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Title: Synthesis and evaluation of new cathode materials for rechargeable lithium batteries. Annual report, April 26, 1976-September 15, 1977

Technical Report ·
DOI:https://doi.org/10.2172/5234243· OSTI ID:5234243

The objective of the first year of this study was the investigation of two new classes of complex sulfide materials of potential value for ambient and high temperature, high energy rechargeable batteries with lithium anodes. The two new classes were the sulfospinels and simple and mixed layered disulfides of transitional metals of groups IVB and VB. In addition, three simple sulfides, CoS, CoS/sub 2/ and FeS/sub 2/ were also investigated. Studies of the synthesis methods have resulted in the development of the two-zone quartz furnace capable of firing temperatures up to 1000/sup 0/C with controllable sulfur vapor pressures. Optimum synthesis methods for preparation of TiS/sub 2/ and substituted disulfides of the type M/sub x/Ti/sub 1-x/S/sub 2/ (M = Co, Cr, Mo, V) as well as for sulfospinels have been established. In the area of mixed disulfides, compounds with 5 mole % molybdenum and 25 mole % chromium or vanadium were found to be superior in electrochemical cell performance to TiS/sub 2/. The higher electrical conductivity of these compounds compared to that of TiS/sub 2/ is the probable reason. The preparation of the Co-substituted disulfide was not successful and resulted in a sulfospinel structure of CoTi/sub 2/S/sub 4/. Among the sulfospinels studied CoCo/sub 2/S/sub 4/ = (Co/sub 3/S/sub 4/) and CoFe/sub 2/S/sub 4/, high capacity densities up to 605 mAH/g have been found with the former showing more electrochemical reversibility. The initial findings in organic electrolyte cells have been confirmed in high temperature tests conducted at Argonne National Laboratory in molten salt cell tests. The simple sulfides have been found to perform in organic electrolyte cells with CoS/sub 2/ showing lower polarization than FeS/sub 2/ or CoS.

Research Organization:
Electrochimica Corp., Mountain View, CA (USA)
DOE Contract Number:
AC03-76SF90363
OSTI ID:
5234243
Report Number(s):
DOE/SF/90363-T1; ON: DE82005392
Resource Relation:
Other Information: Portions of document are illegible
Country of Publication:
United States
Language:
English