The University of Texas at Austin

John B. Goodenough and Youngsik Kim

Texas Materials InstituteThe University of Texas at Austin

Solid Electrolyte Batteries

This presentation does not contain any proprietary or confidential information.

DOE Vehicle Technologies Annual Merit Review Meeting

June 7 - 11, 2010

Project ID: ES060

The University of Texas at Austin

Overview

• Project Start Date – Oct. 2009• Project End Date – Sept. 2010 • Percent Complete – 50 % complete

• Design of the battery cell containing a solid electrolyte

• Search for a solid electrolyte that has a high Li-ion conductivity (σ ≥ 10-3

S/cm) and a wide electrochemical window (0 – 9 V vs. Li+/Li0)

• Funding received in FY09– $ 315 K

• Funding received in FY10– $ 315 K

Timeline

Budget

Barriers

Partners

The University of Texas at Austin

Milestones

Develop and test a suitable test cell (Jan. 10): Complete

Optimize components of the cell (Apr. 10) Complete

Develop a Li/Air cell (July. 10)

Test alternative cathode catalysts (Sept. 10).

Comparison of performance test of cells with that of the best reported Li-Air cell (Oct. 10)

The University of Texas at Austin

0 200 400 600 800 1000 1200 1400 16000

1

2

3

4

5

6

Pote

ntia

l (V)

vs.

Li+ /L

i0

Capacity (mAh/g)

TiS2

LiCoPO4

LixCoO2

LiNi0.5Mn0.5O2

LiFePO4

Li3V2(PO4)3

LixMn2O4

LixNi0.5Mn1.5O4

LiTi2(PO4)3

Li4Ti5O12

Li1+xMn2O4

Graphite

TiS2TiS2

LiCoPO4

LixCoO2

LiNi0.5Mn0.5O2LiNi0.5Mn0.5O2

LiFePO4LiFePO4

Li3V2(PO4)3Li3V2(PO4)3

LixMn2O4

LixNi0.5Mn1.5O4LixNi0.5Mn1.5O4

LiTi2(PO4)3

Li4Ti5O12

Li1+xMn2O4

LiTi2(PO4)3

Li4Ti5O12Li4Ti5O12

Li1+xMn2O4

GraphiteGraphite

Electrochemical window of organic liquid electrolytes

O2S

Fe3+ / Fe2+ in aqueous solutions

Problems with the Present Li-ion Batteries

Insertion compounds have limited capacity

Li / Air batteries are inefficient if used for electrical energy storage

Li / S batteries have too low a voltage and need a new electrolyte and a better cycle life

Liquid cathodes need a solid electrolyte stable against Li and H2O with σ > 10-4 S/cm

The University of Texas at Austin

0

1

2

3

4

5

6

Li+ ion Conductivity (mS/cm)

Poten

tial (V

) vs.

Li+ /Li

720.02 1 40.18 0.810.03

Sulfi

de G

lass

es

Org

anic

Liq

uid

Ioni

c Li

quid

Poly

mer

Poly

mer

+ O

rgan

ic L

iqui

d

Ioni

c Li

quid

+ O

rgan

ic L

iqui

d

Organic Liquid

Ionic Liquid

Polymer

Inorganic Solid

Hybrid

Electrolytes

Li-ion Conductivity ( ×10-3 S/cm)

NAS

ICO

N

The University of Texas at Austin

Li OrganicLiquid

InorganicSolid

Air (Primary)

Aqueous (Primary or Secondary)

Li 1M LiPF6in EC/DEC

Li1.3Ti1.7Al0.3(PO4)3 Sea Water

Li3N

The Use of Inorganic Solid Electrolyte for Li Batteries

Li 1M LiPF6in EC/DEC Li7Zr2R3O12 Fe(NO3)3 / Fe(NO3)2

Concept

Present Practice (Visco, PolyPlus Battery Company)

Proposed Practice

The University of Texas at Austin

Present Li/Air Batteries

1 inch × 1 inch, 150 μm, OHARA in Japan

Steven J. Visco et. al. PolyPlus Battery Company

NASICON structureLiM2(PO4)3

Time, hrs

Pot

entia

l (V

) vs.

