High energy electrochemical cell employing solid-state anode

Improved anodes having active materials consisting substantially of one or more lithium insertion compounds further consisting of transition metal chalcogenides or oxides capable of reversibly intercalating lithium ions are disclosed. Cells utilizing these anodes are also disclosed.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates generally to the field of high energy, 
non-aqueous electrochemical cells and, more particularly, to improvements 
with respect to the anodes applicable to primary or secondary active metal 
cells and specifically including those traditionally using anodes of 
lithium metal. The improved anodes incorporate active materials comprised 
of one or more lithium insertion compounds consisting of transition metal 
chalcogenides or oxides capable of reversibly intercalating lithium ions, 
without the need for the presence of elemental lithium, lithium alloys or 
other alkali metals themselves 
CROSS REFERENCE TO RELATED APPLICATION 
Reference is made to application Ser. No. 07/561,134 now U.S. Pat. No. 
5,147,739 filed of even date and assigned to the same assignee as the 
present application. That invention relates to the use of a composite 
anode consisting of a lithium or lithium alloy substrate to which an 
intercalation type of compound is adhered, mixed, embedded or otherwise 
contacted as a dispersed layer, coating, laminate, or mixture. 
Description of the Related Art 
It is well known that non-aqueous, active metal cells have allowed those 
skilled in the art to achieve much higher energy densities or energy to 
weight ratios than had been possible with other combinations. The wide 
range of potential uses for these cells has led to a great deal of 
interest in improving the performance and safety of the cells and, more 
specifically, to developing reliable secondary or rechargeable cells 
utilizing these materials. Secondary or rechargeable active metal cells 
typically consist of a light, strongly reducing anode, normally an alkali 
metal such as lithium, an aprotic, non-aqueous solvent into which the 
appropriate quantity of an electrolyte salt of the anode metal has been 
dissolved to form a conductive electrolyte solution, and an oxidizing 
agent as the cathode material. 
More recently, intercalating materials have been used for the positive 
cathode electrodes. U.S. Pat. No. 4,804,596 to Ebner et al., common of 
assignee with the present invention, identifies the use of intercalating 
materials such as LiCoO.sub.2, TiS.sub.2, MoS.sub.2, V.sub.2 O.sub.5, 
V.sub.6 O.sub.13 and other such compounds as the cathode electrode when 
coupled with lithium metal anode electrodes in a rechargeable 
electrochemical cell. A further patent, U.S. Pat. No. 4,853,304, to Ebner 
and Lin, also assigned to the same assignee as that of the present 
invention, discloses an improved non-aqueous electrolyte solution for 
lithium cells in which an organic ester of formic acid, preferably methyl 
formate, is combined with an amount of lithium salt and an amount of 
CO.sub.2 to provide improved electrolyte solution performance in secondary 
or rechargeable lithium cells. The ester-based solution is found to 
increase conductivity and the CO.sub.2 appears to reduce anode 
polarization and passivation effects. A further patent to Nagaura, et al. 
is U.S. Pat. No. 4,828,834 which relates to a rechargeable organic 
electrolyte cell in which the cathode is formed of LiMn.sub. 2 O.sub.4 
obtained by sintering manganese dioxide with either lithium carbonate or 
lithium iodide. 
Thus, it can be seen from the above that the related art generally dealt 
with improvements in the electrolyte system or in cathode materials. In 
these electrochemical couples or known cell embodiments, lithium or other 
typical low density, strongly reducing metals or alloys of lithium are 
specified. However, the plating of lithium metal that has been removed 
from the cathode back onto the anode electrode during charging and/or the 
stripping of lithium from the anode during discharging of the cell and 
intercalation into the cathode has been found to be an inefficient 
process. The process generally results in the use of an anode electrode 
dendrite growth or irreversible lithium deposition which leads to eventual 
failure of the cell due to internal shorting of the plates, loss of 
sufficient active lithium material or both. In this regard, various 
additives including electrolyte dopants, changes in electrolyte 
composition, cell separator materials, and various other design 
configurations have been attempted to minimize or negate the effects of 
such inefficient lithium cycling. However, even the best systems which may 
achieve up to 98% lithium cycling efficiency suffer from severe drawbacks. 
