Solid polymer electrolyte-based oxygen batteries

DETAILED DESCRIPTION OF THE INVENTION The invention is understood by referring to FIG.
1 which depicts a polymer electrolyte-based Li/O.
sub.
2 battery cell.
In this FIG.
1 is the solid polymer electrolyte, A is the Li anode (negative electrode), C is the composite positive electrode current collector prepared from graphite powder or carbon black, O.
sub.
2 is oxygen, the electroactive cathode material, which is accessed from the environment, and M is an oxygen permeable membrane through which O.
sub.
2 is transported to the porous carbon electrode.
Among the solid polymer electrolytes suitable for use in the Li/O.
sub.
2 battery are those described by Abraham and Alamgir in Solid State Ionics, 70/71, 20 (1994).
An example is the poly(acrylonitrile)-based electrolytes composed of PAN, EC, PC and LiPF6.
Lithium salts other than LiPF.
sub.
6 can be used and they include LiAsF.
sub.
6, LiClO.
sub.
4, LiN(SO.
sub.
2 CF.
sub.
3).
sub.
2, LiBF.
sub.
4, and LiCF.
sub.
3 SO.
sub.
3.
The requirement for a Li salt useful in this battery is that it is sufficiently soluble in the electrolyte to form a conductive solution.
Other examples of polymer electrolytes are those based on poly(vinyl chloride), poly(vinyl sulfone) poly(vinyl pyrrolidinone), poly(ethylene glycol diacrylate), poly(vinylidine fluoride, poly(tetrahydrofuran), poly(dioxolane) and poly(ethylene oxide), their derivatives and mixtures thereof.
Li salts and solvents suitable for preparing the electrolytes of this invention are preferably selected on the basis of the same principles used for selecting these components for highly conductive liquid electrolytes.
These requirements include: 1 ) Li salts having large anions and low lattice energies such as LiClO.
sub.
4, LiAsF.
sub.
6, LiBF.
sub.
4, FiCF.
sub.
3 SO.
sub.
3, LiPF.
sub.
6 and LiN(CF.
sub.
3 SO.
sub.
2).
sub.
2 ;2)organic solvents with high dielectric constants to promote the dissociation of the low lattice energy Li salts, thereby forming highly conductive electrolyte medium; 3) organic solvents having electron donor atoms such as O and N through which the solvents can form complexes (or solyates) with the Li ions of the Li salt