Li+ /

Li0

LiLi+

Li+

e- e-

+ 1/2O2 + e- = 1/2Li2O2 E = 2.96 V

A. Debart, A.J. Paterson, J. Bao, P.G. Bruce, Angew. Chem. Int, Ed. 47 (2008) 4521.

The University of Texas at Austin

Design of Test Cell

Two design challenges

(1) to find sealing agents stable in both highly reducing and oxidizing environments

(2) to accommodate the electrode volume changes during cycling

-

+

LiSeparatorOrganic Liquid electrolyte

-

+ Current CollectorFe(NO3)3 / Fe(NO3)2

Solid Electrolyte

The University of Texas at Austin

Water as Cathode

0 5 10 15 200

1

2

3

4

5

Pote

ntia

l (V)

vs.

Li+ /L

i0

Time (h)

Li+ + H2O + e- LiOH + ½ H2

LiOH – e- + ½ O2 Li+ + ½ H2O

Poor charge efficiency, Poor cycle life

Theoretical Capacity

O2 1675 mAh/g

H2O 1489 mAh/g

0.1 mA

The University of Texas at Austin

Li1.3Ti1.7Al0.3(PO4)3

Ti4+

Ti4+

Ti4+

Li+

Li+

Li+

Li+

Li

Problems with NASICON Solid Electrolyte for Water Cathode

E

Li+/Li0

2.5 eV

Ti: 4s0

Ti4+/Ti3+

O2-: 2p6

N (E)

Li1.3 Ti1.7Al0.3(PO4)3

Li+ + H2O + e- LiOH + ½ H22.2 eV

100 200 300 400 500

-100

-200

-300

-400

-500

Z"

Z'

Original After Discharge

3.0 × 10-4 S/cm 1.0 × 10-4 S/cm

H2OTin+

After discharge

1400 1200 1000 800 600 400 200

Original

After discharge

Raman

Inte

nsity

(A.U

.)

Wavenumber (cm-1)

The University of Texas at Austin

Problems of NASICON Electrolyte with Cell Designs for Air Cathode

E

Li+/Li0

2.5 eV

Ti: 4s0

Ti4+/Ti3+

O2-: 2p6

N (E)

Li1.3 Ti1.7Al0.3(PO4)3

Pacific Northwest National Laboratory

3.0 eV2Li+ + O2 + e- Li2O2

End of discharge

PolyPlus Battery Company

0.2 mA/cm2

1.0 mA/cm2 0.5 mA/cm2

Solid electrolyte

The current collectors reduceTi4+ to Ti3+

Not rechargeable

The University of Texas at Austin

Transition-Metal Redox Couples in Aqueous Solutions

Li+/Li0

Li1.3 Ti1.7Al0.3(PO4)3

EV

EC

2.5 eV

EC

EV

1.0 eV

4.5 eV

1M LiPF6in EC:DEC (1:1)

EC: 3.1 eV

EV: 4.3 eV

H2O

Separator

SEI

Fe(NO3)3 / Fe(NO3)23.8 eV

0 5 10 15 200

1

2

3

4

5

Pote

ntia

l (V)

vs.

Li+ /L

i

Time (h)

Water Redox Couples in Water0.1 mA

The University of Texas at Austin

Instability of Solid Electrolytes in Acid Solution

The University of Texas at Austin

Future WorkExploration of new solid electrolytes Closed packed O2- framework

a0

Spinel Structure Garnet Structure

A[B2]O4 = B2(AO4) A3B2Si3O12 = A3B2(SiO4)3

The University of Texas at Austin

Future Work

R. Murugan, V. Thangadurai, W. Weppner, Angew. Chem. Int. Ed. 46 (2007) 7778

The University of Texas at Austin

Summary

A Li / aqueous Fe(NO3)3 / Fe(NO3)2 battery has been shown to be feasible and to offer a capacity in excess of 1000 mAh/g compared to a Li/insertion cathode with a Q/W < 250 mAh/g.

Commercial success of an aqueous cathode depends on development of a robust solid electrolyte with σLi > 10-4 S/cm.

The commercially available inorganic Li+-ion solid electrolyte having σLi≈ 10-4 S/cm is unstable with an acidic aqueous cathode.

The inorganic solid electrolyte Li7Zr2R3O12 having σLi ≈ 10-4 S/cm shows promise.