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To be presented at Second Hawaii Battery Conference, Big Island of Hawaii, January 67,1999 and published in conference Proceedings

Recent Developments in Thin-Film Lithium and Lithium-Ion Batteries

J. B. Bates, B. J. Neudecker, and N. J. Dudney Solid State Division, Oak Ridge National Laboratory P.O. Box 2008, Oak Ridge, Tennessee 37831-6030

"The submitted manuscript has been authored by a contractor of the US. Government under contract No. DE-ACOS-960R22464. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US. Government purposes."

prepared by SOLID STATE DIVISION

OAK RIDGE NATIONAL LAE%ORATORY Managed by

LOCKHEED MARTIN ENERGY RESEARCH COW. under

Contract No. DE-AC05-960R22464 with the

U.S. DEPARTMENT OF ENERGY Oak Ridge, Tennessee

November 1998

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that i ts use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply i ts endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

Recent Developments in Thin-Film Lithium and Lithium-Ion Batteries

J. B. Bates, B. J. Neudecker, and N. J. Dudney Oak Ridge National Laboratory

Oak Ridge, Tennessee

Outline

Processing, materials, and performance High rate deposition and annealing Metal foil substrates Tin and zinc nitride anodes Lithium plating ("lithium free" lithium cells)

Manufacturing and applications 0 Challenges and future work

Thin-Film Battery Construction

A thin-film battery is fabricated on a substrate that can be a ceramic, metal, semiconductor, or, depending on subsequent film processing, a plastic. The current collectors are deposited first followed by the cathode, electrolyte, and anode films. Finally the battery is covered with a thin protective coating. Except for lithium metal anodes which are deposited by evapo- ration, the metal current collector and inorganic films are deposited by sputtering.

Batteries Fabricated at Hiah Fiates

LiCoO, : 1 cm2 x 2.5 wn L 4.2

h

a E 3.8 a,

i @A): 0.1, 0.4, 1, 2, 4 5 - .- c

2 L. 3.4

m Q1

0 50 100 150 200 Capacity (pAh)

Discharge curves at 25OC of a Li-LiCoO, cell with the Lipon electrolyte and polycrystalline textured cathode films deposited at 70 Nmin.

LiCoO, : 1 cm2 x 2.5 pm 200 L I I . , . - , I . . I I ' ' I ' 4 2.5

0 - 0.0 0 2 4 6 8 1 0

Current (mA)

Capacity and energy of a Li-LiCoO, battery' vs. discharge current. Cathode and electrolyte films deposited at 70 Nmin.

Metal Foil Substrates "Lithium Free" Lithium Batteries

>

> Flexible batteries

Thinner batteries: reduced inactive volume and mass

4.2 h

5

- 0.002" Ti .--e--- 0.02" alumina

0 20 40 60 80 100 120 140 160 Capacity (pAh) ir

Discharge curves of Li-LiCoO, cells on Ti and alumina substrates. Cathodes 1 cm2 x - 2 pm thick. A battery on 1 mil Ti could be rolled in to a 1" cylinder and flexed repeatedly.

Lithium-Ion Batteries

LiCoO,: 1 cm2 x 1 pm 4.2

3.9

t 3 3.6 0

h

L .- c

a 2 3.3

m Q)

5 3.0

2.7 0 20 40 60 80

Capacity @Ah ) Comparison of discharge curves for cells with LiCoO, cathodes and SiTON, Sn,N,, Zn,N,, and lithium anodes.

Licoo,: 1 cm2 x 1 pm

-

~~~

4.2 i (mA): 0.1, 0.5, 1, 2, 4 h

v > cb E 3.8 - 0 a al

- .- 2

2 3.4 % m

3.0 0 10 20 30 40 50 60 70

Capacity (pAh)

Discharge curves for a "lithium free" lith- ium battery. The anode was formed in- situ by plating lithium between the elec- trolyte and a metal film on the charge cycles.

60

2 - 40 .- E x 20 8 0

0 0 20 40 60 80 100

Cycle Number

4.2 - 3.89 V 0.1 mA

4.2 - 3.0 V

Discharge capacity vs. cycle number 'for a "lithium free" lithium battery. For cycles 1 to 50, the lower cutoff voltage was set above the potential for complete stripping of lithium. For cycles 51 - 100, complete stripping of lithium occurred at the lower cutoff potential. The dashed line indicates the theoretical maximum capacity for re- versible cycling of 0.5 Li per COO,.

2

Manufacturina and Applications

> Large area industrial batch deposition: film quality equivalent to ORNL's

> Scaling demonstrated through performance of large area cells connected in parallel.

4.2 h

L

3.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

Capacity (mAh)

Discharge of a Li-LiCoO, battery consisting of a parallel connection of seven cells of 7.5 crn2 active area each. The average cathode thickness was 1.7 pm.

Pulse discharge of a Li-LiCoO, battery consisting of seven 7.5 cm2 cells con- nected in parallel.

Pulse: 100 mA, 8.5 s; repeat every 2s

Challenaes and Future Work

> Improve yield of batteries on metal foils: electrical isolation of anode cur- rent collector from substrate

> Lower manufacturing costs: increase deposition and processing rates of electrolyte and cathode films

Acknowledaements

This research was sponsored by the Divi- sion of Materials Sciences and the Divi- sion of Chemical Sciences, U.S. Depart- ment of Energy, under contract No. DE- AC05-960R22464 with Lockheed Martin Energy Research Corporation.

Average energy/pulse: 3 J

3