There is a new battery that is suppose to be environmentally that is more efficient, and has a longer life span. The battery only takes 6.6 seconds to recharge. Its made of water-soluble iodide and triiodide ions. This could be great because by having a more efficient battery would keep thing recharged, and good for the environment. The reason this is good for the environment is because this eliminates the fatal acids that are within batteries.
http://spectrum.ieee.org/energywise/energy/renewables/environmentallyfriendly-liquid-battery
http://spectrum.ieee.org/energywise/energy/renewables/environmentallyfriendly-liquid-battery