They have generally been limited to low capacity (less than one-third of 
the theoretical reversible capacity), shallow depths-of-discharge or low 
cycle life (less than 500 cycles to failure). Short cycle life is 
experienced despite the use of excess lithium anode capacity relative to 
available cathode capacity to increase anode life. While the specific 
theoretical energy density of these cells based on active materials 
approaches 600-700 Wh/kg, the actual capacity limitations of the derated 
cells necessary for longer life is little better than conventional 
rechargeable batteries. Nickel cadmium cells, for example, are estimated 
at 225 Wh/kg (on an active material basis). Furthermore, the cells have a 
limited reliability because of tendencies toward adverse anode reactions. 
A secondary battery which includes a lithium intercalated graphite 
compound as the anode active material is disclosed in U.S. Pat. No. 
4,423,125. Other lithium intercalation secondary cells using MoO.sub.2 and 
WO.sub.2 have been reported by J. J. Auborn and Y. L. Barberio in the 
Journal of the Electrochemistry Society, Vol. 134, No. 3, pp. 638-641. 
These, however, have not provided as successful as hoped due to a variety 
of problems including the fact that MoO.sub.2 and WO.sub.2 compounds both 
demonstrated an irreversible transition which degraded cycle capacity and 
life and the voltage profiles of MoO.sub.2 and WO.sub.2 versus lithium 
reference electrodes are too high (i.e., only moderately reducing) to 
provide a system of adequate energy capability when coupled with a higher 
voltage (i.e., strongly oxidizing) cathode such as LiCoO.sub.2. The result 
is an electrochemical cell with less than 3.0 volt nominal operating 
potential. 
Other, similar anode materials which are useful but which exhibit 
performance data which in one or more ways is somewhat less than desired 
are illustrated in several additional references. U.S. Pat. No. 4,668,595 
illustrates and describes a secondary battery in which transition metal 
oxide is specified for use as either anode or cathode material. The 
material, however, provides less than 1-2 volts when used as the anode 
even when used in combination with a cathode as strongly oxidizing as 
LiCoO.sub.2. U.S. Pat. No. 4,194,062 also discloses transition metal 
oxides specified for use as either anode or cathode material but does not 
teach electrochemical cell couples which would produce the desired 3.0+ V 
potentials. U.S. Pat. No. 4,668,596 illustrates and describes a variety of 
materials including transition metal oxide anode compounds but only as one 
of several materials used in a combination, including alkali metals, as 
the anode active material. The reference further requires the use of a 
conjugated backbone polymer. 
Thus, there remains a definite need to improve the cycling ability of such 
cells, particularly in cells capable of operating at higher voltages and 
capacities. Accordingly, it is a primary object of the present invention 
to improve the cycling efficiency of high voltage, high capacity, high 
energy density cells. 
SUMMARY OF THE INVENTION 
By means of the present invention the efficiency of high energy density 
secondary or rechargeable cells has been improved by replacing the entire 
active metal anode, which has normally consisted of pure lithium or alkali 
metals or alloys, with any one of several types of 
intercalation/insertion/transition metal chalcogenide or oxide active 
materials. 
