with lithium metal as the anode and air as the cathode (Figure 9.11).
The electrolyte is similar to that
in the Li-ion battery, consisting of LiPF6in polypropylene carbonate (PPC). There are a number of
problems that remain before this type of cell can be
commercially viable. One of these is that the cathode cannot be exposed to ordinary air, because
water vapour will react with the Li2O2to produce
lithium hydroxide and carbon dioxide will form
lithium carbonate. This means that the cathode
must be enclosed in a protective membrane that
allows the free passage of O2 but excludes H2O and
CO2. Nevertheless, these batteries are eagerly
anticipated and expected to be commercially available in the future.