Lithium-metal batteries have the potential to be "transformational" for underwater applications, says James Bellingham, the Monterey Bay Aquarium Research Institute's chief technologist. Most ocean research takes place close to shore because, as Bellingham says, "in the ocean, there are no plugs" for recharging the sensor-laden autonomous craft that monitor the seas. Higher energy-density batteries could enable much better monitoring of the effects of climate change on the planet, says Bellingham.