Preferable intercalation compounds for the anode are those which combine 
relatively low molecular weight with the highest or relatively high 
lithium insertion capabilities at voltages closest to a lithium reference 
electrode. They can be described using the general formula Li.sub.x 
M.sub.a X.sub.b. The preferable elements for M, the transition metal(s), 
in the general formula (in approximate order of desirability) appear to be 
scandium (Sc), titanium (Ti), yttrium (Y), and zirconium (Zr), either 
individually or as compounds. Higher period or group elements such as 
lanthanum (La), hafnium (Hf), vanadium (V), chromium (Cr), niobium (Nb), 
molybdenum (Mo), tantalum (Ta), tungsten (W), manganese (Mn), iron (Fe), 
cobalt (Co), nickel (Ni), copper (Cu) and zinc (Zn), etc., can also be 
used, provided the lithium intercalation ability is high and the voltage 
levels vs. lithium are low. The preferred maximum oxidation state for the 
above are given by Roman numerals as follows: Sc(III), Ti(III), Y(III), 
Zr(IV), La(III), Hf(IV), V(II), Nb(III), Mo(III), Ta(IV), W(III), Cr(II), 
Mn(II), Fe(I), Co(I), Ni(I), Cu(I) and Zn(I). In some cases lower 
oxidation states may be used. The X element(s) of the general formula, in 
order of preference, are oxygen (O), sulfur (S), selenium (Se) and 
tellurium (Te). The value of x, a and b may be expressed in integers, 
fractions or decimals. It is desirable that the values of a and b be as 
low as possible. This, of course, depends largely upon the number of moles 
of lithium atoms inserted into the structure during charge and discharge 
and also upon their relative ratios. 
For certain types of reversible intercalation materials (LiCoO.sub.2, 
V.sub.6 O.sub.13, etc.), the same exact base compounds potentially can be 
used for both cathode and anode electrodes in the same cell. Thus, if the 
reversible lithium capacity of the material is high and the voltage 
differential between lithium-doped (e.g., Li.sub.1.5 CoO.sub.2 at 1.0-1.5 
volts versus a lithium reference electrode) and lithium-depleted (e.g., 
Li.sub.0.5 CoO.sub.2 at .about.4.3 volts versus a lithium reference 
electrode) phases is significant, the same composition is acceptable. 
Varying the degree of intercalation between the electrodes (lithium rich 
versus lithium poor) as well as the relative amounts of each electrode's 
active materials also allows the selection of the best voltage profile and 
coulombic capacity of the material in question. 
The present invention further contemplates a more optimized combination of 
elements in the form of an electrochemical cell in which the anode 
includes a highly reducing (low voltage vs. lithium reference electrode), 
high energy density intercalation compound operated over the reversible 
range (for example, Li.sub.9 Mo.sub.6 Se.sub.6 corresponding to the 
"charged" anode with a discharged state corresponding to Li.sub.3.2 
Mo.sub.6 Se.sub.6); the cathode is a high voltage (relative to a lithium 
reference electrode), high energy density intercalation compound, such as 
Li.sub.x CoO.sub.2 in the preferred embodiment, operated over the 
reversible range (for Li.sub.x CoO.sub.2, x.ltoreq.0.3 in the charged 
state and x.gtoreq.1.0 in the discharged state); and an electrolyte 
consisting essentially of an organic ester solvent, such as methyl 
formate, used in the preferred embodiment with a double salt (LiAsF.sub.6 
+LiBF.sub.4) and CO.sub.2 additive at the desired levels. The use of 
binders, conductive diluents, electrolyte additives, process aids, high 
purity raw materials, etc., does not appear to diminish or otherwise 
affect the basis for the solid state anode of the invention.

