Scientist Lu Yaxiang, a professor at the Chinese Academy of Sciences’ Institute of Physics, has spent a decade working to make sodium-ion batteries commercially viable.Those years of work on energy storage in April earned Lu a China Youth May Fourth Medal – the nation’s top honour for outstanding achievers under 35.For years, lithium-ion batteries have dominated the market, even though their raw materials are scarce and environmentally demanding to extract.Sodium-ion batteries are seen as an alternative, but they have been constrained by their lower energy density.Lu took the approach that sodium – a mineral that is abundant, cheap and easy to source – was vital for China’s energy security.That led to a focus on materials innovation to boost the performance of sodium-ion batteries.