(Image credit: MirageC/Getty Images) Newly developed sodium-ion (Na-ion) batteries could offer much faster charging speeds, higher energy density and improvements in safety compared with conventional lithium-ion (Li-ion) batteries, scientists say. Using Na-ion batteries, an alternative to the Li-ion batteries found in the majority of today’s devices, researchers at the Tokyo University of Science used a new carbon-based electrolyte to improve Na-ion energy density and charge speeds. All ba...