DETAILED DESCRIPTION 
In the present invention, the pure lithium metal or similar type anode is 
replaced by any one of a number of various types of 
intercalation/insertion/transition metal chalcogenide or oxide active 
materials. As recited above, the preferable intercalation compounds for 
the anode are those of which combine the lowest molecular weight with the 
highest lithium insertion capabilities at voltages closest to the lithium 
reference electrode. The compounds can be described using the general 
formula Li.sub.x M.sub.a X.sub.b ; wherein the preferred elements for M, 
in approximate order of desirability, appear to be reduced (low oxidation) 
states of Sc, Ti, Y, and Zr, either individually or as compounds. In 
addition, provided their intercalation ability is high and voltage levels 
vs. lithium are low, such additional reduced, higher period or group 
elements as La, Hf, V, Cr, Nb, Mo, Ta, W, Mn, Fe, Co, Ni, Cu, Zn, etc., 
may be used. Whereas other lower states may occur in certain useful 
compounds, the maximum oxidation states preferred for the listed elements 
are: Sc(III), Ti(III), Y(III), Zr(IV), La(III), Hf(IV), V(II), Nb(III), 
Mo(III), Ta(IV), W(III), Cr(II), Mn(II), Fe(I), Co(I), Ni(I), Cu(I) and 
Zn(I). The X elements in order of preference are O, S, Se, and Te. The 
value of x, a and b, of course, may be expressed as an integer, fraction 
or decimal. It is preferable that the values of a and b be as low as 
possible relative to the value of x so that the lithium intercalation be 
maximized. 
Under these selection criteria, for example, TiO.sub.2 (in the rutile 
structure) should exhibit up to a 570 mAh/gm faradic capacity at voltages 
relative to lithium of less than 1.0 V for a two Faraday/mole 
intercalation reaction going from the +4 to the +2 oxidation state. These 
relatively high capacities provide cells of rather small energy density 
(when coupled with lithium anodes) in terms of watt hours per kilogram due 
to the relatively low system voltage. However, it is noteworthy that using 
lithium insertion compounds such as TiO.sub.2 for the anode can produce 
high energy density cells if coupled properly with a highly oxidizing 
cathode such as LiCoO.sub.2. This can produce up to 500 watt hours per 
kilogram in a working cell based on active material weights. 
In addition, it is an important aspect of the present invention that for 
certain types of reversible intercalation materials (LiCoO.sub.2, V.sub.6 
O.sub.13, etc.), it is anticipated that the same identical base compounds 
can potentially be used for both cathode and anode electrodes. This is 
feasible provided that the reversible lithium capability of the material 
is high and that the voltage difference between the lithium doped (for 
example, Li.sub.1.5 CoO.sub.2 at 1.0-1.5 volts versus a lithium electrode) 
and lithium-depleted (for example, Li.sub.0.5 CoO.sub.2 at 4.3 volts 
versus lithium reference electrode) phases is significant. 
The system illustrated in the single FIGURE would operate at moderate rate 
discharges at 3.0 V average, and utilizing properly compacted/densified 
electrodes in the proper balance of coulombic capacities (.about.8 moles 
Li.sub.0.3 CoO.sub.2 : 1 mole Li.sub.9 Mo.sub.6 Se.sub.6) would provide up 
to 300-400 Wh/kg and 0.65 Wh/cm.sup.3 based on active electrode materials. 
FIG. 1 shows the projected voltage profiles of the LiCoO.sub.2 /LiMo.sub.6 
Se.sub.6 system. A Li/LiCoO.sub.2 cell incorporating the minimum typical 
excess amounts of lithium to make up for cycle losses has approximately 
600-700 Wh/kg and 1.0-1.5 Wh/cm.sup.3 volumetric energy density . . . 
depending on the cycle life design requirements. However, even with the 
higher levels of the lithium anode materials, the cycle life has still 
been limited to typically less than 300-500 cycles and dendritic shorting 
between the electrodes becomes a greater likelihood as well as a potential 
hazard. 
The highly reversible nature of intercalation anodes and cathodes makes 
cycle lives well in excess of 1000 cycles feasible and also precludes the 
development of dendrites exhibited on pure lithium anodes. Therefore, on a 
total cycle life discharge capacity basis (cumulative energy output), the 
present invention would outperform the standard Li/LiCoO.sub.2 cell. On a 
single discharge cycle capacity basis, a cell in accordance with the 
present invention also could provide up to 2/3 to 3/4 the energy density 
of pure lithium anode cells and 2-3 times the specific energy of 
previously proposed similar systems (Li.sub.x MoO.sub.2 /LiC.sub.2, 
CoO.sub.2, etc.) or conventional standard rechargeable batteries (NiCd). 
