , wherein the carbon-based conductive material has a difference of 10 to 50 in degree of graphitization (DoG) values before and after graphitization in an XRD analysis.

9 . The positive electrode of claim 6 , wherein the positive electrode has a B value from 5 to 50, wherein the B value is calculated by Equation 2:

B
=

R
×
A

wherein R is a value obtained by dividing the weight of the conductive material by the weight of the positive-electrode active material based on the positive-electrode, and A is a value calculated by Equation 1.

10 . The positive-electrode of claim 1 , wherein the positive-electrode active material is selected from a group consisting of LiCoO 2 , LiNiO 2 , LiMnO 2 , Li 2 MnO 3 , LiMn 2 O 4 , Li(Ni a Co b Mn c )O 2 (0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiNi 1-y Co y O 2 (0<y<1), LiCo 1-y Mn y O 2 (0<y<1), LiNi 1-y Mn y O 2 (0<y<1), Li(Ni a Co b Mn c )O 4 (0<a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn 2-z Ni z O 4 (0<z<2), LiMn 2-z Co z O 4 (0<z<2), and combinations thereof.

Assignees

• Lg Energy Solution Ltd

Inventors

• Lee Choonghyeon
• Kim Taegon
• Kim Ki Tae
• Kim Myeongsoo

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2006/10

  Solid density · CPC title