Effects of Doping and/or Atmosphere on the Electrical Conductivity of Li4Ti5O12

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Abstract:

Tantalum Ta doping in lithium titanium oxide, Li4Ti5O12 Li4Ti4.95Ta0.05O12, as function of different heat-treatment atmospheres oxidizingreducing was investigated and compared to Li4Ti5O12 to determine its effect on electrical conductivity and rate capability. The ionic conductivity value of the white colored Li4Ti4.95Ta0.05O12 heated under an oxidizing atmosphere was 3 x 10-8 Scm with a DC electronic conductivity value of 1 x 10-9 Scm. These values are similar to values observed for Li4Ti5O12 heated under the same oxidizing atmosphere. These results suggest that both materials are predominately ionic conductors, with the extra charge of Ta compensated by a lattice defect, most likely titanium Ti vacancies. For the case of Li4Ti4.95Ta0.05O12 heated under a reducing atmosphere, it was purple colored with an electronic conductivity value of 1 x 10-3 Scm. Li4Ti5O12 heated under a reducing atmosphere was also purple colored with an electronic conductivity value of 3 x 10-5 Scm. These results suggest both of these materials are predominately electronic conductors where the electronic conductivity is a result of the reduction of some Ti4 ions into Ti3 ions. For Li4Ti4.95Ta0.05O12 this reduction is a result of the extra charge of the Ta whereas for Li4Ti5O12 it is a result of nonstoichiometry.

Author(s):
Wolfenstein, Jeff ; Foster, Donald ; Read, Jeffrey ; Zhang, Shengshui ; Allen, Jan L.
Author Organization(s):
ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
Descriptive Note:
Interim rept.
Pagination:
0022

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
ARL-TR-4641
Monitor Series:
ARL-SE-EM
 Subject Terms
Joint Capability Areas:
JCA_3.2_Engagement; JCA_3_Force Application; JCA_1.3_Human Capital Management; JCA_1_Force Support; JCA_1.3.2_Personnel Management; JCA_3.2.1_Kinetic Means; JCA_1.2.5_Lessons Learned; JCA_5_Command and Control; JCA_8_Building Partnerships
Modernization Areas:
Microelectronics
Communities of Interest:
Advanced Electronics
Descriptor(s):
*ELECTRICAL CONDUCTIVITY, *DOPING, *LITHIUM COMPOUNDS, *ATMOSPHERES, REDUCTION, ANODES, TANTALUM, ELECTRIC CONDUCTORS, IONIC CURRENT, HEAT TREATMENT, ELECTROCHEMISTRY, RATES, IONS, OXIDATION
Field(s)/Group(s):
Physical Chemistry, Electricity and Magnetism
Keyword(s):
ELECTRONIC CONDUCTIVITY, IONIC CONDUCTIVITY, LITHIUM ION, LITHIUM TITANIUM OXIDE, OXIDIZING ATMOSPHERE, REDUCING ATMOSPHERE
Report Date:
2008 Nov 01
Creation Date:
2009 Jan 14