Table I enumerates a plurality of combinations contemplated for actual 
cells. To the extent necessary, material from the two cited Ebner, et al. 
patents is deemed incorporated by reference herein. Table II provides 
specific energy calculations for certain of these electrochemical systems 
and includes comparison data with representative current known battery 
technology. 
It is anticipated that the cathode and anode electrode in accordance with 
the present invention can both be formed in special but conventional 
processes known to those skilled in the art. The degree of intercalation 
between the electrodes can be varied, i.e., lithium rich versus lithium 
poor, as well as the relative amounts of the active materials of each 
electrode to allow the selection of the best voltage profile and coulombic 
capacity with regard to the material in question. It is important to 
select an anode and cathode intercalation couple having sufficient 
potential and being properly balanced with respect to the reversible 
capacities of both the anode and the cathode. The intercalation anode 
compound selected for coupling with the intercalation cathode of interest, 
must be reversible over the entire range of use and operate in a manner 
which provides adequate energy capability when coupled with the cathode of 
interest. 
The present invention further contemplates a variety of embodiments. For 
example, integral solid-state conductive electrolytes can be impregnated 
into either conventional lithium insertion compound cathodes or lithium 
insertion compound anodes in accordance with the present invention, or 
both, to provide a totally solid-state system which eliminates the need 
for typical liquid electrolytes. It is further contemplated that a lithium 
intercalation compound can be utilized as a solid-state 
electrolyte/separator system between the solid-state lithium intercalation 
anodes and any of the conventional or solid-state cathodes with or without 
the use of a conventional liquid electrolyte system. Of course, the 
solid-state lithium intercalation anode of the invention may also be 
coupled to any of the available type cathodes known in the art for use in 
electrochemical lithium-based cells. 
It is believed that the solid-state anode configured in accordance with the 
present invention may be coupled to a water-based cathode, which may be a 
lithium intercalation type cathode, utilizing an aqueous-based electrolyte 
which may include a non-aqueous co-solvent and any conventional solvent 
additive. The solid-state lithium intercalation compound anode of the 
invention, also may be utilized in a system which employs air, 
specifically O.sub.2 and H.sub.2 O vapor, as the cathode material. 
It is well known that, with respect to safety, lithium cells have long been 
a cause for concern. The present invention further provides certain safety 
benefits with respect to lithium cells. The amount of "free" lithium 
existing in a cell poses a safety hazard. Lithium converted to the molten 
state (&gt;170.degree. C.) as a result of internal shorting, overheating, 
cell reversal, overcharging, or the like, is extremely reactive and can 
produce cell rupture or other catastrophic result. A cell with an 
intercalation compound for the anode contains no free lithium and that 
precludes this type of failure. Additionally, intercalation compounds are 
rate limited by the ionic transport properties within the molecular 
structure of the chalcogenide or oxide. This reduces the risk of cell 
rupture from shorting or abusive conditions. Alternatively, however, the 
porosity of properly compacted intercalation compounds powders still 
allows for good rate capability. Adverse reactions typical between the 
highly reactive lithium metal anodes and the electrolyte or the atmosphere 
are virtually eliminated. Effects such as passivation, poor storage, 
degradation from non-hermetic cell enclosures, structural/morphological 
changes in electrodes with cycling and so on are not critical requirements 
for this newly described technology. 
This invention has been described herein in considerable detail in order to 
comply with the Patent Statutes and to provide those skilled in the art 
with the information needed to apply the novel principles and to construct 
and use such specialized components as are required. However, it is to be 
understood that various modifications can be accomplished without 
departing from the scope of the invention itself. 
TABLE I 
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Electrochemical Cells Using Lithium Intercalation Anode Compounds 
General Description 
Anode Cathode Separator/Electrolyte 
__________________________________________________________________________ 
I. Standard high 
Any intercalation compound 
Li.sub.x CoO.sub.2 (.3 .ltoreq. x .ltoreq. 
