But according to this article, that could change: their latest research shows that this may be possible by putting a pure lithium anode into a protective carbon sheath, which protects it from instabilities. They're not quite there – they only retain 99% capacity after 150 charge cycles, as opposed to 99.9% that commercialization would need – but their research looks quite promising.
Full journal article: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2014.152.html
Team achieves ‘holy grail’ of battery design: A stable lithium anode
Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode Engineers across the globe have been racing to design smaller, cheaper and more efficient rechargeable batteries to meet the power storage…