Negative active material for rechargeable lithium battery and rechargeable lithium battery comprising same

Patent metadata

Field	Value
Publication number	US-2016233501-A1
Application number	US-201615001555-A
Country	US
Kind code	A1
Filing date	Jan 20, 2016
Priority date	Feb 9, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

A negative active material for a rechargeable lithium battery and a rechargeable lithium battery including the same are provided, and the negative active material includes a Si-based alloy; a first graphite material; and a second graphite material having a different average particle diameter from the first graphite material.

First claim

What is claimed is:

1 . A negative active material for a rechargeable lithium battery, comprising
a Si-based alloy; a first graphite material; and a second graphite material having a different average particle diameter from the first graphite material.

2 . The negative active material of claim 1 , wherein a ratio of the average particle diameter of the first graphite material relative to that of the second graphite material is about 0.5 to about 0.92.

3 . The negative active material of claim 1 , wherein the average particle diameter of the first graphite material is about 8 μm to about 28 μm.

4 . The negative active material of claim 1 , wherein the average particle diameter of the second graphite material is about 10 μm to about 30 μm.

5 . The negative active material of claim 1 , wherein a weight ratio of the first graphite material and second graphite material is about 1:0.9 to about 9:0.1.

6 . The negative active material of claim 1 , wherein an amount of the Si-based alloy is about 5 wt % to about 25 wt % based on the total amount 100 wt % of the negative active material.

7 . The negative active material of claim 1 , wherein the Si-based alloy is Si-Q, wherein Q is selected from an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a Group 15 element, a Group 16 element, a transition metal, a rare earth element and a combination thereof, but not Si.

8 . The negative active material of claim 1 , wherein an amount of the first graphite material may be about 50 wt % to about 90 wt % based on the total amount 100 wt % of the negative active material.

9 . The negative active material of claim 1 , wherein an amount of the second graphite material may be about 5 wt % to about 45 wt % based on the total amount 100 wt % of the negative active material.

10 . The negative active material of claim 1 , wherein the Si-based alloy is a Si—Fe alloy.

11 . A rechargeable lithium battery comprising:
the negative electrode comprising the negative active material of claim 1 ; a positive electrode including a positive active material; and a non-aqueous electrolyte.

12 . The rechargeable lithium battery of claim 11 , wherein the negative active material layer comprises of about 95 wt % to about 99 wt % of negative active material based on the total weight of the negative active material layer.

13 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein a ratio of the average particle diameter of the first graphite material relative to that of the second graphite material is about 0.5 to about 0.92.

14 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein the average particle diameter of the first graphite material is about 8 μm to about 28 μm.

15 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein the average particle diameter of the second graphite material is about 10 μm to about 30 μm.

16 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein a weight ratio of the first graphite material and second graphite material is about 1:0.9 to about 9:0.1.

17 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein an amount of the Si-based alloy is about 5 wt % to about 25 wt % based on the total amount 100 wt % of the negative active material.

18 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein the Si-based alloy is Si-Q, wherein Q is selected from an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a Group 15 element, a Group 16 element, a transition metal, a rare earth element and a combination thereof, but not Si.

19 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein an amount of the first graphite material may be about 50 wt % to about 90 wt % based on the total amount 100 wt % of the negative active material.

20 . The rechargeable lithium battery of claim 11 , comprises of the negative active material wherein an amount of the second graphite material may be about 5 wt % to about 45 wt % based on the total amount 100 wt % of the negative active material.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Su-Kyung
• Ahn Sang-Hyuck
• Kim Deok-Hyun
• Meng Xianhui
• Choi Young Jin
• Kim Sang-Pil
• You Yong-Chan

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title