1.0) or Any of the standard non- 
voltage, high energy 
with 1-1.5V (vs. Li) and 
other high voltage (.gtoreq. 4V 
aqueous liquid electrolytes 
density couples 
&gt;200 mAh/gm reversible 
vs. Li), high capacity 
and polymer microporous 
capacity (e.g., TiO.sub.2, MoS.sub.3) 
(&gt;200 mAh/gm), reversible 
separator. 
cathode. 
II. High conductivity, 
As above (I.). 
As above in I. and as shown 
High conductivity, ester- 
electrochemically in U.S. Pat. No. 
based electrolyte solution, 
stable ester-based 4 804 596 to Ebner, et al. 
including those in which 
electrolyte. the ester solvent is 
selected from methyl 
formate (HCOOCH).sub.3, 
methyl 
acetate (CH.sub.3 COOCH.sub.3 
) and the 
like. Electrolyte salts 
include LiAsF.sub.6, 
LiBF.sub.4 (or 
combinations thereof), 
LiClO.sub.4, LiAlCl.sub.4, 
LiGaCl.sub.4, 
etc. See U.S. Pat. No. 
4 804 596. 
III. 
CO.sub.2 additive to 
As above (I.). 
As above in II. 
As in II above, preferably 
organic electrolyte. LiAsF.sub.6 + LiBF.sub.4 in 
methyl 
formate. See also U.S. Pat. 
No. 4 853 304, Ebner, et 
al. 
IV. Solid state Anodes as in I. above or 
Standard cathodes as in I.- 
Any of various solid state, 
polymer and ion 
micro-encapsulated with 
III. above or micro- 
ionic conductive plastics, 
conducting polymer electrolyte 
encapsulated polymer type. 
ceramics, etc. (anode 
electrolyte. (unrestricted by and/or cathode). 
voltage/capacity, etc.). 
V. Intercalation 
As in I.-IV. above. 
As in I.-IV. above or VI.- 
A non-electrically, Li ion 
compound separator/ IX. below. conductive solid state 
electrolyte. electrolyte. 
VI. Conventional As in I.-V. above or any 
Any of the conventional Li 
Any of the common systems 
cathode primary and/ 
other appropriate 
battery cathodes (SO.sub.2, 
as appropriate for the 
or secondary intercalation compound 
SOCl.sub.2, (CF).sub.n, FeS.sub.2, 
CuF.sub.2, specific cathode type. 
batteries. (unrestricted by 
PbI, MnO.sub.2, Bi.sub.2 Pb.sub.2 O.sub.5, 
V.sub.2 O.sub.5, 
voltage/capacities, etc.) 
etc.) 
VII. 
Water cathode 
As in I.-VI. above. 
H.sub.2 O reactive material 
Aqueous solution of salts, 
primary battery carbon pad, metal grid, or 
acids, bases, etc. or other 
(active or reserve). other current collector. 
appropriate additives. 
VIII. 
Lithium aqueous 
As in I.-VI. above. 
As in I.-VII. above 
H.sub.2 O electrolyte with 
salts, 
electrolyte battery. (preferably as in I.-VI. 
co-solvents, etc. for 
for a rechargeable system). 
conductivity, stability, 
etc. 
IX. Lithium/air type. 
As in I.-VI. above. 
Atmospheric O.sub.2 and H.sub.2 O. 
LiOH electrolyte; porous 
screen. 
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TABLE II 
__________________________________________________________________________ 
Hypothetical Examples of Battery Types Detailed in Table I 
Voltage Specific Reversible 
Energy 100% 
Type of Description 
vs. Li Working 
Capacity, Mah/gm 
Density DOD Est. 
