Currently there is no battery technology on the market that has as feasible energy density to charge/discharge cycle ratio as the Li-Ion battery has, this is also the main reason why it is so dominant on the market and will probably not be surpassed in the near future.
There are however promising technologies in research, that could achieve higher energy densities with comparable charge/discharge cycles than LiBs. Namely the one using magnesium instead of lithium, which is currently developed by Toyota. The problems with utilising this technology are marked by the absence of practical cathodes, appropriate electrolytes and extremely sluggish reaction kinetics. The Toyota researchers are estimating that it could be 20 years before these batteries go mainstream.
At the current pace of research, there is no battery technology currently in development that could compete with the Lithium Ion battery for the next 10 - 20 years.
