High energy density secondary lithium batteries

Patent metadata

Field	Value
Publication number	US-10224565-B2
Application number	US-201213651322-A
Country	US
Kind code	B2
Filing date	Oct 12, 2012
Priority date	Oct 12, 2012
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

A lithium ion battery includes a positive electrode comprising carbon fibers, a binder composition with conductive carbon, and a lithium rich composition. The lithium rich composition comprises at least one selected from the group consisting of Li1+x(My MzII MwIII)O2 where x+y+z+w=1, and xLi2MnO3(1−x)LiMO2, where x=0.2-0.7, and where M, MII and MIII are interchangeably manganese, nickel and cobalt, and LiM2−xMxIIO4, where M and MII are manganese and nickel, respectively, with x=0.5. A negative electrode comprises carbon fibers having bound thereto silicon nanoparticles, and a mesophase pitch derived carbon binder between the silicon nanoparticles and the carbon fibers. An electrolyte is interposed between the positive electrode and the negative electrode. Methods of making positive and negative electrodes are also disclosed.

First claim

We claim:

1. A lithium ion battery, comprising:
a positive electrode comprising an integrated conductive non-graphitic carbon fiber mat current collector and a positive electrode composition, the positive electrode composition comprising a binder composition and a lithium rich composition, the binder composition comprising a mixture of carbonized pitch and conductive carbon nanofibers, and the lithium rich composition comprising at least one selected from the group consisting of Li 1+x (M y M z II M w III )O 2 where x+y+z+w=1, xLi 2 MnO 3 (1−x)LiMO 2 , where x=0.2-0.7, wherein M, M II and M III are interchangeably manganese, nickel and cobalt, and LiM* 2−x M* x II O 4 , wherein M* and M* II are manganese and nickel, respectively, with x=0.5, the positive electrode comprising 85-90 wt. % lithium rich composition, 5-7 wt. % carbonized pitch, and 0.5-1 wt. % carbon nanofibers by total weight of the positive electrode, the conductive non-graphitic carbon fiber mat serving as a support for the positive electrode composition and as a current collector for the positive electrode, the thickness of the positive electrode being between 75-150 μm;
a negative electrode comprising an integrated conductive non-graphitic carbon fiber mat current collector having bound thereto silicon nanoparticles, and a binder composition comprising a mixture of carbonized pitch surrounding the silicon nanoparticles and between the silicon nanoparticles and the carbon fiber mat, the conductive non-graphitic carbon fiber mat serving as a support for the silicon nanoparticles and as a current collector for the negative electrode, the thickness of the anode being greater than 100 μm;
the carbon fibers of the conductive non-graphitic carbon fiber mats having a diameter between 2-25 μm, and the carbon nanofibers having a diameter between 100-200 nm, and the void space in the electrodes being 50% to 70%; and
an electrolyte interposed between the positive electrode and the negative electrode, wherein the battery has a nominal voltage greater than 3.75 volts, can be cycled to a voltage greater than 4.6 volts, and wherein the total gravimetric energy density of the battery exceeds 400 Wh/Kg.

2. The battery of claim 1 , wherein the binder composition of the positive electrode, the negative electrode, or both the positive and the negative electrode, comprises a mesophase pitch derived conductive carbon binder.

3. The battery of claim 1 , wherein the silicon nanoparticles are between 50-100 nm in diameter.

4. The battery of claim 1 , the total volumetric energy density of the battery exceeds 600 Wh/L.

5. The battery of claim 1 , wherein the loading of silicon nanoparticles on the carbon fibers of the carbon fiber mat of the negative electrode is between 30 and 50% of the total electrode mass per unit area.

6. The battery of claim 1 , wherein the silicon loading of the negative electrode is between 30-50% of the total electrode mass per unit area.

7. The battery of claim 1 , wherein the negative electrode has an initial capacity that exceeds at least by 10% the capacity of the positive electrode when normalized to thickness and area of the electrode.

8. The battery of claim 1 , wherein the electrodes do not comprise a polymeric binder.

9. The battery of claim 1 , wherein one of the lithium rich composition is Li 1.2 Mn 0.525 Ni 0.175 Co 0.1 O 2 .

10. The battery of claim 1 , wherein the lithium rich composition is LiMn 1.5 Ni 0.5 O 4 .

11. The battery of claim 1 , wherein the lithium rich composition is provided as particles with particle sizes below 100 nm.

12. The battery of claim 1 , wherein the carbon nanofibers of the positive electrode have an outer diameter of between 100 and 200 nm.

13. The battery of claim 1 , wherein the carbon nanofibers of the positive electrode have a hollow core of from ½ to ⅔ of the total fiber diameter.

Assignees

• Ut Battelle Llc

Inventors

• Nanda Jagjit
• Dudney Nancy J
• Narula Chaitanya Kumar
• Pannala Sreekanth
• Unocic Raymond Robert
• Martha Surendra Kumar

Classifications

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic

• 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

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/0471

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