(Anode/Cathode) Anode 
Cathode 
Cell Anode Cathode (Wh/Kg) Cycle 
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Life 
Prior Art: 
1. Li/LiCoO.sub.2 (1:1) 
0 4 4.0 3,860 (1 F/M) 
200 (.7 F/M) 
770 &lt;100 
2. Li/LiCoO (3:1) 
0 4 4.0 700 1-300 
3. Li/LiCoO.sub.2 (6:1) 
0 4 4.0 610 3-500 
200 (@ 1/3 DOD) 
.sup..about. 
1000 
4. Li.sub.9 Mo.sub.6 Se.sub.6 /MO.sub.6 Se.sub.6 
1/2 21/2 2 (1 avg) 
50 (2 F/M) 
50 (2 F/M) 
50 &gt;1000 
5. MoO.sub.2 /LiCoO.sub.2 
11/2 4 2.5 100 (.5 F/M) 
200 (.7 F/M) 
167 &gt;1000 
6. WO.sub.2 /LiCoO.sub.2 
1 4 3.0 62 (.5 F/M) 
200 (.7 F/M) 
142 &gt;1000 
7. Li/MnO.sub.2 (3:1) 
0 31/2 3 3.860 (1 F/M) 
300 (1 F/M) 
700 &lt;3-500 
8. Cd/Ni (non-lithium) 
-- -- 11/4 -- -- 225 500-1000 Typ. 
Present Invention: 
(Refer to Table I Descriptions) 
I.-V. 
Li.sub.x M.sub.a X.sub.b /LiCoO.sub.2 (or 
1-11/2 
4 3.0 avg. 
&gt;200 req'd 
200 (.7 F/M) 
300 nom. &gt;1000 
other similar 
alternate cathode) 
a. Li.sub.2.5 MoS.sub.3 /Li.sub.0.3 CoO.sub.2 
13/4 4 21/4 280 (2 F/M) 
200 (.7 F/M) 
260 &gt;1000 
b. Li.sub.2.4 CoO.sub.2 /Li.sub.0.3 CoO.sub.2 
1/2-11/2 
4 3 400 (1.4 F/M) 
200 (.7 F/M) 
400 &gt;1000 
c. Li.sub.9 Mo.sub.6 /Se.sub.6 Li.sub.0.3 CoO.sub.2 
1/4-3/4 
4 3.5 300 (6 F/M) 
200 (.7 F/M) 
400 &gt;1000 
VI. Conventional 
Cathodes 
a. Li.sub.x M.sub.a X.sub.b /SO.sub.2 
1-11/2 
3 11/2-2 avg. 
200 nom. 
419 250 nom. ? 
(1150 for Li/SO.sub.2) 
b. Li.sub.x M.sub.a X.sub.b /SOCl.sub.2 
1-11/2 
31/2 2-21/2 avg. 
200 nom. 
450 300 nom. ? 
(1450 for Li/SOCl.sub.2) 
c. Li.sub.x M.sub.a X.sub.b /CuF.sub.2 
1-11/2 
31/2 2-21/2 avg. 
200 nom. 
530 325 nom. ? 
d. Li.sub.x M.sub.a X.sub.b MnO.sub.2 
1-11/2 
31/2 2-21/2 avg. 
200 nom. 
300 270 nom. &gt;1000 
VII. 
Li.sub.x M.sub.a X.sub.b /H.sub.2 O 
1-11/2 
3 13/4 avg. 
200 nom. 
1490 (1 F/M) 
300 ? 
VIII. 
Li.sub.x M.sub.a X.sub.b /Li.sub.y M.sub.a X.sub.b 
1-11/2 
3-4 21/2-3 typ. 
200 nom. 
200 nom. 
300 nom. &gt;1000? 
(As in I.-VII. above, using aqueous electrolyte solution instead of 
organic, non-aqueous liquids or solid electrolytes) 
IX. Li.sub.x M.sub.a X.sub.b /Air (O.sub.2, H.sub.2 O) 
1-11/2 
3 13/4 avg. 
200 nom. 
N/A 350 ? 
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