A University of Houston team has pushed sodium-ion energy density up by more than 15 per cent, closing the gap with lithium using an element that can be extracted from seawater.
Lithium mining carries a heavy environmental and geopolitical cost, and most of the world's supply sits in a handful of countries. A University of Houston team, publishing in Nature Materials, developed a sodium vanadium phosphate material that pushes sodium-ion battery energy density up by more than 15 per cent, closing the gap with lithium while using an element that can be extracted from seawater.
This matters because sodium-ion batteries have always been the cheaper but weaker alternative. This closes that gap. Some benefits are:
- Sodium costs nearly 50 times less than lithium
- Energy density rose to 458 watt hours per kilogram, up from 396
- Sodium is abundant and does not depend on a small number of mining regions